JP7378050B2 - Lighting systems, lighting loads, and power supplies - Google Patents

Description

The present disclosure relates to lighting systems, lighting loads, and power supplies.

The power distribution system of Patent Document 1 includes a power conversion unit, an LED controller, a pair of power supply lines, and a plurality of LED lighting terminals. The power conversion unit is a DC/DC converter that receives a commercial AC power source and outputs a predetermined DC voltage. The DC voltage output by the DC/DC converter is applied to the pair of power supply lines via the LED controller. A plurality of LED lighting terminals are connected in parallel between a pair of power supply lines.

The LED controller includes a switch circuit inserted between the output part of the DC/DC converter and the power supply line. Then, by controlling on/off of the DC voltage for supplying DC power to the LED lighting terminal using a switch circuit, the lighting power amount of the LED lighting terminal is controlled and dimming is performed.

Japanese Patent Application Publication No. 2008-43011

In the power distribution system of Patent Document 1 described above, as the number of LED lighting terminals (lighting loads) increases, the current flowing through the pair of power supply lines (output current) also increases. As a result, the current capacity required of the power supply line increases.

An object of the present disclosure is to provide a lighting system, a lighting load, and a power supply device that can dim a plurality of lighting loads at once and suppress output current even when the number of lighting loads increases.

A lighting system according to one aspect of the present disclosure includes a load block and a power supply device. The load block has a plurality of lighting loads connected in series. The power supply device has a pair of output terminals that output DC power, connects the load block between the pair of output terminals, and supplies DC output current to the load block. Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device. The light source is turned on by the output current flowing from the positive terminal to the negative terminal. The power supply device has a function of adjusting the output current. Each of the plurality of lighting loads includes an alternating circuit and a voltage conversion circuit. The alternating circuit converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage. The voltage conversion circuit generates a second DC voltage larger than the first DC voltage from the alternating voltage, and outputs the second DC voltage to the light source. The voltage conversion circuit includes a transformer and a rectifier circuit. The transformer has a primary winding and a secondary winding, and a turns ratio of the secondary winding to the primary winding is greater than 1. The rectifier circuit rectifies the voltage induced in the secondary winding of the transformer. The alternating circuit applies the alternating voltage to the primary winding. The alternating circuit includes a first switch element and a second switch element connected in series between the positive terminal and the negative terminal, and a third switch element connected in series between the positive terminal and the negative terminal. and a fourth switch element. The first switch element and the third switch element are connected to the positive terminal. The second switch element and the fourth switch element are connected to the negative terminal. The primary winding is connected between a connection point between the first switch element and the second switch element and a connection point between the third switch element and the fourth switch element. The first switch element, the fourth switch element, the second switch element, and the third switch element are the first switch element, the fourth switch element, the second switch element, and the third switch element. are turned on and off so that at least one of them is turned on.
A lighting system according to one aspect of the present disclosure includes a load block and a power supply device. The load block has a plurality of lighting loads connected in series. The power supply device has a pair of output terminals that output DC power, connects the load block between the pair of output terminals, and supplies DC output current to the load block. Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device. The light source is turned on by the output current flowing from the positive terminal to the negative terminal. The power supply device has a function of adjusting the output current. Each of the plurality of lighting loads includes an alternating circuit and a voltage conversion circuit. The alternating circuit converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage. The voltage conversion circuit generates a second DC voltage larger than the first DC voltage from the alternating voltage, and outputs the second DC voltage to the light source. The alternating circuit includes a choke coil, a first switch element, and a second switch element. The choke coil has a first end and a second end. The first switch element is connected between the first end and the negative terminal. The second switch element is connected between the second end and the negative terminal. The first switch element and the second switch element are turned on and off, respectively, such that at least one of the first switch element and the second switch element is turned on. The voltage conversion circuit includes an N-fold voltage rectification and smoothing circuit that multiplies the voltage of the choke coil by a positive integer and rectifies and smoothes the voltage.
A lighting system according to one aspect of the present disclosure includes a load block and a power supply device. The load block has a plurality of lighting loads connected in series. The power supply device has a pair of output terminals that output DC power, connects the load block between the pair of output terminals, and supplies DC output current to the load block. Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device. The light source is turned on by the output current flowing from the positive terminal to the negative terminal. The power supply device has a function of adjusting the output current. Each of the plurality of lighting loads includes an alternating circuit and a voltage conversion circuit. The alternating circuit converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage. The voltage conversion circuit generates a second DC voltage larger than the first DC voltage from the alternating voltage, and outputs the second DC voltage to the light source. The alternating circuit includes a series circuit including a first inductor and a first switch element connected in series between the positive terminal and the negative terminal, and a series circuit including a first switch element connected in series between the positive terminal and the negative terminal. A series circuit including two inductors and a second switch element is provided. The first switch element and the second switch element are turned on and off, respectively, such that at least one of the first switch element and the second switch element is turned on. The voltage conversion circuit rectifies and smoothes the voltage between the connection point of the first inductor and the first switch element and the connection point of the second inductor and the second switch element by multiplying it by a positive integer. Equipped with voltage doubler rectifier and smoothing circuit.
A lighting system according to one aspect of the present disclosure includes a load block and a power supply device. The load block has a plurality of lighting loads connected in series. The power supply device has a pair of output terminals that output DC power, connects the load block between the pair of output terminals, and supplies DC output current to the load block. Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device. The light source is turned on by the output current flowing from the positive terminal to the negative terminal. The power supply device has a function of adjusting the output current. The power supply device includes a signal generation circuit. The signal generation circuit transmits a transmission signal to the load block by switching a value of an output voltage, which is a voltage between the pair of output terminals, to one of two or more values. Each of the plurality of lighting loads includes a signal acquisition section. The signal acquisition unit determines which of the two or more values the value of the output voltage is based on a load voltage that is a voltage between the positive terminal and the negative terminal. Demodulate the transmitted signal. The signal acquisition unit detects the load voltage an odd number of three or more times in each repeatedly set detection period, and from the results of the odd number of detections, the value of the output voltage in the detection period is equal to or greater than the two or more times. The value of is determined by majority vote. The two or more values include a first value and a second value. The detection period is either a first detection period corresponding to the first value or a second detection period corresponding to the second value. The signal generating circuit transmits the transmission signal including bit information at each predetermined period by setting the output voltage to either the first value or the second value at each predetermined period, Further, the transmission signal includes a measurement bit string in which the value of the output voltage is alternately switched to the first value or the second value. The signal acquisition unit sets each time length of the first detection period and the second detection period based on the detection result of the load voltage corresponding to the measurement bit string.

A lighting load according to one aspect of the present disclosure is used in the lighting system described above.

A power supply device according to one aspect of the present disclosure is used in the above-described lighting system.

As described above, the present disclosure has the advantage that it is possible to dim the plurality of lighting loads at once, and to suppress the output current even if the number of the plurality of lighting loads increases.

FIG. 1 is a block diagram showing a lighting system according to an embodiment of the invention. FIG. 2 is a block diagram showing an equivalent circuit of the above lighting system. FIG. 3 is a circuit diagram showing the configuration of the above power supply device. FIG. 4 is a circuit diagram showing the configuration of the above lighting fixture. FIG. 5 is a circuit diagram showing the configuration of a power supply device according to a first modification example of the same. FIG. 6A shows changes in output current and load current with respect to on-duty in the first modification. FIG. 6B shows changes in output power and LED power with respect to on-duty. FIG. 7 is a block diagram showing a lighting system according to a second modification example of the same. FIG. 8 is a circuit diagram showing the configuration of a lighting fixture according to a second modification. FIG. 9 shows changes in load current with respect to on-duty in the second modification. FIG. 10 is a circuit diagram showing a first configuration of a lighting fixture according to a third modification example of the same. FIG. 11 is a circuit diagram showing the configuration of a switch control circuit according to a third modification. FIG. 12 is a waveform diagram showing waveforms of a triangular wave signal and a PWM signal according to the third modification. FIG. 13A is a graph showing the relationship between the boost ratio and the output current and the relationship between the boost ratio and the load current according to the third modification. FIG. 13B is a graph showing the relationship between the boost ratio and the output voltage and the relationship between the boost ratio and the load voltage according to the third modification. FIG. 14 is a circuit diagram showing a second configuration of a lighting fixture according to a third modification. FIG. 15 is a circuit diagram showing the configuration of a lighting fixture according to a fourth modification example of the same. FIG. 16A is a circuit diagram showing the configuration of a double voltage rectification and smoothing circuit according to a fourth modification. FIG. 16B is a circuit diagram showing another configuration of the voltage doubler rectifying and smoothing circuit. FIG. 16C is a circuit diagram showing the configuration of a triple voltage rectification and smoothing circuit. FIG. 17A is a circuit diagram showing the configuration of a quadruple voltage rectifying and smoothing circuit according to a fourth modification. FIG. 17B is a circuit diagram showing the configuration of a quintuple voltage rectifying and smoothing circuit. FIG. 18 is a circuit diagram showing the configuration of a lighting fixture according to a fifth modification example of the same. FIG. 19 is a circuit diagram showing the configuration of a lighting fixture according to a sixth modification example of the same. FIG. 20 is a block diagram showing a part of the configuration of the power supply device according to the seventh modification example. FIG. 21 is a circuit diagram showing the configuration of a lighting load according to a seventh modification. FIG. 22A is a waveform diagram showing the waveform of the output voltage according to the seventh modification. FIG. 22B is a waveform diagram showing the waveform of the output voltage according to the seventh modification. FIG. 22C is a waveform diagram showing the waveform of the output voltage according to the seventh modification. FIG. 23A is a waveform diagram for explaining the determination processing according to the seventh modification. FIG. 23B is a waveform diagram for explaining the determination processing according to the seventh modification. FIG. 24A is a waveform diagram showing the waveform of the load voltage during standard load according to the seventh modification. FIG. 24B is a waveform diagram showing the waveform of the load voltage when the load is light. FIG. 24C is a waveform diagram showing the waveform of the load voltage under heavy load. FIG. 25 is a diagram showing a format of a transmission signal according to the seventh modification. FIG. 26 is a diagram showing another transmission signal format according to the seventh modification.

The following embodiments generally relate to lighting systems, lighting loads, and power supplies. More specifically, the present invention relates to a lighting system that supplies DC power to a plurality of lighting loads, and lighting loads and power supplies used therein.

The lighting system, lighting load, and power supply device of this embodiment are mainly used in offices, factories, stores, offices, residential units, and the like. The dwelling unit may be a single-family house or a housing unit in an apartment complex.

Embodiments will be described below based on the drawings.

The lighting system A1 of this embodiment includes a power supply device 1 and a plurality of lighting loads 2, as shown in FIG. The plurality of lighting loads 2 are connected in series, and a series circuit of the plurality of lighting loads 2 constitutes a load block 20. Furthermore, it is preferable that the lighting system A1 further includes a dimming controller 3 as an external device. In addition, although five lighting loads 2 are connected in series in FIG. 1, the number of lighting loads 2 is not limited to a specific number.

The power supply device 1 includes a pair of input terminals P1 and P2 and a pair of output terminals P3 and P4. An alternating current voltage Va of an alternating current power source 9 is connected to a pair of input terminals P1 and P2. The AC power source 9 is, for example, a commercial power source with a nominal voltage of 100 V or 200 V and a frequency of 50 Hz or 60 Hz. The power supply device 1 is supplied with AC power from an AC power supply 9 via a pair of input terminals P1 and P2. Then, the power supply device 1 converts the AC power into power and outputs DC power from the pair of output terminals P3 and P4. A power supply line W1 is connected to the output terminals P3 and P4, respectively. Output terminal P3 is connected to the positive side of load block 20 via power supply line W1. Output terminal P4 is connected to the negative side of load block 20 via power supply line W1. The power supply device 1 outputs a DC output current Io that flows from the output terminal P3 through the power supply line W1, the plurality of load blocks 20, and the power supply line W1, and flows into the output terminal P4. A capacitor C4 is connected between the output terminals P3 and P4, and an output voltage Vo corresponding to the voltage across the load block 20 is generated between both ends of the capacitor C4. Load voltage Vo between output terminals P3 and P4 is smoothed by capacitor C4. Note that the pair of input terminals P1 and P2 and the pair of output terminals P3 and P4 are configured with a terminal block, a connector, a plug, solder, or a receptacle, and may also be configured simply with a conductor.

The load block 20 includes a series circuit of a plurality of lighting loads 2. The lighting load 2 has a positive terminal P11 and a negative terminal P12. In the lighting load 2, the output current Io flows in from the positive terminal P11, and the output current Io that has passed through the interior of the lighting load 2 flows out from the negative terminal P12. Among the plurality of lighting loads 2, the positive terminal P11 of the lighting load 2 located on the most positive side of the load block 20 (uppermost) is connected to the output terminal P3 of the power supply device 1 via the power supply line W1. . Among the plurality of lighting loads 2, the negative terminal P12 of the lighting load 2 located on the most negative side (the lowest) of the load block 20 is connected to the output terminal P4 of the power supply device 1 via the power supply line W1. . Among the plurality of lighting loads 2, the positive terminal P11 of another lighting load 2 is connected to the negative terminal P12 of the adjacent (upper) lighting load 2, and the negative terminal P12 of the other lighting load 2 is connected to the adjacent (upper) lighting load 2. Connect to the positive terminal P11 of the lower) lighting load 2. That is, the plurality of lighting loads 2 are connected in series between the output terminals P3 and P4. The lighting load 2 includes a light source including at least one solid-state light emitting element, and the light source is lit by an output current Io.

The dimming controller 3 is configured to be able to output a signal to the power supply device 1. The signal path between the dimming controller 3 and the power supply device 1 may be either wired or wireless. That is, signal transmission from the dimming controller 3 to the power supply device 1 is configured to be possible by wired communication or wireless communication. Wired communication is performed via a twisted pair cable, a dedicated communication line, a LAN (Local Area Network) cable, or the like. Wireless communication is performed by wireless LAN, low power wireless, infrared communication, or the like.

When dimming a plurality of lighting loads 2 at once, the dimming controller 3 outputs a batch dimming signal Y0 to the power supply device 1 . The power supply device 1 that has received the batch dimming signal Y0 increases or decreases the dimming levels of the plurality of lighting loads 2 all at once by increasing or decreasing the output current Io. As a result, each light output of the plurality of lighting loads 2 also increases or decreases all at once.

Bulk dimming refers to changing the dimming levels of the plurality of lighting loads 2 all at once while maintaining the difference in dimming levels between the plurality of lighting loads 2 . When the dimming levels of the plurality of lighting loads 2 are adjusted to the same dimming level, the dimming levels of the plurality of lighting loads 2 increased or decreased by the collective dimming are also the same. When the respective dimming levels of the plurality of lighting loads 2 are adjusted to mutually different dimming levels, the respective dimming levels of the plurality of lighting loads 2 that are increased or decreased by the collective dimming also differ from each other. Note that a dimming level of 0% corresponds to turning off the light source, and a dimming level of 100% corresponds to full lighting (100% lighting) of the light source.

FIG. 2 is an equivalent circuit in which the power supply device 1 is replaced with a current source J1. Current source J1 supplies output current Io to load block 20 via power supply line W1. During collective dimming, the current source J1 collectively dims the plurality of lighting loads 2 by changing the magnitude of the output current Io. At this time, the magnitude of the output current Io is determined by the instruction of the collective dimming signal Y0, regardless of the number of lighting loads 2 in the load block 20. That is, even if the number of lighting loads 2 increases or decreases, the output current Io does not change. Therefore, the lighting system A1 can dim the plurality of lighting loads 2 at once, and can suppress the output current Io even if the number of the plurality of lighting loads 2 increases.

FIG. 3 shows an example of the circuit configuration of the power supply device 1. The power supply device 1 includes a DC power supply 11 , a converter 12 , a current detection section 13 , and a feedback control circuit 14 .

The DC power supply 11 includes inductors L1, L2, capacitors C1, C2, a rectifier circuit DB1, a switch element Q1, and a diode D1, and receives an AC voltage Va through input terminals P1, P2. A series circuit of inductor L1 and capacitor C1 is connected between input terminal P1 and input terminal P2. Inductor L1 and capacitor C1 constitute a filter circuit. The connection point between the inductor L1 and the capacitor C1 and the input terminal P2 are connected to the rectifier circuit DB1. The rectifier circuit DB1 rectifies the alternating current voltage Va input from the input terminals P1 and P2 via the filter circuit, and outputs a rectified voltage. The rectifier circuit DB1 is, for example, a full-wave rectifier. A series circuit of an inductor L2 and a switch element Q1 is connected between a pair of output ends (a positive output end and a negative output end) of the rectifier circuit DB1. The switch element Q1 is, for example, an N-channel enhancement type MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The drain of switch element Q1 is connected to inductor L2. The source of switch element Q1 is connected to the negative output terminal of rectifier circuit DB1. The drain of switch element Q1 is further connected to the anode of diode D1. The cathode of diode D1 is connected to the positive electrode of capacitor C2. The negative electrode of capacitor C2 is connected to the source of switch element Q1. This DC power supply 11 is a step-up chopper circuit and also functions as a power factor correction circuit. Specifically, the switching element Q1 is turned on and off by a control circuit (not shown), so that a boosted DC input voltage Vi is generated across the capacitor C2.

The converter 12 is a so-called isolated flyback converter that includes a transformer Tr1, a switch element Q2, a diode D2, a capacitor C3, and a drive circuit K1. The transformer Tr1 has a primary winding 101 and a secondary winding 102. A series circuit of primary winding 101 and switch element Q2 is connected across capacitor C2. The switch element Q2 is, for example, an N-channel enhancement type MOSFET. A drain of switch element Q2 is connected to primary winding 101. The source of switch element Q2 is connected to the negative electrode of capacitor C2. The gate of switch element Q2 is connected to drive circuit K1. The drive circuit K1 turns on and off the switch element Q2 by driving the gate of the switch element Q2. One end of the secondary winding 102 is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the positive electrode of the capacitor C3. The positive electrode of capacitor C3 is connected to output terminal P3. The negative electrode of capacitor C3 is connected to the other end of secondary winding 102 and further connected to circuit ground.

The current detection section 13 includes a resistor R1. One end of the resistor R1 is connected to the negative electrode of the capacitor C3, and the other end of the resistor R1 is connected to the output terminal P4.

The feedback control circuit 14 includes resistors R2, R3, R4, a capacitor C4, a DC voltage source E1, an operational amplifier OP1, and a photocoupler PC1. One end of the resistor R2 is connected to the output terminal P4, and the other end of the resistor R2 is connected to the inverting input terminal of the operational amplifier OP1. A parallel circuit of a resistor R3 and a capacitor C4 is connected between the output terminal and the inverting input terminal of the operational amplifier OP1. A DC voltage source E1 is connected between the non-inverting input terminal of the operational amplifier OP1 and the circuit ground. The output terminal of the operational amplifier OP1 is connected to the anode of the light emitting diode of the photocoupler PC1 via a resistor R4. The cathode of the light emitting diode of photocoupler PC1 is connected to circuit ground. The collector of the phototransistor of the photocoupler PC1 is connected to the drive circuit K1, and the emitter of the phototransistor is connected to the negative electrode of the capacitor C2.

The drive circuit K1 turns on and off the switch element Q2. By turning on and off the switching element Q2, an induced electromotive force is generated in the secondary winding 102 of the transformer Tr1, and the capacitor C3 is charged via the diode D2. As a result, an output voltage Vo is generated across the capacitor C3, and an output current Io is supplied to the load block 20.

Output current Io passes through resistor R1. As a result, a voltage proportional to the magnitude of the output current Io is generated as a detection voltage across the resistor R1. The detection voltage is input to the inverting input terminal of the operational amplifier OP1 via the resistor R2. The DC voltage source E1 outputs a DC target voltage Vs1. The DC voltage source E1 can make the value of the target voltage Vs1 variable, and adjusts the value of the target voltage Vs1 according to the batch dimming signal Y0. The higher the dimming level (collective dimming level) indicated by the batch dimming signal Y0, the larger the value of the target voltage Vs1. The operational amplifier OP1, the resistor R3, and the capacitor C4 function as an error amplifier, and the operational amplifier OP1 outputs a voltage obtained by amplifying the difference between the detected voltage and the target voltage Vs1. The error signal Y1 output from the operational amplifier OP1 is input to the light emitting diode of the photocoupler PC1 via the resistor R4, and the phototransistor of the photocoupler PC1 is driven by the error signal Y1. The collector of the phototransistor is connected to the drive circuit K1, and an error signal Y2 corresponding to the conduction state of the phototransistor is input to the drive circuit K1. The drive circuit K1 is configured to adjust the on-duty of a PWM signal (gate voltage) that turns on and off the switch element Q2 according to the error signal Y2. In other words, the greater the degree of conduction of the phototransistor (the smaller the emitter-collector voltage of the phototransistor), the smaller the on-duty of the PWM signal output by the drive circuit K1, thereby achieving negative feedback control of the load current Io. be done. As a result, the switch element Q2 is turned on and off so that the voltage detected by the resistor R1 matches the target voltage Vs1. That is, converter 12 adjusts the magnitude of output current Io so that the value of output current Io matches the value (target current value) corresponding to the instruction of collective dimming signal Y0.

FIG. 4 shows an example of the circuit configuration of the lighting load 2. The lighting load 2 includes an inductor L11, a switch element Q11, a diode D11, a capacitor C11, a switch control circuit K11, and a light source 2a. The switch element Q11 is, for example, an N-channel enhancement type MOSFET. Preferably, the lighting load 2 includes a series circuit of an inductor L11, a diode D11, and a light source 2a.

The light source 2a has an LED array in which a plurality of LED (Light Emitting Diode) elements are connected in series, as at least one solid-state light emitting element. The light source 2a may include a plurality of LED arrays connected in parallel. Here, the anode of the LED element at one end of the LED array is connected to the first end of the light source 2a, and the first end of the light source 2a is called an anode side. Moreover, the cathode of the LED element at the other end of the LED array is connected to the second end of the light source 2a, and the second end of the light source 2a is called a cathode side.

One end of the inductor L11 is connected to the positive terminal P11, and the other end of the inductor L11 is connected to the drain of the switch element Q11. The source of switch element Q11 is connected to negative terminal P12. The drain of switch element Q11 is further connected to the anode of diode D11, and the cathode of diode D11 is connected to the positive electrode of capacitor C11. The negative electrode of capacitor C11 is connected to negative terminal P12. The anode side of the light source 2a is connected to the positive electrode of the capacitor C11, and the cathode side of the light source 2a is connected to the negative electrode of the capacitor C11. A series circuit of the diode D11 and the light source 2a constitutes a load circuit W20, and the switch element Q11 is connected in parallel to the load circuit W20.

The switch control circuit K11 outputs an on-duty PWM signal Y11 according to the individual dimming level (individual dimming level) of each lighting load 2 to the gate of the switching element Q11. Switch element Q11 is turned on and off according to PWM signal Y11 applied to its gate. The switch control circuit K11 adjusts the load current Ib flowing through the light source 2a by controlling the on-duty of the switch element Q11. When the switch element Q11 is turned off, almost no output current Io flows through the switch element Q11, and the output current Io flows through the light source 2a as a load current Ib. When the switch element Q11 is turned on, the output current Io flows through the switch element Q11, almost no output current Io flows to the light source 2a, and the load current Ib becomes zero. Therefore, the smaller the on-duty of the switching element Q11, the larger the load current Ib and the higher the dimming level of the light source 2a. The larger the on-duty of the switching element Q11, the smaller the load current Ib and the lower the dimming level of the light source 2a.

In this embodiment, the PWM frequency of the PWM signal Y11 is 50 kHz. If the on-duty of the switch element Q11 is 100%, the light source 2a is turned off. When the on-duty of the switching element Q11 is reduced, the dimming level (load current Ib) of the light source 2a increases linearly. When the on-duty of the switch element Q11 is increased, the dimming level (load current Ib) of the light source 2a decreases linearly. If the on-duty of the switch element Q11 is 0%, the light source 2a is fully lit. In other words, the load current Ib is approximately inversely proportional to the on-duty of the switching element Q11. Further, the power consumption of the light source 2a is also approximately inversely proportional to the on-duty of the switching element Q11, similar to the load current Ib. Furthermore, when the on-duty of the switch element Q11 is increased, the voltage across the light source 2a gradually decreases, but the voltage across the light source 2a maintains a value equal to or higher than the lighting start voltage until just before the on-duty reaches 100%. do.

Each of the plurality of solid-state light-emitting elements included in the light source 2a is not limited to an LED, and may be another solid-state light-emitting element such as an organic EL (Organic Electro Luminescence, OEL) or a semiconductor laser diode (LD). . Furthermore, the number of solid-state light-emitting elements is not limited to a plurality, and may be one. Although the plurality of solid-state light emitting elements are electrically connected in series, the connection relationship is not limited to this. The electrical connection relationship between the plurality of solid-state light emitting elements may be a parallel connection or a combination of series connection and parallel connection.

(First modification)
FIG. 5 shows another example of the circuit configuration of the power supply device 1. The power supply device 1 includes a DC power supply 11 , a converter 15 , a current detection section 16 , and a current adjustment circuit 17 .

The DC power supply 11 outputs a DC input voltage Vi. The DC power supply 11 has, for example, a configuration similar to that of the above-described embodiment (see FIG. 3).

Converter 15 includes a switch element Q21, an inductor L21, a capacitor C21, a diode D21, resistors R21, R22, a capacitor C22, an operational amplifier OP21, a DC voltage source E21, a comparator CP21, an oscillator K21, and a drive circuit K22. The switch element Q21 is, for example, an N-channel enhancement type MOSFET. Here, converter 15 is a non-insulated buck converter.

A series circuit of a switching element Q21, an inductor L21, and a capacitor C21 is connected between a pair of output terminals (positive and negative electrodes) of the DC power supply 11. The drain of the switching element Q21 is connected to the positive electrode of the DC power supply 11, and the source of the switching element Q21 is connected to one end of the inductor L21. The other end of the inductor L21 is connected to the positive electrode of the capacitor C21, and the negative electrode of the capacitor C21 is connected to the negative electrode of the DC power supply 11. The anode of diode D21 is connected to the negative electrode of capacitor C21, and the cathode of diode D21 is connected to the source of switch element Q21. The positive electrode of capacitor C21 is connected to output terminal P3. The negative electrode of the capacitor C21 is connected to the output terminal P4 via the current detection section 16 and the current adjustment circuit 17.

One end of the resistor R21 is connected to the output terminal P4, and the other end of the resistor R21 is connected to the inverting input terminal of the operational amplifier OP21. A parallel circuit of a resistor R22 and a capacitor C22 is connected between the output terminal and the inverting input terminal of the operational amplifier OP21. A DC voltage source E21 is connected between the non-inverting input terminal of the operational amplifier OP21 and the circuit ground. The output terminal of the operational amplifier OP21 is connected to the non-inverting input terminal of the comparator CP21. An oscillator K21 is connected between the inverting input terminal of the comparator CP21 and the circuit ground. The output terminal of comparator CP21 is connected to drive circuit K22. Drive circuit K22 is further connected to the gate and source of switch element Q21.

The current detection section 16 includes a resistor R23. One end of the resistor R23 is connected to the negative electrode of the capacitor C21, and the other end of the resistor R23 is connected to the output terminal P4 via the current adjustment circuit 17.

The current adjustment circuit 17 includes an operational amplifier OP22, a switch element Q22, and a DC voltage source E22. Switch element Q22 is, for example, an N-channel enhancement type MOSFET. The non-inverting input terminal of the operational amplifier OP22 is connected to the positive pole of the DC voltage source E22. The negative pole of the DC voltage source E22 is connected to one end of the resistor R23 (the negative pole of the capacitor C21). The inverting input terminal of the operational amplifier OP22 is connected to the other end of the resistor R23 (the source of the switch element Q22). The output terminal of operational amplifier OP22 is connected to the gate of switch element Q22. The drain of switch element Q22 is connected to output terminal P4.

That is, the resistor R23 and the switch element Q22 are provided in the main circuit W10 through which the output current Io flows.

Then, by turning on and off the switch element Q21, a DC intermediate voltage Vm, which is a step-down version of the input voltage Vi, is generated across the capacitor C21. Intermediate voltage Vm is adjusted so that the voltage across the series circuit of resistor R23 and switch element Q22, which is generated by output current Io, matches a predetermined reference voltage.

Specifically, the voltage across the series circuit of resistor R23 and switch element Q22 is input to the inverting input terminal of operational amplifier OP21 via resistor R21. The DC voltage source E21 outputs a DC reference voltage Vs2 having a predetermined magnitude. The value of the reference voltage Vs2 is set in advance so that the power loss in the switching element Q22 caused by the output current Io can be made as low as possible. The operational amplifier OP21, the resistor R22, and the capacitor C22 function as an error amplifier, and the operational amplifier OP21 outputs a voltage obtained by amplifying the difference between the voltages at the inverting input terminal and the non-inverting input terminal. The output voltage of the operational amplifier OP21 is input to the non-inverting input terminal of the comparator CP21. The oscillator K21 outputs a triangular waveform (sawtooth waveform) oscillation voltage. The comparator CP21 compares the output voltage of the operational amplifier OP21 and the oscillation voltage of the oscillator K21, and outputs a PWM signal Y21 whose voltage value alternately switches between H level and L level. The drive circuit K22 receives the PWM signal Y21. The drive circuit K22 turns on and off the switch element Q21 with an on-duty according to the PWM signal Y21. As a result, the intermediate voltage Vm is adjusted so that the voltage across the series circuit of the resistor R23 and the switch element Q22 caused by the output current Io matches the reference voltage Vs2.

The current adjustment circuit 17 makes the value of the output current Io match the target current value. The output current Io passes through the resistor R23, and a voltage proportional to the magnitude of the output current Io is generated across the resistor R23 as a detection voltage. The detected voltage is input to the inverting input terminal of the operational amplifier OP22. The DC voltage source E22 outputs a DC target voltage Vs3. The DC voltage source E22 can make the value of the target voltage Vs3 variable, and adjusts the value of the target voltage Vs3 according to the batch dimming signal Y0. The higher the collective dimming level indicated by the collective dimming signal Y0, the larger the value of the target voltage Vs3. The operational amplifier OP22 functions as an error amplifier, and the operational amplifier OP22 outputs a voltage obtained by amplifying the difference between the detected voltage and the target voltage Vs3. The output voltage of operational amplifier OP22 is applied between the gate and source of switching element Q22. When the output voltage of operational amplifier OP22 increases, output current Io increases, and when the output voltage of operational amplifier OP22 decreases, output current Io decreases. As a result, the value of the gate voltage of the switching element Q22 is determined so that the voltage detected by the resistor R23 matches the target voltage Vs3. That is, the current adjustment circuit 17 adjusts the magnitude of the output current Io so that the value of the output current Io matches the value (target current value) corresponding to the instruction of the collective dimming signal Y0.

FIG. 6A shows changes in the output current Io and the load current Ib with respect to the on-duty of the switching element Q11 of the lighting load 2, respectively. The output current Io maintains a constant value regardless of the on-duty of the switching element Q11. On the other hand, the load current Ib is approximately inversely proportional to the on-duty of the switching element Q11.

Furthermore, when the PWM signals Y11 of the plurality of lighting loads 2 are synchronized, the output power Po of the power supply device 1 and the power consumption (load power) Pb of the light source 2a with respect to the on-duty of the switch element Q11 are shown in FIG. 6B. It will be done. If each PWM signal Y11 is synchronized, each switching element Q11 is similarly driven at the same timing. Note that FIG. 6B shows the simulation results when the load block 20 is composed of a series circuit of two lighting loads 2. The output power Po and the load power Pb are approximately inversely proportional to the on-duty of the switching element Q11.

(Second modification)
FIG. 7 shows the configuration of a lighting system A1 according to a second modification. The lighting system A1 connects the dimming controller 3 and the plurality of lighting loads 2 with a signal line W2. The dimming controller 3 can transmit an individual dimming signal Y10 to each of the plurality of lighting loads 2 via the signal line W2. The individual dimming signal Y10 is transmitted to each of the plurality of lighting loads 2, for example, by unicast. The individual dimming signal Y10 is a signal that individually instructs the dimming level (individual dimming level) of the destination lighting load 2.

FIG. 8 shows the configuration of the lighting load 2 of the second modification. The lighting load 2 of the second modification further includes a signal receiving circuit K12. The signal receiving circuit K12 is connected to the signal line W2 and can receive the individual dimming signal Y10 from the dimming controller 3 via the signal line W2. The signal receiving circuit K12 delivers information on the individual dimming level instructed by the individual dimming signal Y10 to the switch control circuit K11. The switch control circuit K11 outputs a PWM signal Y11 with an on-duty corresponding to the instructed individual dimming level to the gate of the switch element Q11. The switch control circuit K11 can adjust the load current Ib flowing through the light source 2a by controlling the on-duty of the switch element Q11 according to the individual dimming signal Y10. This wired communication is performed via a twisted pair cable, a dedicated communication line, a LAN (Local Area Network) cable, or the like.

Therefore, the lighting system A1 can individually adjust the dimming level of each of the plurality of lighting loads 2, and enables individual dimming of the plurality of lighting loads 2.

FIG. 9 shows the change in the load current Ib of the lighting load 2 with respect to the on-duty of the switch element Q11 of the lighting load 2 by Ib1 when one lighting load 2 among the plurality of lighting loads 2 is individually dimmed. show. Load current Ib1 is approximately inversely proportional to the on-duty of switch element Q11. At this time, the on-duty of the switching element Q11 of another lighting load 2 among the plurality of lighting loads 2 is constant, and the load current Ib of the lighting load 2 with respect to the on-duty of the switching element Q11 of this other lighting load 2 is constant. The change is indicated by Ib2. Load current Ib2 maintains a constant value. In this way, the load currents Ib of the plurality of lighting loads 2 do not interfere with each other, so that individual dimming of the plurality of lighting loads 2 is possible.

Further, the dimming controller 3 may transmit the individual dimming signal Y10 as a wireless signal to each of the plurality of lighting loads 2. In this case, the signal receiving circuit K12 receives the individual dimming signal Y10 as a wireless signal from the dimming controller 3. Therefore, the signal line W2 connecting the dimming controller 3 and the plurality of lighting loads 2 is not required, and the system configuration is simplified. This wireless communication is performed by wireless LAN, low power wireless, infrared communication, or the like.

(Third modification)
As shown in FIG. 1, in a configuration in which a plurality of lighting loads 2 are connected in series to the output of a power supply device 1 that performs constant current control of the output current Io, the output voltage Vo is the forward voltage of each light source 2a of the plurality of lighting loads 2. is approximately equal to the sum of Therefore, as the number of lighting loads 2 increases, the output voltage Vo increases. As a result, restrictions arise on the insulation performance of the power supply line W1, the upper limit value of the output voltage Vo, and the like.

Therefore, each of the plurality of lighting loads 2 preferably includes an alternating circuit and a voltage conversion circuit. The alternating circuit converts the first DC voltage generated by the output current Io flowing from the positive terminal P11 to the negative terminal P12 into an alternating voltage. The voltage conversion circuit generates a second DC voltage larger than the first DC voltage from the alternating voltage, and outputs the second DC voltage to the light source 2a.

FIG. 10 shows a first configuration of the lighting load 2 of this modification, and the lighting load 2 includes an alternating current circuit 201 and a voltage conversion circuit 202. The alternating circuit 201 includes an inductor L31, a first switch element Q31, a second switch element Q32, and a switch control circuit K31, and constitutes a so-called parallel converter. The voltage conversion circuit 202 includes a transformer Tr31, a rectifier circuit DB31, and a capacitor C31. The transformer Tr31 includes a primary winding 301 having a center tap (neutral point) and a secondary winding 302. The first switch element Q31 and the second switch element Q32 are, for example, N-channel enhancement type MOSFETs.

A center tap of primary winding 301 is connected to positive terminal P11 via inductor L31. The first end of the primary winding 301 is connected to the drain of the first switch element Q31, and the source of the first switch element Q31 is connected to the negative terminal P12. The second end of the primary winding 301 is connected to the drain of the second switch element Q32, and the source of the second switch element Q32 is connected to the negative terminal P12. The switch control circuit K31 is connected to each gate and each source of the first switch element Q31 and the second switch element Q32, and turns each of the first switch element Q31 and the second switch element Q32 on and off.

The switch control circuit K31 generates on-duty PWM signals Y31 and Y32 according to the individual dimming level (individual dimming level) of each lighting load 2. Switch control circuit K31 outputs PWM signal Y31 to the gate of first switch element Q31, and outputs PWM signal Y32 to the gate of second switch element Q32. The first switch element Q31 is turned on and off according to the PWM signal Y31 applied to its gate. The second switch element Q32 is turned on and off according to the PWM signal Y32 applied to its gate. When the first switch element Q31 and the second switch element Q32 are turned on and off, a DC load voltage (first DC voltage) Vb1 is generated between the positive terminal P11 and the negative terminal P12, and is generated between both ends of the primary winding 301. It is converted into an alternating voltage Vb2.

In this modification, the output voltage Vo can be suppressed by increasing the step-up ratio of the transformer Tr31 to greater than 1. That is, the ratio between the number of turns between the first end and the center tap of the primary winding 301 and the number of turns of the secondary winding 302 (turns ratio or step-up ratio) is greater than 1. Further, the ratio between the number of turns between the second end and the center tap of the primary winding 301 and the number of turns of the secondary winding 302 (turns ratio or step-up ratio) is greater than 1. Therefore, an alternating voltage Vb3, which is the boosted alternating voltage Vb2, is induced between both ends of the secondary winding 302. The alternating voltage Vb3 of the secondary winding 302 is full-wave rectified by the rectifier circuit DB31 to charge the capacitor C31, and a DC load voltage (second DC voltage) Vb4 is generated across the capacitor C31. Depending on the step-up ratio of the transformer Tr31, the load voltage Vb4 becomes larger than the load voltage Vb1. A light source 2a is connected between both ends of the capacitor C31, and a load current Ib flows through the light source 2a.

Here, in order for the output current Io flowing into the positive terminal P11 to flow out from the negative terminal P12, at least one of the first switching element Q31 and the second switching element Q32 needs to be turned on.

Therefore, the switch control circuit K31 is configured as shown in FIG. The switch control circuit K31 includes comparators CP31 and CP32, oscillators K311 and K312, and a DC voltage source E31. Oscillator K311 outputs triangular wave signal Y33. Oscillator K312 outputs triangular wave signal Y34. The DC voltage source E31 outputs a DC target voltage Vs4. The DC voltage source E31 can make the value of the target voltage Vs4 variable, and adjusts the value of the target voltage Vs4 according to the individual dimming signal Y10. The higher the dimming level (individual dimming level) indicated by the individual dimming signal Y10, the greater the value of the target voltage Vs4. A triangular wave signal Y33 is input to the non-inverting input terminal of the comparator CP31. A triangular wave signal Y34 is input to the non-inverting input terminal of the comparator CP32. The target voltage Vs4 is input to the inverting input terminal of the comparator CP31 and the inverting input terminal of the comparator CP32. Comparator CP31 outputs PWM signal Y31. Comparator CP32 outputs PWM signal Y32.

FIG. 12 shows the waveforms of the triangular wave signals Y33 and Y34 and the PWM signals Y31 and Y32. The wave height values Vp of the triangular wave signal Y33 and the triangular wave signal Y34 are the same, and the phases of the triangular wave signal Y33 and the triangular wave signal Y34 are shifted from each other by 180 degrees. In order to always turn on at least one of the first switch element Q31 and the second switch element Q32, it is necessary to set the on-duty of each of the PWM signals Y31 and Y32 to 50% or more. Therefore, the value of the target voltage Vs4 is set to 1/2 or less of the peak value Vp of the triangular wave signals Y33 and Y34. If the value of the target voltage Vs4 is Vp/2, the on-duty of each of the PWM signals Y31 and Y32 is 50%, and the output current Io becomes the maximum value. As the value of target voltage Vs4 decreases from Vp/2, each on-duty of PWM signals Y31 and Y32 increases from 50%, and the overlapping period of each on-duty of PWM signals Y31 and Y32 becomes longer.

The load current Ib, the output voltage Vo, the load power, and the output power are inversely proportional to the step-up ratio of the transformer Tr31. Further, the output voltage Vo does not depend on the output current Io, but depends on the step-up ratio of the transformer Tr31. Therefore, if the step-up ratio of the transformer Tr31 is made larger than 1, the output voltage Vo can be suppressed.

However, in order to keep the load current Ib at a constant value, it is necessary to increase the output current Io as the step-up ratio of the transformer Tr31 increases.

Further, the load power consumed by the light source 2a and the output power of the power supply device 1 do not depend on the step-up ratio of the transformer Tr31, but depend on the load current Ib.

FIG. 13A shows the relationship between the step-up ratio of the transformer Tr31 and the output current Io, and the relationship between the step-up ratio of the transformer Tr31 and the load current Ib when the value of the target voltage Vs4 is set to Vp/2. In FIG. 13A, in order to maintain the load current Ib at a constant value, the output current Io is increased as the boost ratio increases. That is, the output current Io is proportional to the boost ratio.

FIG. 13B shows the relationship between the step-up ratio of the transformer Tr31 and the output voltage Vo, and the relationship between the step-up ratio of the transformer Tr31 and the load voltage Vb4 when the value of the target voltage Vs4 is set to Vp/2. The load voltage Vb4 is generally constant regardless of the boost ratio, but the output voltage Vo decreases as the boost ratio increases. From these, when increasing the step-up ratio to further reduce the output voltage Vo, it becomes possible to keep the output power of the power supply device 1 constant by increasing the output current Io.

FIG. 14 shows a second configuration of the lighting load 2 of this modification, and the lighting load 2 includes an alternating circuit 211 and a voltage conversion circuit 212. The alternating circuit 211 includes an inductor L41, a first switch element Q41, a second switch element Q42, a third switch element Q43, a fourth switch element Q44, and a switch control circuit K31, and constitutes a so-called full bridge converter. . The voltage conversion circuit 212 includes a transformer Tr41, a rectifier circuit DB41, and a capacitor C41. The transformer Tr41 includes a primary winding 401 and a secondary winding 402. The first switch element Q41, the second switch element Q42, the third switch element Q43, and the fourth switch element Q44 are, for example, N-channel enhancement type MOSFETs.

One end of the inductor L41 is connected to the positive terminal P11. The other end of the inductor L41 is connected to each drain of the first switch element Q41 and the third switch element Q43. Each source of the first switch element Q41 and the third switch element Q43 is connected to each drain of the second switch element Q42 and the fourth switch element Q44, respectively. Each source of the second switch element Q42 and the fourth switch element Q44 is connected to the negative terminal P12. That is, a series circuit of a first switch element Q41 and a second switch element Q42, and a series circuit of a third switch element Q43 and a fourth switch element Q44 are connected between the positive terminal P11 and the negative terminal P12. There is.

Primary winding 401 is connected between the source of first switch element Q41 and the source of third switch element Q43. The switch control circuit K31 is connected to each gate and each source of the first switch element Q41, the second switch element Q42, the third switch element Q43, and the fourth switch element Q44. The switch control circuit K31 turns on and off each of the first switch element Q41, the second switch element Q42, the third switch element Q43, and the fourth switch element Q44.

The switch control circuit K31 generates on-duty PWM signals Y31 and Y32 (see FIG. 12) according to the individual dimming level (individual dimming level) of each lighting load 2. The switch control circuit K31 outputs the PWM signal Y31 to each gate of the first switch element Q41 and the fourth switch element Q44. Further, the switch control circuit K31 outputs the PWM signal Y32 to each gate of the second switch element Q32 and the third switch element Q43. The first switch element Q41 and the fourth switch element Q44 are turned on and off according to the PWM signal Y31 applied to each gate. The second switch element Q42 and the third switch element Q43 are turned on and off according to the PWM signal Y32 applied to each gate. When the first switch element Q41, the second switch element Q42, the third switch element Q43, and the fourth switch element Q44 are turned on and off, the DC load voltage (first DC voltage ) Vb11 is converted into an alternating voltage Vb12 generated across the primary winding 401.

In this modification, the output voltage Vo can be suppressed by increasing the step-up ratio of the transformer Tr41 to greater than 1. That is, the turns ratio (step-up ratio) between the primary winding 401 and the secondary winding 402 is greater than 1. Therefore, an alternating voltage Vb13, which is the boosted alternating voltage Vb12, is induced between both ends of the secondary winding 402. The alternating voltage Vb13 of the secondary winding 402 is full-wave rectified by the rectifier circuit DB41 to charge the capacitor C41, and a DC load voltage (second DC voltage) Vb14 is generated across the capacitor C41. Depending on the step-up ratio of the transformer Tr41, the load voltage Vb14 becomes larger than the load voltage Vb11. A light source 2a is connected between both ends of the capacitor C41, and a load current Ib flows through the light source 2a.

Here, in order for the output current Io flowing into the positive terminal P11 to flow out from the negative terminal P12, the first switching element Q41 and the fourth switching element Q44, and the second switching element Q42 and the third switching element Q43 must , at least one must be on. Therefore, the switch control circuit K31 is configured as shown in FIG. 11, similar to the first configuration of the lighting load 2 of this modification (see FIG. 10), and generates the PWM signals Y31 and Y32 shown in FIG. 12.

The output voltage Vo is inversely proportional to the step-up ratio of the transformer Tr31. Further, the output voltage Vo does not depend on the output current Io, but depends on the step-up ratio of the transformer Tr31. Therefore, if the step-up ratio of the transformer Tr31 is made larger than 1, the output voltage Vo can be suppressed.

(Fourth modification)
FIG. 15 shows the configuration of the lighting load 2 of this modification. The alternating circuit 221 includes an inductor L31, a first switch element Q31, a second switch element Q32, a switch control circuit K31, and a transformer Tr32, and constitutes a so-called parallel converter. The voltage conversion circuit 222 includes an N-fold voltage rectification and smoothing circuit 223. The transformer Tr32 includes a primary winding 311 having a center tap (neutral point) and a secondary winding 312. The first switch element Q31 and the second switch element Q32 are, for example, N-channel enhancement type MOSFETs.

The inductor L31, the first switch element Q31, the second switch element Q32, and the switch control circuit K31 of this modification are the same as the first configuration of the lighting load 2 of the third modification (see FIG. 10). The transformer Tr32 of this modification is connected to the inductor L31, the first switch element Q31, and the second switch element Q32, similarly to the transformer Tr31 of the third modification. The turns ratio (step-up ratio) of the transformer Tr32 is set to 1, unlike the step-up ratio of the transformer Tr31.

When the first switch element Q31 and the second switch element Q32 are turned on and off, a DC load voltage (first DC voltage) Vb21 is generated between the positive terminal P11 and the negative terminal P12, and is generated between both ends of the primary winding 401. It is converted into an alternating voltage Vb22. In this modification, since the step-up ratio of the transformer Tr32 is set to 1, an alternating voltage Vb23 having the same magnitude as the alternating voltage Vb22 is induced between both ends of the secondary winding 312. The alternating voltage Vb23 of the secondary winding 312 is input to the N-fold voltage rectification and smoothing circuit 223.

16A, FIG. 16B, FIG. 16C, FIG. 17A, and FIG. 17B each show an example of the circuit configuration of the N-fold voltage rectification and smoothing circuit 223. In addition, in the following description, the N-fold voltage rectification and smoothing circuit may be abbreviated as an N-fold circuit.

FIG. 16A shows a doubling circuit 223A. In the doubler circuit 223A, a series circuit of a diode D101 and a capacitor C101 is connected between both ends of the secondary winding 312. Furthermore, a series circuit of a capacitor C102 and a diode D102 is connected in parallel to a series circuit of a diode D101 and a capacitor C101. Then, the positive voltage of the alternating voltage Vb23 of the secondary winding 312 is rectified and smoothed by the diode D101 and the capacitor C101, and the negative voltage of the alternating voltage Vb23 is rectified and smoothed by the diode D102 and the capacitor C102. Then, the sum of the voltages of the series-connected capacitors C101 and C102 is output to the light source 2a as a DC load voltage (second DC voltage) Vb24. The magnitude of load voltage Vb24 is twice the magnitude of load voltage Vb21.

FIG. 16B shows a doubling circuit 223B. In the doubler circuit 223B, a series circuit of a capacitor C111 and a diode D111 is connected between both ends of the secondary winding 312. Furthermore, a series circuit of a diode D112 and a capacitor C112 is connected in parallel to the diode D111. Then, the positive voltage of the alternating voltage Vb23 is rectified by the diode D112, and the capacitor C112 is charged. Furthermore, the negative voltage of the alternating voltage Vb23 is rectified by the diode D111, and the capacitor C111 is charged. Then, a DC load voltage (second DC voltage) Vb24 is generated across the capacitor C112. The magnitude of the load voltage Vb24 becomes twice the magnitude of the load voltage Vb21 due to the positive level shift of the potential of the anode of the diode D111.

FIG. 16C is a triple circuit 223C. In the triple circuit 223C, a series circuit of a diode D121 and a capacitor C121 is connected between both ends of the secondary winding 312. A series circuit of a diode D122 and a capacitor C122 is connected in parallel to the diode D121. A series circuit of a diode D123 and a capacitor C123 is connected in parallel to the diode D122. That is, the triple circuit 223C has a configuration in which a double circuit is added to a half-wave rectifier circuit. In the triple circuit 223C, the sum of the voltages of the series-connected capacitors C123 and C121 is output to the light source 2a as a DC load voltage (second DC voltage) Vb24. The magnitude of load voltage Vb24 is three times the magnitude of load voltage Vb21.

FIG. 17A shows a quadruple circuit 223D. In the quadruple circuit 223D, a series circuit of a capacitor C131 and a diode D131 is connected between both ends of the secondary winding 312. A series circuit of a diode D132 and a capacitor C132 is connected in parallel to the diode D131. A series circuit of a diode D133 and a capacitor C133 is connected in parallel to the diode D132. A series circuit of a diode D134 and a capacitor C134 is connected in parallel to the diode D133. In the quadruple circuit 223D, the sum of the voltages of the series-connected capacitors C134 and C132 is output to the light source 2a as a DC load voltage (second DC voltage) Vb24. The magnitude of load voltage Vb24 is four times the magnitude of load voltage Vb21.

FIG. 17B shows a quintuple circuit 223E. In the quintuple circuit 223E, a series circuit of a capacitor C141, a diode D141, and a capacitor C142 is connected between both ends of the secondary winding 312. A series circuit of a diode D142 and a capacitor C143 is connected in parallel to the diode D141. A series circuit of a diode D143 and a capacitor C145 is connected in parallel to the diode D142. A series circuit of a diode D144 and a capacitor C144 is connected in parallel to the diode D143. A series circuit of a diode D145 and a capacitor C146 is connected in parallel to the diode D144. In the quintuple circuit 223E, the sum of the voltages of the series-connected capacitors C146, C145, and C142 is output to the light source 2a as a DC load voltage (second DC voltage) Vb24. The magnitude of load voltage Vb24 is five times the magnitude of load voltage Vb21.

By increasing the magnitude of the load voltage Vb24 by N times the magnitude of the load voltage Vb21 (N is greater than 1) by the N-multiplying circuit 223, the output voltage increases as in the case where the step-up ratio of the transformer is made greater than 1. Vo can be suppressed.

(Fifth modification)
In the fourth modification (see FIG. 15), the transformer Tr32 is used, but the secondary winding 312 of the transformer Tr32 is not required unless the insulation function of the transformer Tr32 is required. FIG. 18 shows the configuration of the lighting load 2 of this modification, and corresponds to the configuration in which the secondary winding 312 of the transformer Tr32 in FIG. 15 is omitted. The alternating circuit 221 includes a choke coil L32 having a center tap instead of the transformer Tr32. A first end of the choke coil L32 is connected to the drain of the first switch element Q31, and a second end of the choke coil L32 is connected to the drain of the second switch element Q32. This modification can also be said to have a configuration in which the secondary winding 312 of the transformer Tr32 is removed and the N-times circuit 223 is provided between both ends of the primary winding 311.

When the first switch element Q31 and the second switch element Q32 are turned on and off, the DC load voltage (first DC voltage) Vb31 generated between the positive terminal P11 and the negative terminal P12 is an alternating voltage generated between both ends of the choke coil L32. It is converted into voltage Vb32. The alternating voltage Vb32 of the choke coil L32 is input to the N-fold circuit 223. The N-times circuit 223 rectifies and smoothes the alternating voltage Vb32 and outputs a voltage N times as high as the DC load voltage (second DC voltage) Vb33 to the light source 2a. The magnitude of load voltage Vb33 is N times the magnitude of load voltage Vb31.

Therefore, in the same way as when the step-up ratio of the transformer is made larger than 1 by increasing the magnitude of the load voltage Vb33 by N times the magnitude of the load voltage Vb31 (N is greater than 1) by the N-multiplying circuit 223, The output voltage Vo can be suppressed.

Furthermore, the effect of suppressing the output voltage Vo when the multiple N of the N-fold circuit 223 of the fourth modification is set to N1, and the output voltage Vo when the multiple N of the N-fold circuit 223 of the present modification is set to N1/2. The suppressive effect is the same as that of

(Sixth variation)
In the fifth modification (see FIG. 18), a magnetically coupled choke coil L32 having a center tap is used. However, as shown in FIG. 19, instead of the choke coil L32, a first inductor L33 and a second inductor L34 may be used as two inductors that are not magnetically coupled.

The first inductor L33 is connected in series to the first switch element Q31 between the positive terminal P11 and the negative terminal P12. The second inductor L34 is connected in series to the second switch element Q32 between the positive terminal P11 and the negative terminal P12.

When the first switch element Q31 and the second switch element Q32 are turned on and off, the DC load voltage (first DC voltage) Vb41 generated between the positive terminal P11 and the negative terminal P12 is It is converted into an alternating voltage Vb42 generated between each drain of element Q32. The alternating voltage Vb42 is input to the N-fold circuit 223. The N-times circuit 223 rectifies and smoothes the alternating voltage Vb42 and outputs a voltage N times as high as the DC load voltage (second DC voltage) Vb43 to the light source 2a. The magnitude of load voltage Vb43 is N times the magnitude of load voltage Vb41.

Therefore, in the same way as when the step-up ratio of the transformer is made larger than 1 by increasing the magnitude of the load voltage Vb43 by N times the magnitude of the load voltage Vb41 (N is greater than 1) by the N-multiplying circuit 223, The output voltage Vo can be suppressed.

Furthermore, the effect of suppressing the output voltage Vo when the multiple N of the N-fold circuit 223 of the fourth modification is set to N1, and the output voltage Vo when the multiple N of the N-fold circuit 223 of the present modification is set to N1/2. The suppressive effect is the same as that of

(Seventh modification)
FIG. 20 shows the configuration of the power supply device 1 of this modification. Power supply device 1 includes a signal generation circuit 18 connected to the output of converter 12. The signal generation circuit 18 adjusts the value of the output voltage Vo of the converter 12 to either the first value Vo1 or the second value Vo2. The signal generation circuit 18 can receive an individual dimming signal Y10 including an instruction of an individual dimming level as transmission data from an external device such as the dimming controller 3. As shown in FIG. 22A, the signal generation circuit 18 changes the value of the output voltage Vo to either the first value Vo1 or the second value Vo2 based on the individual dimming signal Y10. That is, the signal generation circuit 18 transmits a binary transmission signal including transmission data for individually controlling the lighting load 2 to the lighting load 2 based on the individual dimming signal Y10 (baseband transmission). The signal generation circuit 18 sets the output voltage Vo to either the first value Vo1 or the second value Vo2 at each predetermined period Ts, thereby generating a transmission signal containing bit information (bit value) at each period Ts. Send. The transmission signal is a binary signal, and when the value of the output voltage Vo is Vo1, it represents bit information "1", and when the value of the output voltage Vo is Vo2, it represents bit information "0". That is, the transmission data is a bit string in which a plurality of bit information representing "1" or "0" is transmitted in time series. Note that the first value Vo1>0 and the second value Vo2>0, and the magnitude relationship between the first value Vo1 and the second value Vo2 is Vo1>Vo2. Further, instead of the individual dimming signal Y10, an individual toning signal for changing the toning state of the lighting load 2 may be used.

FIG. 21 shows the configuration of the lighting load 2 of this modification. The lighting load 2 includes a signal acquisition section K13. The signal acquisition unit K13 acquires the transmission signal by determining whether the value of the output voltage Vo is Vo1 or Vo2 based on the load voltage Vb5, which is the voltage between the positive terminal P11 and the negative terminal P12. Demodulate.

Specifically, the signal acquisition unit K13 monitors the load voltage Vb5, and determines whether the value of the output voltage Vo is Vo1 or Vo2 by comparing the voltage value of the load voltage Vb5 with a threshold value. to read the transmitted data from the transmitted signal. Since a change in the output voltage Vo is reflected in a change in the load voltage Vb5, determining the value of the load voltage Vb5 is synonymous with determining the value of the output voltage Vo. That is, the signal acquisition unit K13 can detect a change in the value of the load voltage Vb5 and acquire transmission data (instruction of individual dimming level). The signal acquisition unit K13 is configured to output the transmission data to the switch control circuit K11. The switch control circuit K11 outputs an on-duty PWM signal Y11 according to the individual dimming level (individual dimming level) of each lighting load 2 to the gate of the switching element Q11 based on the transmission data.

For example, the signal acquisition unit K13 determines the bit information as "1" if the voltage value of the load voltage Vb5 is equal to or higher than the threshold value, and determines the bit information as "0" if the voltage value of the load voltage Vb5 is less than the threshold value. do. Then, the signal acquisition unit K13 can recognize the instructed individual dimming level based on the read transmission data consisting of a plurality of bit information (bit string).

However, as shown in FIGS. 22B and 22C, surge-like voltage fluctuations may occur in the output voltage Vo due to causes such as noise. In FIG. 22B, a surge-like voltage fluctuation F1 (downward voltage fluctuation) occurs twice in the output voltage Vo during the period corresponding to bit information “1”. In FIG. 22C, a surge-like voltage fluctuation F2 (voltage fluctuation in the rising direction) occurs twice in the output voltage Vo during the period corresponding to bit information "0". In this way, the waveform of the output voltage Vo deteriorates due to the surge-like voltage fluctuations F1 and F2. As a result, the signal acquisition unit K13 may erroneously determine the bit information as "0" during the period corresponding to the bit information "1" in FIG. 22B. Furthermore, the signal acquisition unit K13 may erroneously determine the bit information as "1" during the period corresponding to the bit information "0" in FIG. 22C.

Therefore, the signal acquisition unit K13 performs the detection process three or more odd times in each period Ts, and determines the bit information as "0" or "1" by majority vote.

Specifically, the signal acquisition unit K13 can synchronize with the period Ts of the transmission signal using a synchronization bit string included in the transmission signal. Then, the signal acquisition unit K13 sets the period Ts as a detection period, and performs bit information detection processing at each of three detection timings t1, t2, and t3 for each period Ts, as shown in FIGS. 23A and 23B. . The detection timing t1 is the timing at which a time T1 has elapsed from the start timing t0 of the cycle Ts. The detection timing t2 is a timing at which a time T2 has elapsed from the detection timing t1. The detection timing t3 is a timing at which a time T3 has elapsed from the detection timing t2.

The signal acquisition unit K13 compares the voltage value of the load voltage Vb5 with the threshold value Vr as a bit information detection process. The signal acquisition unit K13 detects bit information "1" if the voltage value of the load voltage Vb5 is equal to or higher than the threshold value Vr. The signal acquisition unit K13 detects bit information "0" if the voltage value of the load voltage Vb5 is less than the threshold value Vr. Note that FIGS. 23A and 23B each represent the waveform of the load voltage Vb5, where the load voltage Vb51 corresponds to the first value Vo1 of the output voltage Vo, and the load voltage value Vb52 corresponds to the second value of the output voltage Vo. Compatible with Vo2. That is, Vb51>0 and Vb52>0, and the magnitude relationship between Vb51 and Vb52 is Vb51>Vb52.

Then, the signal acquisition unit K13 determines bit information as "0" or "1" by majority vote from the detection results of three detection timings t1, t2, and t3 for each period Ts.

FIG. 23A shows the waveform of the load voltage Vb5 in the period Ts corresponding to bit information "0". In FIG. 23A, the surge-like voltage fluctuation F2 occurs twice. Then, the signal acquisition unit K13 detects bit information "1" at detection timing t1, detects bit information "0" at detection timing t2, and detects bit information "0" at detection timing t3. Therefore, the signal acquisition unit K13 can normally determine that the bit information of the period Ts is "0" by majority vote.

FIG. 23B shows the waveform of the load voltage Vb5 in the period Ts corresponding to the bit information "1". In FIG. 23B, the surge-like voltage fluctuation F1 occurs twice. Then, the signal acquisition unit K13 detects bit information "1" at detection timing t1, detects bit information "1" at detection timing t2, and detects bit information "0" at detection timing t3. Therefore, the signal acquisition unit K13 can normally determine that the bit information of the period Ts is "1" by majority vote.

Therefore, the signal acquisition unit K13 can suppress misjudgment of bit information even if the waveform of the output voltage Vo including the transmission signal is degraded by noise or the like. That is, the noise resistance of the signal acquisition section K13 can be improved.

The times T1, T2, and T3 for determining the three detection timings t1, t2, and t3 may be the same length of time. In this case, the three detection timings t1, t2, and t3 occur at the same time interval.

Furthermore, the times T1, T2, and T3 for determining the three detection timings t1, t2, and t3 may have different time lengths. In this case, the three detection timings t1, t2, and t3 occur at different time intervals.

Further, the time T1 and the times T2 and T3 may have different time lengths.

Further, it is preferable that the signal acquisition unit K13 determines the length of the time T1 in each cycle Ts according to the load voltage Vb5 at the start timing t0 of the cycle Ts. For example, the time T1 when the value of the load voltage Vb5 at the start timing t0 of the period Ts is Vb51 is longer than the time T1 when the value of the load voltage Vb5 is Vb52 at the start timing t0 of the period Ts.

Moreover, it is preferable that the threshold value Vr is an average value of the values Vb51 and Vb52 of the load voltage Vb5. That is, Vr=(Vb51+Vb52)/2.

The following description will be made assuming that the threshold value Vr is the average value of Vb51 and Vb51.

FIG. 24A shows the waveform of the load voltage Vb5 during a standard load when the power consumption value of the lighting load 2 is a standard value. For the load voltage Vb5 at standard load, the absolute value of the slope (falling slope) when falling from the value Vo51 to the value Vb52, and the absolute value of the slope (rising slope) when rising from the value Vo52 to the value Vb51. are equal (or nearly equal). That is, for the load voltage Vb5 during standard load, the time length of the H period T11 in which the value of the load voltage Vb5 is equal to or greater than the threshold value Vr is the same as the time length of the L period T12 in which the value of the load voltage Vb5 is less than the threshold value Vr. (or almost the same). Therefore, under standard load, the signal acquisition unit K13 uses the period Ts as the detection period and detects the period even when two or more pieces of bit information "0" or two or more pieces of bit information "1" continue. Discrimination processing can be performed for each Ts.

However, if the power consumption value of the lighting load 2 becomes smaller than the standard value or larger than the standard value, the time length of the H period T11 and the time length of the L period T12 will differ.

FIG. 24B shows the waveform of the load voltage Vb5 during light load when the power consumption value of the lighting load 2 is smaller than the standard value. At load voltage Vb5 during light load, the absolute value of the falling slope is smaller (gentle) than the absolute value of the rising slope. That is, in the load voltage Vb5 during light load, the time length of the H period T11 is longer than the time length of the L period T12. FIG. 24C shows the waveform of the load voltage Vb5 during heavy load when the power consumption value of the lighting load 2 is larger than the standard value. At load voltage Vb5 under heavy load, the absolute value of the falling slope is larger (steeper) than the absolute value of the rising slope. That is, in the load voltage Vb5 at the time of heavy load, the time length of the H period T11 is shorter than the time length of the L period T12. Therefore, under light load and heavy load, the signal acquisition unit K13 uses the period Ts as the detection period when two or more consecutive bit information "0"s and when two or more consecutive bit information "1"s occur. This makes it difficult to perform normal discrimination processing.

Therefore, the signal generation circuit 18 includes the measurement bit string in the transmission signal. The signal acquisition unit K13 detects each time length of the H period T11 and the L period T12 based on the detection result of the load voltage Vb5 corresponding to the measurement bit string included in the transmission signal. The signal acquisition unit K13 then sets the time length of the H period T11 as the time length of the first detection period. Further, the signal acquisition unit K13 sets the time length of the L period T12 as the time length of the second detection period.

The signal acquisition unit K13 performs detection processing three or more odd times in the first detection period, and determines bit information as "0" or "1" by majority vote. Further, the signal acquisition unit K13 performs detection processing an odd number of times, 3 or more, in the second detection period, and determines the bit information as “0” or “1” by majority vote. Therefore, the signal acquisition unit K13 can perform normal discrimination processing even under light load and heavy load.

FIG. 25 shows a transmission signal S1 as a first example of the transmission signal. The transmission signal S1 sequentially includes a 3-bit measurement bit string B1, a 1-bit start bit B2, a 10-bit main bit string B3, and a 1-bit stop bit B4. That is, it is preferable that the measurement bit string B1 is provided at the beginning of the transmission signal S1.

In the 3-bit measurement bit string B1, the value of the output voltage Vo is alternately switched to the first value Vo1 or the second value Vo2 every cycle Ts. In the measurement bit string B1 of FIG. 25, the value of the output voltage Vo is switched in the order of the second value Vo2, the first value Vo1, and the second value Vo2. The signal acquisition unit K13 detects each time length of the H period T11 and the L period T12 based on the detection result of the load voltage Vb5 corresponding to the measurement bit string B1 included in the transmission signal S1.

The start bit B2 notifies the signal acquisition unit K13 of the start of transmission of transmission data. Main bit string B3 represents transmission data. The stop bit B4 notifies the signal acquisition unit K13 of the end of transmission of the transmission data.

FIG. 26 shows a transmission signal S2 as a second example of the transmission signal. The transmission signal S2 sequentially includes a 3-bit measurement bit string B1, a 10-bit main bit string B3, a 1-bit parity bit B5, and a 1-bit stop bit B4. That is, it is preferable that the measurement bit string B1 is provided at the beginning of the transmission signal S2. In the transmission signal S2, the measurement bit string B1 also serves as a start bit. The signal acquisition unit K13 can detect whether there is an error in the data based on the parity bit B5.

Moreover, it is preferable that the signal generation circuit 18 makes at least one of the first value Vo1 and the second value Vo2 variable based on the waveform of the output voltage Vo. As the waveform of the output voltage Vo, if the time length of the H period T11 is longer than the time length of the L period T12 as shown in FIG. 24B, the first value Vo1 is made smaller than the current value, or the second value Vo2 is made larger than the current value. . As the waveform of the output voltage Vo, if the time length of the H period T11 is shorter than the time length of the L period T12 as shown in FIG. 24C, the first value Vo1 is made larger than the current value, or the second value Vo2 is made smaller than the current value. . In this way, the signal generation circuit 18 can adjust the length of each of the H period T11 and the L period T12 based on the waveform of the output voltage Vo.

As described above, the lighting system (A1) of the first aspect according to the embodiment includes the load block (20) and the power supply device (1). The load block (20) has a plurality of lighting loads (2) connected in series. The power supply device (1) has a pair of output terminals (P3, P4) that output DC power, and a load block (20) is connected between the pair of output terminals (P3, P4) to output DC power. (Io) is supplied to the load block (20). The plurality of lighting loads (2) include a positive terminal (P11) into which the output current (Io) flows, a negative terminal (P12) into which the output current (Io) flows out, and a light source (2a) including at least one solid state light emitting element. have each. The light source (2a) is turned on by the output current (Io) flowing from the positive terminal (P11) to the negative terminal (P12). The power supply device (1) has a function of adjusting output current (Io).

The above-described lighting system (A1) can dim the plurality of lighting loads (2) at once, and can suppress the output current (Io) even if the number of the plurality of lighting loads (2) increases.

In the lighting system (A1) of the second aspect according to the embodiment, in the first aspect, the power supply device (1) includes a converter (12), a current detection section (13), and a feedback control circuit (14). It is preferable to include the following. The converter (12) receives an input voltage (Vi), converts the input voltage (Vi) into power, and generates an output current (Io). The current detection section (13) detects the output current (Io). The feedback control circuit (14) controls the converter (12) so that the value of the output current (Io) detected by the current detection section (13) matches the target current value, and makes the target current value variable.

The above-described lighting system (A1) can dim the plurality of lighting loads (2) at once, and can suppress the output current (Io) even if the number of the plurality of lighting loads (2) increases.

In the third aspect of the lighting system (A1) according to the embodiment, in the first aspect, the power supply device (1) includes a converter (15), a current detection section (16), and a current adjustment circuit (17). It is preferable to include the following. The converter (15) receives an input voltage (Vi), converts the input voltage (Vi) into a DC voltage (Vo), and applies the DC voltage (Vo) between a pair of output terminals (P3, P4). . The current detection section (16) detects the output current (Io). The current adjustment circuit (17) is provided in the main circuit (W10) through which the output current (Io) flows, and matches the value of the output current (Io) with a target current value, making the target current value variable. The converter (15) adjusts the DC voltage (Vo) so that the value of the voltage across the current adjustment circuit (17) in the main circuit (W10) matches a predetermined value.

The above-described lighting system (A1) can dim the plurality of lighting loads (2) at once, and can suppress the output current (Io) even if the number of the plurality of lighting loads (2) increases.

In the lighting system (A1) of the fourth aspect according to the embodiment, in any one of the first to third aspects, each of the plurality of lighting loads (2) includes a switch element (Q11) and a switch control It is preferable to further include a circuit (K11). The switch element (Q11) is connected in parallel to the load line (W20) including the light source (2a). The switch control circuit (K11) dims the light source (2a) by controlling the on-duty of the switch element (Q11).

The lighting system (A1) described above further allows individual dimming of a plurality of lighting loads (2).

In the lighting system (A1) of the fifth aspect according to the embodiment, in the fourth aspect, the load circuit (W20) preferably includes a series circuit of a light source (2a) and a diode (D11).

The lighting system (A1) described above is capable of individually dimming a plurality of lighting loads (2).

In the lighting system (A1) of the sixth aspect according to the embodiment, in the fourth or fifth aspect, each of the plurality of lighting loads (2) is connected to the external device (3) via the signal line (W2). It is preferable to include a signal receiving circuit (K12) that receives the individual dimming signal (Y10). The switch control circuit (K11) controls on-duty based on the individual dimming signal (Y10).

The above-mentioned lighting system (A1) can individually dim a plurality of lighting loads (2) using wired communication.

In the lighting system (A1) of the seventh aspect according to the embodiment, in the fourth or fifth aspect, each of the plurality of lighting loads (2) receives an individual dimming signal ( It is preferable to include a signal receiving circuit (K12) that receives the signal Y10). The switch control circuit (K11) controls on-duty based on the individual dimming signal (Y10).

The lighting system (A1) described above can individually dim a plurality of lighting loads (2) using wireless communication.

In the lighting system (A1) of the eighth aspect according to the embodiment, in any one of the first to fifth aspects, each of the plurality of lighting loads (2) includes an alternating circuit (201, 211, 221). and a voltage conversion circuit (202, 212, 222). The alternating circuit (201, 211, 221) converts the first DC voltage (Vb1, Vb11, Vb21, Vb31, Vb41) generated by the output current (Io) flowing from the positive terminal (P11) to the negative terminal (P12) into an alternating voltage. (Vb2, Vb12, Vb23, Vb32, Vb42). The voltage conversion circuit (202, 212, 222) converts the alternating voltage (Vb2, Vb12, Vb23, Vb32, Vb42) into a second DC voltage (Vb4) which is higher than the first DC voltage (Vb1, Vb11, Vb21, Vb31, Vb41). , Vb14, Vb24, Vb33, Vb43) and outputs the second DC voltage (Vb4, Vb14, Vb24, Vb33, Vb43) to the light source (2a).

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the lighting system (A1) of the ninth aspect according to the embodiment, in the eighth aspect, the voltage conversion circuit (202, 212) includes a transformer (Tr31, Tr41) and a rectifier circuit (DB31, DB41). It is preferable to have one. The transformer (Tr31, Tr41) has a primary winding (301, 401) and a secondary winding (302, 402), and the number of turns of the secondary winding (302, 402) with respect to the primary winding (301, 401) is The ratio is greater than 1. The rectifier circuits (DB31, DB41) rectify the voltages (Vb3, Vb13) induced in the secondary windings (302, 402) of the transformers (Tr31, Tr41). The alternating circuit (201, 211) applies an alternating voltage (Vb2, Vb12) to the primary winding (301, 401).

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the lighting system (A1) of the tenth aspect according to the embodiment, in the ninth aspect, the primary winding (301) has a first end, a second end, and a connection between the first end and the second end. It is preferable to have a center tap provided therebetween. The center tap is connected to the positive terminal (P11) via an inductor (L31). The alternating circuit (201) includes a first switch element (Q31) connected between a first end and a negative terminal (P12), and a second switch element (Q31) connected between a second end and a negative terminal (P12). It has a switch element (Q32). The first switch element (Q31) and the second switch element (Q32) are turned on and off, respectively, so that at least one of the first switch element (Q31) and the second switch element (Q32) is turned on.

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the illumination system (A1) of the eleventh aspect according to the embodiment, in the ninth aspect, the alternating circuit (211) includes a first circuit connected in series between the positive terminal (P11) and the negative terminal (P12). A switch element (Q41) and a second switch element (Q42), and a third switch element (Q43) and a fourth switch element (Q44) connected in series between the positive terminal (P11) and the negative terminal (P12). It is preferable to have the following. The first switch element (Q41) and the third switch element (Q43) are connected to the positive terminal (P11). The second switch element (Q42) and the fourth switch element (Q44) are connected to the negative terminal (P12). The primary winding (401) is connected between the connection point of the first switch element (Q41) and the second switch element (Q42) and the connection point of the third switch element (Q43) and the fourth switch element (Q44). be done. The first switch element (Q41), the fourth switch element (Q44), the second switch element (Q42), and the third switch element (Q43) are the first switch element (Q41) and the fourth switch element (Q44). Each of the second switching element (Q42) and the third switching element (Q43) is turned on and off so that at least one of them is turned on.

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the lighting system (A1) of the twelfth aspect according to the embodiment, in the eighth aspect, the alternating circuit (221) includes a transformer (Tr32) having a primary winding (311) and a secondary winding (312). In preparation for this, it is preferable to induce an alternating voltage (Vb23) in the secondary winding (312). The voltage conversion circuit (222) preferably includes an N-fold voltage rectification and smoothing circuit (223) that multiplies the alternating voltage (Vb23) by a positive integer and rectifies and smooths it.

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the lighting system (A1) of the thirteenth aspect according to the embodiment, in the eighth aspect, the alternating circuit (221) includes a choke coil (L32), a first switch element (Q31), and a second switch element ( Q32). The choke coil (L32) has a first end and a second end. The first switch element (Q31) is connected between the first end and the negative terminal (P12), and the second switch element (Q32) is connected between the second end and the negative terminal (P12). Ru. The first switch element (Q31) and the second switch element (Q32) are turned on and off, respectively, so that at least one of the first switch element (Q31) and the second switch element (Q32) is turned on. The voltage conversion circuit (222) includes an N-fold voltage rectification and smoothing circuit (223) that multiplies the voltage of the choke coil (L32) by a positive integer and rectifies and smooths it.

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the lighting system (A1) of the fourteenth aspect according to the embodiment, in the eighth aspect, the alternating circuit (221) includes a first circuit connected in series between the positive terminal (P11) and the negative terminal (P12). A series circuit of an inductor (L33) and a first switch element (Q31), and a second inductor (L34) and a second switch element (Q32) connected in series between a positive terminal (P11) and a negative terminal (P12). ) is preferably provided. The first switch element (Q31) and the second switch element (Q32) are turned on and off, respectively, so that at least one of the first switch element (Q31) and the second switch element (Q32) is turned on. The voltage conversion circuit (222) converts the voltage between the connection point of the first inductor (L33) and the first switch element (Q31) and the connection point of the second inductor (L34) and the second switch element (Q32) to a positive value. An N-fold voltage rectifying and smoothing circuit (223) is provided which rectifies and smoothes the voltage by an integral multiple of the voltage.

The above-described lighting system (A1) can suppress the output voltage (Vo) even if the number of lighting loads (2) increases.

In the illumination system (A1) of the fifteenth aspect of the embodiment, in any one of the first to fourteenth aspects, the power supply device (1) preferably includes a signal generation circuit (18). The signal generation circuit (18) controls the load by switching the value of the output voltage (Vo), which is the voltage between the pair of output terminals (P3, P4), to one of two or more values (Vo1, Vo2). Transmit transmission signals (S1, S2) to block (20). It is preferable that each of the plurality of lighting loads (2) includes a signal acquisition section (K13). The signal acquisition unit (K13) determines whether the output voltage (Vo) has two or more values (Vo1) based on the load voltage (Vb5), which is the voltage between the positive terminal (P11) and the negative terminal (P12). , Vo2), the transmission signal is demodulated. The signal acquisition unit (K13) detects the load voltage (Vb5) an odd number of three or more times in each repeatedly set detection period (Ts), and determines the output in the detection period (Ts) from the odd number of detection results. It is determined by majority vote which of two or more values (Vo1, Vo2) the value of the voltage (Vo) is.

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the illumination system (A1) of the sixteenth aspect according to the embodiment, in the fifteenth aspect, the signal acquisition unit (K13) adjusts the load voltage (Vb5) to an odd number at the same time interval in each of the detection periods (Ts). It is preferable to detect it twice.

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the illumination system (A1) of the seventeenth aspect according to the embodiment, in the fifteenth aspect, the signal acquisition unit (K13) adjusts the load voltage (Vb5) at different time intervals in each of the detection periods (Ts). It is preferable to detect an odd number of times.

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the illumination system (A1) of the eighteenth aspect according to the embodiment, in the fifteenth aspect, the signal acquisition unit (K13) determines the start timing (t0) of the detection period (Ts) in each of the detection periods (Ts). The time (T1) from to the first detection timing (t1) among the odd numbered detection timings, and the generation cycle (T2, T3) of the second and subsequent detection timings (t2, t3) among the odd numbered detection timings. It is preferable to make them different.

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the illumination system (A1) of the nineteenth aspect according to the embodiment, in any one of the fifteenth to eighteenth aspects, the signal acquisition unit (K13) is configured to detect the detection period (Ts) in each of the detection periods (Ts). It is preferable to determine the first detection timing (t1) among the odd number of detection timings according to the load voltage (Vb5) at the start timing (t0) of Ts).

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the lighting system (A1) of the twentieth aspect according to the embodiment, in any one of the fifteenth to nineteenth aspects, the two or more values are a first value (Vo1) and a second value (Vo2). It is preferable to include. The detection period is either a first detection period corresponding to the first value (Vo1) or a second detection period corresponding to the second value (Vo2). The signal generation circuit (18) sets the output voltage (Vo) to either a first value (Vo1) or a second value (Vo2) at each predetermined period (Ts), thereby changing the period (Ts). A transmission signal (S1, S2) containing bit information is transmitted each time. Further, the signal generation circuit (18) includes a measurement bit string (B1) in which the value of the output voltage (Vo) is alternately switched to the first value (Vo1) or the second value (Vo2) to the transmission signal (S1, S2). ). The signal acquisition unit (K13) sets the time lengths of the first detection period and the second detection period, respectively, based on the detection result of the load voltage (Vb5) corresponding to the measurement bit string (B1).

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the lighting system (A1) of the twenty-first aspect according to the embodiment, in the twentieth aspect, the measurement bit string (B1) is preferably located at the beginning of the transmission signal (S1, S2).

The above-described illumination system (A1) can improve the noise resistance of the signal acquisition unit (K13).

In the lighting system (A1) of the 22nd aspect according to the embodiment, in the 20th or 21st aspect, the power supply device (1) determines the first value (Vo1) and the output voltage (Vo) based on the waveform of the output voltage (Vo). Preferably, at least one of the second values (Vo2) is variable.

In the above-mentioned illumination system (A1), the signal acquisition unit (K13) can perform normal discrimination processing even under light load and heavy load.

In the lighting system (A1) of the 23rd aspect of the embodiment, in any one of the 20th to 22nd aspects, the signal acquisition unit (K13) compares the load voltage (Vb5) with the threshold value (Vr). By doing so, it is determined whether the value of the output voltage (Vo) is the first value (Vo1) or the second value (Vo2). It is preferable that the threshold value (Vr) is an average value of the first value (Vo1) and the second value (Vo2).

In the above-mentioned illumination system (A1), the signal acquisition unit (K13) can perform normal discrimination processing even under light load and heavy load.

The twenty-fourth lighting load (2) according to the embodiment is used in the lighting system (A1) of any one of the first to twenty-third aspects.

The above-mentioned lighting load (2) can suppress the output current (Io) even if the number of lighting loads (2) in the lighting system (A1) increases.

The twenty-fifth power supply device (1) according to the embodiment is used in the lighting system (A1) of any one of the first to twenty-third aspects.

The above-described power supply device (1) can suppress the output current (Io) even if the number of lighting loads (2) in the lighting system (A1) increases.

Furthermore, the above-described embodiments and modifications are merely examples. Therefore, the present invention is not limited to the above-described embodiments and modified examples, and even if the present invention is not limited to the above-described embodiments and modified examples, as long as it does not deviate from the technical idea of the present invention, the design Of course, various changes can be made depending on the situation.

A1 Lighting system 1 Power supply 12 Converter 13 Current detection unit 14 Feedback control circuit 15 Converter 16 Current detection unit 17 Current adjustment circuit 18 Signal generation circuit P3, P4 Pair of output terminals 2 Lighting load 2a Light source 20 Load block 201, 211, 221 Alternating circuit 202, 212, 222 Voltage conversion circuit P11 Positive terminal P12 Negative terminal Q11 Switch element K11 Switch control circuit D11 Diode K12 Signal receiving circuit K13 Signal acquisition section Tr31, Tr41 Transformer DB31, DB41 Rectifier circuit 301, 401 Primary winding 302, 402 Secondary winding Vb3, Vb13 Voltage L31 Inductor Q31 First switch element Q32 Second switch element Q41 First switch element Q42 Second switch element Q43 Third switch element Q44 Fourth switch element 311 Primary winding 312 Secondary winding Tr32 Transformer 223 N double voltage rectification smoothing circuit L32 Choke coil L33 First inductor L34 Second inductor Vi Input voltage Io Output current Vo Output voltage (DC voltage)
Vo1 First value of output voltage Vo Vo2 Second value of output voltage Vo Vb1, Vb11, Vb21, Vb31, Vb41 First DC voltage Vb2, Vb12, Vb23, Vb32, Vb42 Alternating voltage Vb4, Vb14, Vb24, Vb33, Vb43 2 DC voltage Vb5 Load voltage W10 Main line W20 Load line S1, S2 Transmission signal Ts Period (detection period)
t0 Start timing t1 First detection timing t2, t3 Second and subsequent detection timings T1 Time until first detection timing t1 T2, T3 Time (occurrence cycle)
B1 Measurement bit string 3 Dimming controller (external device)
W2 Signal line Y10 Individual dimming signal

Claims (16)

a load block having multiple lighting loads connected in series;
a power supply device having a pair of output terminals that output DC power, connecting the load block between the pair of output terminals, and supplying a DC output current to the load block;
Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device, and the light source is configured to connect the light source from the positive terminal to the light source. Illuminated by the output current flowing to the negative terminal,
The power supply device has a function of adjusting the output current,
Each of the plurality of lighting loads is
an alternating circuit that converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage;
a voltage conversion circuit that generates a second DC voltage larger than the first DC voltage from the alternating voltage and outputs the second DC voltage to the light source,
The voltage conversion circuit includes:
a transformer having a primary winding and a secondary winding, the turn ratio of the secondary winding to the primary winding being greater than 1;
a rectifier circuit that rectifies the voltage induced in the secondary winding of the transformer,
The alternating circuit is
applying the alternating voltage to the primary winding;
The alternating circuit includes a first switch element and a second switch element connected in series between the positive terminal and the negative terminal, and a third switch element connected in series between the positive terminal and the negative terminal. and a fourth switch element,
the first switch element and the third switch element are connected to the positive terminal,
the second switch element and the fourth switch element are connected to the negative terminal,
The primary winding is connected between a connection point between the first switch element and the second switch element and a connection point between the third switch element and the fourth switch element,
The first switch element, the fourth switch element, the second switch element, and the third switch element are the first switch element, the fourth switch element, the second switch element, and the third switch element. turn each on and off so that at least one of them is on.
lighting system. a load block having multiple lighting loads connected in series;
a power supply device having a pair of output terminals that output DC power, connecting the load block between the pair of output terminals, and supplying a DC output current to the load block;
Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device, and the light source is configured to connect the light source from the positive terminal to the light source. Illuminated by the output current flowing to the negative terminal,
The power supply device has a function of adjusting the output current,
Each of the plurality of lighting loads is
an alternating circuit that converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage;
a voltage conversion circuit that generates a second DC voltage larger than the first DC voltage from the alternating voltage and outputs the second DC voltage to the light source,
The alternating circuit is
a choke coil having a first end and a second end;
a first switch element connected between the first end and the negative terminal;
a second switch element connected between the second end and the negative terminal,
the first switch element and the second switch element are turned on and off, respectively, such that at least one of the first switch element and the second switch element is turned on;
The voltage conversion circuit includes an N-fold voltage rectification and smoothing circuit that multiplies the voltage of the choke coil by a positive integer and rectifies and smoothes it.
lighting system. a load block having multiple lighting loads connected in series;
a power supply device having a pair of output terminals that output DC power, connecting the load block between the pair of output terminals, and supplying a DC output current to the load block;
Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device, and the light source is configured to connect the light source from the positive terminal to the light source. Illuminated by the output current flowing to the negative terminal,
The power supply device has a function of adjusting the output current,
Each of the plurality of lighting loads is
an alternating circuit that converts a first DC voltage generated by the output current flowing from the positive terminal to the negative terminal into an alternating voltage;
a voltage conversion circuit that generates a second DC voltage larger than the first DC voltage from the alternating voltage and outputs the second DC voltage to the light source,
The alternating circuit includes a series circuit including a first inductor and a first switch element connected in series between the positive terminal and the negative terminal, and a series circuit including a first switch element connected in series between the positive terminal and the negative terminal. It comprises a series circuit of two inductors and a second switch element,
the first switch element and the second switch element are turned on and off, respectively, such that at least one of the first switch element and the second switch element is turned on;
The voltage conversion circuit rectifies and smoothes the voltage between the connection point of the first inductor and the first switch element and the connection point of the second inductor and the second switch element by multiplying it by a positive integer. Equipped with voltage doubler rectifier and smoothing circuit
lighting system. The power supply device includes:
comprising a signal generation circuit that transmits a transmission signal to the load block by switching the value of the output voltage, which is the voltage between the pair of output terminals, to one of two or more values;
Each of the plurality of lighting loads is
A signal that demodulates the transmission signal by determining which of the two or more values the value of the output voltage is based on a load voltage that is a voltage between the positive terminal and the negative terminal. Equipped with an acquisition section,
The signal acquisition unit detects the load voltage an odd number of three or more times in each repeatedly set detection period, and from the results of the odd number of detections, the value of the output voltage in the detection period is equal to or greater than the two or more times. Determine by majority vote which of the values is
A lighting system according to any one of claims 1 to 3. a load block having multiple lighting loads connected in series;
a power supply device having a pair of output terminals that output DC power, connecting the load block between the pair of output terminals, and supplying a DC output current to the load block;
Each of the plurality of lighting loads has a positive terminal into which the output current flows, a negative terminal into which the output current flows out, and a light source including at least one solid state light emitting device, and the light source is configured to connect the light source from the positive terminal to the light source. Illuminated by the output current flowing to the negative terminal,
The power supply device has a function of adjusting the output current,
The power supply device includes:
comprising a signal generation circuit that transmits a transmission signal to the load block by switching the value of the output voltage, which is the voltage between the pair of output terminals, to one of two or more values;
Each of the plurality of lighting loads is
A signal that demodulates the transmission signal by determining which of the two or more values the value of the output voltage is based on a load voltage that is a voltage between the positive terminal and the negative terminal. Equipped with an acquisition section,
The signal acquisition unit detects the load voltage an odd number of three or more times in each repeatedly set detection period, and from the results of the odd number of detections, the value of the output voltage in the detection period is equal to or greater than the two or more times. Determine by majority vote which value is
the two or more values include a first value and a second value,
The detection period is either a first detection period corresponding to the first value or a second detection period corresponding to the second value,
The signal generating circuit transmits the transmission signal including bit information at each predetermined period by setting the output voltage to either the first value or the second value at each predetermined period, and the transmission signal includes a measurement bit string in which the value of the output voltage is alternately switched to the first value or the second value,
The signal acquisition unit sets each time length of the first detection period and the second detection period based on the detection result of the load voltage corresponding to the measurement bit string.
lighting system. The measurement bit string is located at the beginning of the transmission signal.
The lighting system according to claim 5. The power supply device makes at least one of the first value and the second value variable based on the waveform of the output voltage.
The lighting system according to claim 5 or 6. The signal acquisition unit compares the load voltage with a threshold value to determine whether the value of the output voltage is the first value or the second value,
The threshold value is an average value of the first value and the second value.
A lighting system according to any one of claims 5 to 7. The signal acquisition unit detects the load voltage the odd number of times at the same time interval in each of the detection periods.
A lighting system according to any one of claims 4 to 8. The signal acquisition unit detects the load voltage the odd number of times at different time intervals in each of the detection periods.
A lighting system according to any one of claims 4 to 8. In each of the detection periods, the signal acquisition unit is configured to determine, in each of the detection periods, the time from the start timing of the detection period to the first detection timing of the odd number of detection timings, and the time from the second and subsequent detection timings of the odd number of detection timings. Differentiate the detection timing generation cycle
A lighting system according to any one of claims 4 to 8. The signal acquisition unit determines a first detection timing among the odd number of detection timings in each of the detection periods, according to the load voltage at the start timing of the detection period.
A lighting system according to any one of claims 4 to 11. The power supply device includes:
a converter that receives an input voltage and converts the input voltage into power to generate the output current;
a current detection unit that detects the output current;
a feedback control circuit that controls the converter and makes the target current value variable so that the value of the output current detected by the current detection section matches a target current value.
A lighting system according to any one of claims 1 to 12. The power supply device includes:
a converter that receives an input voltage, converts the input voltage into a DC output voltage, and applies the output voltage between the pair of output terminals;
a current detection unit that detects the output current;
a current adjustment circuit that is provided in a main circuit through which the output current flows, matches the value of the output current to a target current value, and makes the target current value variable;
The converter adjusts the output voltage so that the value of the voltage across the current adjustment circuit in the main circuit matches a predetermined value.
A lighting system according to any one of claims 1 to 12. A lighting load for use in a lighting system according to any one of claims 1 to 14. A power supply device used in the lighting system according to any one of claims 1 to 14.

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