JP2016091643A - Lighting control signal generation circuit, led power source and led illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting control signal generation circuit capable of generating a lighting control signal from electric signals for lighting control in simple configuration even if the number of systems of electric signals for lighting control from an AC power source is increased.SOLUTION: A lighting control signal generation circuit (1) generates the lighting control signal based on ON/OFF of a plurality of AC electric signals inputted from the AC power source. The lighting control signal generation circuit (1) comprises: a smoothing circuit (10) for generating a rectified and smoothed voltage from a first AC electric signal (E1); a pulsation circuit (20) for generating a rectified pulsation voltage from a second AC electric signal (E2); a photocoupler (30) including a photodiode (31) to which the smoothed voltage is applied; a switching circuit (40) for controlling a current that flows in the photodiode, based on the pulsation voltage; and an output circuit (50) which outputs a lighting control signal (D) corresponding to an operation state of a photo-transistor (32) in the photocoupler.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dimming signal generation circuit, an LED power source, and an LED lighting device.

  Patent Document 1 discloses a discharge lamp lighting device used in a dimming lighting system. The discharge lamp lighting device includes a control circuit for generating a DC dimming signal from an electrical signal of a PWM signal input from the dimmer. The control circuit includes a rectifier circuit that performs full-wave rectification of the PWM signal, a capacitor that filters the rectified output, and a photocoupler for transmitting the rectified output voltage to the lighting device. As a result, the secondary output of the photocoupler is used as a dimming signal in the lighting device, and the dimming control is performed on the discharge lamp.

  Patent Document 2 discloses an emergency lighting fixture having a dimming function. The emergency lighting apparatus includes a dimming interface connected to a commercial power source via a switch, and a photocoupler for transmitting an output of the dimming interface to a control circuit of the lighting device. An AC electrical signal is input to the dimming interface in response to opening and closing of a switch connected to the commercial power supply, and a dimming signal generated by the dimming interface and the photocoupler is output to the control circuit. Thereby, dimming control of the LED lamp is performed according to the dimming signal in the lighting device including the control circuit.

JP 2003-86392 A JP 2014-102956 A

  By the way, the dimming interface configured to generate the dimming signal in response to the on / off of the AC electrical signal from the commercial power source as in Patent Document 2 corresponds to the PWM signal from the dimmer as in Patent Document 1. Therefore, the circuit configuration for generating the dimming signal cannot be applied as it is. Since the PWM signal of the dimmer is generally a low-voltage high-frequency signal, the PWM signal is input to the photocoupler without being stepped down, and a low-voltage and small-capacity small capacitor is used for smoothing the input or output signal of the photocoupler. Is used. On the other hand, since the AC electrical signal from the commercial power source is a low frequency signal of 50 Hz or 60 Hz such as AC 100 V, AC 200 V, etc., a resistor with a large rated power for step-down is required to input the AC electrical signal to the photocoupler. At the same time, a smoothing capacitor having a relatively high breakdown voltage and a large capacity for smoothing the AC electric signal is required. Specifically, for example, a dimming signal generation circuit 100 as shown in FIG. 10 is used. In the dimming signal generation circuit 100, the commercial power source is full-wave rectified by the full-wave rectifier circuit 110, the full-wave rectified output is smoothed by the smoothing capacitor 120, and the smoothed output is stepped down (current controlled) by the resistor 140, and the photocoupler 130. (Photodiode). The secondary output of the photocoupler 130 (phototransistor) is converted into a predetermined voltage by the output circuit 150 and output to the control unit of the lighting device (lighting circuit).

  Here, when the dimming signal generation circuit 100 as shown in FIG. 10 is deployed in a configuration in which a plurality of systems of dimming AC electric signals are input from a commercial power supply, the rectifier circuit 110, the smoothing capacitor 120, and the photocoupler 130, the step-down (current limiting) resistor 140 and the output circuit 150 are connected in parallel to one lighting device by the number of systems. However, according to such a parallel configuration, the dimming signal generation circuit or the entire lighting device is increased in size and cost. In addition, when a plurality of dimming signals generated by the plurality of dimming signal generation circuits 100 are input in parallel to the control unit of the lighting circuit, the configuration of the control unit becomes complicated, and the lighting circuit side is also expensive. End up.

  Therefore, the present invention provides a small and low-cost dimming signal generation that can generate a dimming signal from a dimming electric signal with a simple configuration even when the number of dimming electric signals from an AC power supply increases. It is an object to provide a circuit and an LED power source and an LED lighting device using the circuit.

  The dimming signal generation circuit of the present invention generates a dimming signal based on ON / OFF of a plurality of AC electric signals input from an AC power supply. The dimming signal generation circuit includes a smoothing circuit that generates a smoothed voltage rectified and smoothed from the first AC electrical signal, a pulsating circuit that generates a pulsating voltage rectified from the second AC electrical signal, A photocoupler having a photodiode to which a voltage is applied, a switching circuit that controls a current flowing through the photodiode based on a pulsating voltage, and an output circuit that outputs a dimming signal corresponding to the operating state of the phototransistor of the photocoupler With.

  According to the dimming signal generation circuit, in the configuration for generating the dimming signal from the AC electric signals of a plurality of systems, the number of parts is greatly reduced compared to the case where a plurality of single system configurations (see FIG. 10) are connected in parallel. Therefore, it is possible to provide a dimming signal generation circuit that is small and low in cost.

  In the first embodiment of the dimming signal generation circuit, the smoothing circuit includes a first rectifier circuit to which the first AC electric signal is input, and a capacitor that smoothes the rectified output of the first rectifier circuit, The flow circuit includes a second rectifier circuit to which a second AC electrical signal is input, and a voltage divider circuit that generates a divided value of the pulsating output voltage of the second rectifier circuit, and the switching circuit includes a photodiode. Are connected in series to each other, and the operation state of the PNP transistor is controlled based on the divided voltage value. According to this configuration, a single capacitor, a photocoupler, an output circuit, and a resistor connected in series to the photodiode are required for two AC electric signals, so the dimming signal generation circuit can be downsized. In addition, the cost can be reduced.

  In the second form of the dimming signal generation circuit, an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal is further provided, and the smoothing circuit receives the first AC electric signal. And a capacitor for smoothing the rectified output of the first rectifier circuit, the pulsating circuit includes a second rectifier circuit to which the second AC electric signal is input, and a second rectifier. A first voltage dividing circuit for generating a first divided voltage value of the pulsating output voltage of the circuit, wherein the additional pulsating circuit includes a third rectifier circuit to which a third AC electrical signal is input; And a second voltage dividing circuit for generating a second voltage dividing value of the pulsating output voltage of the rectifying circuit of the first rectifier circuit, wherein the switching circuit is a series of a first resistor and a first PNP transistor connected in series to the photodiode. A second resistor and a second PNP connected in series with the circuit and the photodiode A series circuit of transistors is provided, and the operating state of the first PNP transistor is controlled based on the first divided voltage value, and the operating state of the second PNP transistor is controlled based on the second divided voltage value. The resistance value of the first resistor is different from the resistance value of the second resistor. According to this configuration, only one set of a smoothing capacitor, a photocoupler and an output circuit is required for three AC electric signals, and two sets of resistors connected in series to the photodiode are sufficient. It is possible to reduce the size and cost of the dimming signal generation circuit.

  In the third form of the dimming signal generation circuit, an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal is further provided, and the smoothing circuit receives the first AC electric signal. Rectifier circuit, a capacitor for smoothing the rectified output of the rectifier circuit, the pulsating circuit includes a first half-wave rectifier circuit to which the second AC electrical signal is input, and a first half-wave rectifier circuit. A first voltage dividing circuit for generating a first divided voltage value of the pulsating output voltage, wherein the additional pulsating circuit receives a third AC electric signal in an opposite phase to the second AC electric signal; And a second voltage dividing circuit for generating a second voltage dividing value of the pulsating output voltage of the second half wave rectifying circuit, the switching circuit being connected in series to the photodiode A series connection of a first resistor and a first PNP transistor, and a photodiode connected in series A second PNP transistor and a series circuit of a second PNP transistor, the operating state of the first PNP transistor is controlled based on the first voltage division value, and the first voltage is determined based on the second voltage division value. The operation state of the two PNP transistors is controlled so that the resistance value of the first resistor is different from the resistance value of the second resistor. As a result, only one set of smoothing capacitor, photocoupler and output circuit is required for three AC electric signals, and two sets of step-down resistors connected in series to the photodiode are required. The dimming signal generation circuit can be reduced in size and cost.

  In the fourth embodiment of the dimming signal generation circuit, an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal is further provided, and the smoothing circuit receives the first AC electric signal. Rectifier circuit, a capacitor for smoothing the rectified output of the rectifier circuit, the pulsating circuit includes a first half-wave rectifier circuit to which the second AC electrical signal is input, and a first half-wave rectifier circuit. A first voltage dividing circuit for generating a first divided voltage value of the pulsating output voltage, wherein the additional pulsating circuit receives a third AC electric signal in an opposite phase to the second AC electric signal; And a second voltage dividing circuit for generating a second voltage dividing value of the pulsating output voltage of the second half wave rectifying circuit, the switching circuit being connected in series to the photodiode Resistor, first NPN transistor, and first NPN transistor connected in parallel Two NPN transistors, and the operation state of the first NPN transistor is controlled based on the first divided voltage value, and the operation state of the second NPN transistor is controlled based on the second divided voltage value. The first partial pressure value is different from the second partial pressure value. As a result, with respect to the three systems of AC electrical signals, a smoothing capacitor, a photocoupler, an output circuit, and a single step-down resistor connected in series to the photodiode suffice. The generation circuit can be reduced in size and cost.

  In the dimming signal generation circuit according to any one of the first to third embodiments, when the OFF state of the first AC electric signal is an electric signal instructing lighting of all light, the first AC electric current is generated in the generation of the dimming signal. It is preferred that the signal off-state input takes precedence over the remaining AC electrical signal state input. As a result, even if there is any failure in the remaining AC electrical signal side system (when it cannot be turned on or off), as long as the first AC electrical signal is turned off, the all-light lighting state is secured and the illuminance is secured. This is preferable as a safety measure.

  In each of the dimming signal generation circuits, the output circuit is preferably configured to generate a dimming signal by integrating a voltage based on the operating state of the phototransistor. Thus, the configuration in which the smoothed integrated value is output as the dimming signal facilitates the processing of the dimming signal in the circuit on the side receiving the dimming signal, and the configuration is simplified.

  An LED power source according to the present invention includes any one of the dimming signal generation circuit, a rectifier that rectifies an input AC voltage, and a DC / DC converter that converts the rectified output of the rectifier into a predetermined DC output and supplies the DC output to the LED. And an LED lighting circuit having a control unit that controls the output current based on the dimming rate corresponding to the dimming signal. Moreover, the LED lighting apparatus of this invention is equipped with the said LED power supply and LED connected to LED power supply. Due to the advantageous effects of the dimming signal generation circuits described above, it is possible to provide a small and low-cost LED power supply and LED lighting device.

1 is a diagram illustrating a dimming signal generation circuit, an LED power source, and an LED lighting device according to a first embodiment of the present invention. It is a figure explaining operation | movement of the light control signal generation circuit of 1st Embodiment. It is a figure which shows the dimming signal generation circuit by the 2nd Embodiment of this invention. It is a figure explaining operation | movement of the light control signal generation circuit of 2nd Embodiment. It is a figure which shows the dimming signal generation circuit by the 3rd Embodiment of this invention. It is a figure explaining operation | movement of the light control signal generation circuit of 3rd Embodiment. It is a figure which shows the dimming signal generation circuit by the 4th Embodiment of this invention. It is a figure explaining operation | movement of the light control signal generation circuit of 4th Embodiment. It is a figure which shows the modification of 4th Embodiment. It is a figure which shows a general dimming signal generation circuit.

<First Embodiment>
FIG. 1 shows a dimming signal generation circuit 1, an LED power source 6, and an LED lighting device 8 according to a first embodiment of the present invention. The LED power source 6 includes a dimming signal generation circuit 1 and an LED lighting circuit 2, and the LED lighting device 8 includes an LED power source 6 and an LED 7. The LED 7 is an LED array in which a plurality of LED elements are connected in series or in series and parallel.

  The schematic configuration of the LED lighting device 8 is as follows. The dimming signal generation circuit 1 receives dimming AC electric signals (hereinafter referred to as “electric signals”) E1 and E2 from AC power sources AC1 and AC2 of a commercial power source (for example, AC 200V), and receives the electric signals E1 and E2. The light control signal D is generated from the light and supplied to the LED lighting circuit 2. The commercial power source is not limited to AC 200V, and may be AC 100V, AC 110V, AC 120V, AC 220V, AC 230V, AC 240V, and the like. The LED lighting circuit 2 converts an input AC power supply AC0 such as a commercial power supply into a direct current having a current value based on the dimming signal D, and supplies the direct current to the LED 7. Thereby, LED7 is dimmed. The dimming rate indicated by the dimming signal D is determined by the on / off combination of the electric signals E1 and E2 (the combination of on / off of the AC power supplies AC1 and AC2). Such a configuration in which an AC power source such as a commercial power source is used as an electrical signal is more affected by noise and signal distortion than a configuration in which a high-frequency and low-voltage PWM signal of a dimmer is used as an electrical signal. This is useful for tunnel lighting, road lights, etc., which are difficult and have a long signal transmission distance.

  The LED lighting circuit 2 includes a rectifier 3, a DC / DC converter 4, and a control unit 5. The input voltage from the AC power supply AC 0 is full-wave rectified by the rectifier 3 formed of a diode bridge, and the full-wave rectified output is input to the DC / DC converter 4. The DC / DC converter 4 converts the full-wave rectified input into a predetermined direct current and supplies the direct current to the LED 7. The DC / DC converter 4 may be a switching power supply composed of a flyback converter, for example, or may be a switching power supply composed of a step-up chopper circuit (power factor correction circuit) and a step-down chopper circuit. In the flyback converter, the output side (transformer secondary side) capacitor is used for smoothing and the input side (transformer primary side) capacitor is made smaller than the output side capacitor to provide a power factor improvement function. In addition, a so-called one-converter type flyback converter is included. The output of the output current of the DC / DC converter 4 is controlled by the control unit 5. In the following description, a wiring having the same potential as the common anode end of the rectifier 3 is referred to as a ground G2. In the LED lighting circuit 2, the DC / DC converter 4 and the control unit 5 use the ground G2 as a reference potential.

  The control unit 5 controls the output of the DC / DC converter 4, that is, the LED current, according to the dimming signal D transmitted from the dimming signal generation circuit 1. It is assumed that the control unit 5 includes a microcomputer and stores a dimming rate corresponding to the dimming signal D, that is, a target output current value or a target output power value of the DC / DC converter 4 in advance. The control unit 5 may perform constant current control in which the LED current is fed back with respect to the target output current value, or may perform constant power control in which the LED power is fed back with respect to the target output power value. Good. Further, control in an open loop in which LED current or LED power is feedforward controlled may be performed.

  The dimming signal generation circuit 1 includes a smoothing circuit 10, a pulsating circuit 20, a photocoupler 30, a switching circuit 40, and an output circuit 50. As an outline, the smoothing circuit 10 generates a rectified and smoothed smoothed voltage from the electric signal E1, and the pulsating current circuit 20 generates a rectified pulsating voltage from the electric signal E2. The photocoupler 30 has a photodiode 31 to which the smoothing voltage is applied, and the switching circuit 40 controls the current flowing through the photodiode 31 based on the pulsating voltage. The output circuit 50 transmits a dimming signal D corresponding to the operation state of the phototransistor 32 of the photocoupler 30 to the control unit 5 of the LED lighting circuit 2. In the following description, the division of each circuit element into each circuit is for convenience of description, and does not restrict the present invention.

In the present embodiment, three lighting patterns (dimming patterns) are set depending on the combination of on / off of the electric signals E1 and E2. For example,
(E1, E2) = (ON, OFF): 25% dimming,
(E1, E2) = (ON, ON): 50% dimming,
(E1, E2) = (OFF, OFF): 100% dimming (that is, total light)
Is set. Note that the correspondence between the combination of the electric signals E1 and E2 and the dimming rate is an example, and other correspondence or other dimming rate may be employed. However, it is desirable that one of the combinations of the electrical signals E1 and E2 is an instruction to turn on all light.

  The smoothing circuit 10 includes a rectifier circuit 11 formed of a diode bridge and a capacitor 12. The electric signal E1 input from the AC power supply AC1 through the current fuse F1 is full-wave rectified by the rectifier circuit 11, and the rectified output of the rectifier circuit 11 is smoothed by the capacitor 12. In the following, the wiring having the same potential as the common anode end of the rectifier circuit 11 and the negative electrode of the capacitor 12 is referred to as a ground G1.

  The pulsating circuit 20 includes a rectifier circuit 21 formed of a diode bridge, a resistor 22 and a resistor 23. The electric signal E2 input from the AC power supply AC2 via the current fuse F2 is full-wave rectified by the rectifier circuit 21. The anode terminal of the rectifier circuit 21 is connected to the ground G1, and when the electrical signals E1 and E2 are both on, the smoothed voltage value of the smoothing circuit 10 and the peak value of the pulsating output voltage of the rectifier circuit 21 are ground. It is approximately equal to G1. A series circuit of resistors 22 and 23 is connected between the output terminals of the rectifier circuit 21, and the pulsating output voltage of the rectifier circuit 21 is divided by the resistors 22 and 23 at a predetermined voltage dividing ratio.

  The switching circuit 40 includes a resistor 41, a PNP transistor 42 (hereinafter referred to as “transistor 42”), and a diode 43. The resistor 41, the photodiode 31 of the photocoupler 30 and the transistor 42 are connected in series, and this series circuit is connected in parallel to the capacitor 12. The resistor 41 functions as a step-down (current limiting) resistor. The emitter terminal of the transistor 42 is connected to the cathode side of the photodiode 31, the collector terminal is connected to the ground G 1, and the base terminal (control terminal) is connected to the anode of the diode 43. The cathode of the diode 43 is connected to the voltage dividing point of the voltage dividing circuit composed of the resistors 22 and 23. Therefore, the operation state (ON / OFF) of the transistor 42 is controlled based on the voltage division value generated by the voltage dividing circuit.

  The output circuit 50 includes a resistor 51, a resistor 52, and a capacitor 53, and is connected between the control voltage Vdd generated in the control unit 5 of the LED lighting circuit 2 and the ground G2. In the output circuit 50, the collector terminal of the phototransistor 32 is connected to the control voltage Vdd via the resistor 51, and the emitter terminal is connected to the ground G2. One end of the resistor 52 is connected to the collector terminal of the phototransistor 32, the other end of the resistor 52 is connected to the capacitor 53, and the capacitor 53 is connected to the ground G2. The voltage generated at the other end of the resistor 52, that is, the capacitor 53 is output to the control unit 5 as the dimming signal D. In the following description, a node on one end side (the collector terminal of the phototransistor 32) of the resistor 52 is referred to as a point P1, and a node on the other end side (the capacitor 53 side) of the resistor 52 is referred to as a point P2. The resistor 52 and the capacitor 53 constitute an integrating circuit, and the voltage at the point P1 is integrated to generate the voltage at the point P2, that is, the dimming signal D.

  The outline of the operation of the dimming signal generation circuit 1 is as follows. In a momentary viewpoint, when a relatively large amount of current flows through the photodiode 31, the phototransistor 32 is turned on more and the potential at the point P1 becomes relatively low. When the phototransistor 32 is completely turned on, the potential at the point P1 is equal to the ground G2. On the other hand, when a relatively small current flows through the photodiode 31, the phototransistor 32 is further turned off, and the potential at the point P1 is relatively high. When the phototransistor 32 is completely turned off, the potential at the point P1 is equal to the control voltage Vdd. The amount of current flowing through the photodiode 31 is determined by the on / off state of the electric signals E1 and E2, the resistance value of the resistor 41, the operating state of the transistor 42 (when the electric signal E2 is on), and the like. From the viewpoint of a long period of one cycle or more of the commercial power supply frequency, the potential at the point P1 at the instantaneous viewpoint is integrated and appears at the potential at the point P2.

  FIG. 2 shows the operation of the dimming signal generation circuit 1 of the present embodiment. In FIG. 2, (a) (E1, E2) = (ON, OFF), (b) (E1, E2) = (ON, ON), (c) (E1, E2) from the left for the electrical signals E1 and E2. ) = (OFF, OFF) shows the operation. In FIG. 2, the vertical axis indicates, from the top, the smoothing voltage V10 of the smoothing circuit 10, the pulsating voltage V20 of the pulsating circuit 20, the current i31 flowing through the photodiode 31, the voltage VP1 of the point P1, and the voltage VP2 of the point P2. The horizontal axis indicates time. The smoothing voltage V10 and the pulsating voltage V20 are voltages with respect to the ground G1, and the voltages VP1 and VP2 are voltages with respect to the ground G2. In addition, each part waveform shown in each following embodiment may be simplified, exaggerated, or transformed for convenience of explanation.

  When (E1, E2) = (ON, OFF) in (a), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1 (AC power supply AC1), and the pulsating voltage V20 is zero. As a result, the divided voltage value by the resistors 22 and 23 also becomes zero, the base current continues to flow to the transistor 42 via the diode 43 and the resistor 23, and the transistor 42 maintains the on state. Thus, when the resistance value of the resistor 41 is R41, the current i31 of the photodiode 31 is maintained at the maximum value (≈V10 / R41), and the phototransistor 32 is maintained in the on state. Thereby, the voltages VP1 and VP2 at the points P1 and VP2 are maintained at zero. In other words, each circuit constant is set so that the phototransistor 32 is completely turned on at a current i31≈V10 / R41. As a result, a dimming signal D having a zero voltage is output from the output circuit 50 to the control unit 5.

  When (E1, E2) = (ON, ON) in (b), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and the pulsating voltage V20 is the electric signal E2 (AC power supply AC2). Wave rectified pulsating waveform. As a result, the voltage division by the resistors 22 and 23 becomes a full-wave rectified waveform. In a voltage region close to the zero cross, a base current flows to the transistor 42 via the diode 43 and the resistor 23, and the transistor 42 is turned on according to the base current. It becomes a state. On the other hand, in a voltage region close to the peak of the full-wave rectified waveform in the divided voltage of the resistors 22 and 23, no base current flows through the transistor 42 and the transistor 42 is turned off.

  By the on / off operation of the transistor 42, the current i31 is substantially inverted to the pulsating voltage V20 and turned on / off, and the phototransistor 32 is turned on / off correspondingly. Therefore, the voltage VP1 at the point P1 has an amplitude waveform having the inversion phase of the current i31, that is, the same phase as the pulsating voltage V20. Assuming that the integrated value of the voltage VP1 is V1, the dimming signal D of the voltage V1 is output from the output circuit 50 to the control unit 5.

  When (E1, E2) = (OFF, OFF) in (c), the smoothing voltage V10 and the pulsating voltage V20 are zero, the current i31 is maintained at zero, and the phototransistor 32 is turned off. Thereby, the voltages VP1 and VP2 at the points P1 and VP2 are maintained at the control voltage Vdd. Therefore, the dimming signal D having the voltage Vdd is output from the output circuit 50 to the control unit 5.

  The dimming signal D (all light) of the voltage Vdd obtained in (c) is also obtained in the same manner when (E1, E2) = (OFF, ON) (see dotted line). In other words, even if there is some failure in the system on the electric signal E2 side (when it cannot be turned on or off), the all-light lighting state is ensured as long as the electric signal E1 is turned off. Therefore, the configuration in which the input by the off state of the electric signal E1 is given priority over the input of the state of the electric signal E2 is preferable as a safety measure by securing the illuminance. In particular, this is a useful safety measure when the LED lighting device 7 is installed in a tunnel, a closed place, or the like.

  As a result of the above processing, in the LED lighting circuit 2, the control unit 5 performs 25% dimming in response to the dimming signal D having a voltage of zero, and 50% dimming in accordance with the dimming signal D having the voltage V1. And the all-light lighting is executed according to the dimming signal D of the voltage Vdd.

  As described above, the dimming signal generation circuit 1 according to this embodiment includes the smoothing circuit 10 that generates a smoothed voltage that is rectified and smoothed from the electrical signal E1, and the pulse that generates the pulsating voltage that is rectified from the electrical signal E2. Operation of the current circuit 20, the photocoupler 30 having the photodiode 31 to which the smoothing voltage is applied, the switching circuit 40 that controls the current flowing through the photodiode 31 based on the pulsating voltage, and the operation of the phototransistor 32 of the photocoupler 30 An output circuit 50 that outputs a dimming signal D corresponding to the state is provided. Thereby, in the structure which produces | generates a light control signal from two electric signals, compared with the case where two sets of single system structures (refer FIG. 10) are connected in parallel, a number of parts can be reduced significantly. Therefore, it is possible to provide a dimming signal generation circuit 1, an LED power source 6, and an LED lighting device 8 that are small and low in cost.

  In particular, in the dimming signal generation circuit 1, the smoothing circuit 10 includes a capacitor 12 that smoothes the rectified output of the rectifier circuit 11, and the switching circuit 40 includes a resistor 41 and a transistor 42 connected in series to the photodiode 31, The pulsating circuit 20 includes resistors 22 and 23 that generate a divided value of the pulsating output voltage of the rectifier circuit 21, and is configured such that the operation state of the transistor 42 is controlled based on the divided value. As a result, only one set of a smoothing capacitor, a photocoupler, an output circuit, and a step-down (current limiting) resistor is required for the two electrical signals, so that the dimming signal generation circuit 1 and the LED power source 6 In addition, the LED lighting device 8 can be reduced in size and cost. Further, since the dimming signal output from the output circuit 50 is one wiring, the controller 5 having a simple configuration is realized, and the LED power source 6 and the LED lighting device 8 can be reduced in size and cost.

<Second Embodiment>
In the first embodiment, a configuration in which three dimming signals are generated from two electrical signals is shown. In this embodiment, a configuration in which five dimming signals are generated from three electrical signals is shown. . FIG. 3 shows a dimming signal generation circuit 1 of the present embodiment. In addition, although illustration is abbreviate | omitted, the light control signal generation circuit 1 of this embodiment is also connected to the LED lighting circuit 2 (control part 5) similarly to 1st Embodiment.

  The dimming signal generation circuit 1 includes a smoothing circuit 10, a pulsating circuit 20, a photocoupler 30, a switching circuit 40, an output circuit 50, and a pulsating circuit 60. Since the smoothing circuit 10, the pulsating circuit 20, the photocoupler 30, and the output circuit 50 are the same as those in the first embodiment (see FIG. 1), detailed description thereof is omitted. Inputs from the AC power source AC to the smoothing circuit 10, the pulsating current circuit 20 and the pulsating current circuit 60 are turned on / off via the switches SW1, SW2 and SW3, respectively, whereby the electric signals E1, E2 and E3 are supplied to the respective circuits. Entered. That is, the electric signal E1 is turned on / off by turning on / off the switch SW1, the electric signal E2 is turned on / off by turning on / off the switch SW2, and the electric signal E3 is turned on / off by turning on / off the switch SW3. . In each of the drawings showing the present embodiment below, the illustration of the current fuse connected to the AC power supply AC is omitted.

In the present embodiment, five lighting patterns (dimming patterns) are set by a combination of the electric signals E1, E2, and E3. For example,
(E1, E2, E3) = (ON, OFF, OFF): 10% dimming,
(E1, E2, E3) = (ON, ON, OFF): 25% dimming,
(E1, E2, E3) = (ON, OFF, ON): 50% dimming,
(E1, E2, E3) = (ON, ON, ON): 75% dimming,
(E1, E2, E3) = (OFF, OFF, OFF): 100% dimming (ie, total light)
Is set.

  The switching circuit 40 includes a resistor 44, a PNP transistor 45 (hereinafter referred to as “transistor 45”), a diode 46, a resistor 47, a PNP transistor 48 (hereinafter referred to as “transistor 48”), and a diode 49. The series circuit of the resistor 44 and the transistor 45 and the series circuit of the resistor 47 and the transistor 48 are connected in parallel between the cathode of the photodiode 31 and the ground G1. The anode of the photodiode 31 is connected to the positive electrode of the capacitor 12. The resistors 44 and 47 function as a step-down (current limiting) resistor. The emitter terminal of the transistor 45 is connected to the cathode of the photodiode 31 via the resistor 44, the collector terminal is connected to the ground G1, and the base terminal (control terminal) is connected to the anode of the diode 46. The emitter terminal of the transistor 48 is connected to the cathode of the photodiode 31 through the resistor 47, the collector terminal is connected to the ground G 1, and the base terminal (control terminal) is connected to the anode of the diode 49. Here, assuming that the resistance values of the resistors 44 and 47 are R44 and R47, respectively, it is assumed that R44 <R47.

  The pulsating circuit 60 includes a rectifier circuit 61 including a diode bridge, a resistor 62, and a resistor 63. The electric signal E3 input from the AC power supply AC via the switch SW3 is full-wave rectified by the rectifier circuit 61. The anode end of the rectifier circuit 61 is connected to the ground G1, and when the electrical signals E1 and E3 are both on, the smoothed voltage value of the smoothing circuit 10 and the peak value of the pulsating output voltage of the rectifier circuit 61 are ground. It is approximately equal to G1. A series circuit of resistors 62 and 63 is connected between the output terminals of the rectifier circuit 61, and the pulsating output voltage of the rectifier circuit 61 is divided by the resistors 62 and 63 at a predetermined voltage dividing ratio.

  The cathode of the diode 49 is connected to the voltage dividing point of the voltage dividing circuit composed of the resistors 62 and 63, and the operation state (ON / OFF) of the transistor 48 is controlled based on the voltage dividing value generated by the voltage dividing circuit. . Similarly, in the pulsating circuit 20, the cathode of the diode 46 is connected to the voltage dividing point of the voltage dividing circuit composed of the resistors 22 and 23, and the transistor 45 has a voltage dividing value generated by the voltage dividing circuit. The operating state (on / off) is controlled. The voltage dividing ratio of the resistors 62 and 63 may be the same as or different from the voltage dividing ratio of the resistors 22 and 23, but is assumed to be the same in this embodiment.

  FIG. 4 shows the operation of the dimming signal generation circuit 1 of the present embodiment. In FIG. 4, (a) (E1, E2, E3) = (ON, OFF, OFF), (b) (E1, E2, E3) = (ON, ON, (OFF), (c) (E1, E2, E3) = (ON, OFF, ON), (d) (E1, E2, E3) = (ON, ON, ON), (e) (E1, E2, E3 ) = (OFF, OFF, OFF) shows the operation. In FIG. 4, the vertical axis indicates the smoothing voltage V10 of the smoothing circuit 10, the pulsating voltage V20 of the pulsating circuit 20, the pulsating voltage V60 of the pulsating circuit 60, the current i31 flowing through the photodiode 31, and the voltage at the point P1 from the top. The voltage VP2 of VP1 and the point P2 is shown, and the horizontal axis shows time. The smoothing voltage V10, the pulsating voltage V20, and the pulsating voltage V60 are voltages with respect to the ground G1, and the voltages VP1 and VP2 are voltages with respect to the ground G2.

  When (E), (E1, E2, E2) = (ON, OFF, OFF) in (a), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1 (AC power supply AC), and the pulsating voltage V20 and V60. Becomes zero. Therefore, the divided voltage value by the resistors 22 and 23 and the divided voltage value by the resistors 62 and 63 are also zero. As a result, the base current continues to flow to the transistor 45 via the diode 46 and the resistor 23, and the base current continues to flow to the transistor 48 via the diode 49 and the resistor 63, so that the transistors 45 and 48 remain on. . Therefore, the current i31 is maintained at the maximum value (≈V10 / R44 + V10 / R47), and the phototransistor 32 is maintained in the on state. In other words, each circuit constant is set so that the phototransistor 32 is completely turned on at a current i31≈V10 / R44 + V10 / R47. Accordingly, the voltages VP1 and VP2 are maintained at zero, and the dimming signal D having a voltage of zero is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, ON, OFF) in (b), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and the pulsating voltage V20 is the electric signal E2 (AC power supply). AC) is a full-wave rectified pulsating waveform, and the pulsating voltage V60 is zero. In this case, the voltage division by the resistors 22 and 23 becomes a full-wave rectified waveform, and in a voltage region close to the zero cross, a base current flows to the transistor 45 via the diode 46 and the resistor 23, and the transistor 45 is turned on according to the base current. It becomes a state. On the other hand, in a voltage region close to the peak of the full-wave rectified waveform in the divided voltage of the resistors 22 and 23, no base current flows through the transistor 45, and the transistor 45 is turned off. On the other hand, the transistor 48 maintains the ON state as in the case of (a).

  By the on / off operation of the transistor 45 and the on state of the transistor 48, the current i31 is substantially inverted from the maximum value (≈V10 / R44 + V10 / R47) to the pulsating voltage V20 from the first amplitude (≈V10 / R44). In this manner, the waveform is reduced. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 is a second amplitude that is approximately in proportion to the first amplitude at a predetermined ratio in the inversion phase of the current i31 (that is, in phase with the pulsating voltage V20). It becomes the waveform. If the integrated value of the voltage VP1 in the voltage VP2 is V1, the dimming signal D of the voltage V1 is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, OFF, ON) in (c), the smoothing voltage V10 is substantially constant at the peak voltage of the AC power supply AC, the pulsating voltage V20 is zero, and the pulsating voltage V60 becomes a pulsating waveform obtained by full-wave rectification of the electric signal E3 (AC power supply AC). In this case, the voltage division by the resistors 62 and 63 is a full-wave rectified waveform. In a voltage region close to the zero cross, a base current flows to the transistor 48 via the diode 46 and the resistor 63, and the transistor 48 is turned on according to the base current. It becomes a state. On the other hand, in the voltage region near the peak of the full-wave rectified waveform in the divided voltage of the resistors 62 and 63, the base current does not flow through the transistor 48, and the transistor 48 is turned off. On the other hand, the transistor 45 maintains the ON state as in the case (a).

  By the ON state of the transistor 45 and the ON / OFF operation of the transistor 48, the current i31 is substantially inverted from the maximum value (≈V10 / R44 + V10 / R47) to the pulsating voltage V60 from the third amplitude (≈V10 / R47). In this manner, the waveform is reduced. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 is the inversion phase of the current i31 (that is, the same phase as the pulsating voltage V60), and is approximately proportional to the third amplitude at the predetermined ratio. It becomes an amplitude waveform. Since R44 <R47, the fourth amplitude is larger than the second amplitude in (b) above. Therefore, when the integrated value of the voltage VP1 in the voltage VP2 is V2, the integrated value V2 is higher than the integrated value V1 in the case (b). The dimming signal D having the voltage V <b> 2 is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, ON, ON) in (d), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and the pulsating voltage V20 and V60 are both AC power sources AC. Becomes a pulsating waveform obtained by full-wave rectification. In this case, the transistor 45 is turned on in the voltage region near the zero cross of the AC power supply AC, and the transistor 48 is turned on in the voltage region near the peak, as in the case of (b) and the transistor 48 in the case of (c). Turns off.

  Due to the on / off operation of the transistor 45 and the on / off operation of the transistor 48, the current i31 is between the maximum value (≈V10 / R44 + V10 / R47) and zero in a phase that reverses with the pulsating current voltages V20 and V60. It becomes an amplitude waveform. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 becomes a waveform of the inversion phase of the current i31, that is, the amplitude Vdd having the same phase as the pulsating current voltages V20 and V60. Therefore, the integrated value of the voltage VP1 in the voltage VP2 is V3 higher than the integrated values V1 and V2 in the cases (a) and (b). The dimming signal D having the voltage V3 is output from the output circuit 50 to the control unit 5.

  When (E), (E1, E2, E3) = (OFF, OFF, OFF), the smoothing voltage V10, the pulsating voltage V20, and the pulsating voltage V60 are zero, the current i31 is maintained at zero, and the phototransistor 32 Is turned off. Thus, the voltages VP1 and VP2 are maintained at the control voltage Vdd, and the dimming signal D of the voltage Vdd is output from the output circuit 50 to the control unit 5.

  The dimming signal D (all light) of the voltage Vdd obtained in (e) is obtained in the same manner when at least one of the electric signals E2 and E3 is ON (see dotted line). In other words, even if there is some failure in the system on the side of the electric signal E2 or E3 (when it cannot be turned on or off), the all-light lighting state is ensured as long as the electric signal E1 is turned off. Therefore, as in the first embodiment, the configuration in which the input by the off state of the electric signal E1 is given priority over the input of the remaining electric signal state is preferable as a safety measure by securing illuminance.

  As a result of the above processing, in the LED lighting circuit 2, the control unit 5 performs 10% dimming in response to the dimming signal D having a voltage of zero, and 25% dimming in accordance with the dimming signal D having the voltage V1. And 50% dimming according to the dimming signal D of the voltage V2, 75% dimming according to the dimming signal D of the voltage V3, and according to the dimming signal D of the voltage Vdd. Perform all-lights.

  According to the dimming signal generation circuit 1 configured as described above, in the configuration for generating the dimming signal from the three electric signals, the configuration of the single system (see FIG. 10) is compared to the case where the three sets are connected in parallel. The number of parts can be greatly reduced. Therefore, it is possible to provide a dimming signal generation circuit 1, an LED power source 6, and an LED lighting device 8 that are small and low in cost. In particular, for three electrical signals, only one set of smoothing capacitor, photocoupler and output circuit is required, and two sets of step-down resistors connected in series to the photodiode 31 are sufficient. The dimming signal generation circuit 1 can be reduced in size and cost. Further, similarly to the first embodiment, since the dimming signal output from the output circuit 50 is one wiring, the control unit 5 having a simple configuration is realized.

<Third Embodiment>
In the second embodiment, the dimming signal is generated by using the full-wave rectification waveform of the electric signal. However, in this embodiment, the dimming signal is generated by using the half-wave rectification waveform of the electric signal. The generated configuration is shown. FIG. 5 shows a dimming signal generation circuit 1 of the present embodiment. In addition, although illustration is abbreviate | omitted, the light control signal generation circuit 1 of this embodiment is also connected to the LED lighting circuit 2 (control part 5) similarly to 1st Embodiment.

  The dimming signal generation circuit 1 includes a smoothing circuit 10, a photocoupler 30, a switching circuit 40, an output circuit 50, a pulsating circuit 70, and a pulsating circuit 80. Since the smoothing circuit 10, the photocoupler 30, the switching circuit 40, and the output circuit 50 are the same as those of the second embodiment (see FIG. 3), detailed description thereof is omitted. Inputs from the AC power supply AC to the smoothing circuit 10, the pulsating current circuit 70, and the pulsating current circuit 80 are turned on / off via switches SW1, SW2, and SW3, respectively. That is, as in the second embodiment, the electric signal E1 is turned on / off by turning on / off the switch SW1, the electric signal E2 is turned on / off by turning on / off the switch SW2, and the switch SW3 is turned on / off. The electric signal E3 is turned on / off.

Also in this embodiment, five lighting patterns (dimming patterns) are set by combinations of the electrical signals E1, E2, and E3. For example,
(E1, E2, E3) = (ON, OFF, OFF): 10% dimming,
(E1, E2, E3) = (ON, ON, OFF): 25% dimming,
(E1, E2, E3) = (ON, OFF, ON): 50% dimming,
(E1, E2, E3) = (ON, ON, ON): 75% dimming,
(E1, E2, E3) = (OFF, OFF, OFF): 100% dimming (ie, total light)
Is set.

  The pulsating circuit 70 includes a half-wave rectifier circuit 71, a resistor 72, and a resistor 73. Half-wave rectifier circuit 71 has diodes 71a and 71b, the anode of diode 71a is connected to one line H of AC power supply AC, the cathode of diode 71b is connected to the other line C of AC power supply AC, and diode 71b Are connected to the ground G1. Thereby, the half-wave rectification is performed by the half-wave rectification circuit 71 on the electric signal E2 input from the AC power supply AC via the switch SW2. A series circuit of resistors 72 and 73 is connected between the cathode of the diode 71a and the anode of the diode 71b, and the pulsating output voltage of the half-wave rectifier circuit 71 is divided by the resistors 72 and 73 at a predetermined voltage dividing ratio. The cathode of the diode 46 is connected to the connection point between the resistor 72 and the resistor 73, and the operation state (ON / OFF) of the transistor 45 is controlled based on the voltage dividing value generated by the voltage dividing circuit composed of the resistors 72 and 73. The

  The pulsating circuit 80 includes a half-wave rectifier circuit 81, a resistor 82, and a resistor 83. Half-wave rectifier circuit 81 has diodes 81a and 81b, the anode of diode 81a is connected to line C of AC power supply AC, the cathode of diode 81b is connected to line H of AC power supply AC, and the anode of diode 81b is grounded. Connected to G1. As a result, the half-wave rectifier circuit 81 is configured to be turned on in the opposite phase of the AC power supply AC with respect to the half-wave rectifier circuit 71, and in that phase, the electric signal E3 input from the AC power supply AC via the switch SW3. Is half-wave rectified by the half-wave rectifier circuit 81. A series circuit of resistors 82 and 83 is connected between the cathode of the diode 81a and the anode of the diode 81b, and the pulsating output voltage of the half-wave rectifier circuit 81 is divided by the resistors 82 and 83 at a predetermined voltage dividing ratio. The cathode of the diode 49 is connected to the connection point of the resistor 82 and the resistor 83, and the operation state (ON / OFF) of the transistor 48 is controlled based on the voltage dividing value generated by the voltage dividing circuit composed of the resistors 82 and 83. The The voltage dividing ratio of the resistors 82 and 83 may be the same as or different from the voltage dividing ratio of the resistors 72 and 73, but is assumed to be the same in this embodiment.

  FIG. 6 shows the operation of the dimming signal generation circuit 1 of the present embodiment. In FIG. 6, (a) (E1, E2, E3) = (ON, OFF, OFF), (b) (E1, E2, E3) = (ON, ON, E3) from the left for the electric signals E1, E2, and E3. (OFF), (c) (E1, E2, E3) = (ON, OFF, ON), (d) (E1, E2, E3) = (ON, ON, ON), (e) (E1, E2, E3 ) = (OFF, OFF, OFF) shows the operation. In FIG. 6, the vertical axis indicates the smoothing voltage V10 of the smoothing circuit 10, the pulsating voltage V70 of the pulsating circuit 70, the pulsating voltage V80 of the pulsating circuit 80, the current i31 flowing through the photodiode 31, and the voltage at the point P1. The voltage VP2 of VP1 and the point P2 is shown, and the horizontal axis shows time. The smoothing voltage V10, the pulsating voltage V70, and the pulsating voltage V80 are voltages with respect to the ground G1, and the voltages VP1 and VP2 are voltages with respect to the ground G2.

  When (E), (E1, E2, E2) = (ON, OFF, OFF) in (a), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1 (AC power supply AC), and the pulsating voltage V70 and V80. Becomes zero. Therefore, the divided voltage values by the resistors 72 and 73 and the divided voltage values by the resistors 82 and 83 are also zero. As a result, the base current continues to flow to the transistor 45 via the diode 46 and the resistor 73, and the base current continues to flow to the transistor 48 via the diode 49 and the resistor 83, so that the transistors 45 and 48 remain on. . Therefore, the current i31 is maintained at the maximum value (≈V10 / R44 + V10 / R47), and the phototransistor 32 is maintained in the on state. In other words, each circuit constant is set so that the phototransistor 32 is completely turned on at a current i31≈V10 / R44 + V10 / R47. Thereby, the voltages VP1 and VP2 at the points P1 and VP2 are maintained at zero, and the dimming signal D having a voltage of zero is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, ON, OFF) in (b), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and the pulsating voltage V70 is the electric signal E2 (AC power supply). AC) is a half-wave rectified pulsating waveform, and the pulsating voltage V80 is zero. As a result, the divided voltage by the resistors 72 and 73 becomes a half-wave rectified waveform. In the zero and near-zero voltage region, the base current flows to the transistor 45 via the diode 46 and the resistor 73, and the transistor 45 responds to the base current. Turned on. On the other hand, in a voltage region close to the peak of the half-wave rectified waveform in the divided voltages of the resistors 72 and 73, no base current flows through the transistor 45, and the transistor 45 is turned off. On the other hand, the transistor 48 maintains the ON state as in the case of (a).

  Due to the on / off operation of the transistor 45 and the off state of the transistor 48, the current i31 changes from the maximum value (≈V10 / R44 + V10 / R47) to the first amplitude (≈V10 / R44) as a half-wave pulsating voltage V70. The waveform is reduced in such a manner that it is substantially inverted. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 is a second amplitude that is approximately in proportion to the first amplitude at a predetermined ratio in the inversion phase of the current i31 (that is, the same phase as the pulsating voltage V70). It becomes the waveform. As a result, if the integrated value of the voltage VP1 in the voltage VP2 is V1, the dimming signal D of the voltage V1 is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, OFF, ON) in (c), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, the pulsating voltage V70 is zero, and the pulsating voltage V80 has a pulsating waveform obtained by half-wave rectifying the electric signal E3 (AC power supply AC). As a result, the divided voltage by the resistors 82 and 83 becomes a half-wave rectified waveform. In the zero and near-zero voltage region, the base current flows to the transistor 48 via the diode 49 and the resistor 83, and the transistor 48 responds to the base current. Turned on. On the other hand, in the voltage region near the peak of the half-wave rectified waveform in the divided voltage of the resistors 82 and 83, no base current flows through the transistor 48, and the transistor 48 is turned off. On the other hand, the transistor 45 maintains the ON state as in the case (a).

  Due to the off state of the transistor 45 and the on / off operation of the transistor 48, the current i31 changes from the maximum value (≈V10 / R44 + V10 / R47) to the third amplitude (≈V10 / R47) as a half-wave pulsating voltage V80. The waveform is reduced in such a manner that it is substantially inverted. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 is the inversion phase of the current i31 (that is, the same phase as the pulsating voltage V80), and is approximately proportional to the third amplitude at the predetermined ratio. It becomes an amplitude waveform. Since R44 <R47, the fourth amplitude is larger than the second amplitude in (b) above. Therefore, when the integrated value of the voltage VP1 in the voltage VP2 is V2, the integrated value V2 is higher than the integrated value V1 in the case (b). The dimming signal D having the voltage V <b> 2 is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (ON, ON, ON) in (d), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and both the pulsating voltages V70 and V80 are the electric signal E2. And E3 becomes a pulsating waveform obtained by half-wave rectification in mutually opposite phases. In this case, the transistor 45 is in the same state as in the case of (b) and the transistor 48 is in the on state in the voltage range of the AC power supply AC and near zero as in the case of (c), and the voltage close to the peak is reached. The region is turned off. As a result, the transistors 45 and 48 are alternately turned on and off.

  By the on / off operation of the transistor 45 and the on / off operation of the transistor 48, the current i31 has a waveform obtained by synthesizing the current i31 in (b) and the current i31 in (c). Works accordingly. Thus, when the integrated value of the voltage VP1 in the voltage VP2 is V3, the integrated value V3 is higher than the integrated values V1 and V2 in the cases (a) and (b). The dimming signal D having the voltage V3 is output from the output circuit 50 to the control unit 5.

  When (E1, E2, E3) = (OFF, OFF, OFF) in (e), the smoothing voltage V10, the pulsating voltage V70 and the pulsating voltage V80 are zero, the current i31 is maintained at zero, and the phototransistor 32 Is turned off. Thus, the voltages VP1 and VP2 are maintained at the control voltage Vdd, and the dimming signal D of the voltage Vdd is output from the output circuit 50 to the control unit 5.

  The dimming signal D (all light) of the voltage Vdd obtained in (e) is obtained in the same manner when at least one of the electric signals E2 and E3 is ON (see dotted line). Therefore, as in the case of the second embodiment, the configuration in which the input by the off state of the electric signal E1 is given priority over the input of the remaining electric signal state is preferable as a safety measure by securing the illuminance.

  As a result of the above processing, in the LED lighting circuit 2, the control unit 5 performs 10% dimming in response to the dimming signal D having a voltage of zero, and 25% dimming in accordance with the dimming signal D having the voltage V1. And 50% dimming according to the dimming signal D of the voltage V2, 75% dimming according to the dimming signal D of the voltage V3, and according to the dimming signal D of the voltage Vdd. Perform all-lights.

  According to the dimming signal generation circuit 1 configured as described above, in the configuration for generating the dimming signal from the three electric signals, the configuration of the single system (see FIG. 10) is compared to the case where the three sets are connected in parallel. The number of parts can be greatly reduced. Therefore, it is possible to provide a dimming signal generation circuit 1, an LED power source 6, and an LED lighting device 8 that are small and low in cost. In particular, for three electrical signals, only one set of smoothing capacitor, photocoupler and output circuit is required, and two sets of step-down resistors connected in series to the photodiode 31 are sufficient. The dimming signal generation circuit 1 can be reduced in size and cost. Further, similarly to the first and second embodiments, the dimming signal output from the output circuit 50 is one wiring, and thus the control unit 5 having a simple configuration is realized.

<Fourth Embodiment>
In the second and third embodiments, a configuration in which five dimming signals are generated from three systems of electrical signals using PNP transistors is shown. In this embodiment, three systems using NPN transistors are used. The structure which produces | generates four kinds of light control signals from this electrical signal is shown. FIG. 7 shows a dimming signal generation circuit 1 according to this embodiment. In addition, although illustration is abbreviate | omitted, the light control signal generation circuit 1 of this embodiment is also connected to the LED lighting circuit 2 (control part 5) similarly to 1st Embodiment.

  The dimming signal generation circuit 1 includes a smoothing circuit 10, a photocoupler 30, an output circuit 50, a pulsating circuit 70, a pulsating circuit 80, and a switching circuit 90. Since the smoothing circuit 10, the photocoupler 30, and the output circuit 50 are the same as those in the first embodiment (see FIG. 1), detailed description thereof is omitted. The smoothing circuit 10 is always connected to the AC power supply AC, and the pulsating flow circuit 70 and the pulsating flow circuit 80 are turned on / off with respect to the AC power supply AC via the switches SW2 and SW3. That is, the electrical signal E2 is turned on / off by turning on / off the switch SW2, and the electrical signal E3 is turned on / off by turning on / off the switch SW3.

Four lighting patterns (dimming patterns) are set by the combination of the electric signals E2 and E3. For example,
(E2, E3) = (ON, ON): 25% dimming,
(E2, E3) = (ON, OFF): 50% dimming,
(E2, E3) = (OFF, ON): 75% dimming,
(E2, E3) = (OFF, OFF): 100% dimming (that is, total light)
Is set (the electric signal E1 is ON).

  The switching circuit 90 includes a resistor 91 and NPN transistors 92 and 93. The NPN transistors 92 and 93 are connected in parallel, and this parallel circuit is connected in series to the resistor 91 and the photodiode 31. The resistor 91 functions as a step-down (current limiting) resistor. In this embodiment, the NPN transistors 92 and 93 are assumed to be MOSFETs, and the NPN transistors 92 and 93 are referred to as FETs 92 and 93 in the following description. The drain terminals of the FETs 92 and 93 are connected to the cathode side of the photodiode 31, and the source terminal is connected to the ground G1. The gate terminals (control terminals) of the FETs 92 and 93 are connected to the anodes of Zener diodes 76 and 86, which will be described later.

  The pulsating circuit 70 includes a half-wave rectifier circuit 71, a resistor 74, a resistor 75, and a Zener diode 76. Similarly to the third embodiment, the half-wave rectifier circuit 71 includes diodes 71a and 71b, the anode of the diode 71a is connected to one line H of the AC power supply AC, and the cathode of the diode 71b is the other of the AC power supply AC. The anode of the diode 71b is connected to the ground G1. Thereby, the half-wave rectification is performed by the half-wave rectification circuit 71 on the electric signal E2 input from the AC power supply AC via the switch SW2. A series circuit of resistors 74 and 75 is connected between the cathode of the diode 71 a and the anode of the diode 71 b, and the cathode of the Zener diode 76 is connected to the connection point of the resistors 74 and 75. When the pulsating output voltage of the half-wave rectifier circuit 71 is divided by the resistors 74 and 75 at a predetermined voltage dividing ratio and the divided value exceeds the Zener voltage of the Zener diode 76 and the gate threshold value of the FET 92, the FET 92 is turned on. Note that the voltage of the anode of the Zener diode 76 with respect to the ground G1 is referred to as a divided value Va1.

  The pulsating circuit 80 includes a half-wave rectifier circuit 81, a resistor 84, a resistor 85, and a Zener diode 86. The half-wave rectifier circuit 81 has diodes 81a and 81b as in the third embodiment, the anode of the diode 81a is connected to the line C of the AC power supply AC, and the cathode of the diode 81b is connected to the line H of the AC power supply AC. The anode of the diode 81b is connected to the ground G1. As a result, the half-wave rectifier circuit 81 is configured to be turned on in the opposite phase of the AC power supply AC with respect to the half-wave rectifier circuit 71, and in that phase, the electric signal E3 input from the AC power supply AC via the switch SW3. Is half-wave rectified by the half-wave rectifier circuit 81. A series circuit of resistors 84 and 85 is connected between the cathode of the diode 81 a and the anode of the diode 81 b, and the cathode of the Zener diode 86 is connected to the connection point between the resistor 84 and the resistor 85. When the pulsating output voltage of the half-wave rectifier circuit 81 is divided by the resistors 84 and 85 at a predetermined voltage dividing ratio and the divided value exceeds the Zener voltage of the Zener diode 86 and the gate threshold value of the FET 93, the FET 93 is turned on. Note that the anode voltage of the Zener diode 86 with respect to the ground G1 is referred to as a divided value Va2.

  In the present embodiment, it is assumed that the amplitude of the partial pressure value Va1> the amplitude of the partial pressure value Va2. This relationship is obtained by setting the voltage dividing ratio of the resistors 74 and 75> the voltage dividing ratio of the resistors 84 and 85, or the Zener voltage of the Zener diode 76 <the Zener voltage of the Zener diode 86. In short, the constants of the circuit elements may be set so that the FET 92 is more easily turned on than the FET 93.

  FIG. 8 shows the operation of the dimming signal generation circuit 1 of the present embodiment. In FIG. 8, (a) (E2, E3) = (ON, ON), (b) (E2, E3) = (ON, OFF), (c) (E2, E3) from the left for the electric signals E2 and E3. ) = (OFF, ON), (d) (E2, E3) = (OFF, OFF). In FIG. 6, the vertical axis indicates the smoothing voltage V10 of the smoothing circuit 10, the pulsating voltage V70 of the pulsating circuit 70, the pulsating voltage V80 of the pulsating circuit 80, the current i31 flowing through the photodiode 31, and the voltage at the point P1. The voltage VP2 of VP1 and the point P2 is shown, and the horizontal axis shows time. The smoothing voltage V10, the pulsating voltage V70, and the pulsating voltage V80 are voltages with respect to the ground G1, and the voltages VP1 and VP2 are voltages with respect to the ground G2.

  First, the case where (E2, E3) = (ON, OFF) in (b) will be described. In this case, the smooth voltage V10 is substantially constant at the peak voltage of the electric signal E1 (AC power supply AC), and the pulsating voltage V70 is a pulsating waveform obtained by half-wave rectifying the electric signal E2 (AC power supply AC). The voltage V80 becomes zero. In this case, in the voltage region on the peak side of the half-wave rectification waveform of the pulsating voltage V70, the divided voltage value Va1 exceeds the gate threshold value of the FET 92, the FET 92 is turned on, and the current i31 flows. On the other hand, in the voltage region on the zero side of the half-wave rectified waveform of the pulsating voltage V70, the divided voltage value Va1 is equal to or lower than the gate threshold value of the FET 92, the FET 92 is turned off, and the current i31 does not flow. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 becomes a waveform of the off width T1 of the inversion phase of the current i31. If the integrated value of the voltage VP1 in the voltage VP2 is V1, the dimming signal D of the voltage V1 is output from the output circuit 50 to the control unit 5.

  When (E2, E3) = (OFF, ON) in (c), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, the pulsating voltage V70 is zero, and the pulsating voltage V80 is the electric signal. It becomes a pulsating waveform obtained by half-wave rectifying E3 (AC power supply AC). In this case, in the voltage region on the peak side of the half-wave rectified waveform of the pulsating voltage V80, the divided voltage Va2 exceeds the gate threshold value of the FET 93, the FET 93 is turned on, and the current i31 flows. On the other hand, in the voltage region on the zero side of the half-wave rectified waveform of the pulsating voltage V80, the divided voltage value Va2 is equal to or less than the gate threshold value of the FET 93, the FET 93 is turned off, and the current i31 does not flow. Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 has a waveform of the off width T2 of the inversion phase of the current i31. When the integrated value of the voltage VP1 in the voltage VP2 is V2, the dimming signal D of the voltage V2 is output from the output circuit 50 to the control unit 5. Here, since divided voltage value Va1> divided voltage value Va2, assuming that the gate threshold values of FETs 92 and 93 are the same, off width T1> off width T2. As a result, the integral value V1 <the integral value V2.

  When (E2, E2) = (ON, ON) in (a), the smoothing voltage V10 is substantially constant at the peak voltage of the electric signal E1, and the pulsating current voltages V70 and V80 are both equal to the electric signals E2 and E3. The pulsating current waveform is half-wave rectified in the opposite phase. In this case, the FET 92 is turned on in the voltage region on the zero side of the AC power supply AC, and is turned off in the voltage region on the peak side, as in the case of (b), and the FET 93 is turned on. It becomes. As a result, the FETs 92 and 93 are alternately turned on and off. Therefore, the current i31 has a waveform obtained by combining the current i31 in (b) and the current i31 in (c). Due to the operation of the phototransistor 32 corresponding to the current i31, the voltage VP1 becomes a waveform of the off width T1 + T2 of the inversion phase of the current i31. Therefore, when the integrated value of the voltage VP1 in the voltage VP2 is V0, the integrated value V0 is lower than the integrated values V1 and V2 in the cases (a) and (b). The dimming signal D having the voltage V0 is output from the output circuit 50 to the control unit 5.

  When (E2, E3) = (OFF, OFF) in (d), the smoothing voltage V10, the pulsating voltage V70, and the pulsating voltage V80 are zero. In this case, the current i31 is maintained at zero, and the voltages VP1 and VP2 are maintained at the control voltage Vdd due to the OFF state of the phototransistor 32. Therefore, the dimming signal D having the voltage Vdd is output from the output circuit 50 to the control unit 5.

  As a result of the above processing, in the LED lighting circuit 2, the control unit 5 performs 25% dimming according to the dimming signal D of the voltage V0 and 50% dimming according to the dimming signal D of the voltage V1. , 75% dimming is performed according to the dimming signal D of the voltage V2, and all-light lighting is performed according to the dimming signal D of the voltage Vdd.

  According to the dimming signal generation circuit 1 configured as described above, three sets of a single system configuration (see FIG. 10) are connected in parallel in a configuration for generating a dimming signal from electrical signals from three AC power sources. Compared to the case, the number of parts can be greatly reduced. Therefore, it is possible to provide a dimming signal generation circuit 1, an LED power source 6, and an LED lighting device 8 that are small and low in cost. In particular, for a three-system electric signal, only one set of a smoothing capacitor, a photocoupler, an output circuit, and a current-limiting (step-down) resistor is required, so the dimming signal generation circuit 1 for the three systems is small. And cost reduction are realized. Further, similarly to the first to third embodiments, the dimming signal output from the output circuit 50 is one wiring, so that the control unit 5 having a simple configuration is realized.

<Modification>
Although preferred embodiments of the present invention have been described above, the present invention can be modified into various modes as shown below, for example.

(1) Modification of Rectifier Circuits 21 and 61 In the first and second embodiments, full-wave rectifier circuits are employed as the rectifier circuits 21 and 61, but these may be half-wave rectifier circuits (second In the embodiment, one or both of the rectifier circuits 21 and 61 may be a half-wave rectifier circuit).

(2) Modification of output circuit 50 (inversion of output logic)
In each of the embodiments described above, the voltage VP1 at the point P1 has a low output when the phototransistor 32 is on and a high output when the phototransistor 32 is off. However, this logic is inverted. Also good. For example, the resistor 51 is connected between the emitter terminal of the phototransistor 32 and the ground G2, the collector terminal of the phototransistor 32 is connected to the control voltage Vdd, and the voltage of the emitter terminal is set to the voltage VP1 (that is, the resistor 52 is Connected to the emitter terminal). Thus, the voltage VP1 at the point P1 becomes a high output when the phototransistor 32 is on, and becomes a low output when the phototransistor 32 is off.

(3) Deformation of output circuit 50 (processing of dimming signal)
In each of the above embodiments, the configuration in which the voltage VP1 at the point P1 is integrated by the resistor 52 and the capacitor 53 to generate the dimming signal D has been shown. The configuration in which the smoothed integration value is input to the control unit 5 facilitates the processing of the dimming signal D in the microcomputer of the control unit 5 and simplifies the configuration. On the other hand, when the microcomputer of the control unit 5 has a waveform discrimination function, the voltage VP1 may be directly output to the control unit 5 as the dimming signal D. In this case, the microcomputer of the control unit 5 may associate the amplitude of the voltage VP1 (see the first, second, and third embodiments) with the dimming rate, or the on width or the off width of the voltage VP1 ( You may make it make a light control rate correspond (refer 1st and 4th embodiment). Further, the microcomputer of the control unit 5 may make the dimming rate correspond to the combination of the amplitude of the voltage VP1 and the ON width or OFF width of the voltage VP1.

(4) Modification of switching circuits 40 and 90 In the first to third embodiments, a bipolar transistor is used as the PNP transistor, and in the fourth embodiment, a MOSFET is used as the NPN transistor. However, the type of transistor is not limited to this. . For example, a MOSFET may be used for the PNP transistor in the first to third embodiments, and a bipolar transistor may be used for the NPN transistor in the fourth embodiment. In this case, the peripheral circuit configuration of the base terminal of the bipolar transistor or the gate terminal of the MOSFET may be set as appropriate.

(5) Modification of Fourth Embodiment In the fourth embodiment, the configuration in which one current limiting resistor 91 is used is shown. However, as shown in FIG. It may be modified so that the resistors 94 and 95 are connected between the cathodes, respectively. In this case, the pulsating voltage to the resistors 74 and 75 and the resistors 84 and 85 may be supplied by a full-wave rectifier circuit (see the second embodiment) or a half-wave rectifier circuit (see the third embodiment). ). As a result, the current flowing through the photodiode 31 differs between when the electrical signal E2 is ON (FET 92 is on) and when the electrical signal E3 is ON (FET 93 is on), and the voltage at the voltage VP1 at the point P1. Are differentiated in amplitude. Therefore, the integrated value VP2 of the voltage VP1 in each case is also differentiated. In the present modification, the amplitude of the partial pressure value Va1 and the amplitude of the partial pressure value Va2 may be the same.

(5) Expansion of the number of systems In each of the above-described embodiments, a configuration in which three electric signals at the maximum are input to the dimming signal generation circuit 1 has been shown. This is possible by extending In this case, in the expansion of the second and third embodiments, the resistance connected in series with the PNP transistor may be different for each system. In the expansion of the fourth embodiment, the voltage dividing ratio of the voltage dividing circuit is changed. What is necessary is just to make it differ for every system | strain.

DESCRIPTION OF SYMBOLS 1 Dimming signal generation circuit 2 LED lighting circuit 6 LED power supply 7 LED
8 LED Lighting Device 10 Smoothing Circuit 20 Pulsed Circuit 30 Photocoupler 31 Photodiode 32 Phototransistor 40 Switching Circuit 50 Output Circuit 60 Pulsed Circuit (Additional Pulsed Circuit)
70 pulsating circuit 80 pulsating circuit (additional pulsating circuit)
90 Switching circuit

Claims (9)

A dimming signal generation circuit that generates a dimming signal based on ON / OFF of a plurality of AC electric signals input from an AC power source,
A smoothing circuit that generates a smoothed voltage that is rectified and smoothed from the first AC electrical signal;
A pulsating circuit that generates a rectified pulsating voltage from the second AC electrical signal;
A photocoupler having a photodiode to which the smoothing voltage is applied;
A switching circuit for controlling a current flowing through the photodiode based on the pulsating voltage;
A dimming signal generation circuit comprising: an output circuit that outputs a dimming signal corresponding to an operation state of a phototransistor of the photocoupler. The dimming signal generation circuit according to claim 1,
The smoothing circuit includes a first rectifier circuit to which the first AC electric signal is input, and a capacitor for smoothing a rectified output of the first rectifier circuit,
The pulsating circuit includes a second rectifying circuit to which the second AC electric signal is input, and a voltage dividing circuit that generates a divided value of the pulsating output voltage of the second rectifying circuit,
A dimming signal generation circuit, wherein the switching circuit includes a resistor and a PNP transistor connected in series to the photodiode, and an operation state of the PNP transistor is controlled based on the divided voltage value. The dimming signal generation circuit according to claim 1, further comprising an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal,
The smoothing circuit includes a first rectifier circuit to which the first AC electric signal is input, and a capacitor for smoothing a rectified output of the first rectifier circuit,
The pulsating flow circuit generates a first divided voltage value of the second rectifier circuit to which the second AC electric signal is input and a first divided voltage value of the pulsating output voltage of the second rectifier circuit. With a circuit,
The additional pulsating circuit generates a second voltage dividing value of a third rectifying circuit to which the third AC electric signal is input and a pulsating output voltage of the third rectifying circuit. Pressure circuit,
The switching circuit includes a series circuit of a first resistor and a first PNP transistor connected in series to the photodiode, and a series circuit of a second resistor and a second PNP transistor connected in series to the photodiode. And an operating state of the first PNP transistor is controlled based on the first divided voltage value, and an operating state of the second PNP transistor is controlled based on the second divided voltage value. A dimming signal generating circuit configured, wherein a resistance value of the first resistor is different from a resistance value of the second resistor. The dimming signal generation circuit according to claim 1, further comprising an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal,
The smoothing circuit includes a rectifier circuit to which the first AC electric signal is input, and a capacitor that smoothes the rectified output of the rectifier circuit,
The pulsating circuit generates a first half-wave rectifier circuit to which the second AC electric signal is input, and a first divided value of the pulsating output voltage of the first half-wave rectifier circuit. 1 voltage divider circuit,
The additional pulsating circuit includes a second half-wave rectifier circuit in which the third AC electrical signal is input in a phase opposite to that of the second AC electrical signal, and a pulsating output of the second half-wave rectifier circuit. A second voltage dividing circuit for generating a second voltage divided value;
The switching circuit includes a series circuit of a first resistor and a first PNP transistor connected in series to the photodiode, and a series circuit of a second resistor and a second PNP transistor connected in series to the photodiode. The operating state of the first PNP transistor is controlled based on the first divided voltage value, and the operating state of the second PNP transistor is controlled based on the second divided voltage value. A dimming signal generation circuit configured in which the resistance value of the first resistor is different from the resistance value of the second resistor. The dimming signal generation circuit according to claim 1, further comprising an additional pulsating circuit for generating a pulsating voltage rectified from the third AC electric signal,
The smoothing circuit includes a rectifier circuit to which the first AC electric signal is input, and a capacitor that smoothes the rectified output of the rectifier circuit,
The pulsating circuit generates a first half-wave rectifier circuit to which the second AC electric signal is input, and a first divided value of the pulsating output voltage of the first half-wave rectifier circuit. 1 voltage divider circuit,
The additional pulsating circuit includes a second half-wave rectifier circuit in which the third AC electrical signal is input in a phase opposite to that of the second AC electrical signal, and a pulsating output of the second half-wave rectifier circuit. A second voltage dividing circuit for generating a second voltage divided value;
The switching circuit includes a resistor connected in series to the photodiode, a first NPN transistor, and a second NPN transistor connected in parallel to the first NPN transistor, and is based on the first divided voltage value. The operation state of the first NPN transistor is controlled, and the operation state of the second NPN transistor is controlled based on the second divided voltage value, and the first divided voltage value is A dimming signal generation circuit different from the second divided voltage value.   5. The dimming signal generation circuit according to claim 1, wherein the dimming signal is generated when the off state of the first AC electric signal is an electric signal indicating all-light lighting. The dimming signal generating circuit, wherein the off-state input of the first alternating electrical signal is prioritized over the remaining alternating electrical signal state input.   7. The dimming signal generation circuit according to claim 1, wherein the output circuit is configured to generate the dimming signal by integrating a voltage based on an operation state of the phototransistor. 8. , Dimming signal generation circuit. A dimming signal generation circuit according to any one of claims 1 to 7,
A rectifier that rectifies an input AC voltage, a DC / DC converter that converts a rectified output of the rectifier into a predetermined DC output and supplies the DC output to an LED, and a dimming rate corresponding to the dimming signal An LED power supply comprising an LED lighting circuit having a control unit for controlling an output current. An LED lighting device comprising: the LED power source according to claim 8; and the LED connected to the LED power source.

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