JP2008234588A - Power control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power control device that can protect switch elements and a load from overcurrent, such as, inrush current at load connection or start, and can be applied to different loads, such as, incandescent and fluorescent lamps. <P>SOLUTION: The power control device comprises the switching elements Q1 and Q2 for turning on/off supply power flowing from an AC power supply 1 to a load 2, a control part 7 for controlling the on/off action of the switching elements Q1 and Q2, and resistors R1 and R2 functioning as current detection parts for detecting the currents flowing through the switching elements Q1 and Q2. The control part 7 repeats a temporary off action of the switching elements Q1 and Q2 upon overcurrent detection, at predetermined short periods, for a predetermined time from the supply start of the AC power supply, and after the predetermined time, extends the predetermined periods at which the switching elements Q1 and Q2 are turned off upon overcurrent detection or keeps them off. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power control apparatus for performing power control of an AC load such as a lighting load.

  Phase control or anti-phase control that controls the conduction angle of the load current (phase angle of the conduction period) as a device used to adjust the power supplied to the AC load, such as dimming of an illumination load such as an incandescent lamp Various power control devices that adjust the supplied power by performing the above have been proposed.

  This type of conventional power control device using phase control includes a switch means (switch element) for turning on and off the power supplied from the AC power source to the load, and monitors the current flowing through the load. Is known (see, for example, Patent Document 1).

Further, in reverse phase control, a power control device (reverse phase control dimmer) is disclosed which has a configuration in which the turn-off period of the switch means is lengthened when an overcurrent is detected and the surge voltage applied to the switch means is reduced. (For example, refer to Patent Document 2).
JP-A-60-101620 JP 2000-340371 A

  However, in the configuration of the conventional example as described above, although it has a protection function against an overcurrent, no consideration is given to the inrush current that occurs instantaneously when the load is removed during energization. There was a possibility of adverse effects such as failure and deterioration. For example, when performing reverse phase control that turns on at the zero point (voltage zero volts) of the AC power supply and turns off at a phase of 90 degrees, an inrush current is detected if a load is attached during a transient near the phase 90 degree turn-off. There is a possibility that an excessive current flows through the switch means and the load.

  In the above conventional example, an overcurrent is detected and turned off to the next zero point of the AC power supply. In this configuration, since there is only a pause period of about 10 msec at the maximum, when a failed load is connected There is a risk of problems such as heat generation of the switch means.

  In addition, the load in the above-described conventional example assumes an incandescent lamp, and in order to switch on / off of a so-called fluorescent lamp using a discharge lamp lighting device such as a bulb-type fluorescent lamp as a load by turning on / off the power supply. It was not available as a power control device. For example, when an overcurrent is detected, current does not flow to the next zero point by turning off the switch means, so that sufficient power is not supplied to the inverter circuit of the discharge lamp lighting device, and the fluorescent lamp does not start up. It is possible that the lamp cannot be lit.

  The present invention has been made in view of the above circumstances, and not only when a load is short-circuited or abnormal, but also when a switch element or load is applied against an overcurrent such as an inrush current or an excessive current at the time of load connection or startup. An object of the present invention is to provide a power control device that can be protected and can be applied to a plurality of different types of loads such as an incandescent lamp and a discharge lamp lighting device.

  The power control apparatus according to the present invention is a power control apparatus that adjusts supply power flowing from an AC power supply to a load, a switch element that turns on and off the supply power, a control unit that controls on and off of the switch element, and the switch A current detection unit that detects a current flowing through the element, and when the current flowing through the switch element exceeds a predetermined value, the control unit determines overcurrent detection and temporarily turns off the switch element, From the start of supply of the AC power supply until a predetermined time, the switch element is temporarily turned off by the overcurrent detection at a predetermined cycle, and after the predetermined time, the switch element is turned off by the overcurrent detection. It will increase the time.

  With the above configuration, it is possible to protect the switch element and the load not only when the load is short-circuited or abnormal, but also against an overcurrent such as an inrush current or an overcurrent when the load is connected or started. The present invention can also be applied to a plurality of different types of loads such as an incandescent lamp and a discharge lamp lighting device. For example, the discharge lamp lighting device can be reliably turned on and operated.

Further, the present invention is the above-described power control device, wherein the switch element is connected in series with opposite polarities between the AC power source and a load connected in series with the AC power source. Including a first switch element and a second switch element for turning on and off the power supplied from the AC power source based on the control signal.
Further, the present invention includes the power control device described above, wherein the current detection unit is connected in series with the switch element, and detects a current flowing through the switch element by a current flowing through the current detection unit. .

Further, the present invention is the above-described power control apparatus, wherein the control unit first turns off the switch element by the overcurrent detection from a start of supply of the AC power supply to a predetermined time. After the predetermined time, the repetition time for turning off the switch element by the overcurrent detection is a second period longer than the first period.
Further, the present invention is the above-described power control apparatus, wherein the control unit sets a predetermined time from the start of supply of the AC power supply to about 100 msec and sets a first cycle for temporarily turning off the switch element. 1 msec is included, and the second period is approximately 100 msec.

Further, the present invention is the above-described power control device, wherein the control unit temporarily turns off the switch element by the overcurrent detection from a start of supply of the AC power source to a predetermined time. After the predetermined time, the switch element is continuously turned off by the overcurrent detection.
Further, the present invention is the power control apparatus described above, wherein the control unit sets a predetermined time from the start of supply of the AC power supply to about 100 msec, and sets a predetermined period for temporarily turning off the switch element to about 1 msec. , And the switch element that keeps the switch element off after the predetermined time.

  With the above configuration, from the start of supply of the AC power supply at the start to a predetermined time, when the overcurrent is detected, the switch element is temporarily turned off in a short cycle to reduce the overcurrent such as the inrush current. On the other hand, the switch element and the load can be protected. At this time, even if the load is a discharge lamp lighting device or the like, the load can be reliably started and turned on. In addition, after a predetermined time, the overcurrent can be suppressed even if there is a load abnormality such as a short circuit by increasing the cycle for temporarily turning off the switch element or by keeping the switch element off.

Moreover, this invention provides the illuminating device which has an electric power control apparatus in any one of the said, and used at least any one of the incandescent lamp or the discharge lamp lighting device for load.
The present invention also provides a power supply system in which a plurality of the power control devices described above are connected.
In addition, the present invention provides an illumination system in which a plurality of the power control devices described above are connected and at least one of an incandescent lamp or a discharge lamp lighting device is used as a load.

  According to the present invention, it is possible to protect the switch element and the load not only when the load is short-circuited or abnormal, but also against an overcurrent such as an inrush current or an overcurrent when the load is connected or started, for example, It is possible to provide a power control device that can be applied to a plurality of different types of loads such as an incandescent lamp and a discharge lamp lighting device.

  Hereinafter, embodiments of the present invention will be described. However, the embodiments are merely exemplary embodiments adopted based on the present invention, and the present invention should not be interpreted in a limited manner based on matters specific to the embodiments. Rather, the technical scope of the present invention should be determined based on the matters shown in the claims of the claims and matters substantially equivalent thereto.

  In the following embodiments, an illumination device such as a discharge lamp lighting device such as an incandescent lamp or a bulb-type fluorescent lamp is used as a load as an AC load, and power supplied from the AC power source is controlled by reverse phase control or phase control. The example of a structure applied to the illuminating device which performs light control or lighting / extinguishing is shown.

(First embodiment)
FIG. 1 is a circuit diagram showing the configuration of the power control apparatus according to the first embodiment of the present invention. The power control apparatus of this embodiment can perform power switching by antiphase control or phase control. The power control apparatus includes a power supply connection portion CN1 to which an AC power supply 1 having a commercial frequency is connected, a load connection portion CN2 to which a load 2 such as an incandescent lamp or a fluorescent lamp is connected in series to the AC power supply 1, and an AC power supply. A first switch element Q1 and a second switch element Q2 which are connected in series in opposite directions between 1 and a load 2 and turn on / off power supplied from the AC power supply 1 to the load 2, and a pair of these switch elements A drive unit 5 that drives Q1 and Q2 and a control unit 7 that outputs a control signal to the drive unit 5 to control on / off of the switch elements Q1 and Q2 are configured. As the load 2, incandescent lamps such as incandescent lamps and halogen lamps (hereinafter collectively referred to as incandescent lamps), fluorescent lamps such as discharge lamp lighting devices including bulb-type fluorescent lamps (hereinafter collectively referred to as fluorescent lamps) Etc.) are connected and used.

  The switch elements Q1 and Q2 are constituted by semiconductor switching elements such as field effect transistors (MOS-FETs). As the switch elements Q1 and Q2, in addition to a field effect transistor, an insulated gate transistor (IGBT), a bipolar transistor, or the like can be used. When the switch elements Q1 and Q2 are MOS-FETs, the source and drain are connected in series with opposite polarities between the AC power supply 1 and the load 2, and both sources are connected to the ground GND via resistors R1 and R2, respectively. It is grounded and the gate is connected to the drive unit 5 via resistors R3 and R4, respectively. The switch elements Q1 and Q2 turn on and off between the source and the drain according to the drive control signal (gate voltage) when the drive control signal from the drive unit 5 is input to the gate. Hereinafter, a case where the switch elements Q1 and Q2 are MOS-FETs will be described.

  A fuse FUSE is provided in the power supply line of the AC power supply 1, and the control power supply 3 and the zero point detection unit 4 are connected via the fuse FUSE. Note that a surge absorption element (varistor), a noise reduction filter, and the like may be provided in the power supply line.

  The control unit 7 includes comparators CP1 and CP2, and a microcomputer (microcomputer) 6 including a control computer having a processor and a memory. The drive unit 5 has an input terminal connected to an output terminal of the comparator CP1 and a control output terminal of the microcomputer 6. Based on the comparison result output of the comparator CP1 and the control output of the microcomputer 6, a drive control signal will be described later. A predetermined control voltage is output at a predetermined timing and supplied to the switch elements Q1 and Q2. The microcomputer 6 includes an output terminal of the zero point detection unit 4, an output terminal of the light receiving unit 8 that receives a remote control signal from the remote control transmitter 9 and inputs the signal to the microcomputer 6, and the load 2 is an incandescent lamp. And a load setting switch 10 for switching and setting the case of a fluorescent lamp.

  The power supply output of the control power supply 3 is connected to the drive unit 5, the microcomputer 6, and the light receiving unit 8, and supplies a DC voltage as an operation power supply to these circuits. Also, resistors R7 and R8 connected in series for dividing the DC voltage of the output of the control power supply 3 to generate a reference voltage for overcurrent determination are provided, and one end of one resistor R7 is the power supply of the control power supply 3. Connected to the output. One end of the other resistor R8 is connected to the ground GND, and the connection point of the resistors R7 and R8 is connected to the positive input ends of the comparators CP1 and CP2.

  The resistors R1 and R2 have a function of a current detection unit that detects currents flowing through the switch elements Q1 and Q2, respectively. The connection point between the resistors R1 and R2 and the switch elements Q1 and Q2 is connected to one end of the resistor R5 via the diodes D1 and D2, respectively, and the other end of the resistor R5 is connected to the negative input ends of the comparators CP1 and CP2. Yes. As a result, the comparators CP1 and CP2 compare the voltage proportional to the current detected by the resistors R1 and R2 (the voltages at both ends of the resistors R1 and R2) with the reference voltage by the resistors R7 and R8. One end of the resistor R6 is connected to the output end of the comparator CP2, the other end of the resistor R6 is connected to the positive input ends of the comparators CP1 and CP2, and the comparison result output of the comparator CP2 is stepped down by the resistor R6 and fed back. Is done. In addition to the resistance, a manganin wire, a current transformer, or the like may be used as the current detection unit.

  Further, a capacitor C1 is provided between the negative input terminals of the comparators CP1 and CP2 and the ground GND, and resistors R9 and R10 connected in series for dividing the voltage therebetween are provided. One end (collector or the like) of a switch element Q3 made of a transistor or the like is connected to the connection point. The other end (emitter, etc.) of the switch element Q3 is installed on the ground GND, and the control input end (base, etc.) is connected to the control output end of the microcomputer 6. The microcomputer 6 of the control unit 7 controls the drive unit 5 and the switch element Q3 based on the detection output of the zero point detection unit 4, the remote control signal from the light receiving unit 8, and the setting signal according to the setting state of the load setting switch 10. A signal is output to control the operation of these circuits.

  The power control apparatus according to the present embodiment includes an overcurrent protection function for the switch elements Q1 and Q2 for turning on and off the power supplied to the load 2 as described above. As this overcurrent protection function, when the voltages at both ends of the resistors R1 and R2 for detecting the currents flowing through the switch elements Q1 and Q2 become an overcurrent detection value equal to or higher than a predetermined value, based on the comparison result output of the comparator CP1. Then, the drive unit 5 turns off the switch elements Q1 and Q2. Then, after a predetermined time elapses, the switch elements Q1 and Q2 are turned on again. When no overcurrent is detected, the normal operation is resumed. When the overcurrent continues, the switch elements Q1 and Q2 are turned off, An intermittent switch operation is performed so as to turn on the switch elements Q1 and Q2 after a lapse of time. The period of the intermittent switch operation at the time of overcurrent (hereinafter referred to as the overcurrent operation intermittent period) is an intermittent overcurrent operation in a steady state for a period from when power is supplied to the load 2 until a predetermined time elapses. Set shorter than the cycle.

  Next, power control by the switch elements Q1 and Q2 in the power control apparatus of the present embodiment will be described. Here, an operation example of power control by antiphase control is shown. FIG. 2 is a diagram showing operation waveforms when performing power control in the present embodiment. FIG. 2 shows the load voltage and the switch element current (drain current). Further, the hatched portion in the figure indicates a section in which current flows by the antiphase control. Here, an example is shown in which light control is performed by 90-degree reverse phase control. Note that T is a half cycle of the frequency (commercial frequency) of the AC power supply.

  When performing anti-phase control, the drive unit 5 drives the switch elements Q1 and Q2 under the control of the microcomputer 6 of the control unit 7, and the timing 13 (that is, the switch element Q1) when the load voltage is approximately zero volts (zero cross, phase 0 degree). The switch element Q1 is turned on at a timing at which the voltage and current applied to are substantially zero, and the drain current flows from zero. At this time, the drain current returns to the AC power source 1 via the parasitic diode of the switch element Q2, and the load current flows through the load 2. Further, the switch element Q1 is turned off at the timing 14 of the substantially peak (phase 90 degrees) when the load voltage increases (that is, the voltage and current applied to the switch element Q1 are approximately the peak point). Then, the switch element Q2 is turned on at the timing 11 (that is, the voltage and current applied to the switch element Q2 are substantially zero points) at which the load voltage is substantially zero volts (zero cross, phase 180 degrees) so that the drain current flows from zero. To do. At this time, the drain current returns to the AC power source 1 via the parasitic diode of the switch element Q1, and the load current flows through the load 2. Further, the switch element Q2 is turned off at the timing 12 of the substantially peak (phase 270 degrees) when the load voltage has increased (that is, the voltage and current applied to the switch element Q2 are approximately the peak point). The above operation is repeated at a cycle of the AC power supply frequency.

  By the above operation, power switching of the antiphase control (antiphase power control) is performed. The light control when the load 2 is an incandescent lamp is performed by such power control based on the reverse phase control. Further, when the load 2 is a fluorescent lamp, it can be turned on and off by turning on and off the switch elements Q1 and Q2. The user operates the load setting switch 10 to switch the load setting between when the incandescent lamp is connected to the load 2 and when the fluorescent lamp is connected. Thereby, a setting signal from the load setting switch 10 is input to the microcomputer 6, and power control such as on / off of the switch elements Q <b> 1 and Q <b> 2 according to the connected load is executed under the control of the microcomputer 6.

  Next, the overcurrent protection operation in this embodiment will be described in detail. In order to protect the switch elements Q1 and Q2 from an inrush current due to attachment / detachment of the load 2, etc., the drain currents of the switch elements Q1 and Q2 are detected by the resistors R1 and R2, and it is determined whether or not there is an overcurrent. At this time, the voltage generated at both ends of the resistors R1 and R2 is charged in the capacitor C1, and the comparator CP1 compares the detected voltage with the reference voltage (the divided voltage of the resistors R7 and R8). When the detected voltage is higher than the reference voltage, a low level is output as the comparison result output of the comparator CP1, the gate voltage of the switch elements Q1 and Q2 is lowered by the drive control signal from the drive unit 5, and the switch elements Q1 and Q2 are Turn off. Further, another comparator CP2 is used to lower the reference voltage by the resistor R6 provided between the input and output, thereby forming a hysteresis in the overcurrent determination threshold.

  FIG. 3 is a time chart showing an operation related to the overcurrent protection function of the present embodiment. When an incandescent lamp or a fluorescent lamp is connected to the load 2, power is supplied from the AC power source 1 to the load 2 by turning on the power by turning on a power switch (not shown) or by a lighting instruction by a remote control signal from the remote control transmitter 9. Is started and the load 2 is lit. At this time, the control signal from the microcomputer 6 is input to the switch element Q3 with the start of power supply to the load 2, the switch element Q3 is turned on in response to this control signal, and the resistor R10 is equivalently short-circuited. is there. Therefore, at the time of starting, when the detection voltage by the resistors R1 and R2 exceeds the reference voltage which is a threshold for overcurrent determination, once the overcurrent detection level (overcurrent threshold) Ith is reached and the switch elements Q1 and Q2 are turned off. The switch elements Q1 and Q2 remain off until discharged by the resistor R9 so that the potential of the capacitor C1 is equal to or lower than the reference voltage. Therefore, from the start of power supply to the load 2 until a predetermined time, while the overcurrent is flowing, the period according to the time constant of the resistor R9 and the capacitor C1 (first overcurrent operation intermittent period (first period)) Repeat intermittent operation with.

  Further, after a predetermined time has elapsed from the start of power supply to the load 2, the switch element Q3 is turned off by the control signal from the microcomputer 6 and the resistor R10 is inserted, and the potential of the capacitor C1 is set by the resistors R9 and R10. Discharged. Therefore, after the predetermined time has elapsed, the intermittent operation is repeated at a cycle (second overcurrent operation intermittent cycle (second cycle)) according to the time constant of the resistor R9 + R10 and the capacitor C1 while the overcurrent flows.

  As described above, the overcurrent operation intermittent cycle is set to be short for a period T1 from when power is supplied to the load 2 at the time of start-up until a predetermined time elapses after power is supplied to the load 2, and thereafter the steady state period. At T2, it is set longer than at the start. FIG. 4 is a diagram showing a short-cycle intermittent operation at the start in the overcurrent protection operation, and FIG. 5 is a diagram showing a long-cycle intermittent operation in a steady state in the overcurrent protection operation. 4 and 5 show the drain current waveforms of the switch elements Q1 and Q2 when an overcurrent is detected exceeding the overcurrent detection level Ith corresponding to the reference voltage for overcurrent determination.

  Here, a short overcurrent operation intermittent period T1 from the start of power supply at the start to the elapse of a predetermined time is set to approximately 100 msec corresponding to five periods of the AC power supply frequency (commercial frequency). A period T1 (= 100 msec) from the start of power supply at the time of starting until a predetermined time elapses corresponds to a time during which the switch element Q3 is turned on under the control of the microcomputer 6. In the short cycle period T1 at the start, as shown in FIG. 4, the short cycle overcurrent operation intermittent cycle t1 based on the time constant of the resistor R9 and the capacitor C1 is set to 1 msec, and the switch elements Q1 and Q2 are turned on / off every 1 msec. repeat. This short-period overcurrent operation intermittent cycle t1 (= 1 msec) corresponds to the discharge time by the resistor R9. At this time, the time ton when the current continuously flows through the switch elements Q1 and Q2 is 40 μsec, and a triangular current waveform flows every overcurrent operation intermittent period t1 (1 msec). After the overcurrent is detected, the oscillation by the intermittent operation with the current waveform is repeated until the current returns to the current below the overcurrent detection level. The overcurrent detection level (overcurrent threshold) Ith is, for example, 8A, and the current Is that flows during the intermittent operation is, for example, about 5-8A.

  Further, after 100 msec from the start of power supply, in the long-period period T2 in the steady state thereafter, as shown in FIG. 5, the long-cycle overcurrent operation intermittent period t2 due to the time constant of the resistor R9 + R10 and the capacitor C1 is set to 100 msec. The switching elements Q1 and Q2 are repeatedly turned on and off every 100 msec. This long-period overcurrent operation intermittent cycle t2 (= 100 msec) corresponds to the discharge time by the resistors R9 + R10. At this time, a triangular current waveform flows through the switching elements Q1 and Q2 at every overcurrent operation intermittent period t2 (100 msec). After the overcurrent is detected, the oscillation by the intermittent operation with the current waveform is repeated until the current returns to the current below the overcurrent detection level.

  When an incandescent lamp is connected as the load 2, the resistance value of the load is relatively small at the cold start, and the current value flowing when the power is turned on becomes excessive. At this time, while repeating the intermittent operation by the overcurrent protection operation described above, the filament of the incandescent lamp is heated by the intermittently flowing current, and when the overcurrent threshold is eventually reached, the overcurrent protection intermittent operation is stopped and the steady operation is stopped. Transition to the lighting state.

  When a fluorescent lamp is connected as the load 2, a large inrush current flows to the internal rectifying / smoothing or power factor improving step-up chopper electrolytic capacitor when the power is turned on in the inverter load. In this case, the electrolytic capacitor is charged by the intermittently flowing current while repeating the above intermittent operation by the overcurrent protection operation, and when the overcurrent threshold is eventually reached, the overcurrent protection intermittent operation is stopped and the steady lighting state Migrate to

  As described above, the overcurrent operation intermittent period t1 in the predetermined period T1 from the time of turning on the power is shortened, and the overcurrent operation intermittent period t2 in the subsequent period T2 is increased in the inverter circuit such as a fluorescent lamp. This is to consider the case where a load having the same is connected. When the power is turned on, it is necessary to shorten the cycle of the intermittent operation so that the inverter circuit can start up and to charge the electrolytic capacitor inside the inverter circuit. On the other hand, for an overcurrent in a steady state, the period of intermittent operation is lengthened so that power is not supplied to the inverter circuit.

  When a component in the inverter circuit is in a certain failure state, the expected operation from the inverter circuit side is that the current fuse originally arranged on the inverter circuit side is disconnected. However, in the present embodiment, since the current flowing by the overcurrent protection operation is suppressed, the current fuse on the inverter circuit side does not break, and as a result, an unexpected operation may occur. For this reason, although power supply to the inverter circuit is suppressed, there is a risk that the components on the inverter circuit side will be in an unsafe state such as smoke or fire. In order to avoid this, sufficient safety is ensured by extending the overcurrent operation intermittent period so that almost no power is supplied to the inverter circuit of the load after a predetermined period from power-on. is doing.

  Regardless of whether the load is an incandescent lamp load or a fluorescent lamp load, if an overcurrent occurs due to some reason such as a load short-circuit and the transition from the steady operation state to the overcurrent protection operation is performed, a predetermined time after turning on the power Similarly to the period t2, by setting the overcurrent operation intermittent period to be long, the current to the switch elements Q1 and Q2 is suppressed. As a result, the heat generation of the switch elements Q1 and Q2 can be suppressed, and the apparatus can be reduced in size.

  Further, as described above, when an overcurrent is detected at the time of start and an overcurrent protection operation is performed, the time from when the switch elements Q1 and Q2 are turned off to when the switch elements are turned on is a reference that is an overcurrent threshold value. This is the time until the potential of the capacitor C1 charged to the voltage drops again to the overcurrent threshold voltage due to the discharge of the resistor R9. At this time, in this embodiment, the comparator CP2 is used to feed back the comparison result output via the resistor R6, thereby forming a hysteresis in the overcurrent threshold voltage. The setting of the hysteresis is determined by equivalently connecting the resistor R8 that sets the threshold voltages of the comparators CP1 and CP2 and the resistor R6 connected between the input and output of the comparator CP2.

  At this time, the potential of the capacitor C1 is discharged by the resistor R9 at the time of starting, but after a predetermined time has elapsed, the switch element Q3 is turned off by the control signal from the microcomputer 6 and discharged by the resistor R9 + R10. The overcurrent operation intermittent cycle is switched by the on / off operation of the switch element Q3.

  As described above, in the present embodiment, when an overcurrent is detected, an intermittent operation is performed in which the switch elements Q1 and Q2 are turned on and off in a short period (1 msec) from the start of power supply at the start to a predetermined time, and the predetermined time After elapses, the load 2 and the switch elements Q1 and Q2 are protected against overcurrent by performing an intermittent operation of turning on and off the switch elements Q1 and Q2 with a long period (100 msec). As a result, it is possible to protect the switch element and the load not only when the load is short-circuited or when an abnormality occurs, but also when the load is connected or when an overcurrent such as an inrush current or an excessive current is generated at startup. At the same time, it can be lit regardless of the type of load such as incandescent lamp and fluorescent lamp, and can be applied to different types of loads.

(Second Embodiment)
FIG. 6 is a circuit diagram showing a configuration of a power control apparatus according to the second embodiment of the present invention. The second embodiment is a modification of the first embodiment, in which the configuration of the input / output portions of the comparators CP1 and CP2 is changed. Here, only a different part from 1st Embodiment is demonstrated, the same code | symbol is attached | subjected about the same component and description is abbreviate | omitted.

  The power control device of the second embodiment is configured such that the switch element Q3 and the resistor R10 are omitted from the configuration of the first embodiment, and the output terminal of the comparator CP2 is also connected to the microcomputer 6. The microcomputer 6 can also turn off the switch elements Q1 and Q2 by controlling the drive unit 5 also by the comparison result output of the comparator CP2.

  In the second embodiment, when an overcurrent is detected, from the start of power supply to the load 2 until a predetermined time, as in the first embodiment, the resistor R9 and the capacitor C1 are used while the overcurrent is flowing. The intermittent operation is repeated in a cycle (first overcurrent operation intermittent cycle t1) based on the time constant of. At this time, the microcomputer 6 receives the comparison result output from the comparator CP2 and determines the occurrence of overcurrent. After a predetermined time has elapsed, the switch elements Q1 and Q2 are kept off while an overcurrent is detected by a control signal from the microcomputer 6. In this case, the overcurrent protection operation is canceled and reset by a power cut-off by turning off a power switch (not shown) or a turn-off instruction by a remote control signal from the remote control transmitter 9.

  As described above, in the second embodiment, when an overcurrent is detected, an intermittent operation is performed in which the switching elements Q1 and Q2 are turned on and off in a short cycle (1 msec) from the start of power supply at the start to a predetermined time, After the elapse of time, the switch elements Q1 and Q2 are kept off to protect the load 2 and the switch elements Q1 and Q2 against overcurrent. Thus, as in the first embodiment, the switch element and the load are not limited to an overcurrent such as an inrush current or an excessive current at the time of load connection or starting, as well as an overcurrent at the time of a load short circuit or an abnormality. Can be protected and can be lit regardless of the type of load, such as an incandescent lamp and a fluorescent lamp, and can be applied to different types of loads.

  As described above, according to the present embodiment, when any load such as an incandescent lamp or a fluorescent lamp is connected, an overcurrent such as an inrush current at the time of load connection or at start-up as well as an overcurrent when the load is abnormal is used. The switch element and load can be protected against current, and unsafe conditions such as heat generation can be prevented. Further, during normal operation, even when a load including an inverter circuit such as a fluorescent lamp is connected, it can be reliably turned on and operated.

  In addition, when the fluorescent lamp is connected as a load by turning on and off the switch elements Q1 and Q2 every 1 msec, which is a short overcurrent operation intermittent period t1, at the time of start-up, the overcurrent is protected and rapidly at about 1 kHz. In this case, power can be supplied to the inverter circuit to start up the load quickly (light up).

  When an overcurrent is detected after a lapse of a predetermined time (100 msec) from the start of power supply at start-up, the switch elements Q1 and Q2 are turned on or off every 100 msec which is a long overcurrent operation intermittent cycle, or the switch element Q1 By keeping Q2 off, the switch elements Q1 and Q2 can be stopped for at least 100 msec. Therefore, stress can be prevented from being applied to circuits such as the load and the switch element, and an abnormality of the apparatus can be avoided.

  Further, by connecting the capacitor C1 between the drains at both ends of the switch elements Q1 and Q2 connected in opposite directions, dV / dt when the switch element is off can be reduced, and stress can be avoided. In the present embodiment, since the overcurrent is detected by the resistors R1 and R2, the overcurrent can be detected regardless of the operation of the switch elements Q1 and Q2. Note that if an inductor is provided between the switch elements Q1 and Q2 and the power supply connection portion CN1 to which the AC power supply 1 is connected, a more slope is formed in the drain current waveform of the switch element and the current conduction time is lengthened. Therefore, it is possible to detect the overcurrent reliably by absorbing the delay time of the circuit operation.

  In addition, for example, in the above-described conventional example, when the load is short-circuited, it is assumed that the power control device without the overcurrent protection function avoids an unsafe state as a breaker breakage outside the device, and the device itself may be damaged. It is done. On the other hand, in this embodiment, even when the load is short-circuited, the current flowing to the device can be suppressed by the overcurrent protection function, so that an unsafe state can be avoided without breaking the breaker, and damage to the device can also be prevented. . This means that when a device incorporating the power control device of this embodiment is used, it is not necessary to provide a breaker in the device, and damage to the device can be prevented, so that a device that is very convenient for the user can be realized.

  In addition, the power control apparatus according to the present embodiment can be used as a system by connecting a plurality of power control apparatuses, for example, when a plurality of lighting apparatuses are connected to the same wiring duct. It is also possible to connect a plurality of loads to the power control apparatus and collectively control the supplied power.

  FIG. 7 is a diagram illustrating a configuration example of a power supply system in which a plurality of power control apparatuses are connected. In this power supply system, a plurality of power control devices 51 a, 51 b, 51 c are connected to the same power line wiring 55 and connected to the AC power supply 1. The power line wiring 55 is provided with a switch 56 such as a wall switch for turning on / off the power source and a breaker 57 for overcurrent protection. The power control devices 51a, 51b, 51c are connected to loads 52a, 52b, 52c such as lighting devices such as incandescent lamps and fluorescent lamps, respectively, to constitute an illumination system, and to these loads 52a, 52b, 52c. The power supply can be controlled.

  As in this configuration example of the power supply system, when a plurality of power control devices are connected, the inrush current when the power is collectively turned on for the loads of these power control devices can be reduced. In addition, there is a possibility that the power supply capacity of the switch can be reduced, so that the size and cost of the apparatus and equipment can be reduced.

  In addition, when multiple power control devices are connected, if one of them fails due to its lifetime, etc., for example, when overcurrent flows due to a load short circuit or device failure, the overcurrent of other power control devices The current flowing by the protection function can be reduced. For this reason, it is possible to avoid a state in which all loads are stationary, such as all connected lighting devices are extinguished due to breaker breakage. In addition, when a wall switch is used as a switch for turning on / off the power, it is possible to reduce the possibility of problems such as welding of the switch.

  It should be noted that the present invention is not limited to those shown in the above-described embodiments, and those skilled in the art can also make changes and applications based on the description in the specification and well-known techniques. Yes, included in the scope of protection.

  In the above-described embodiment, an example in which the power control device is applied to an illumination device using an illumination device such as an incandescent lamp or a fluorescent lamp as an AC load as an AC load is shown. However, the present invention is not limited thereto, and the load is a heater. As long as the power supply is controlled by switching the power supplied to the AC load with a switching element, and can be adapted, it can be applied to various other devices.

  The present invention can protect the switch element and the load not only when the load is short-circuited or abnormal, but also against an overcurrent such as an inrush current or an overcurrent when the load is connected or started, and for example, an incandescent lamp It has the effect that it can be applied to different types of loads, such as lighting devices and discharge lamp lighting devices, and is applied to dimming devices and lighting devices for controlling the power of AC loads such as lighting loads It is useful as a possible power control device.

1 is a circuit diagram showing a configuration of a power control apparatus according to a first embodiment of the present invention. The figure which shows the operation waveform at the time of performing power control in this embodiment Time chart showing operation related to overcurrent protection function of this embodiment The figure which shows the short period intermittent operation at the time of the start in the overcurrent protection operation of this embodiment The figure which shows the long period intermittent operation at the time of the steady state in the overcurrent protection operation of this embodiment The circuit diagram which shows the structure of the power control apparatus which concerns on the 2nd Embodiment of this invention. The figure which shows the structural example of the power supply system which connected the power control apparatus of this embodiment in multiple numbers

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Load 3 Control power supply 4 Zero point detection part 5 Drive part 6 Microcomputer 7 Control part 8 Light-receiving part 9 Remote control transmitter 10 Load setting switch CN1 Power supply connection part CN2 Load connection part Q1, Q2, Q3 Switch element CP1, CP2 Comparator R1, R2, R3, R4, R5, R6, R7, R8, R9, R10 Resistor C1 Capacitor

Claims (10)

A power control device for adjusting supply power flowing from an AC power source to a load,
A switch element for turning on and off the supplied power;
A control unit for controlling on / off of the switch element;
A current detection unit that detects a current flowing through the switch element;
The controller is
When the current flowing through the switch element exceeds a predetermined value, overcurrent detection is determined and the switch element is temporarily turned off,
From the start of supply of the AC power supply until a predetermined time, the switch element is temporarily turned off by the overcurrent detection at a predetermined cycle, and after the predetermined time, the switch element is turned off by the overcurrent detection. Power control device that lengthens time. The power control apparatus according to claim 1,
The switch element is connected in series with opposite polarities between the AC power source and a load connected in series with the AC power source, and turns on / off power supplied from the AC power source based on a control signal from the control unit. A power control apparatus comprising first and second switch elements. The power control apparatus according to claim 1,
The current detection unit is a power control device that is connected in series with the switch element and detects a current flowing through the switch element by a current flowing through the current detection unit. The power control apparatus according to claim 1,
The control unit repeats, in a first period, temporarily turning off the switch element by the overcurrent detection from the start of supply of the AC power supply to a predetermined time, and after the predetermined time, the overcurrent detection The power control apparatus according to claim 1, wherein a repetition time for turning off the switch element is a second period longer than the first period. The power control device according to claim 4,
The control unit sets a predetermined time from the start of supply of the AC power supply to about 100 msec, sets a first period for temporarily turning off the switch element to about 1 msec, and sets the second period to about 100 msec. apparatus. The power control apparatus according to claim 1,
The control unit repeats, in a predetermined cycle, temporarily turning off the switch element by the overcurrent detection from the start of supply of the AC power supply to a predetermined time, and after the predetermined time, the control unit detects the overcurrent by the overcurrent detection. A power control device that continues to turn off a switch element. The power control device according to claim 6,
The control unit sets a predetermined time from the start of supply of the AC power supply to about 100 msec, sets a predetermined cycle for temporarily turning off the switch element to about 1 msec, and keeps the switch element off after the predetermined time. Control device.   An illumination device comprising the power control device according to claim 1, wherein at least one of an incandescent lamp and a discharge lamp lighting device is used as a load.   A power supply system in which a plurality of the power control devices according to claim 1 are connected.   A lighting system in which a plurality of power control devices according to claim 1 are connected and at least one of an incandescent lamp or a discharge lamp lighting device is used as a load.

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