JP2012080644A - Load control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load control device which allows a sensor, a control circuit, or the like to stably obtain operating power and can be reduced in size and cost.SOLUTION: A switch device 5 is provided in series with a load 2 and a power source 1 and, in response to input of a control signal from a control unit 10, turns on to allow power of the power source to be supplied to the load,. An operating power supply unit 6 is provided in parallel with the switch device, and is charged with power of the power source when the switch device is turned off. A charge control unit 12 monitors a voltage value of the operating power supply unit and turns off the switch device in a short time if the voltage value becomes lower than a predetermined value, thereby charging the operating power supply unit with power of the power source.

Description

  One embodiment of the present invention relates to a load control apparatus that can control operation, stop, and the like of a load and obtains its own operation voltage from power supplied to the load.

  Conventionally, as a switch device, an electronic device that controls blinking, dimming, etc. of a lighting load according to a control signal such as a sensor such as a human sensor or an illuminance sensor, a timer, or a dimming signal has been proposed. Yes. For example, Patent Document 1 discloses a two-wire electronic switch device that controls a lighting load by a timer.

  In the switch device of Patent Document 1, a self-holding type switching element composed of a triac is provided between a pair of terminals connected in series with an AC power source and a load. Further, an input terminal of a full-wave rectifier is connected in series with a time constant circuit connected to the gate of the switching element, and a switching element such as a thyristor is provided between the output terminals of the full-wave rectifier. Therefore, when a switching element such as this thyristor is turned on by a control signal from a timer or the like, a time constant circuit acts via a full-wave rectifier, and a self-holding type switching element composed of a triac is turned on. When the triac is turned on, power is supplied to the lighting load via the triac, and the lighting load is turned on. Conversely, when there is no control signal, the triac never turns on, and the lighting load is turned off.

  Moreover, in patent document 1, the power supply circuit part provided between the output terminals of a full-wave rectifier is charged with the alternating current power supply input via the said full-wave rectifier during the period when a triac is OFF. It is comprised so that. That is, during the period when the load is lit by a control signal from a timer or the like, it is a low voltage period at the time of rising of the AC power supply voltage half cycle and before the thyristor is turned on (that is, the triac is turned on) The power supply circuit portion can be charged in the previous period).

  During periods when there is no control signal from the timer or the like and the load is going to be extinguished, the switching element inserted in the charging circuit of the power circuit section is opened, and the power circuit section is charged via a resistor connected in parallel to the switching element. Like to do. During this period, the power supply circuit unit is charged through the parallel resistor in substantially the entire period of a half cycle of the AC power supply voltage.

  The power supply circuit section supplies power for operation to the timer and its own control circuit section.

Japanese Patent No. 4308500

  Although the power supply circuit unit is charged as described above in Patent Document 1, in order to always supply power stably to the control circuit unit or the like, the capacity of the power supply circuit unit has some margin. It is necessary to make it a thing, and it becomes a factor of large size and high price.

  The present invention is intended to solve such a problem, and an object of the present invention is to provide a load control device that can stably obtain power for operation of a sensor, a control circuit, etc., and can be reduced in size and price. It is what.

  In the load control device according to one embodiment of the present invention, the switch device is provided in series with the load and the power source, and is turned on when a control signal is input to enable supply of power to the load. An operation power supply unit is provided in parallel to the switch device, and is charged with power supply power when the switch device is turned off. The operation power supply unit supplies operation power to an internal control circuit or the like. The charge control unit monitors the voltage value of the operation power supply unit, and when it falls below a predetermined value, the switch device is turned off for a short time to charge the operation power supply unit with power supply power.

  In another embodiment of the present invention, the charging control unit periodically turns off the switch device for a short time to charge the operation power supply unit with power supply power.

  According to one embodiment of the present invention, the voltage value of the operating power supply unit is monitored, and when the voltage value falls below a predetermined value, the operating power supply unit is charged. Etc. can be maintained at values that can be stably operated. In addition, since it is not necessary to design the operating power supply unit with a capacity having an excessive margin, it is possible to reduce the size and the price.

  Further, according to another embodiment of the present invention, the operating power supply unit is periodically charged, so that the voltage of the operating power supply unit is always kept stable in its own control circuit without using voltage monitoring means. It becomes possible to keep the value operable.

FIG. 1 is a circuit diagram showing an embodiment of the present invention. FIG. 2 is a circuit diagram showing another embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described. A lighting load 2 such as a light bulb and a light emitting diode is connected to a power source 1 (for example, a smoothing DC power source of 100 V or more), and a load control device 3 is connected in series to the power source 1 and the lighting load 2. In addition, in the present invention, the term “series” means that both the case where they are connected in series without intervening other components and the case where they are connected in series with being interposed are included. The same applies to parallelism.

  In the load control device 3, the input terminal of the full-wave rectifier 4 is connected in series with the power source 1 and the lighting load 2, and the switch device 5 is connected between the output terminals of the full-wave rectifier 4. The switch device 5 is constituted by a field effect transistor in the present embodiment.

  The power supply unit 6 for operation is provided in parallel with the switch device 5. Therefore, it can be charged while the switch device 5 is off. In this embodiment, it is composed of a smoothing capacitor and is charged via the constant current control means 7 and the backflow preventing diode 8.

  This operating power supply unit 6 supplies operating power for its own control circuit such as a sensor, a timer, and its signal processing unit, and is set to be charged to, for example, about 7V.

  A control unit 10 generates a control signal for controlling the operation, stop, etc. of the load 2. The control unit 10 will not be described in detail, but may be one that processes signals from sensors, timers, remote controllers, etc., and outputs control signals, one that includes sensors, timers, remote control receivers, etc. Something like that. A control signal from the control unit 10 is input to the gate electrode of the switch device 5. Thereby, on / off of the switch device 5 is controlled by the control signal, and lighting on / off of the lighting load 2 or dimming lighting can be controlled.

  In this embodiment, a constant voltage circuit 11 such as a three-terminal regulator is provided between the operating power supply unit 6 and the control unit 10 so that a stable voltage of about 5 V is supplied to the control unit 10. .

  The charge control unit 12 compares the voltage value of the operating power supply unit 6 with the voltage value of the constant voltage circuit 11 and monitors the voltage value of the operating power supply unit 6. That is, it has a comparing means 15 for comparing the voltage obtained by dividing the voltage of the operating power supply 6 through the voltage dividing circuit of the resistor 13 and the resistor 14 with the voltage of the constant voltage circuit 11. The comparison means 15 outputs a signal when the divided output of the operating power supply 6 falls below the voltage of the constant voltage circuit 11, and outputs a signal to the control signal generation means 16 comprising a one-shot pulse circuit, a monostable multivibrator and the like. It comes to input. When receiving a signal from the comparison unit 15, the control signal generation unit 16 outputs a short-time inverted signal (low signal in the present embodiment). The short time is set to an extent that does not affect the operation of the load 2 or the user. For example, in the case of an illumination load, it is set between 0.1 milliseconds and several tens of milliseconds. This time can be set according to the capacity of the external capacitor 17, for example.

  The inverted signal is input to the gate electrode of the switch device 5 through the diode 18. Therefore, the switch device 5 is turned off for a short time every time a signal is input from the charge control unit 12.

  When the switch device 5 is turned off, the voltage of the power source 1 is applied to the operating power source unit 6 via the full-wave rectifier 4 during this off period, and the operating power source unit 6 is charged to increase the voltage value.

  The operation of the voltage monitoring or charging control unit 12 of the operating power supply unit 6 as described above is performed during the period when the operation signal of the load 2 is output from the control unit 10 (the switch device 5 is on). This is performed regardless of the period during which no output is made (the switch device 5 is off). Even during the period in which the load 2 is operating, the switch device 5 is turned off for a short period of time, so that the operation of the load 2 or the user is not substantially affected as described above.

  Further, in this embodiment, the power source 1 is a smoothed DC power source, and synchronization is performed such that the operating power source unit is charged at the rising edge every half cycle of the AC voltage as in the case of an AC power source (for example, Patent Document 1). Although it is difficult to take, in the above embodiment, it is possible to maintain the voltage of the power supply unit 6 for operation at a value that can stably operate the sensor and its own control circuit unit.

  Next, another embodiment will be described with reference to FIG. In the present embodiment, the same or corresponding parts as those in FIG.

  In the present embodiment, the charging control unit 20 periodically outputs a short-time inversion signal (low signal in the present embodiment). Although the period can be designed arbitrarily, for example, it can be set to the same period as the full-wave rectified voltage of a commercial AC power supply (50 Hz or 60 Hz). In this case, the short time can be 0.1 ms to several ms, for example 1-2 ms.

  The charging control unit 20 mainly includes an oscillating unit 21 and inputs an output of the oscillating unit 21 to a gate electrode of the switch device 5 via a diode 22.

  Therefore, the switch device 5 is turned off for a short time every time a signal is input from the charge control unit 20. When the switch device 5 is turned off, the voltage of the power source 1 is applied to the operating power source unit 6 via the full-wave rectifier 4 during this off period, and the operating power source unit 6 is charged to increase the voltage value. This action is repeated periodically.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the gist of the invention, and the above embodiments can be combined.

  For example, the power source may be another power source such as a commercial AC power source instead of the smoothed DC power source.

  Further, although the switching device is mainly composed of FETs, it may be composed mainly of triacs, antiparallel connected thyristors, combinations of thyristors and full-wave rectifiers, or other switching elements.

  In addition, the load can be applied to any lighting load, ventilation fan, electric heater, etc. In addition to operating and stopping as a control mode, in addition to this, the supplied power is adjusted like dimming in the lighting load And so on.

  Further, the charging control unit can design various concrete circuits by those skilled in the art based on the disclosure of the present invention, and is not limited to the above embodiment.

  Further, the charging control unit may be configured to combine the one that turns off the switching device by monitoring the voltage of the operating power supply unit and the one that periodically turns off the switching device. In this case, the cycle can be lengthened, or the switch device can be periodically turned off only when the voltage of the operating power supply unit falls below a predetermined value.

DESCRIPTION OF SYMBOLS 1 ... Power supply, 2 ... Load, 3 ... Load control apparatus, 5 ... Switch apparatus, 6 ... Operation power supply part, 10 ... Control part, 12, 20 ... Charge control part.

Claims (2)

A switch device that is provided in series with the load and the power source, and that is turned on when a control signal is input and that can supply power to the load;
An operation power supply unit such as an internal control circuit which is provided in parallel to the switch device and is charged with power supply power;
A charge control unit that monitors the voltage value of the power supply unit for operation and turns off the switch device for a short time when the voltage value falls below a predetermined value, and charges the power supply unit for operation with power supply power;
A load control device comprising: A switch device that is provided in series with the load and the power source, and that is turned on when a control signal is input and that can supply power to the load;
An operation power supply unit such as an internal control circuit which is provided in parallel to the switch device and is charged with power supply power;
A charge control unit that periodically turns off the switch device for a short time and charges the power supply unit for operation with power supply power;
A load control device comprising:

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