JP2022151888A - Dimming device - Google Patents

Abstract

To provide a dimming device having a simple mechanism that can reduce inrush current and perform accurate dimming control for a lighting load having a capacitor input type rectification circuit regardless of whether it adopts a positive phase control method or a reverse phase control method.SOLUTION: A dimming device 100 is configured to turn on/off bi-directional current of an AC power supply, and includes a bidirectional switch 10 that turns on when a voltage applied to a gate reaches or exceeds a predetermined threshold value, a control system circuit 20 that is electrically connected to the gate of the bidirectional switch and controls on/off switching of the bidirectional switch, and a charge/discharge speed control circuit 30 which is electrically connected between the gate and the control system circuit. The charge/discharge speed control circuit is configured to increase the reduction speed of the voltage to be applied to the gate when switching the bidirectional switch from off to on as compared with the increasing speed of the voltage to be applied to the gate when switching the bidirectional switch from off to on.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dimming device for dimming a lighting load.

2. Description of the Related Art Conventionally, a dimming device for dimming a lighting load connected to a commercial power supply has been known. In such a dimmer, when the absolute value of the AC voltage is greater than zero, the positive phase control method, in which the voltage is applied when the absolute value of the AC voltage is greater than zero, can be used. , to reduce the inrush current to the lighting load.

For example, Patent Literature 1 discloses a reverse phase control dimmer that can reduce the surge voltage applied to the switching element and can reduce the size and cost of conventional reverse phase control dimmers. do. This dimmer controls the timing of turning on/off the power applied to the lighting load, especially at the 0 point, by controlling the reverse phase of alternating current power with a semiconductor that is a switching element. This dimmer has an overcurrent protection function that turns off to the next zero point regardless of the control signal when the inrush current during lighting reaches a predetermined overcurrent level, and only when overcurrent flows during lighting. By increasing the time constant of the driving circuit for the switching element, the turn-off time of the switching element is extended, and the surge voltage applied to the switching element is reduced.

Also, in the mechanism for lighting LEDs in LED lighting, it has recently become mainstream to provide a rectifier circuit having a full-wave rectifier diode and a capacitor input type rectifier circuit having a smoothing section. The smoothing unit includes a capacitor connected between the output terminals of the rectifier circuit for smoothing the output voltage of the rectifier circuit, and a DC/DC converter connected between both ends of the capacitor for converting the voltage across the capacitor into a predetermined DC voltage. It consists of a conversion section. Even when the dimmer controls LED lighting in which such a mechanism is incorporated, a large inrush current may damage the capacitor, so it is important for the dimmer to reduce the inrush current.

Also, it is preferable that a dimming device for dimming LED lighting with a capacitor can be controlled to accurately change the light output of the lighting load in the first place. However, in a dimmer that performs reverse-phase control, the switching element changes from the ON state to the OFF state when the absolute value of the AC voltage is greater than zero. Since the electric charge is accumulated in the LED, the electric charge is supplied to the LED, resulting in a longer ON time and an inaccurate dimming control.

For example, Patent Literature 2 discloses a dimming device capable of changing the light output of an LED lighting device with a capacitor in the same way as changing the light output of an incandescent lamp. In this light control device, it is determined whether the lighting load is an LED lighting device or an incandescent lamp based on the DC voltage in a period from when the AC voltage is supplied to the rectifier circuit until a predetermined time elapses, When the lighting device is determined to be an LED lighting device, the conduction angles other than the conduction angles corresponding to the minimum and maximum values of the DC voltage are controlled to be smaller than when the lighting device is determined to be an incandescent lamp.

JP-A-2000-340371 Japanese Patent Application Laid-Open No. 2019-033098

However, in the above conventional technology, when dimming a lighting load having a capacitor input type rectifier circuit, it is necessary to provide a determination mechanism, resulting in an increase in cost.
Therefore, the present invention has been devised in view of such circumstances. To provide a dimming device having a simple mechanism capable of reducing and performing accurate dimming control.

In order to solve the above-mentioned problems, a dimmer is electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply to dim the lighting load, comprising: a bidirectional switch that turns on when the voltage applied to the control terminal reaches or exceeds a predetermined threshold; and the bidirectional switch is electrically connected to the control terminal of the bidirectional switch. A control unit for controlling switching between on and off, and a charge/discharge speed control circuit electrically connected between the control terminal and the control unit, wherein the charge/discharge speed control circuit turns off the bidirectional switch by the control unit. The speed of decrease of the voltage applied to the control terminal when switching the bidirectional switch from the on state to the off state is faster than the speed of increase of the voltage applied to the control terminal when switching from the on state to the on state. A dimmer is provided.
According to this, the rate of increase of the voltage applied to the control terminal when the charge/discharge speed control circuit switches the bidirectional switch from the off state to the on state is higher when the bidirectional switch is switched from the on state to the off state. By increasing the rate of decrease of the voltage applied to the control terminal, the inrush current can be reduced and It is possible to provide a dimming device capable of performing accurate dimming control.

Furthermore, when performing reverse phase control, the control unit switches the bidirectional switch from the ON state to the OFF state faster than the rate of increase of the voltage applied to the control terminal when switching the bidirectional switch from the OFF state to the ON state. It may be characterized in that it is configured to increase the rate of decrease of the voltage applied to the control terminal when switching.
According to this, when reverse phase control is performed, the bidirectional switch is switched from the on state to the off state compared to the rate of increase of the voltage applied to the control terminal when the bidirectional switch is switched from the off state to the on state. By increasing the rate of decrease of the voltage applied to the control terminal in this case, the bidirectional switch can be turned off quickly, reducing the increase in on time and enabling accurate dimming control.

Furthermore, when performing the positive phase control, the control unit changes the bidirectional switch from the off state to the on state faster than the voltage applied to the control terminal when switching the bidirectional switch from the on state to the off state. It may be characterized in that the speed of increase of the voltage applied to the control terminal when switching is slowed down.
According to this, when the positive phase control is performed, the bidirectional switch is switched from the off state to the on state compared to the decrease speed of the voltage applied to the control terminal when the bidirectional switch is switched from the on state to the off state. Inrush current to the lighting load can be reduced by slowing down the rate of increase of the voltage applied to the control terminal in this case.

Further, the charging/discharging speed control circuit includes a charging circuit through which current flows when the bidirectional switch is switched from the off state to the on state, and a discharging circuit through which current flows when the bidirectional switch is switched from the on state to the off state. , the impedance of the discharge circuit may be smaller than that of the charge circuit.
According to this, since the impedance of the discharge circuit in the charge/discharge speed control circuit is smaller than that of the charge circuit, either the positive phase control method or the reverse phase control method can be used for the lighting load having a capacitor input type rectifier circuit. Even so, it is possible to provide a simple mechanism capable of reducing rush current and performing accurate dimming control.

Furthermore, the charging circuit comprises a first resistor having one end connected to the control unit and the other end connected to a control terminal, and the discharging circuit comprises a diode having an anode connected to the control terminal and a cathode connected to one end of the second resistor. and a second resistor having one end connected to the cathode of the diode and the other end connected to the controller, and a parallel circuit of the first resistor.
According to this, by configuring the charge/discharge speed control circuit from such a circuit, the lighting load having a capacitor input type rectifier circuit can be controlled by either the positive phase control method or the reverse phase control method. It is possible to provide a dimming device with a simple mechanism capable of reducing current and performing accurate dimming control.

In order to solve the above-mentioned problems, a dimmer is electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply to dim the lighting load, comprising: a bidirectional switch configured to turn on/off the bidirectional switch; a capacitive element electrically connected to a control terminal of the bidirectional switch; a control unit for switching on/off; and a charge/discharge speed control circuit electrically connected between a connection point between the capacitive element and the control terminal and the control unit, wherein the charge/discharge speed control circuit Provided is a light control device configured to increase the discharging speed when the control unit discharges the capacitive element compared to the charging speed when the controller charges the capacitive element.
According to this, the charging/discharging speed control circuit is configured to increase the discharging speed when discharging the capacitive element compared to the charging speed when charging the capacitive element, so that the capacitor input type It is possible to provide a light control device capable of reducing inrush current and performing accurate light control for a lighting load having a rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. can.

Furthermore, the control unit is configured to increase the speed of discharging the capacitive element compared to the speed of charging the capacitive element when performing the reverse phase control. may be characterized.
According to this, when the reverse phase control is performed, the charge rate of the capacitive element is increased by setting the discharge rate to be faster than the charge rate to charge the capacitive element. is discharged quickly, reducing long on-time and enabling accurate dimming control.

Furthermore, the control unit is configured to slow down the charging speed when charging the capacitive element compared to the discharging speed when discharging the capacitive element when performing the positive phase control. may be characterized.
According to this, when the positive phase control is performed, the charging speed for charging the capacitive element is set to be slower than the discharging speed for discharging the capacitive element. Current can be reduced.

Furthermore, the charge/discharge speed control circuit includes a charge circuit through which current flows when the capacitive element is charged, and a discharge circuit through which current flows when the capacitive element is discharged. may be characterized by a small .
According to this, since the impedance of the discharge circuit in the charge/discharge speed control circuit is smaller than that of the charge circuit, either the positive phase control method or the reverse phase control method can be used for the lighting load having a capacitor input type rectifier circuit. Even so, it is possible to provide a simple mechanism capable of reducing rush current and performing accurate dimming control.

Further, the charging circuit includes a first resistor having one end connected to the control section and the other end connected to a connection point between the capacitive element and the control terminal, and the discharging circuit having an anode connected to the capacitive element and the control terminal. a series circuit composed of a diode having a cathode connected to one end of a second resistor and a second resistor having one end connected to the cathode of the diode and the other end connected to a controller; may be characterized by being composed of parallel circuits of
According to this, by configuring the charge/discharge speed control circuit from such a circuit, the lighting load having a capacitor input type rectifier circuit can be controlled by either the positive phase control method or the reverse phase control method. It is possible to provide a dimming device with a simple mechanism capable of reducing current and performing accurate dimming control.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a lighting load having a capacitor input type rectifier circuit can be accurately adjusted with reduced inrush current regardless of whether the positive phase control method or the reverse phase control method is used. It is possible to provide a light control device having a simple mechanism capable of performing light control.

BRIEF DESCRIPTION OF THE DRAWINGS The circuit diagram of the light modulation apparatus of 1st embodiment which concerns on this invention. (A) Ideal out-of-phase control waveforms and (B) out-of-phase control waveforms for a lighting load having a capacitor input rectifier circuit. (A) Waveform of anti-phase control for a lighting load having a capacitor input rectifier circuit, (B) Anti-phase control waveform for a lighting load having a capacitor input rectifier circuit in the light control device of the first embodiment according to the present invention waveform. (A) Waveform of positive phase control, (B) Inrush current when the speed of increase when turning the bidirectional switch from OFF to ON is not slowed in positive phase control in the prior art, (C) The first according to the present invention FIG. 10 shows an inrush current when the speed of increase in turning the bidirectional switch from off to on in positive phase control is slowed down in the dimmer of one embodiment. FIG. The circuit diagram of the light control apparatus of 2nd embodiment which concerns on this invention. A circuit diagram of a general MOSFET.

Each embodiment according to the present invention will be described below with reference to the drawings.
<First Embodiment>
A light control device 100 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. The dimming device 100 is a two-wire device that dims the LED fixture 200 (lighting load) having a capacitor input rectifier circuit, and is electrically connected in series between the LED fixture 200 and the AC power supply AC. . The LED fixture 200 includes an LED element (not shown) as a light source, an LED power system circuit for lighting the LED element, and a capacitor input type rectifier circuit. A capacitor input type rectifier circuit is a circuit that converts an alternating current from an alternating current power supply AC into a direct current. is configured as a circuit for smoothing the waveform input to the The AC power supply AC is, for example, a single-phase 100 V, 60 Hz/50 Hz commercial power supply.

The light control device 100 includes a bidirectional switch 10 , a control system circuit 20 (control section), a charge/discharge speed control circuit 30 and an input section 40 . The bidirectional switch 10 consists of two elements, a first switching element Q1 and a second switching element Q2, electrically connected in series between the LED fixture 200 and the AC power supply AC. For example, each of the switch elements Q1 and Q2 is a semiconductor switch element composed of an enhancement-type n-channel MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor).

The bidirectional switch 10 is configured to switch on/off the bidirectional current of the alternating current power supply AC. Specifically, the switching elements Q1 and Q2 are connected to each other at the sources of the switching elements Q1 and Q2, so-called anti-series connection. A drain of the switching element Q1 is connected to the AC power supply AC, and a drain of the switching element Q2 is connected to the LED fixture 200. The sources of both switch elements Q1 and Q2 are connected to the ground of the light control device 100 . In the bidirectional switch 10, when an alternating voltage is applied from an alternating current power source AC, current flows in the positive direction if the switching element Q1 is in the ON state in the half cycle in which the alternating voltage is positive, that is, the drain of the switching element Q1 is positive. . Conversely, when an alternating voltage is applied from the alternating current power supply AC, the bidirectional switch 10 operates in the negative direction if the switch element Q2 is in the ON state in a half cycle in which the AC voltage is negative, that is, the drain of the switch element Q2 is positive. current flows.

The switching elements Q1 and Q2 of the bidirectional switch 10 are turned on when the voltage applied to the gate (control terminal) reaches or exceeds a predetermined threshold. As shown in FIG. 6, the switch elements Q1 and Q2 generally have parasitic capacitive elements inside between their respective terminals. The switch elements Q1 and Q2 have, for example, a capacitor Cgs between the gate/source, a capacitor Cdg between the gate/drain, and a capacitor Cds between the source/drain. The switch elements Q1 and Q2 are turned on when a voltage is applied to the gates, charge is accumulated in the capacitor Cgs, and the predetermined threshold voltage is exceeded.

The input unit 40 receives a signal representing a dimming level from an operation unit operated by a user, and outputs the signal to the control system circuit 20 as a dimming signal. A dimming signal is a numerical value or the like that specifies the magnitude of the light output of the LED fixture 200 . The operation unit is configured to receive a user's operation and output a signal representing the dimming level to the input unit 40, and is, for example, a rotary switch that is a variable resistor.

The control system circuit 20 has a microcomputer that controls ON/OFF switching of the bidirectional switch 10 . A program for controlling the bidirectional switch 10 is stored in the microcomputer, and the function of the control system circuit 20 is realized by the microcomputer executing this program. The control system circuit 20 also has a circuit that detects the phase of the AC voltage applied to the light control device 100, that is, the zero cross point of the AC voltage and the polarity (positive polarity, negative polarity) of the AC voltage. The control system circuit 20 has a zero-crossing point when the AC voltage shifts from a negative half-cycle to a positive half-cycle, and a zero-crossing point when the AC voltage shifts from the positive half-cycle to the negative half-cycle. Detect points.

The control system circuit 20 controls the bidirectional switch 10 based on this detection signal and the dimming signal from the input section 40 . The control system circuit 20 separately controls the switch elements Q1 and Q2 by the control signals S1 and S2. The control system circuit 20 is electrically connected to the gates of the switch elements Q1 and Q2 of the bidirectional switch 10 via charge/discharge speed control circuits 31 and 32, and is adjusted by outputting control signals S1 and S2 individually. Light control.

The control system circuit 20 has a dimming power supply unit (not shown) including an electrolytic capacitor electrically connected to the AC power supply line via a diode. The ground of the dimming power supply is electrically connected to the connection point of the parasitic diodes provided in each of the switch elements Q1 and Q2. As a result, the applied AC voltage is full-wave rectified in the diode bridge composed of these diodes and the parasitic diode, and supplied to the dimming power supply unit. Therefore, when the bidirectional switch 10 is in the OFF state, a full-wave rectified AC voltage is applied to the dimming power supply. The dimming power supply unit smoothes the full-wave rectified AC voltage and supplies an operating voltage for driving the control system circuit 20 and the switch elements Q1 and Q2.

The charging/discharging speed control circuits 31 and 32 are electrically connected between the gates of the switch elements Q1 and Q2 and the control system circuit 20 . The charging/discharging speed control circuits 31 and 32 include a charging circuit (a turn-on circuit indicated by a solid line arrow) through which current flows when the bidirectional switch 10 is switched from the off state to the on state, and a turn-on circuit in which the bidirectional switch 10 is switched from the on state to the off state. and a discharge circuit (turn-off circuit indicated by the dotted arrow) through which current flows when switching.

The charging circuit of the charging/discharging speed control circuit 31 is composed of a resistor R1 (first resistor) having one end connected to the control system circuit 20 and the other end connected to the gate (control terminal) of the switch element Q1. The discharge circuit of the charge/discharge speed control circuit 31 includes a diode D1 whose anode is connected to the gate of the switch element Q1, whose cathode is connected to one end of a resistor R2 (second resistor), and whose one end is connected to the cathode of the diode D1 and whose other end is connected to It is composed of a series circuit composed of a resistor R2 connected to the control system circuit 20 and a parallel circuit composed of a resistor R1.

The charging circuit of the charging/discharging speed control circuit 32 is composed of a resistor R3 (first resistor) having one end connected to the control system circuit 20 and the other end connected to the gate (control terminal) of the switch element Q2. The discharge circuit of the charge/discharge speed control circuit 32 includes a diode D2 whose anode is connected to the gate of the switch element Q2, whose cathode is connected to one end of a resistor R4 (second resistor), and whose one end is connected to the cathode of the diode D2 and whose other end is connected to It is composed of a series circuit composed of a resistor R4 connected to the control system circuit 20 and a parallel circuit composed of a resistor R3.

In the charge/discharge speed control circuit 30 having such a configuration, the charging circuit that flows when the gates of the switch elements Q1 and Q2 are turned on consists of only the resistors R1 and R3. Since the discharging circuit through which current flows is composed of a parallel circuit of resistors R1 and R2 and a parallel circuit of resistors R3 and R4, the impedance of the discharging circuit is smaller than that of the charging circuit. In other words, the charging/discharging speed control circuit 30 is faster than the rate of increase in the voltage applied to the gates of the switching elements Q1 and Q2 when the control system circuit 20 switches the bidirectional switch 10 from the OFF state to the ON state. 10 is configured to increase the rate of decrease of the voltage applied to the gates of the switch elements Q1 and Q2 when switching from the ON state to the OFF state.

Here, the waveforms of the anti-phase control will be described with reference to FIGS. 2 and 3. FIG. The reverse phase control controls the bidirectional switch 10 so that the bidirectional switch 10 is switched from the ON state to the OFF state when a variable time corresponding to the dimming level has elapsed from the start point of the half cycle of the AC voltage of the AC power supply AC. do. In dimming control by reverse phase control, dimming control is performed by turning on the bidirectional switch 10 at the zero-crossing point and turning it off when the ON time corresponding to the dimming level has elapsed. This figure (A) shows an ideal anti-phase control waveform in which the voltage drops almost vertically when turned off, that is, the voltage drop speed is very fast. If the lighting load is an incandescent bulb, the waveform will be like this because the ON period of the voltage can be accurately grasped. If dimming control can be performed with such a waveform, accurate dimming control becomes possible.

On the other hand, when the LED fixture 200 equipped with a capacitor input type rectifier circuit is the lighting load, as shown in FIG. The voltage decrease speed is gentle, that is, the voltage decrease speed is slow. Therefore, there is a difference between the timing when the bidirectional switch 10 is turned off and the timing when the voltage of the actual LED fixture 200 becomes zero. difficult to control.

Compared to the case without the charging/discharging speed control circuit 30 (FIG. 3(A)), the case with the charging/discharging speed control circuit 30 (FIG. 3(B)) allows the bidirectional switch 10 to turn on from the ON state. Since it is configured to increase the rate of decrease of the voltage applied to the gates of the switch elements Q1 and Q2 when switching to the off state, the timing when the bidirectional switch 10 is turned off and the voltage at the actual LED fixture 200 are zero. The deviation of the timing to become smaller becomes smaller, and accurate dimming control can be approached.

In this way, when the reverse phase control is performed, the speed of increasing the voltage applied to the gates of the switching elements Q1 and Q2 when the bidirectional switch 10 is switched from the OFF state to the ON state is relatively high. By speeding up the reduction speed of the voltage applied to the gate when switching from the off state to the off state, the bidirectional switch 10 is quickly turned off, reducing the on time and enabling accurate dimming control. can be

Also, the waveforms of the positive phase control will be described with reference to FIG. The positive phase control continues the off state from the beginning of the half cycle of the alternating voltage of the alternating current power supply AC, and the two-way switch 10 switches from the off state to the on state at the time when the variable time according to the dimming level remains. The direction switch 10 is controlled (this figure (A)). In dimming control by positive phase control, dimming control is performed by turning on the bidirectional switch 10 at a timing that secures an ON period corresponding to the dimming level and turning it off at a zero cross point. In this case, since the voltage may be high at the timing when the bidirectional switch 10 is turned on, the rush current to the LED fixture 200 may increase as shown in FIG. However, when the charging/discharging speed control circuit 30 is provided ((C) in this figure), the decrease speed of the voltage applied to the gates of the switching elements Q1 and Q2 when switching the bidirectional switch 10 from the ON state to the OFF state is Therefore, by slowing down the rate of increase of the voltage applied to the gates of the switch elements Q1 and Q2 when the bidirectional switch 10 is switched from the off state to the on state, the inrush current to the LED fixture 200 can be reduced.

Note that even in the case of reverse phase control by the charge/discharge speed control circuit 30, the rate of increase of the voltage applied to the gates of the switch elements Q1 and Q2 when switching the bidirectional switch 10 from the off state to the on state is relatively It's slower, but it doesn't cause problems. Also, in the positive phase control, the charge/discharge speed control circuit 30 reduces the voltage applied to the gates of the switch elements Q1 and Q2 when switching the bidirectional switch 10 from the ON state to the OFF state. It's faster but doesn't cause any problems.

As described above, compared to the rate of increase of the voltage applied to the gates of the switch elements Q1 and Q2 when the charge/discharge speed control circuit 30 switches the bidirectional switch 10 from the off state to the on state, the bidirectional switch 10 is turned on. By increasing the rate of decrease of the voltage applied to the gates of the switch elements Q1 and Q2 when switching from to OFF state, the LED fixture 200 having a capacitor input type rectifier circuit is controlled by a positive phase control method or a reverse phase control method. In either case, it is possible to provide the dimming device 100 capable of reducing the rush current and performing accurate dimming control. In addition, since the impedance of the discharge circuit in the charge/discharge speed control circuit 30 is smaller than that of the charge circuit, the LED fixture 200 having a capacitor input type rectifier circuit can be either a positive phase control method or a reverse phase control method. Even so, it is possible to provide a simple mechanism capable of reducing inrush current and performing accurate dimming control.

<Second embodiment>
The light control device 100A in this embodiment will be described with reference to FIG. In order to avoid duplication of description, the same reference numerals are given to the same components as in the above embodiment, and the description thereof is omitted. The dimming device 100A is a dimming device for dimming an LED fixture 200 (lighting load) having a capacitor input rectifier circuit, and includes a bidirectional switch 10, a control system circuit 20 (control unit), and charge/discharge speed control. A circuit 30 , an input section 40 , and an oscillation suppression circuit 50 are provided.

The oscillation suppression circuit 50 is a series circuit of a capacitor C1 and a resistor R5 and a series circuit of a capacitor C2 and a resistor R6. One side of the capacitor C1 and the capacitor C2 (capacitive element) is connected to the connection point between the charge/discharge speed control circuit 30 and the gates of the switching elements Q1 and Q2, and one side of the resistor R5 and the resistor R6 is connected to the ground. It is When the control system circuit 20 turns off/on the switch elements Q1 and Q2, the oscillation suppressing circuit 50 generates an oscillating voltage between the gate and the source due to a sudden change in voltage or current between the drain and the source, causing oscillation. However, this is a circuit for suppressing this.

In the configuration of this embodiment, since the capacitor Cgs is provided between the gate/source of the switch elements Q1 and Q2 (FIG. 6), the capacitors C1 and C2 are externally connected between the gate/source of the switch elements Q1 and Q2. It is positioned as a capacitive element connected in parallel with the capacitor Cgs. Therefore, as compared with the above-described embodiment, the voltage is applied to the gate and the charge is accumulated in the capacitor Cgs at a slower rate. to be late.

However, when comparing the capacitance of the capacitor Cgs, which is the parasitic capacitance between the gate and source of the switch elements Q1 and Q2, and the capacitance of the capacitors C1 and C2, which are capacitive elements connected externally, it is found that even the rated drain current is However, the latter has 5 to 10 times greater capacity. Therefore, when the light control device 100A has the oscillation suppressing circuit 50, the switching speed of the switching elements Q1 and Q2 depends substantially on the capacities of the externally connected capacitors C1 and C2. Then, it can be said that the control system circuit 20 switches ON/OFF of the bidirectional switch 10 by controlling charging and discharging of the capacitors C1 and C2.

Then, in order to switch the bidirectional switch 10 from the off state to the on state, the charge/discharge speed control circuit 30 reduces the charging speed of the bidirectional switch 10 compared to the charging speed when the control system circuit 20 charges the capacitors C1 and C2. is configured to increase the discharge speed when the control system circuit 20 discharges the capacitors C1 and C2 in order to switch from the ON state to the OFF state. The charging speed means the speed at which the voltage across the capacitive element increases, and the discharging speed means the speed at which the voltage across the capacitive element decreases. According to this, the inrush current can be reduced and accurate dimming control can be performed for the LED fixture 200 having the capacitor input type rectifier circuit in either the positive phase control method or the reverse phase control method. 100 A of light control apparatuses which can be performed can be provided.

The charge/discharge speed control circuit 30 includes a charging circuit through which current flows when charging the capacitors C1 and C2, and a discharging circuit through which current flows when discharging the capacitors C1 and C2. It may be characterized by a low circuit impedance. According to this, inrush current can be reduced and accurate dimming control can be performed for a lighting load having a capacitor input type rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. A simple mechanism can be provided.

The charging circuit has one end connected to the control circuit 20 and the other end connected to the connection point between the capacitors C1, C2 and the gates of the switch elements Q1, Q2. to the connection points between the capacitors C1 and C2 and the relevant gates, diodes D1 and D2 whose cathodes are connected to one ends of the resistors R2 and R4, one end to the cathodes of the diodes D1 and D2, and the other end to the control system circuit 20. It may be characterized in that it is composed of a series circuit composed of connected resistors R2 and R4 and a parallel circuit composed of resistors R1 and R3. According to this, inrush current can be reduced and accurate dimming control can be performed for a lighting load having a capacitor input type rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. 100 A of light control apparatuses provided with a simple mechanism can be provided.

It should be noted that the present invention is not limited to the exemplified embodiments, and can be implemented with a configuration that does not deviate from the content described in each item of the claims. That is, although the present invention has been particularly illustrated and described primarily with respect to particular embodiments, there may be modifications, quantities, Various modifications can be made to other detailed configurations by those skilled in the art.

REFERENCE SIGNS LIST 100 dimmer 10 bidirectional switch 20 control system circuit (control unit)
30 charge/discharge speed control circuit 40 input unit 50 oscillation suppression circuit 200 LED fixture (lighting load)

In order to solve the above-mentioned problems, a dimmer is electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply to dim the lighting load, comprising: a bidirectional switch that turns on when the voltage applied to the control terminal reaches or exceeds a predetermined threshold; and the bidirectional switch is electrically connected to the control terminal of the bidirectional switch. A control unit for controlling switching between on and off, and a charge/discharge speed control circuit electrically connected between the control terminal and the control unit, wherein the charge/discharge speed control circuit turns off the bidirectional switch by the control unit. The speed of decrease of the voltage applied to the control terminal when switching the bidirectional switch from the on state to the off state is faster than the speed of increase of the voltage applied to the control terminal when switching from the on state to the on state. The charge/discharge speed control circuit includes a charge circuit through which current flows when the bidirectional switch is switched from the off state to the on state, and a discharge circuit through which current flows when the bidirectional switch is switched from the on state to the off state. the impedance of the discharge circuit is smaller than that of the charge circuit, the charge circuit is composed of a first resistor having one end connected to the control section and the other end connected to the control terminal; the discharge circuit has an anode connected to the control terminal; From a series circuit composed of a diode whose cathode is connected to one end of a second resistor, a second resistor whose one end is connected to the cathode of the diode and the other end to a control unit, and a parallel circuit of the first resistor A constructed dimmer is provided.
According to this, the rate of increase of the voltage applied to the control terminal when the charge/discharge speed control circuit switches the bidirectional switch from the off state to the on state is higher when the bidirectional switch is switched from the on state to the off state. By increasing the rate of decrease of the voltage applied to the control terminal, the inrush current can be reduced and It is possible to provide a dimming device capable of performing accurate dimming control. Furthermore, in the charge/discharge speed control circuit, the impedance of the discharge circuit is smaller than that of the charge circuit. , it is possible to provide a simple mechanism capable of reducing inrush current and performing accurate dimming control. In addition, by configuring the charge/discharge speed control circuit with such a circuit, inrush current can be reduced for lighting loads with a capacitor input rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. Moreover, it is possible to provide a dimming device having a simple mechanism that can perform accurate dimming control.

In order to solve the above-mentioned problems, a dimmer is electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply to dim the lighting load, comprising: a bidirectional switch configured to turn on/off the bidirectional switch; a capacitive element electrically connected to a control terminal of the bidirectional switch; a control unit for switching on/off; and a charge/discharge speed control circuit electrically connected between a connection point between the capacitive element and the control terminal and the control unit, wherein the charge/discharge speed control circuit The charging /discharging speed control circuit is configured to increase the discharging speed when the control unit discharges the capacitive element compared to the charging speed when charging the capacitive element. and a discharge circuit through which current flows when discharging the capacitive element. The impedance of the discharge circuit is smaller than that of the charge circuit, and one end of the charge circuit , the other end of which is connected to a connection point between the capacitive element and the control terminal. The discharge circuit has an anode connected to the connection point between the capacitive element and the control terminal and a cathode connected to one end of the second resistor. and a second resistor connected at one end to the cathode of the diode and the other end to the controller, and a parallel circuit of the first resistor. is provided.
According to this, the charging/discharging speed control circuit is configured to increase the discharging speed when discharging the capacitive element compared to the charging speed when charging the capacitive element, so that the capacitor input type It is possible to provide a light control device capable of reducing inrush current and performing accurate light control for a lighting load having a rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. can. Furthermore, in the charge/discharge speed control circuit, the impedance of the discharge circuit is smaller than that of the charge circuit. , it is possible to provide a simple mechanism capable of reducing inrush current and performing accurate dimming control. In addition, by configuring the charge/discharge speed control circuit with such a circuit, inrush current can be reduced for lighting loads with a capacitor input rectifier circuit, regardless of whether the positive phase control method or the reverse phase control method is used. Moreover, it is possible to provide a dimming device having a simple mechanism that can perform accurate dimming control.

Claims (10)

A light control device electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply for dimming the lighting load,
a bidirectional switch configured to switch on/off the bidirectional current of the AC power supply and turned on when the voltage applied to the control terminal reaches or exceeds a predetermined threshold;
a control unit electrically connected to the control terminal of the bidirectional switch and controlling on/off switching of the bidirectional switch;
a charge/discharge speed control circuit electrically connected between the control terminal and the control unit;
with
The charge/discharge speed control circuit switches the bidirectional switch from the on state to the off state in comparison with the rate of increase of the voltage applied to the control terminal when the control unit switches the bidirectional switch from the off state to the on state. configured to increase the rate of decrease of the voltage applied to the control terminal when switching to
dimmer. When the reverse phase control is performed, the control unit turns off the bidirectional switch from the on state compared to the rate of increase of the voltage applied to the control terminal when switching the bidirectional switch from the off state to the on state. 2. The light control device according to claim 1, wherein the light control device is configured to speed up the decrease speed of the voltage applied to the control terminal when switching to the state. When the control unit performs positive phase control, the control unit turns on the bidirectional switch from an off state in comparison with a decrease speed of the voltage applied to the control terminal when switching the bidirectional switch from an on state to an off state. 2. The light control device according to claim 1, wherein the speed of increase of the voltage applied to the control terminal is slowed when switching to the state. The charge/discharge speed control circuit includes a charge circuit through which current flows when the bidirectional switch is switched from an off state to an on state, and a discharge circuit through which current flows when the bidirectional switch is switched from an on state to an off state. The light control device according to any one of claims 1 to 3, wherein the impedance of the discharge circuit is smaller than that of the charge circuit. The charging circuit comprises a first resistor having one end connected to the control unit and the other end connected to the control terminal,
The discharge circuit comprises a diode having an anode connected to the control terminal and a cathode connected to one end of a second resistor, and the second resistor having one end connected to the cathode of the diode and the other end connected to the control section. 5. The light control device according to claim 4, comprising a series circuit and a parallel circuit of the first resistor. A light control device electrically connected in series between a lighting load having a capacitor input type rectifier circuit and an AC power supply for dimming the lighting load,
a bidirectional switch configured to switch bidirectional current of the AC power supply on and off;
a capacitive element electrically connected to a control terminal of the bidirectional switch;
a control unit for switching on/off of the bidirectional switch by controlling charging and discharging of the capacitive element;
a charge/discharge speed control circuit electrically connected between a connection point between the capacitive element and the control terminal and the controller;
with
The charging/discharging speed control circuit is configured to increase the discharging speed when the control unit discharges the capacitive element compared to the charging speed when the control unit charges the capacitive element. has been
dimmer. The control unit is configured to increase a discharging speed when discharging the capacitive element compared to a charging speed when charging the capacitive element when performing reverse phase control. The light control device according to claim 6, characterized in that: The control unit is configured to slow the charging speed when charging the capacitive element compared to the discharging speed when discharging the capacitive element when performing positive phase control. The light control device according to claim 6, characterized in that: The charge/discharge speed control circuit includes a charge circuit through which current flows when the capacitive element is charged, and a discharge circuit through which current flows when the capacitive element is discharged. 9. The light control device according to any one of claims 6 to 8, wherein the impedance of the circuit is small. The charging circuit includes a first resistor having one end connected to the control unit and the other end connected to a connection point between the capacitive element and the control terminal,
The discharge circuit includes a diode having an anode connected to a connection point between the capacitive element and the control terminal, a cathode connected to one end of a second resistor, one end connected to the cathode of the diode, and the other end connected to the control unit. 10. The light control device according to claim 9, comprising a series circuit configured with the connected second resistor and a parallel circuit configured with the first resistor.

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