JP2011044353A - Dimmer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make common operating feeling of a dimming operation by enabling lighting at a dimming ratio in accordance with dimming operations. <P>SOLUTION: The dimmer is provided with a phase control element T for controlling supply to a lighting load of power obtained from an alternating-current power source through on-off operations, first control means VR1, C1 controlling a conduction angle of the phase control element with signals given based on the dimming operation, and second control means 12, C2, S for correcting the conductive angle of the phase control element in order to have the signal based on the dimming operation and an actual dimming ratio of the lighting load correspond at one to one. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dimmer that performs phase control type dimming.

  Conventionally, a lighting system in which a power source, a lighting load fixture, and a controller are connected in series and lighting control is performed on the lighting load fixture by the controller may be employed. In such an illumination system, electric power is supplied to the illumination load device using a two-wire wiring. And dimmer control is performed because a dimmer adjusts the electric power supplied to an illumination load instrument by a phase control system.

  In such a two-wire illumination system, a bidirectional three-terminal thyristor (hereinafter referred to as triac) or the like is used as a switching element that performs power supply phase control. By turning the triac on and off, the power supply from the power source to the lighting load is controlled to perform dimming. That is, by turning on the triac after the delay time based on the dimming control from the zero cross point of the power supply voltage, the power supply time to the lighting load is controlled and dimming is performed. Such a phase control method is described in detail in Patent Document 1.

  The delay time until the triac is turned on is controlled by a time constant circuit including a variable resistor and a capacitor. The capacitor of this time constant circuit is charged during the off period of the triac, and the triac is turned on when the terminal voltage of the capacitor reaches a predetermined value. The user can arbitrarily set the brightness of the illumination by changing the resistance value of the variable resistor by operating the knob of the volume constituting the variable resistor.

JP 2004-273267 A

  As described above, the delay time is determined by the time constant circuit of the variable resistor and the capacitor. If this delay time is set to a half cycle or more of the power cycle, the TRIAC is always non-conductive and the lighting load is not lit. That is, the delay time capable of dimming is at most a half cycle of the power supply cycle.

  However, the power supply frequency varies from region to region. For example, if the resistance value giving the maximum delay time is 60Ω in the region where the power supply voltage is 50 Hz, the resistance value giving the maximum delay time is 50Ω in the region where the power supply voltage is 60 Hz. If the resistance value is set to 60Ω in an area where the power supply voltage is 60 Hz, the delay time exceeds the half cycle of the power supply cycle.

  That is, in a dimmer that controls dimming by operating a knob of a volume that constitutes a variable resistor, the brightness of the illumination light with respect to the operating position of the knob of the volume has an area where the power supply frequency is 50 Hz and an area of 60 Hz Further, in a region where the power supply frequency is 60 Hz, a part of the volume knob does not contribute to brightness adjustment and cannot be used.

  In addition, the power supply voltage of the power supply may fluctuate. In this case, the load current also fluctuates due to fluctuations in the power supply voltage, and the brightness changes. Further, in the phase control, the delay time due to the time constant circuit also fluctuates due to fluctuations in the power supply voltage, increasing the change in brightness. That is, when the power supply voltage fluctuates, the relationship between the operation position of the volume knob and the brightness of the illumination light changes.

  Various types of lighting load appliances are conceivable. Due to differences in characteristics among different types of lighting load fixtures, the dimming rate may be different for the same conduction angle of power supply control, and the range of conduction angles that can be dimmed may be different. For this reason, the light control rate with respect to the operation position of the knob of a volume may change for every kind of lighting load fixture.

  Thus, in the conventional dimmer, the dimming operation for obtaining the same dimming rate may be different, and there is a problem that it may not be possible to operate with a common operational feeling. .

  The present invention has been made in view of such a problem, and provides a dimmer capable of improving operability by making the dimming operation for obtaining the same dimming rate a common operation feeling. The purpose is to do.

  The dimmer according to claim 1 is connected in series to the AC power source that generates power for lighting the lighting load together with the lighting load, and the power obtained from the AC power source is turned on and off to the lighting load. A phase control element that controls supply; a first control unit that controls a conduction angle of the phase control element based on a dimming operation; and a one-to-one correspondence between the dimming operation and the dimming rate of the illumination load. And a second control means for correcting a conduction angle of the phase control element.

  The second control means includes frequency detection means for detecting the power supply frequency of the AC power supply, so that the conduction angle of the phase control element is the same regardless of the power supply frequency, and the light control according to the light control operation is performed. Allows lighting at rate.

  In addition, by providing a current detection means for detecting the load current of the lighting load as the second control means, the conduction angle of the phase control element is made the same regardless of the power supply voltage fluctuation, etc. Enables lighting at the appropriate dimming rate.

  Further, as the second control means, by including the voltage current detection means for detecting the load voltage and load current of the lighting load, regardless of the characteristics of the lighting load, the conduction angle of the phase control element is the same, Enable lighting at dimming rate according to dimming operation.

  According to invention of Claim 1, it has the effect that operativity can be improved by making the light control operation for obtaining the same light control rate into a common operation feeling.

  According to the invention of claim 2, by providing the frequency detection means for detecting the power supply frequency, the conduction angle of the phase control element is made the same regardless of the power supply frequency, and the light control rate according to the light control operation Enable lighting.

  According to the invention of claim 3, by providing the current detection means for detecting the load current, the conduction angle of the phase control element is made the same regardless of the power supply voltage fluctuation or the like, and the dimming rate according to the dimming operation Enables lighting with.

  According to the invention of claim 4, by providing the voltage / current detection means for detecting the load voltage and the load current, the conduction angle of the phase control element is made the same regardless of the characteristics of the illumination load, and the dimming operation is performed. It enables lighting at a dimming rate.

The circuit diagram which shows the lighting fixture provided with the dimmer which concerns on the 1st Embodiment of this invention. FIG. 4 is a waveform diagram for explaining the control of the AC power supply voltage of the power supply 11 and the triac T with time on the horizontal axis and voltage on the vertical axis. The circuit diagram which shows the modification of this invention. The circuit diagram which shows the 2nd Embodiment of this invention. The circuit diagram which shows the 3rd Embodiment of this invention. The wave form diagram for demonstrating the operation | movement of 3rd Embodiment. The circuit diagram which shows the 4th Embodiment of this invention. The graph which shows the characteristic of load current and load voltage at the time of taking an incandescent lamp or an LED bulb | bulb as the lighting load fixture 13, taking a voltage on a horizontal axis and taking a current on a vertical axis. FIG. 5 is a waveform diagram for explaining the relationship between the AC power supply voltage of the power supply 11 and the conduction angle, with time on the horizontal axis and voltage on the vertical axis. The flowchart for demonstrating operation | movement of 4th Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a circuit diagram showing a dimmer according to a first embodiment of the present invention and a lighting load fixture that is dimmed and controlled by the dimmer.

  The dimmer shown in FIG. 1 supplies power from a power source 11 to a lighting load fixture 13 connected between terminals I1 and I2 by a two-wire wiring. A triac T that performs phase control is provided between the power source 11 and the lighting load device 13 connected to the terminals I1 and I2, and the power source 11, the triac T, and the lighting load device 13 are connected in series. The power source 11 generates an AC power supply voltage such as AC 100V. In this embodiment, an example in which a triac is used as an element for performing phase control will be described. However, a thyristor that is a self-holding element may be used as in the triac.

  A triac T is connected between the AC power supply 11 and the terminal I1, and a series circuit of a variable resistor VR1 and a capacitor C1 is connected to the triac T in parallel. The connection point between the variable resistor VR1 and the capacitor C1 as the first control means is connected to the control end of the triac T via a bidirectional diode (hereinafter referred to as a diac) TD.

  In the present embodiment, a series circuit of a capacitor C2 and an analog switch S is connected in parallel with the capacitor C1. A frequency discrimination circuit 12 is connected in parallel with the triac T. The frequency discriminating circuit 12 is supplied with an AC voltage from the power supply 11, determines the frequency of the AC voltage (power supply frequency), and controls the analog switch S based on the determination result. The analog switch S is ON / OFF controlled according to the frequency discrimination result, and when it is ON, the capacitor C2 is connected in parallel to the capacitor C1. The frequency discriminating circuit 12, the capacitor C2, and the analog switch S constitute a second control means. The variable resistor VR1 and the capacitors C1 and C2 constitute a time constant circuit that determines the dimming rate of the lighting load fixture 13.

  Next, the operation of the embodiment configured as described above will be described with reference to FIG. FIG. 2 is a waveform diagram for explaining the control of the AC power supply voltage of the power supply 11 and the triac T with time on the horizontal axis and voltage on the vertical axis. 2A shows an example in which the power supply frequency is 50 Hz, and FIG. 2B shows an example in which the power supply frequency is 60 Hz.

  Now, in order to simplify the description, it is assumed that the analog switch S is off. In this case, the time constant circuit is configured by only the variable resistor VR1 and the capacitor C1. The variable resistor VR1 is set to a resistance value corresponding to dimming control. When the triac T is off, the capacitor C1 is charged by the AC power supply 11 via the variable resistor VR1. After a predetermined delay time based on the time constants of the variable resistor VR1 and the capacitor C1 from the start of charging of the capacitor C1, the terminal voltage of the capacitor C1 reaches a voltage for turning on the diac TD. As a result, a pulse is generated in the diac TD, and the pulse is supplied to the control end of the triac T. Thus, the triac T becomes conductive.

  The triac T is supplied with current from the power source 11 and maintains conduction. During the on period of the triac T, the capacitor C1 is discharged, and the triac T is turned off when the holding current is not maintained. When the polarity of the power supply voltage applied to the triac T is reversed, the capacitor C1 is charged again, and the diac TD is turned on after the delay time. Thus, the triac T is turned on after a predetermined delay time from the zero cross point of the AC power supply voltage. Thereafter, the same operation is repeated, and power from the power source 11 is supplied to the lighting load device 13 through the triac T in a period excluding the delay time from the power cycle (hereinafter referred to as a power supply period). The electric power supplied to the lighting load device 13 changes according to the on time of the triac T. As a result, the brightness of the lighting load device 13 is controlled to be dimmed.

  The AC waveform in FIG. 2 indicates the voltage generated by the power supply 11, and the shaded portion indicates the power supply period in which the triac T is conducted. 2A shows an example in which the power supply frequency of the power supply 11 is 50 Hz, and FIG. 2B shows an example in which the power supply frequency is 60 Hz.

The dimming rate of the lighting load device 13 depends on the ratio of the power supply period (or delay time) to the half cycle of the AC waveform in FIG. Therefore, when the power supply frequency is 60 Hz, by setting a delay time that is 5/6 of the delay time when the power supply frequency is 50 Hz, dimming with the same brightness is possible regardless of the power supply frequency. It is.
The power supply frequency is determined by the frequency discrimination circuit 12. The frequency discriminating circuit 12 turns the analog switch S on and off according to the determination result of the power supply frequency.

  In the present embodiment, the capacitor C2 is provided in the time constant circuit so that the same dimming rate can be obtained by the same resistance value of the variable resistor VR1 regardless of the power supply frequency. The capacitor C2 is connected in parallel to the capacitor C1 when the analog switch S is turned on.

  The delay time depends on the time constant of the time constant circuit. Assuming that the capacitance of the capacitor C1 is C1, the combined capacitance of the capacitors C1 and C2 is Cx, and the resistance value of the variable resistor VR1 is R, the time constant when the analog switch S is off is R · C1, The time constant in this case is R · Cx. That is, the delay time is proportional to the resistance value R or the capacitances C1 and Cx.

  For example, the frequency discriminating circuit 12 turns off the analog switch S when the power supply frequency is 50 Hz, and turns on the analog switch S when the power supply frequency is 60 Hz. In this case, by setting the capacitances of the capacitors C1 and C2 so that Cx = (5/6) C1, the same dimming can be performed with the same resistance value of the variable resistor VR1 regardless of the power supply frequency. Rate can be obtained.

  Thus, in the present embodiment, the power supply frequency is discriminated and the constant of the time constant circuit is changed based on the discrimination result. Thereby, the same dimming rate can be obtained with the same resistance value regardless of the power supply frequency. In other words, even when used in regions with different power supply frequencies, the relationship between the volume knob operation and the dimming rate that make up the variable resistance value can be shared, and dimming operations with a common feeling of operation are possible. Can be.

(Modification)
FIG. 3 is a circuit diagram showing a modification of the present invention. In FIG. 3, the same components as those of FIG.
The circuit of FIG. 3 differs from the embodiment of FIG. 1 in that a variable resistor VR2 is employed instead of the capacitor C2. A series circuit of a variable resistor VR2 and an analog switch S is provided in parallel with the variable resistor VR1. Only when the analog switch S is on, the variable resistors VR1 and VR2 are connected in parallel, and the time constant of the time constant circuit is determined by the variable resistors VR1 and VR2 and the capacitor C1.

  That is, in the example of FIG. 1, the capacitance of the capacitor of the time constant circuit is changed according to the power supply frequency, whereas in this modification, the resistance value of the time constant circuit is changed according to the power supply frequency. It is. By setting the ratio of the resistance value R of the variable resistor VR1 and the combined resistance value Rx of the variable resistors VR1 and VR2 according to the ratio of the power supply frequencies, the power supply frequency is controlled regardless of the power supply frequency. The same dimming rate can be obtained with a common operational feeling. Note that it is desirable that the resistance values of the variable resistors VR1 and VR2 can be controlled simultaneously by a common knob, for example.

(Second Embodiment)
FIG. 4 is a circuit diagram showing a second embodiment of the present invention. In FIG. 4, the same components as those of FIG.
This embodiment is an example in which a thyristor is used as a self-holding element for performing phase control.

  Also in FIG. 4, a dimmer 10 that performs phase control for dimming is connected between the power supply 11 and the lighting load fixture 13 connected to the terminals I <b> 1 and I <b> 2. The dimmer 10 includes a rectifier circuit 21 between the AC power supply 11 and the terminal I1. The rectifier circuit 21 rectifies the power supply voltage. A thyristor TH is connected between the positive output terminal and the negative output terminal of the rectifier circuit 21.

  A series circuit of a resistor R1 and a Zener diode ZD is connected in parallel to the thyristor TH. A series circuit of a diode D2 and a capacitor C3 is connected in parallel to the Zener diode ZD. A pulsating current is output from the rectifier circuit 21, and this pulsating current is sliced by the Zener diode ZD, and a DC voltage of a predetermined level is generated across the capacitor C3. This DC voltage is supplied to the power supply terminal of the control unit 22 as the power supply voltage VDD. The control unit 22 can be configured by a CPU or the like.

  The control unit 22 has a control end connected to a reference potential point via a variable resistor VR3. The variable resistor VR3 is set to a resistance value based on dimming control, and a control voltage based on dimming control is supplied to the control end of the control unit 22. The control unit 22 sets a delay time based on the control voltage supplied to the control terminal, and controls the thyristor TH on and off with this delay time.

  In the present embodiment, a connection point between the resistor R1 and the Zener diode ZD is connected to the detection end of the control unit 22. The controller 22 takes in the pulsating flow from the rectifier circuit 21 from this connection point. The controller 22 can determine the power supply frequency by detecting the zero cross point of the pulsating flow output of the rectifier circuit 21.

  The control unit 22 sets a delay time that defines the conduction time of the thyristor TH using not only the control voltage at the control end but also the power supply frequency. That is, even when the control voltage is the same, the control unit 22 sets the delay time to 1 / n when the power supply frequency is increased n times.

Next, the operation of the embodiment configured as described above will be described.
A control voltage based on the resistance value of the variable resistor VR3 is applied to the control unit 22. The control unit 22 obtains the delay time based on the control voltage and corrects the obtained delay time according to the power supply frequency.

  That is, the control unit 22 determines the power supply frequency based on the pulsating flow. For example, in the region where the power supply frequency is 60 Hz, the control unit 22 sets a delay time that is 5/6 times the delay time set in the region where the power supply frequency is 50 Hz. Thereby, even when the power supply frequencies are different, it is possible to make the operation feeling for the knob of the volume constituting the variable resistor VR3 common.

The control unit 22 grasps the zero cross point of the AC power supply by the pulsating current input to the detection end, and outputs a control signal for turning on the thyristor TH after a delay time from the zero cross point to the thyristor TH. As a result, the thyristor TH is turned on for a period defined by the delay time, and supplies power to the lighting load device 13. In this way, even when the power supply frequency is different, lighting with a common dimming rate is possible by a common dimming operation.
As described above, also in this embodiment, the same effect as that of the first embodiment can be obtained.

(Third embodiment)
FIG. 5 is a circuit diagram showing a third embodiment of the present invention. In FIG. 5, the same components as those in FIG.
A series circuit of a thyristor TH and a resistor R3 is connected between the positive output terminal and the negative output terminal of the rectifier circuit 21 as a self-holding element for performing phase control. The thyristor TH is controlled to be turned on / off by a control signal from the control unit 31. The constant voltage circuit including the resistor R1, the Zener diode ZD, and the capacitor C3 generates a constant voltage from the output of the rectifier circuit 21 and supplies it to the control unit 31 as the power supply voltage VDD of the control unit 31.

  The control unit 31 has a control end connected to a reference potential point via a variable resistor VR3. The variable resistor VR3 is set to a resistance value based on dimming control, and a control voltage based on dimming control is supplied to the control end of the control unit 31. The control unit 31 obtains a delay time based on the control voltage supplied to the control terminal.

  The positive output terminal of the rectifier circuit 21 is connected to the control unit 31 through the resistor R2, and the control unit 31 takes in the pulsating flow from the rectifier circuit 21 through the resistor R2. The control unit 31 generates a control signal for conducting the thyristor TH after the delay time with reference to the zero cross point detected from the pulsating flow output of the rectifier circuit 21.

  In the present embodiment, a voltage based on the current (load current) detected by the current detection resistor R3 is supplied to the control unit 31. The control unit 31 corrects the delay time obtained based on the control voltage according to the load current detected by the resistor R3. That is, the control unit 31 sets the delay time that defines the conduction time of the thyristor TH using not only the control voltage at the control end but also the load current. For example, even when the control voltage is the same, the control unit 31 sets the delay time to be large when the load current increases.

Note that the current flowing through the resistor R3 varies depending on the power supply voltage. Therefore, the control unit 31 sequentially stores the current value in a memory (not shown), and obtains the load current by calculating the stored current value.
Next, the operation of the embodiment configured as described above will be described with reference to the waveform diagram of FIG. FIG. 6 is a waveform diagram for explaining the control of the AC power supply voltage of the power supply 11 and the thyristor TH, with time on the horizontal axis and voltage on the vertical axis.
A control voltage based on the resistance value of the variable resistor VR3 is applied to the control unit 31. The control unit 31 obtains a delay time based on the control voltage.

  Assume that the power supply voltage from the power supply 11 is as shown by the waveform A1 in FIG. In this case, it is assumed that the delay time obtained by the control unit 31 based on the resistance value of the variable resistor VR3 is T1. The hatched portion at the lower left of FIG. 6 indicates the power supply period in the power supply half cycle.

  Here, it is assumed that the power supply voltage fluctuates and the amplitude increases as shown by a waveform A2 in FIG. In this case, if the delay time is determined only by the control voltage obtained by the control unit 31 according to the variable resistor VR3, the amount of power supplied to the lighting load device 13 is increased by the increase in the amplitude of the power supply voltage. As a result, the light control rate becomes high.

  In addition, if the phase control element is controlled by a time constant circuit using a variable resistor and a capacitor, the delay time is shortened due to the increase in the amplitude of the power supply voltage, and the amount of power supplied to the lighting load fixture 13 is further increased. As a result, the light control rate is significantly increased.

  Therefore, in the present embodiment, the control unit 31 detects the load current that accompanies the fluctuation of the power supply voltage, and corrects the delay time based on the detection result. That is, the control unit 31 is given a voltage based on the load current flowing through the resistor R3. The control unit 31 generates a delay time according to the voltage based on the load current and the control voltage. For example, when the control voltage is constant, the control unit 31 controls the delay time so that the load current flowing through the resistor R3 is constant.

  The control unit 31 grasps the zero cross point of the AC power supply from the pulsating current input to the detection end, and outputs a control signal for turning on the thyristor TH after a delay time from the zero cross point to the thyristor TH. As a result, the thyristor TH is turned on for a period defined by the delay time, and supplies power to the lighting load device 13.

  For example, in the example of FIG. 6, the control unit 31 changes the delay time to T2 larger than T1 when the power supply voltage becomes higher. As a result, the power supply period is shortened, and the load current can be made constant regardless of fluctuations in the power supply voltage. In this way, the dimming rate can be made constant regardless of fluctuations in the power supply voltage, and the dimming rate is based on the resistance value of the variable resistor VR3.

  As described above, in the present embodiment, the fluctuation of the power supply voltage is determined by detecting the load current, and the delay time is adjusted based on the load current. As a result, a desired dimming rate can be obtained with a common operational feeling regardless of fluctuations in the power supply voltage.

  In this embodiment, the example in which the load current changes due to the fluctuation of the power supply voltage has been described. However, the load current also changes depending on the change in the power supply frequency as in the first embodiment. Therefore, this embodiment can also make it possible to control dimming with a common operational feeling regardless of the power supply frequency.

(Fourth embodiment)
FIG. 7 is a circuit diagram showing a fourth embodiment of the present invention. In FIG. 7, the same components as those in FIG.

  This embodiment is different from the third embodiment in that a control unit 41 is used instead of the control unit 31. The control unit 41 is different from the control unit 31 only in the way of controlling the thyristor TH. As an operation mode, the control unit 41 has a use mode during normal use and a registration mode for storing information related to the lighting load device 13 before normal use.

  FIG. 8 is a graph showing characteristics of load current and load voltage when an incandescent bulb or an LED bulb is adopted as the lighting load fixture 13 with voltage on the horizontal axis and current on the vertical axis. As shown in FIG. 8, the incandescent bulb has a characteristic that the load current increases as the voltage increases, whereas the LED bulb has almost no load current until the applied voltage reaches a predetermined threshold voltage. It does not flow. For example, depending on the configuration of the LED bulb, the threshold voltage can be set to about 100 V. In this case, the LED bulb can be turned on by applying 100 V as the applied voltage.

  FIG. 9 is a waveform diagram for explaining the relationship between the AC power supply voltage of the power supply 11 and the conduction angle, with time on the horizontal axis and voltage on the vertical axis. FIG. 9 shows a range in which lighting is possible when the power source 11 generates an AC voltage of 100 V and an incandescent bulb or an LED bulb that lights at 100 V is adopted as the lighting load device 13.

  A period T3 indicates a period in which the AC power supply is in a range of 100 V or more and the LED bulb can be lit. A period T4 indicates a period during which the incandescent bulb can be lit. When an incandescent light bulb is used as the lighting load device 13, it is possible to set a power supply period within the period T4. However, when an LED light bulb is used as the lighting load device 13, the power supply range is within the period T3. It is necessary to set as a supply period.

  The control unit 41 detects the characteristics of the lighting load fixture 13, for example, the characteristics shown in FIG. 8 by supplying power to the lighting load fixture 13 in the registration mode, and stores them in a storage unit (not shown). In the use mode, the control unit 41 determines the delay time based on the control voltage corresponding to the resistance value of the variable resistor VR3 and the characteristics of the lighting load device 13 obtained in the registration mode, and the thyristor TH is determined based on the delay time. It comes to drive.

Next, the operation of the embodiment configured as described above will be described with reference to the flowchart of FIG.
In step S1, the control unit 41 sets the registration mode. In the registration mode, the control unit 41 gives a control signal to the thyristor TH to control conduction, and changes the conduction angle of the power supply voltage (step S2). The control unit 41 detects a voltage via the resistor R2 and detects a load current using the resistor R3 (step S3). The control unit 41 stores the detected voltage and current in a storage unit (not shown) (step S4).

  In general, since the type of the lighting load device 13 is not frequently changed, the registration mode only needs to be performed once after the dimmer is installed. When the type of the lighting load device 13 is changed, the control unit 41 performs the registration mode again.

  When the use mode is set in step S5, the control unit 41 takes in a control voltage based on the resistance value of the variable resistor VR3 in step S6, and obtains a dimming rate according to the control voltage. Next, the control unit 41 calculates a delay time according to the dimming rate (step S7). In this case, the control unit 41 calculates the delay time based on the information stored in the storage unit. Thus, for example, when an LED bulb that is lit at 100 V is employed as the lighting load fixture 13, the control unit 41 responds to the dimming rate so that the range within the period T3 in FIG. 9 is the power supply period. Set the delay time. Similarly, for example, when an incandescent light bulb is employed as the lighting load device 13, the control unit 41 sets a delay time according to the dimming rate with the range within the period T4 in FIG. 9 as the power supply period. To do.

  The controller 41 controls conduction of the thyristor TH according to the calculated delay time (step S8). Thereby, even if any kind of lighting load is connected as the lighting load device 13, the dimming rate is based on the resistance value of the variable resistor VR3. Therefore, the operation on the knob of the volume constituting the variable resistor VR3 is performed. A feeling can be made common.

  As described above, also in this embodiment, it is possible to make the operation feeling of the dimming operation to obtain a common dimming rate the same.

    DESCRIPTION OF SYMBOLS 10 ... Dimmer, 11 ... Power supply, 12 ... Frequency discrimination circuit, 13 ... Lighting load apparatus, C1, C2 ... Capacitor, T ... Triac, TD ... Diac, VR1 ... Variable resistance, S ... Analog switch.

Claims (4)

A phase control element that is connected in series with the lighting load to an AC power source that generates power for lighting the lighting load, and controls the supply of the power obtained from the AC power source to the lighting load by turning on and off;
First control means for controlling a conduction angle of the phase control element based on a dimming operation;
Second control means for correcting a conduction angle of the phase control element so that the dimming operation and the dimming rate of the illumination load are in a one-to-one correspondence;
A dimmer characterized by comprising: The second control means includes
Frequency detection means for detecting a power supply frequency of the AC power supply;
Correction means for correcting a conduction angle of the phase control element based on a detection result of the frequency detection means;
The dimmer according to claim 1, comprising: The second control means includes
Current detection means for detecting a load current of the lighting load;
Correction means for correcting a conduction angle of the phase control element based on a detection result of the current detection means;
The dimmer according to claim 1, comprising: The second control means includes
Voltage-current detection means for detecting a load voltage and a load current of the lighting load;
Correction means for correcting a conduction angle of the phase control element based on a detection result of the voltage / current detection means;
The dimmer according to claim 1, comprising:

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