JP4687393B2 - Dimmer - Google Patents

Description

  The present invention relates to a dimmer that performs dimming of a light source by supplying AC power to a light source (lighting fixture) installed in a facility such as a stage, a studio, or a hall.

JP-A-11-97186

  For example, in Patent Document 1, a trigger signal (gate signal) is given to a switch element interposed between an AC power source and a light source to start and stop the supply of AC power from the AC power source to the light source. A dimmer has been proposed that performs once each time.

  By the way, in such a dimmer, since the start and stop of supply of AC power from the AC power source to the light source are performed once every half cycle of AC power, a stop period of supply of AC power to the light source occurs. As a result, it is difficult to smoothly supply the AC power of the AC power source to the light source. In addition, since irregular voltage fluctuations may occur in the AC power supply, it is difficult for such a dimmer to supply AC power to the light source with constant AC voltage fluctuations.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a dimmer capable of smoothly supplying AC power to a light source with constant AC voltage fluctuation.

  The dimmer of the present invention includes a switch unit that connects and disconnects an AC power source and a light source in each of a predetermined time division period with respect to an AC power source voltage every half cycle, and an AC power source by the switch unit. By smoothing means for smoothing the AC voltage applied to the light source based on connection and non-connection with the light source, and by the switching means so that the AC voltage applied to the light source via the smoothing means matches a preset AC voltage set in advance. Control means for controlling connection and disconnection.

  According to the dimmer of the present invention, in particular, switch means for connecting and disconnecting the AC power source and the light source in each of the time division periods set in advance for the AC power supply voltage every half cycle, and the switch means And a smoothing means for smoothing the AC voltage applied to the light source based on the connection and disconnection between the AC power source and the light source, so that the AC voltage can be constantly applied to the light source. Control means for controlling connection and non-connection by the switch means so that the AC power supply stop period to the power source can be eliminated and the AC voltage applied to the light source via the smoothing means matches a preset AC voltage set in advance Therefore, the AC voltage fluctuation of the AC voltage applied to the light source can be made constant, and thus the AC power can be smoothly supplied to the light source with the constant AC voltage fluctuation. Can. Further, according to the dimmer of the present invention, even when an AC power supply having a high AC voltage is used by controlling the switch means by the control means, AC power can be smoothly supplied to the light source with a constant AC voltage fluctuation. Therefore, it is possible to reduce the resistance of a power supply line connecting a large number of dimmers installed in a facility such as a stage, a studio, a hall, and the AC power source.

  In a preferred example of the dimmer of the present invention, the control means monitors the AC voltage applied to the light source, and the AC voltage applied to the light source matches the set AC voltage based on the result of monitoring by the monitoring means. A determination means for determining a connection period between the AC power source and the light source in each of the time division periods, and a command for giving a command for connecting the AC power source and the light source to the switch means with the connection period determined by the determination means Means. According to such a preferable example, the switch means can be controlled promptly according to the AC voltage applied to the light source.

  In a preferred example of the dimmer of the present invention, the switch means includes a switching element that connects and disconnects the AC power source and the light source in each of the time division periods in one half cycle of one cycle of the AC power source voltage. And a switching element for connecting and disconnecting the AC power source and the light source in each of the time division periods in the other half cycle of the one cycle. According to such a preferable example, it is possible to reduce the electrical load on the switch element and reduce the heat generation of the switch element. In addition, the AC voltage applied to the light source in one half cycle and the other half The AC voltage applied to the light source in the period can be easily adjusted independently of each other.

  ADVANTAGE OF THE INVENTION According to this invention, the dimmer which can supply alternating current power to a light source smoothly with a fixed alternating voltage fluctuation can be provided.

  Next, an example of an embodiment of the present invention will be described in more detail based on an example shown in the figure. The present invention is not limited to these examples.

  1 and 2, the dimmer 1 of this example includes an AC power source 2 in each of the time division periods T1 and T2 set in advance with respect to the AC power source voltage for each of the half periods H1 and H2 shown in FIG. Switch means 4 for connecting and disconnecting the light source 3; smoothing means 5 for smoothing the AC voltage applied to the light source 3 based on the connection and disconnection of the AC power source 2 and the light source 3 by the switch means 4; Control means 6 for controlling connection and disconnection by the switch means 4 is provided so that the alternating voltage applied to the light source 3 via the smoothing means 5 matches preset AC voltages G1 and G2.

  The AC power source 2 is composed of a commercial power source of 50 Hz or 60 Hz, for example, and is connected to the input terminals 23 and 35 of the dimmer 1. The AC power supply 2 is 50 Hz in this example. The AC power of the AC power supply 2 has an AC voltage waveform 10 as shown in FIG. The light source 3 includes a halogen lamp or the like and is connected to output terminals 33 and 34 of the dimmer 1.

  The switch means 4 includes the switch element 11 for connecting and disconnecting the AC power source 2 and the light source 3 in each of the time division periods T1 in one half cycle H1 of one cycle C of the AC power source voltage. A switching element 12 is provided for connecting and disconnecting the AC power supply 2 and the light source 3 in each of the time division periods T2 in the other half cycle H2 of the cycles C.

  Each of the switch elements 11 and 12 is composed of a MOSFET such as an IGBT (Insulated Gate Bipolar Transistor). Each of the switch elements 11 and 12 is configured to electrically connect the AC power supply 2 and the light source 3 when the drain and the source are allowed to be energized (ON state). The AC power supply 2 and the light source 3 are electrically disconnected from each other in a state where energization is prohibited (OFF state). The AC voltage applied to the light source 3 based on the operation of the switch elements 11 and 12 and before being smoothed by the smoothing means 5 becomes an AC voltage waveform 14 as shown in FIG.

  The switch element 11 has a gate at the command unit 81, a drain through a diode 21 as a backflow prevention means and an AC filter 22 as a high-frequency removal means, at one input terminal 23, and a drain at the switch element 12 and a smoothing means Each of the five coils 31 is connected to one end.

  The switch element 12 has a gate connected to the command unit 82, a drain connected to the source of the switch element 11 and one end of the coil 31, and a source connected to the input terminal 23 via the diode 24 and the AC filter 22 as backflow element means. Yes.

  The smoothing means 5 comprises a smoothing circuit having a coil 31 such as a choke coil and a smoothing capacitor 32 such as an electrolytic capacitor, and a connection period A1 in which the AC power source 2 and the light source 3 are connected by the switch element 11 within the time division period T1. And the AC voltage applied to the light source 3 in the non-connection period B1 in which the AC power source 2 and the light source 3 are disconnected by the switch element 11 in the time division period T1 and the switch in the time division period T2. In addition to the light source 3 in the connection period A2 in which the AC power source 2 and the light source 3 are connected by the element 12 and in the non-connection period B2 in which the AC power source 2 and the light source 3 are disconnected by the switch element 12 in the time division period T2. The AC voltage is smoothed. The AC voltage smoothed by the smoothing means 5 becomes an AC voltage waveform 13 as shown in FIG.

  One end of the coil 31 is connected to the source of the switch element 11 and the drain of the switch element 12, and the other end is connected to one end of the smoothing capacitor 32 and one output terminal 33.

  The smoothing capacitor 32 has one end connected to the other end of the coil 31 and the other end connected to the other input terminal 35 via the other output terminal 34 and the AC filter 22. The input terminal 35 is connected to the other end of the smoothing capacitor 32 and the output terminal 34 via the AC filter 22.

  Such a smoothing means 5 smoothes the alternating voltage by the cooperation of the coil 31 and the smoothing capacitor 32, whereby the alternating voltage is applied to the light source 3 even in the non-connection periods B1 and B2 shown in FIG. In addition, the AC voltage with respect to the light source 3 can be stepped down in relation to the control of the switch elements 11 and 12 by the control means 6. For example, the AC power source 2 having an effective voltage of 200V (about 280V peak voltage) can be used. The alternating voltage of effective voltage 100V (peak voltage about 140V) can be applied to the light source 3 by stepping down the alternating voltage.

  In this example, the AC filter 22 includes capacitors 41 and 42 connected to the input terminals 23 and 35, a coil 43 connected to one end of each of the capacitors 41 and 42, and the other end of each of the capacitors 41 and 42. A coupled coil 44 is combined. The capacitor 41 has one end connected to the input terminal 23 and one end of the coil 43, and the other end connected to the input terminal 35 and one end of the coil 44. One end of the capacitor 42 is connected to the other end of the coil 43, the anode of the diode 21 and the cathode of the diode 24, and the other end is connected to the other end of the smoothing capacitor 32 of the smoothing means 5 and the output terminal 34. . The cathode of the diode 21 is connected to the drain of the switch element 11, and the anode of the diode 24 is connected to the source of the switch element 12.

  The control means 6 monitors the AC voltage applied to the light source 3, and based on the result of monitoring by the monitoring means 51, the AC voltage applied to the light source 3 matches the set AC voltages G1 and G2. In order to connect the AC power source 2 and the light source 3 to the switch means 4 with the determination means 52 for determining the connection periods A1 and A2 in the time division periods T1 and T2, respectively, and the connection periods A1 and A2 determined by the determination means 52. And command means 53 for giving the above command.

  The control means 6 further includes a current detection means 55 for detecting an alternating current flowing through a power supply line 54 that connects the alternating current power source 2 and the light source 3, and the alternating current detected by the current detection means 55 is a preset alternating current. When the electric current is exceeded, the operation of the dimmer 1 itself is stopped. The current detection means 55 includes a detection coil 56 installed between the other end of the smoothing capacitor 32 and the other end of the capacitor 42 of the AC filter 22.

  The monitoring means 51 includes a detection transformer 61 as a voltage detection means for detecting an AC voltage applied to the light source 3, and a detected AC voltage as a digital quantity obtained by sampling and quantizing the AC voltage detected by the detection transformer 61. And an A / D conversion unit 62 as a voltage conversion unit for conversion into D.

  The detection transformer 61 has one end connected to the output terminal 33 and one end of the smoothing capacitor 32 and the other end connected to the output terminal 34 and the other end of the smoothing capacitor 32, and A / D conversion. A secondary coil 66 connected to the unit 62 is provided, and an AC voltage applied to the secondary coil 66 via the primary coil 65 is detected.

  The A / D conversion unit 62 is connected to the determination unit 52 and transmits the detected AC voltage D to the determination unit 52.

  The determining means 52 has a preset AC voltage G1 that presets the AC voltage to be applied to the light source 3 in the half cycle H1, a preset AC voltage G2 that preset the AC voltage to be applied to the light source 3 in the half cycle H2, and a half cycle H1. Is preset based on a time division period T1 set in advance so as to be time-divided, a time division period T2 set in advance so that the half cycle H2 is time-divided, a set AC voltage G1, and an AC power supply voltage. The monitoring means 51 adjusts the connection period A2 set in advance based on the connection period A1, the set AC voltage G2 and the AC power supply voltage, and the AC voltage applied to the light source 3 in the half cycle H1 to coincide with the set AC voltage G1. The connection period A1 is corrected based on the monitoring result, and the AC voltage applied to the light source 3 in the half cycle H2 is monitored so as to match the set AC voltage G2. A storage unit 72 that stores a correction program 71 that corrects the connection period A2 based on the monitoring result of the means 51; an arithmetic processing unit 73 that executes processing by the correction program 71 stored in the storage unit 72; The zero cross 76 of the AC power supply voltage in relation to the time t is detected, and based on the detection, the time division periods T1 and T2, the connection periods A1 and A2, and the non-connection periods B1 and B2 are unit periods by vibration of the vibrator or the like. By counting for each U, the half cycle H1 is synchronized with the time division period T1, the connection period A1 and the non-connection period B1, and the half cycle H2 is time-division period T2, the connection period A2 and the non-connection period B2. And a synchronization unit 74 for synchronization.

  The storage unit 72 is realized by a ROM, a RAM, and the like, and the arithmetic processing unit (CPU) 73 is realized by a microprocessor and the like.

  As shown in FIG. 3, the correction program 71 waits for the detected AC voltage D from the monitoring unit 51 and receives the detected AC voltage D in the half cycle H <b> 1 from the monitoring unit 51. When the detected AC voltage D matches the set AC voltage G1 (including an allowable error) as a result of the comparison in step 101 and the set AC voltage G1, the correction period is set as the zero period and the connection period If the detected AC voltage D and the set AC voltage G1 do not match as a result of the comparison between the stage 102 set for A1 and the stage 101, the correction according to the voltage difference between the detected AC voltage D and the set AC voltage G1 Based on the step 103 of setting the period with respect to the connection period A1 and the reception of the detected AC voltage D in the half cycle H2 from the monitoring means 51, the detected AC power Step 104 for comparing D with the set AC voltage G2, and when the detected AC voltage D matches the set AC voltage G2 (including an allowable error) as a result of the comparison at step 104, the correction period is set to zero. If the detected AC voltage D and the set AC voltage G2 do not match as a result of the comparison between the stage 105 set for the period A2 and the stage 104, the detected AC voltage D corresponds to the voltage difference with respect to the set AC voltage G2. And a step 106 of setting a correction period for the connection period A2. After setting the correction period (including the zero period setting) in step 102 or 103 or step 105 or 106, the connection period A1 or A2 in which the correction period is set is transmitted to the command means 53 (step 107). Returning to step 100, the detection AC voltage D is awaited again. The processing from steps 101 to 103 is executed during the period of the half cycle H2, and the command unit 81 operates according to the connection period A1 in which the correction period is set from the next half cycle H1 of the half cycle H2. The processing from steps 104 to 106 is executed during the period of the half cycle H1, and the command unit 82 operates according to the connection period A2 in which the correction period is set from the next half cycle H2 of the half cycle H1.

  The correction period set in step 103 may be increased or decreased according to the voltage difference. For example, when the detected AC voltage D is larger or smaller than the set AC voltage G1, a predetermined fixed period is set. A minus period or a plus period may be set for the connection period A1 as a correction period. The correction period set in step 106 may also be set for the connection period A2 with a predetermined fixed negative period or positive period as the correction period.

  The arithmetic processing unit 73 reads the correction program 71 from the storage unit 72, executes the above steps, and transmits the connection periods A1 and A2 obtained by the execution to the command units 81 and 82, respectively. The arithmetic processing unit 73 reads various data and programs such as a period stored in the storage unit 72 as appropriate.

  In this example, each of the time division periods T1 and T2 is set to about 32 μsec so that each of the 10 msec half periods H1 and H2 is time-divided into 320 pieces.

  In this example, the unit period U is set to about 125 nsec so that each of the time division periods T1 and T2 is time-divided into 255 pieces.

  Each of the connection periods A1 and A2 is selected by selecting zero, one, or a plurality of units with a minimum unit period U set so that each of the time division periods T1 and T2 is time-divisional. When each of the periods A1 and A2 is the minimum period, zero unit periods U are selected, and when each of the connection periods A1 and A2 is the maximum period, the connection periods A1 and A2 belong to All the unit periods U in which the divided periods T1 and T2 are time-divided, in this example, 255 unit periods U are selected. Each of the connection periods A1 and A2 can be set in 256 steps (including a zero period) in this example.

  The time division periods T1 and T2 and the set AC voltages G1 and G2 are set, for example, by an operation of an operation unit (not shown) and stored in the storage unit 72. The connection periods A1 and A2 are automatically calculated by the arithmetic processing unit 73 at a predetermined ratio based on the AC power supply voltage of the AC power supply 2 connected to the input terminals 23 and 35 and the set AC voltages G1 and G2. Is set and stored in the storage unit 72. The connection periods A1 and A2 are, for example, 128 when the AC voltage of the AC power supply 2 is the effective voltage 200V (peak voltage 280V) and the set AC voltages G1 and G2 are the effective voltage 100V (peak voltage 140V). About one unit period U is selected and set as a period of about 50% with respect to the time division periods T1 and T2.

  The time division period T1 and the time division period T2 are set to have the same length in this example, but may be set to have different lengths, for example. Each of the time division periods T1 and T2 and the unit period U may be set longer or shorter than the above period.

  The command unit 53 receives the connection period A1 as a result of the calculation process in the calculation processing unit 73 and gives a command for connecting the AC power source 2 and the light source 3 to the switch element 11 during the connection period A1. And a command unit 82 that receives the connection period A2 as a result of the calculation process in the calculation processing unit 73 and gives a command to the switch element 12 to connect the AC power source 2 and the light source 3 with the connection period A2. is doing.

  In this example, the command units 81 and 82 apply a predetermined voltage as a command for connecting the AC power source 2 and the light source 3 to the gates of the switch elements 11 and 12.

  Mainly, the command units 81 and 82 and the arithmetic processing unit 73 are operated according to the detection and counting of the zero cross 76 by the synchronization unit 74, respectively.

  Hereinafter, dimming of the light source 3 using the dimmer 1 of this example will be described in detail. First, the switching element 11 is turned on by the command unit 81 in synchronization with the arrival of the start period of the connection period A1 in the time division period T1, so that the AC power supply is supplied via the AC filter 22, the diode 21, the smoothing means 5, and the like. 2 and the light source 3 are electrically connected. With this connection, an AC power supply voltage is applied to the coil 31 and the smoothing capacitor 32, and an AC voltage is applied to the light source 3 via the smoothing means 5. Next, the switch unit 11 is turned off by the command unit 81 in synchronization with the arrival of the end period of the connection period A1, thereby electrically connecting the AC power source 2 and the light source 3 via the switch element 11 and the diode 21. The connection state is not connected, and this non-connection state is maintained until the start of the connection period A1 in the next time division period T1, and the switch element 11 is turned on / off in the same manner as described above when the next time division period T1 arrives. I do. In synchronization with the arrival of the final connection period A1 in the half cycle H1, the command unit 81 turns off the switch element 11 in synchronization with the arrival of the final connection period A1 in the half cycle H1, and maintains the off state until the first connection period A1 in the next half cycle H1. . In the connection period A1 and the non-connection period B1, the AC voltage smoothed by the smoothing means 5 is applied to the light source 3, and thus the AC voltage applied to the light source 3 in the half cycle H1 is detected by the detection transformer 61. The detected AC voltage is converted into a detected AC voltage D as a digital quantity sampled and quantized by the A / D conversion unit 62 and transmitted to the determining means 52.

  Next, the switching element 12 is turned on by the command unit 82 in synchronization with the arrival of the start period of the connection period A2 in the time division period T2, so that the alternating current is exchanged via the AC filter 22, the smoothing means 5, the diode 24, and the like. The power source 2 and the light source 3 are electrically connected. With this connection, an AC power supply voltage is applied to the coil 31 and the smoothing capacitor 32, and an AC voltage is applied to the light source 3 via the smoothing means 5. Next, the switching element 12 is turned off by the command unit 82 in synchronization with the arrival of the end period of the connection period A2, thereby electrically connecting the AC power source 2 and the light source 3 via the switching element 12 and the diode 24. The connection state is not connected, and this non-connection state is maintained until the start of the connection period A2 in the next time division period T2, and the switch element 12 is turned on / off in the same manner as described above by the arrival of the next time division period T2. I do. In synchronization with the arrival of the final period of the final connection period A2 in the half cycle H2, the command unit 92 turns off the switch element 12 and maintains the off state until the arrival of the first connection period A2 in the next half period H2. . In the connection period A2 and the non-connection period B2, the AC voltage smoothed by the smoothing means 5 is applied to the light source 3, and thus the AC voltage applied to the light source 3 in the half cycle H2 is detected by the detection transformer 61. The detected AC voltage is converted into a detected AC voltage D as a digital quantity sampled and quantized by the A / D conversion unit 62 and transmitted to the determining means 52.

  The determining means 52 determines the connection period A1 in which the correction period is set during the half cycle H2, and the command unit 81 follows the determined connection period A1 in the half cycle H1 that comes next to the half cycle H2. A command is given to the switch element 11. Further, the determining means 52 determines the connection period A2 during the half cycle H1, and the command unit 82 supplies the switch element 12 to the switch element 12 according to the determined connection period A2 in the half cycle H1 that comes next to the half cycle H1. Give a directive. In this way, by controlling the connection and disconnection of the AC power source 2 and the light source 3 by the switch unit 4 by the control unit 6, an AC voltage similar to the preset AC voltages G1 and G2 set in advance can be applied to the light source 3. Thus, AC power can be smoothly supplied to the light source 3. As the AC voltage input from the AC power source 2 to the dimmer 1, an effective voltage from 100 V to 240 V can be applied. In such a case, the AC voltage output from the dimmer 1 to the light source 3 is applicable. The effective voltage can be adjusted from 100V to 240V, for example, 100V, 110V, 120V, 200V, 240V, and the like. In this example, the AC voltage output from the dimmer 1 to the light source 3 is adjusted to be lower than the AC voltage input from the AC power source 2 to the dimmer 1.

  According to the dimmer 1 of this example, the AC power source 2 and the light source 3 are connected and disconnected in each of the time division periods T1 and T2 set in advance with respect to the AC power source voltage for each of the half cycles H1 and H2. Switch means 4 for performing, smoothing means 5 for smoothing the AC voltage applied to the light source 3 based on connection and disconnection of the AC power source 2 and the light source 3 by the switch means 4, and the light source 3 via the smoothing means 5 Since the control means 6 for controlling connection and disconnection by the switch means 4 is provided so that the applied AC voltage coincides with preset AC voltages G1 and G2, the AC voltage is applied to the light source 3. The AC power supply to the light source 3 can be eliminated at all times, and the AC voltage fluctuation of the AC voltage applied to the light source 3 can be made constant. AC voltage change It can be smoothly supplied AC power to the light source 3 with. Further, according to the dimmer 1 of this example, even when the AC power supply 2 having a high AC voltage is used by the control of the switch means 4 by the control means 6, the AC power is smoothly supplied to the light source 3 with a constant AC voltage fluctuation. Since the power can be supplied, it is possible to reduce the resistance of a power supply line connecting a large number of dimmers 1 and AC power supply 2 installed in facilities such as a stage, a studio, and a hall.

  According to the dimmer 1 of this example, the control unit 6 monitors the AC voltage applied to the light source 3, and the AC voltage applied to the light source 3 is based on the result of monitoring by the monitoring unit 51. A determination unit 52 for determining connection periods A1 and A2 between the AC power source 2 and the light source 3 in each of the time division periods T1 and T2 so as to coincide with the set AC voltages G1 and G2, and a connection period determined by the determination unit 52 Since the switch means 4 is provided with a command means 53 for giving a command for connecting the AC power supply 2 and the light source 3 to the switch means 4 with A1 and A2, the switch means 4 is quickly adapted to the AC voltage applied to the light source 3. Can be controlled.

  According to the dimmer 1 of this example, the switch means 4 is connected to the AC power source 2 and the light source 3 in each of the time division periods T1 in one half cycle H1 of one cycle C of the AC power source voltage. A switching element 11 for disconnecting, and a switching element 12 for connecting and disconnecting the AC power source 2 and the light source 3 in each of the time division periods T2 in the other half cycle A2 of the one period C are provided. Therefore, the switch elements 11 and 12 can be stopped every half cycle H1 and H2, the electrical load on the switch elements 11 and 12 can be reduced, and the switch elements 11 and 12 generate heat. The AC voltage applied to the light source 3 in one half cycle H1 and the AC voltage applied to the light source 3 in the other half cycle H2 can be easily adjusted independently of each other. For example, since the path of the AC current flowing from the AC power source 2 to the light source 3 in the half cycle H1 is different from the path of the AC current flowing from the AC power source 2 to the light source 3 in the half cycle H2, the AC applied to the light source 3 in the half cycle H1. Even when there is a difference between the voltage and the AC voltage applied to the light source 3 in the half cycle H2, it is applied to the light source 3 in the half cycle H1 based on the operation of the switch elements 11 and 12 controlled by the control means 6. It is possible to mutually adjust the AC voltage and the AC voltage applied to the light source 3 in the half cycle H2.

  The dimmer 1 of this example is connected to the detection transformer 61 and the detection transformer 61 instead of the monitoring means 51, and the AC voltage detected by the detection transformer 61 and the set AC voltages G1 and G2. And a comparator (comparator) for comparing the two. In such a case, the steps 101 and 104 of the correction program 71 are unnecessary.

It is a conceptual explanatory view of an example of an embodiment of the invention. It is a conceptual explanatory drawing mainly of a control means of the example shown in FIG. It is explanatory drawing regarding the process sequence of the correction program mainly of the example shown in FIG. It is explanatory drawing regarding the action | operation and alternating current power supply voltage of the example shown in FIG. It is explanatory drawing of the alternating voltage waveform which arises in relation to the action | operation of the example shown in FIG. It is explanatory drawing of the alternating voltage waveform which arises in relation to the action | operation of the example shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dimmer 2 AC power supply 3 Light source 4 Switch means 5 Smoothing means 6 Control means

Claims (3)

Switch means for connecting and disconnecting the AC power source and the light source in each of the preset time division periods with respect to the AC power supply voltage for each half cycle, and connecting and disconnecting the AC power source and the light source by the switch means And smoothing means for smoothing the AC voltage applied to the light source, and control for controlling connection and disconnection by the switch means so that the AC voltage applied to the light source via the smoothing means matches a preset AC voltage set in advance. And the switch means is an IGBT as a switch element for connecting and disconnecting the AC power source and the light source in each of the time division periods in one half cycle of one cycle of the AC power supply voltage. And another IGBT as another switching element for connecting and disconnecting the AC power source and the light source in each of the time division periods in the other half cycle of the one cycle. The smoothing means comprises a smoothing circuit having a coil and a smoothing capacitor. The IGBT has a gate serving as a control means, a drain serving as an AC power supply through one input terminal, and a source serving as another IGBT. The other IGBT is connected to one end of the drain and the coil of the smoothing means, and the gate of the other IGBT is connected to the control means, the drain is the source of the IGBT and the one end of the coil of the smoothing means, and the source is AC through one input terminal. The coil of the smoothing means is connected to the power source, one end of which is connected to the IGBT source and the other IGBT drain, and the other end is connected to the light source via one end of the smoothing capacitor and one output terminal. The smoothing capacitor is connected at one end to the other end of the coil of the smoothing means, and connected to the light source at the other end via the other output terminal. The smoothing means is connected to the AC power source and the light source by the IGBT within the time division period in the half cycle and the time division. During the period, the AC power supply and the AC voltage applied to the light source in the non-connection period in which the light source is disconnected from the IGBT are smoothed, and the AC power supply is supplied by another IGBT in the time division period in the other half cycle. In addition, the AC voltage applied to the light source is smoothed in the other connection period in which the light source is connected and the AC power source by another IGBT and the non-connection period in which the light source is disconnected in the time division period. Dimmer. The control means includes a monitoring means for monitoring the AC voltage applied to the light source, and an AC power source in each of the time division periods so that the AC voltage applied to the light source matches the set AC voltage based on the monitoring result by the monitoring means. Determining means for determining a connection period between the light source and the light source, and a command means for giving a command for connecting the AC power source and the light source to the switch means with the connection period determined by the determining means. A preset AC voltage that presets the AC voltage to be applied to the light source in the one half cycle, another preset AC voltage that preset the AC voltage to be applied to the light source in the other half cycle, and the one half cycle. Time-division period set in advance so as to be time-division, time-division period preset so that the other half cycle is time-division, set AC voltage and AC The connection period preset based on the source voltage, the other connection period preset based on the other set AC voltage and the AC power supply voltage, and the AC voltage applied to the light source in the one half cycle are set AC The connection period is corrected based on the monitoring result of the monitoring means so as to coincide with the voltage, and the monitoring means monitors so that the AC voltage applied to the light source in the other half cycle matches the other set AC voltage. The storage part which memorize | stores the correction program which correct | amends another connection period based on a result, and the arithmetic processing part which performs the process by the correction program memorize | stored in this memory | storage part are comprised. Dimmer. The monitoring means includes a detection transformer that detects an AC voltage applied to the light source, and a voltage conversion unit that samples the AC voltage detected by the detection transformer and converts it into a detected AC voltage as a quantized digital quantity. The correction program includes a first stage waiting for a detected AC voltage from the monitoring unit, and the detected AC voltage and the set AC voltage based on reception of the detected AC voltage in the one half cycle from the monitoring unit. And the third stage of setting the correction period as the zero period for the connection period when the detected AC voltage matches the set AC voltage as a result of the comparison in the second stage If the detected AC voltage does not match the set AC voltage as a result of the comparison in the second stage, the correction according to the voltage difference of the detected AC voltage with respect to the set AC voltage A fourth stage for setting the interval for the connection period, and a fifth stage for comparing the detected AC voltage with another set AC voltage based on reception of the detected AC voltage in the other half cycle from the monitoring means As a result of the comparison between the stage and the fifth stage, if the detected AC voltage and the other set AC voltage match, the sixth stage is set for the other connection period with the correction period as the zero period, If the detected AC voltage does not match the other set AC voltage as a result of the comparison in the fifth stage, a correction period corresponding to the voltage difference of the detected AC voltage with respect to the other set AC voltage is set with respect to the other connection period. The dimmer according to claim 2, further comprising a seventh stage of setting.

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