JP2012221714A - Power supply and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply which even if changing the current being output to one load, can prevent variation in the current being output to the other load when currents are output to a plurality of loads, and to provide a luminaire.SOLUTION: A constant current circuit 10 controls a current being supplied to have a constant level. PWM circuits 20 and 30 adjust the on time and the off time of the currents being output to LED loads 1 and 2. When a light control signal for changing the current being output to the LED load 1 is received by a receiving unit 40, a control unit 50 controls the PWM circuit 20 so that the current being output to the LED load 1 becomes a current corresponding with the light control signal thus received, and controls the PWM circuit 30 so that the current being output to the LED load 2 does not vary.

Description

  The present invention relates to a power supply device that supplies current to a plurality of loads and a lighting device including the power supply device.

  In recent years, lighting devices using LEDs (light emitting diodes) as light sources have been developed for various applications, and replacement of lighting devices using conventional light sources such as incandescent bulbs and fluorescent lamps is being performed. In addition, lighting devices having a dimming function capable of adjusting the light source to a desired brightness have already been commercialized.

  In such an illuminating device, a power supply device including a constant current circuit is used so that a required constant current flows through the LED so that the brightness of the LED is kept constant. In addition, in order to adjust the brightness of the LED, there is a power supply device having a dimming function that can adjust the current flowing through the LED based on a dimming signal.

  For example, a lighting device is disclosed that includes a plurality of power supply circuits for each of a plurality of LED loads, and a PWM control unit that PWM-controls a voltage / current supplied to the LED load between each power supply circuit and each LED load. (See Patent Document 1).

  However, in the lighting device as shown in Patent Document 1, since it is necessary to provide a plurality of power supply circuits for each LED load, there is a problem that the lighting device is expensive, or a problem that the lighting device is enlarged. was there. In view of this, it has been studied to reduce the cost and size by using a common power supply circuit for a plurality of LED loads.

  FIG. 11 is a block diagram showing a main part of the configuration of a conventional lighting device 200. The lighting device 200 includes a common power supply circuit 201 for a plurality of loads (LEDs), a PWM control unit 202 that adjusts on / off times (for example, duty ratio) of voltages and currents supplied to the respective LEDs 204 and 205, 203 and the like.

  The power supply circuit 201 includes a constant current circuit. For example, when the rated current (average value) of each of the LEDs 204 and 205 is 1 A, a constant current of 2 A is output as an output current to supply the rated current to the LEDs 204 and 205. To control.

  The PWM control units 202 and 203 include a PWM control circuit, and adjust the on / off time of the voltage / current supplied from the power supply circuit 201 (PWM control) to adjust the current value supplied to the LEDs 204 and 205.

JP 2010-129212 A

  However, in the conventional lighting device 200 as shown in FIG. 11, since two LEDs 204 and 205 are connected in parallel to the power supply circuit 201, when one LED 205 is dimmed, to the other LED 204. There is a problem that the supplied current fluctuates and the brightness of the LED 204 changes. The same problem may occur when a switch circuit for turning on / off the LEDs 204 and 205 is provided instead of the PWM control unit.

  FIG. 12 is a time chart showing an example of the operating state of the conventional lighting device 200. As shown in FIG. 12, it is assumed that the LED 204 and the LED 205 are initially lit at a dimming rate of 100% (all lights). Since the set value of the output current of the power supply circuit 201 is 2 A, a current having a peak value of 1 A flows through each of the LEDs 204 and 205.

  When the dimming rate of the LED 205 is changed from 100% to 50% at an arbitrary time, the PWM control unit 203 sets the ON time of the current supplied to the LED 205 to 50% and the OFF time to 50% (duty ratio 50%). PWM control is performed as described above.

  However, since the set value of the output current of the power supply circuit 201 is 2A, while the current flowing to the LED 205 is off, the current flowing to the LED 204 is increased from 1A to 2A. For this reason, the average value of the current supplied to the LED 204 increases from 1 A to 1.5 A, and there arises a problem that the brightness of the LED 204 varies before and after the dimming of the LED 205.

  The present invention has been made in view of such circumstances, and when current is output to a plurality of loads, even when the current output to one load is changed, fluctuation of the current output to another load is prevented. It is an object of the present invention to provide a power supply device that can be used and a lighting device including the power supply device.

  A power supply device according to the present invention is provided between a current supply unit that supplies a predetermined current, and the current supply unit and each of a plurality of loads connected in parallel to the current supply unit. A power supply apparatus comprising: a plurality of pulse width modulation units that output current from each unit to each load; and a reception unit that receives a signal for pulse width modulation of the current output to an arbitrary load. When a signal for pulse width modulation of the current output to the other load is received, a current maintaining unit that maintains the current output to another load before and after the reception is provided.

  In this invention, when the signal for performing pulse width modulation of the current output to one load is received by the receiving unit, the current maintaining unit that maintains the current output to another load before and after the receiving is provided. For example, when the load is a light source, the signal for pulse width modulating the current output to an arbitrary load is a signal for dimming the brightness of the light source. The current maintaining unit maintains the current output to other loads even when the current output to one load is changed by pulse width modulation. Even when the current output to the other load is changed, fluctuations in the current output to other loads can be prevented.

  In the power supply device according to the present invention, when the reception unit receives a signal for pulse width modulating the current output to the one load, the pulse width modulation unit for pulse width modulating the current output to the one load is The on / off time of the current to be output is adjusted, and the current maintaining unit is adjusted so that the on time of the current output to each load is not overlapped by each pulse width modulation unit. It is configured to maintain a current to be output to the load.

  In the present invention, when the reception unit receives a signal for pulse width modulation of the current output to one load, the pulse width modulation unit for pulse width modulating the current output to the one load Adjust the on / off time of. That is, the one pulse width modulation unit adjusts the current on / off time in order to perform pulse width modulation on the current output to the one load. And a current maintenance part adjusts so that the ON time of the current outputted to each load by each pulse width modulation part may not overlap, and maintains the current outputted to other loads.

  For example, when the current supply unit supplies current to the two loads 1 and 2, it is assumed that the rated currents of the loads 1 and 2 are set to 1A, and the current output from the current supply unit is set to 2A. The load 1 is adjusted such that the peak value is 2 A, the current on time is 50%, the off time is 50%, and a current (rated current) having an average value of 1 A is output. Suppose that the peak value is 2A, the current on time is 25%, the off time is adjusted to 75%, and an average value of 0.5A (50% of the rated current) is output. In this case, the duty ratio is set so that when the current of one load is on, the current of the other load is off so that the on times of the currents output to the loads 1 and 2 do not overlap. Adjusted.

  For example, in order to change the current of the load 1 (for example, to change the dimming rate when the load is a light source), the peak value is 2A, the on time of the current is 25%, and the off time is 75. %, And the average value is 1A to 0.5A (50% of the rated current). In this case, for example, the load 2 has a peak value of 2 A, a current on time of 25%, and an off time of 75% so that the on times of the currents output to the loads 1 and 2 do not overlap. It is adjusted and maintained to output a current with an average value of 0.5 A (50% of the rated current). Prevents fluctuations in the current output to other loads even when the current output to one load is changed to a desired value by preventing the ON times of the currents adjusted by each pulse width modulator from overlapping. can do.

  The power supply device according to the present invention includes a current setting unit that sets the predetermined current, and when the reception unit receives a signal for pulse width modulating the current output to the one load, The pulse width modulation unit that performs pulse width modulation of the output current adjusts the on / off time of the output current, and the current maintaining unit is a time period in which the on time adjusted by each pulse width modulation unit overlaps. The current value set by the current setting unit is increased to maintain the current output to the other load.

  The present invention includes a current setting unit that sets a predetermined current. For example, the current supplied by the current supply unit can be changed by 2A, 1A, or the like. When the reception unit receives a signal for pulse width modulation of the current output to one load, the one pulse width modulation unit for adjusting the on / off time of the current output to the one load / Adjust the off time. That is, one pulse width modulation unit adjusts the on / off time of the current output to one load. The current maintaining unit maintains a current output to another load by increasing a current value set by the current setting unit in a time zone in which the ON times adjusted by the respective pulse width modulation units overlap.

  For example, when the current supply unit supplies current to the two loads 1 and 2, it is assumed that the rated currents of the loads 1 and 2 are set to 1A, and the current supplied by the current supply unit is set to 2A. Then, it is assumed that the loads 1 and 2 are each adjusted to have a peak value of 1 A, a current on time of 100%, and an average value of 1 A (rated current). In this case, the current supply unit sets the set value of the predetermined current to 2A in a time zone in which the ON times adjusted by the respective pulse width modulation units overlap.

  For example, in order to change the current of the load 1 (for example, to change the dimming rate when the load is a light source), the peak value is 1 A, the current on time is 50%, and the off time is 50. %, And the average value is 1A to 0.5A (50% of the rated current). In this case, the current value set by the current setting unit is increased in the time zone in which the ON times of the currents output to the loads 1 and 2 overlap. For example, when the current on-time overlaps, the predetermined current set value is 2A, and when the current on-time does not overlap, the predetermined current set value is 1A. The load 2 is adjusted so as to output a current (rated current) having a peak value of 1 A and a current on time of 100% and an average value of 1 A. Even when the current output to one load is changed to a desired value by increasing the current value set by the current setting unit in the time zone in which the ON times adjusted by each pulse width modulation unit overlap, Variations in the current output to the load can be prevented.

  In the power supply device according to the present invention, when the current maintaining unit receives a signal for pulse width modulating the current output to the one load at the receiving unit, the current output to the one load is pulse width modulated. The on / off time of the current is adjusted by a pulse width modulation unit other than the pulse width modulation unit.

  In the present invention, when the current maintaining unit receives a signal for pulse width modulating the current output to one load at the receiving unit, in addition to the one pulse width modulating unit, the other pulse width modulating unit Also adjusts the current on / off time. For example, when the current supply unit supplies current to the two loads 1 and 2, it is assumed that the rated currents of the loads 1 and 2 are set to 1A, and the current supplied by the current supply unit is set to 2A. The loads 1 and 2 are adjusted so that the peak value is 1A, the current on-time is adjusted to 100%, and a current (rated current) having an average value of 1A is output.

  For example, in order to change the current of the load 1 (for example, to change the dimming rate when the load is a light source), the peak value is 2A, the on time of the current is 25%, and the off time is 75. %, And the average value is 1A to 0.5A (50% of the rated current). In this case, the duty ratio for the load 2 is adjusted so that the ON times of the currents output to the loads 1 and 2 do not overlap. For example, the load 2 is adjusted so that the peak value is 2 A, the current on time is 50%, the off time is 50%, and the current (rated current) having an average value of 1 A is output. Preventing fluctuations in the current output to other loads even when the current output to one load is changed to a desired value by preventing the ON times that are adjusted by each pulse width modulator from overlapping Can do.

  Moreover, you may change the electric current value set with an electric current supply part. For example, when the current supply unit supplies current to the two loads 1 and 2, it is assumed that the rated currents of the loads 1 and 2 are set to 1A, and the current supplied by the current supply unit is set to 2A. The load 1 is adjusted such that the peak value is 2A, the current on time is 25%, the off time is 75%, and a current having an average value of 0.5A is output. It is assumed that a current having an average value of 1 A is output with the high value being adjusted to 2 A, the current on time being 50%, and the off time being 50%. In this case, it is assumed that the current supply unit has set the set value of the predetermined current to 2A.

  For example, in order to change the current of the load 1 (for example, to change the dimming rate when the load is a light source), the peak value is 1 A, the current on time is 75%, and the off time is 25. %, And the average value is 0.5A to 0.75A (75% of the rated current). In this case, the current value set by the current setting unit is increased in the time zone in which the ON times of the currents output to the loads 1 and 2 overlap. For example, when the current on-time overlaps, the predetermined current set value is 2A, and when the current on-time does not overlap, the predetermined current set value is 1A. The load 2 is adjusted so as to output a current (rated current) having a peak value of 1 A and a current on time of 100% and an average value of 1 A. Even when the current output to one load is changed to a desired value by increasing the current value set by the current setting unit in the time zone where the on-time adjusted by each pulse width modulation unit overlaps, Variations in the current output to the load can be prevented.

  The power supply device according to the present invention includes a storage unit that stores in advance an on / off time of a current output from each pulse width modulation unit in association with a signal received by the reception unit, and the current maintenance unit includes the reception unit The on / off time of the current output from each pulse width modulation unit is adjusted in accordance with the signal received in (5).

  The present invention includes a storage unit that stores in advance the on / off time of the current output from each pulse width modulation unit in association with the signal received by the reception unit. The current maintaining unit adjusts the on / off time of the current output from each pulse width modulation unit in response to the signal received by the reception unit. Thereby, even when the current output to one load is changed to a desired value, fluctuation of the current output to another load can be prevented.

  A power supply device according to the present invention is provided between a current supply unit that supplies a predetermined current, and the current supply unit and each of a plurality of loads connected in parallel to the current supply unit. In a power supply device comprising: a plurality of switch units that turn on / off current from the unit and output current to each load; and a reception unit that receives a signal for turning on / off the current output to an arbitrary load. A current maintaining unit that maintains a current output to another load before and after the reception when the reception unit receives a signal for turning on / off a current output to the one load; .

  In this invention, when the signal for turning off the electric current output to one load is received in the reception part, the current maintenance part which maintains the electric current output to other loads before and after reception is provided. Even if the current maintenance unit maintains the current output to other loads even when the current output to one load is turned off, when supplying current to multiple loads from the current supply unit, output to one load Even when the current to be changed is changed, fluctuations in the current output to other loads can be prevented.

  The power supply device according to the present invention includes a current setting unit that sets the predetermined current, and the current maintaining unit receives the signal for turning off the current to be output to one load by the receiving unit, The current setting unit is configured to set a current value smaller than the current value set before the reception of the signal to maintain a current output to the other load.

  The present invention includes a current setting unit that sets a predetermined current. For example, the current supplied by the current supply unit can be changed by 2A, 1A, or the like. When the current maintaining unit accepts a signal for turning off the current output to one load at the accepting unit, the current maintaining unit causes the current setting unit to set a current value smaller than the current value set before accepting the signal to another load. Maintain the output current.

  For example, when the current supply unit supplies current to the two loads 1 and 2, it is assumed that the rated currents of the loads 1 and 2 are set to 1A, and the current supplied by the current supply unit is set to 2A. When the current output to the load 1 is turned off, the current setting value of the current supply unit is changed from 2A to 1A, and the current output to the load 1 is turned off. Since the current set value of the current output to the load 2 is 1A, it can be maintained at 1A without change before and after the current output to the load 1 is turned off.

  An illumination device according to the present invention includes the power supply device according to any one of the above-described inventions, and a light source that outputs a current from the power supply device.

  In the present invention, when outputting current to a plurality of light sources, the power supply apparatus can prevent fluctuations in the current output to other light sources even when the current output to one light source is changed. Therefore, it is possible to prevent the brightness of other light sources from changing according to the light control of one light source.

  According to the present invention, when current is supplied to a plurality of loads, fluctuations in current output to other loads can be prevented even when the current output to one load is changed.

3 is a block diagram illustrating a configuration example of a lighting device including the power supply device according to Embodiment 1. FIG. FIG. 3 is an explanatory diagram illustrating an example of a control parameter for a dimming rate of an LED load of the power supply device according to the first embodiment. 3 is a time chart illustrating an example of current control by the power supply device according to the first embodiment. 6 is a time chart showing another example of current control by the power supply device of the first embodiment. 10 is a block diagram illustrating a configuration example of a lighting device including the power supply device according to Embodiment 2. FIG. FIG. 10 is an explanatory diagram illustrating an example of a current set value by the power supply device according to the second embodiment. FIG. 10 is an explanatory diagram illustrating an example of a control parameter for a dimming rate of an LED load of the power supply device according to the second embodiment. 6 is a time chart illustrating an example of current control by the power supply device according to the second embodiment. 10 is a time chart illustrating another example of current control by the power supply device according to the second embodiment. 10 is a block diagram illustrating a configuration example of a lighting device including the power supply device according to Embodiment 3. FIG. It is a block diagram which shows the principal part of a structure of the conventional illuminating device. It is a time chart which shows an example of the operation state of the conventional illuminating device.

(Embodiment 1)
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram illustrating a configuration example of a lighting device including the power supply device 100 according to the first embodiment. The lighting device of Embodiment 1 includes a power supply device 100, LED loads 1 and 2 as light source loads, and the like. In the following, a lighting device including an LED load (light source) as a load of the power supply device 100 will be described. However, the load is not limited to the light source, and the light source is not limited to the LED.

  The power supply device 100 functions as a constant current circuit 10 as a current supply unit, and a pulse width modulation unit that adjusts the on / off time of the current output to the LED loads 1 and 2 connected in parallel to the constant current circuit 10. The PWM circuits 20 and 30, a control unit 50 that controls the entire power supply device 100, and a reception unit 40 that receives a dimming signal for adjusting the brightness of the LED loads 1 and 2 from a remote controller (not shown). The dimming signal is not limited to the configuration that is received from the remote controller, but may be a configuration that is obtained from an operation switch provided in the lighting device body or a dimmer provided separately from the lighting device. .

  The LED loads 1 and 2 are, for example, one or a plurality of LED modules mounted on a substrate. The LED modules of the LED load 1 may have different emission colors (for example, a light bulb color and a neutral white color) or the same color. The same applies to the LED module of the LED load 2. Further, the emission colors may be different between the LED loads 1 and 2. In the following description, for the sake of simplicity, the rated current of LED loads 1 and 2 (the average value of current at a dimming rate of 100%) is 1 A, but is not limited thereto.

  The constant current circuit 10 includes a rectifier circuit and converts an input voltage (for example, AC 100 V, AC 200 V, etc.) into a DC voltage. The constant current circuit 10 includes an output current control circuit 11 that controls the output current to be constant. Since the rated currents of the LED loads 1 and 2 are each 1 A, the output current control circuit 11 requires the sum of both currents to flow the rated current 1 A to the LED loads 1 and 2 connected in parallel. Control is performed to supply a constant current of 2A. The input voltage is not limited to an AC voltage, and may be a DC voltage.

  The PWM circuit 20 includes a switching element such as an FET for turning on / off the current output to the LED load 1, a PWM (Pulse Width Modulation) control circuit for performing pulse width modulation, and the like. By applying the pulse waveform, the on time and off time of the current flowing through the FET are adjusted, and the on time and off time of the current output to the LED load 1 are adjusted. The PWM circuit 30 has a similar configuration.

  The modulation frequency of the pulse waveform can be, for example, about 100 Hz to 20 kHz, but is not limited thereto. The sum of the on time and off time of the current is one cycle, and the ratio of the on time to one cycle is referred to as the duty ratio. By adjusting the on time and the off time, for example, the dimming rate of the LED loads 1 and 2 can be adjusted from 0% (lights off) to 100% (all lights).

  The receiver 40 performs pulse width modulation on the current output to the LED load 1 or the LED load 2 and changes the average value of the current (current integrated value, that is, current integrated value per cycle of the pulse width modulation). It has a function as a reception part which receives the signal for. The receiving unit 40 receives a signal for dimming the LED loads 1 and 2 by, for example, wireless or wired. The receiving unit 40 outputs the received dimming signal to the control unit 50.

  When receiving a signal for pulse width modulating the current output to one load, the control unit 50 is a current maintaining unit that maintains the current (average current value) output to another load before and after the reception. It has the function of.

  That is, for example, when the receiving unit 40 receives a dimming signal for changing the current (average value) output to the LED load 1, the control unit 50 outputs the current output to the LED load 1 to the receiving unit. The PWM circuit 20 is controlled so as to obtain a current corresponding to the dimming signal received at 40, and the average value of the current output to the LED load 2 by controlling the PWM circuit 30 is Do not fluctuate before and after receiving.

  Since the control unit 50 maintains the average value of the current output to the LED load 2 even when the current (average value) output to the LED load 1 is changed, the current is supplied from the constant current circuit 10 to a plurality of loads. In this case, even when the current output to one load is changed, fluctuations in the average value of the current output to another load can be prevented.

  Further, when the control unit 50 receives a signal (dimming signal) for changing the current (average value) output to the LED load 1 by the receiving unit 40, the control unit 50 controls the PWM circuit 20 to control the PWM circuit. 20 causes a current corresponding to the received signal to be output to the LED load 1. At the same time, the control unit 50 controls the PWM circuit 30 so that the current (average value) output to the LED load 2 does not change before and after receiving the dimming signal.

  More specifically, the control unit 50 controls the PWM circuits 20 and 30 so that the ON times of the currents output from the PWM circuits 20 and 30 to the LED loads 1 and 2 do not overlap each other. That is, the control unit 50 determines the duty ratio of the pulse waveform output from the PWM circuits 20 and 30 to the gates of the FETs as control parameters according to the dimming rates of the LED loads 1 and 2, respectively. The timing of the pulse waveform is adjusted so that each FET is not turned on at the same time.

  That is, the control unit 50 includes a storage unit that stores in advance control parameters including on / off times of currents output from the PWM circuits 20 and 30 in association with signals received by the reception unit 40. The control unit 50 adjusts the on / off time of the current output from the PWM circuits 20 and 30 in response to the signal received by the receiving unit 40. Thereby, even when the current (average value) output to one load is changed to a desired value, fluctuation of the average value of the current output to another load can be prevented.

  FIG. 2 is an explanatory diagram illustrating an example of control parameters for the dimming rates of the LED loads 1 and 2 of the power supply apparatus 100 according to the first embodiment. The horizontal column in FIG. 2 shows the dimming rate of the LED load 1, and the vertical column shows the dimming rate of the LED load 2. In FIG. 2, examples of dimming rates of 25%, 50%, 75%, and 100% (all lamps) are shown, but the dimming rate is an example and is not limited to this. For example, the dimming rate can be changed every 5% between 0 and 100%, the dimming rate can be changed every 10%, or continuously. It may be changed.

  In each column corresponding to the dimming rate of the LED loads 1 and 2, the upper three values are the peak value of the current output to the LED load 1 in order from the left, the on / off duty ratio, and the LED load 1 Indicates the average value (integrated value per cycle) of the output current, and the lower three values are the peak value of the current output to the LED load 2 in order from the left, the on / off duty ratio, and the LED load. The average value of the current output to 2 is shown.

  For example, when the dimming rate of the LED load 1 is 100% and the dimming rate of the LED load 2 is 25%, the peak value of the current output to the LED load 1 is 2A, and the current on / off duty is The ratio is 50%, and the average value of the current output to the LED load 1 is 1 A (2 A × 0.5). Further, the peak value of the current output to the LED load 2 is 2A, the duty ratio of current on / off is 12.5%, and the average value of the current output to the LED load 2 is 0.25A (2A × 0. 125). The same applies to other dimming rates.

  The control unit 50 stores control parameters as illustrated in FIG. 2 in advance, and selects the stored control parameters in accordance with the received dimming signal to control the PWM circuits 20 and 30. Alternatively, control parameters may not be stored in advance, but parameters for controlling the PWM circuits 20 and 30 may be calculated each time a dimming signal is received.

  Next, the operation of the power supply device 100 according to the first embodiment will be described. FIG. 3 is a time chart showing an example of current control by the power supply device 100 according to the first embodiment. As shown in FIG. 3A, the LED load 1 is adjusted to have a peak value of 2 A, a current on time of 50%, an off time of 50%, and an average current of 1 A (rated current) is output. The LED load 2 is adjusted such that the peak value is 2 A, the current on time is 25%, the off time is 75%, and an average value of 0.5 A (50% of the rated current) is output. And That is, in the state shown in FIG. 3A, the dimming rate of the LED load 1 is 100%, and the dimming rate of the LED load 2 is 50%.

  When the dimming signal for changing the dimming rate of the LED load 1 from 100% to 50% is received, the control unit 50 changes the average value of the current output to the LED load 1 from 1 A to 0.5 A. In order to change, as shown in FIG. 3B, the LED load 1 is adjusted to have a peak value of 2A, a current on time of 25%, an off time of 75%, and an average current value of 1A to 0.5A ( 50% of the rated current).

  In this case, in order to prevent the ON times of the currents output to the LED loads 1 and 2 from overlapping, for example, the control unit 50 sets the LED load 2 to a peak value of 2A and a current ON time of 25%. The off time is adjusted to 75% and the average value is maintained to output a current of 0.5 A (50% of the rated current).

  In order to adjust the duty ratio of the pulse waveforms of the PWM circuits 20 and 30 so that the current ON times do not overlap, the pulse waveform rise time (current ON start time) of one PWM circuit and the other PWM circuit What is necessary is just to synchronize with the OFF start time of the electric current of a circuit.

  Even if the current (average value) output to one load is changed to a desired value by preventing the ON times of the currents adjusted by the PWM circuits 20 and 30 from overlapping, the currents output to other loads The fluctuation of the average value can be prevented.

  FIG. 4 is a time chart showing another example of current control by the power supply apparatus 100 according to the first embodiment. As shown in FIG. 4A, it is assumed that the LED loads 1 and 2 are adjusted to output a current (rated current) having a peak value of 1 A, a current on time of 100%, and an average value of 1 A. That is, in the state shown in FIG. 4A, the dimming rate of the LED loads 1 and 2 is 100%.

  When the dimming signal for changing the dimming rate of the LED load 1 from 100% to 50% is received, the control unit 50 changes the current of the LED load 1, so that the peak value is 2A, The on time is adjusted to 25%, the off time is adjusted to 75%, and the average value of the current is changed from 1 A to 0.5 A (50% of the rated current).

  In this case, the control unit 50 adjusts the duty ratio for the LED load 2 so that the ON times of the currents output to the LED loads 1 and 2 do not overlap. For example, the control unit 50 adjusts the LED load 2 so that the peak value is 2A, the current on time is 50%, the off time is 50%, and the current (rated current) having an average value of 1A is output. maintain. Even if the current (average value) output to one load is changed to a desired value by preventing the ON times of the currents adjusted by the PWM circuits 20 and 30 from overlapping, the currents output to other loads The fluctuation of the average value can be prevented.

  3 and 4 are common in that the ON times of the currents adjusted by the PWM circuits 20 and 30 do not overlap, but in the example of FIG. 3, the current output to the LED load 2 is the same. However, in the example of FIG. 4, it is necessary to change the on / off duty ratio of the current output to the LED load 2.

(Embodiment 2)
FIG. 5 is a block diagram illustrating a configuration example of a lighting device including the power supply device 110 according to the second embodiment. The difference from the first embodiment is that a current setting unit 12 that sets a predetermined current is provided. In the power supply device 110 according to the second embodiment, the current value supplied by the constant current circuit 10 can be varied, and the output current control circuit 11 controls the current so that the current value set by the current setting unit 12 is obtained. Under the control of the control unit 50, the current setting unit 12 can change the current supplied by the constant current circuit 11 to 2A, 1A, or the like, for example.

  FIG. 6 is an explanatory diagram illustrating an example of a current setting value by the power supply device 110 according to the second embodiment. The control unit 50 varies the current set by the current setting unit 12 depending on whether or not the ON times of the currents adjusted by the PWM circuits 20 and 30 overlap. More specifically, the control unit 50 increases the current set by the current setting unit 12 in a time zone in which the ON times of the currents adjusted by the PWM circuits 20 and 30 overlap.

  For example, as shown in FIG. 6, when both of the currents output to the LED loads 1 and 2 are turned on, the current setting value is set to 2A (the current value is increased). In addition, when one of the currents output to the LED loads 1 and 2 is turned on and the other is turned off, the current setting value is set to 1A (the current value is reduced).

  FIG. 7 is an explanatory diagram illustrating an example of control parameters for the dimming rates of the LED loads 1 and 2 of the power supply device 110 according to the second embodiment. The horizontal column of FIG. 7 shows the dimming rate of the LED load 1, and the vertical column shows the dimming rate of the LED load 2. In FIG. 7, examples of the dimming rate of 25%, 50%, 75%, and 100% (all lamps) are shown, but the dimming rate is an example and is not limited thereto. For example, the dimming rate can be changed every 5% between 0 and 100%, the dimming rate can be changed every 10%, or continuously. It may be changed.

  In the columns corresponding to the dimming rates of the LED loads 1 and 2, as in the case of FIG. 2, the upper three values are the peak values of the current output to the LED load 1 in order from the left, on / off Duty ratio, the average value of the current output to the LED load 1 (the integrated value per one cycle of the pulse width), and the lower three values are the wave of the current output to the LED load 2 in order from the left A high value, an on / off duty ratio, and an average value of current output to the LED load 2 are shown.

  For example, when the dimming rate of the LED load 1 is 100% and the dimming rate of the LED load 2 is 25%, the peak value of the current output to the LED load 1 is 1 A, and the current on / off duty is The ratio is 100%, and the average value of the current output to the LED load 1 is 1A. Moreover, the peak value of the current output to the LED load 2 is 1 A, the duty ratio of current on / off is 25%, and the average value of the current output to the LED load 2 is 0.25 A (1 A × 0.25). It is. The same applies to other dimming rates.

  FIG. 8 is a time chart illustrating an example of current control by the power supply device 110 according to the second embodiment. As shown in FIG. 8A, the LED loads 1 and 2 are adjusted to have a peak value of 1A, an on-time of current of 100%, and an average current of 1A (rated current) is output. That is, in the state shown in FIG. 8A, the dimming rates of the LED loads 1 and 2 are 100%, and the current setting value is 2A.

  When the dimming signal for changing the dimming rate of the LED load 1 from 100% to 50% is received, the control unit 50 changes the average value of the current output to the LED load 1 from 1 A to 0.5 A. To change, as shown in FIG. 8B, the peak value is adjusted to 1A, the current on time is adjusted to 50%, the off time is adjusted to 50%, and the average value of the current is changed from 1A to 0.5A (50% of the rated current). To.

  In this case, the control unit 50 varies the current set by the current setting unit 12 between the time zone in which the ON times of the currents output to the LED loads 1 and 2 overlap and the time zone in which they do not overlap. For example, the control unit 50 sets the output current set value to 2A (increases the set current value) and does not overlap the current on time in the time zone indicated by the symbol b in FIG. 8B where the current on times overlap. In the time zone indicated by the symbol a of 8B, the set value of the output current is 1A.

  Then, as shown in FIG. 8B, the control unit 50 adjusts the LED load 2 so that the peak value is 1A, the current on time is adjusted to 100%, and the current (rated current) having an average value of 1A is output. To maintain. Even when the current output to one load is changed to a desired value by increasing the current value set by the current setting unit 12 in a time zone in which the ON times of the currents adjusted by the PWM circuits 20 and 30 overlap. Thus, fluctuations in the current output to other loads can be prevented.

  FIG. 9 is a time chart illustrating another example of current control by the power supply device 110 according to the second embodiment. As shown in FIG. 9A, it is assumed that the LED load 1 is adjusted to have a peak value of 2A, a current on time of 25%, an off time of 75%, and an average value of 0.5A. It is assumed that the LED load 2 is adjusted to have a peak value of 2 A, a current on time of 50%, an off time of 50%, and an average value of 1 A. That is, in the state shown in FIG. 9A, the dimming rate of the LED load 1 is 50%, the dimming rate of the LED load 2 is 100%, and the current setting value is 2A.

  When the dimming signal for changing the dimming rate of the LED load 1 from 50% to 75% is received, the control unit 50 changes the current of the LED load 1, so that the peak value is 1A, The on time is adjusted to 75%, the off time is adjusted to 25%, and the average value of the current is changed from 0.5 A to 0.75 A (75% of the rated current).

  In this case, the control unit 50 increases the current value set by the current setting unit 12 in a time zone in which the ON times of the currents output to the LED loads 1 and 2 overlap. For example, in the time zone indicated by reference symbol b in FIG. 9B where the current on-time overlaps, the set value of the output current is 2A, and in the time zone indicated by reference symbol a in FIG. The value is 1A.

  Then, the control unit 50 adjusts the LED load 2 so as to output a current (rated current) with an average value of 1 A by adjusting the peak value to 1 A and the current on time to 100%. The current (average value) output to one load is changed to a desired value by increasing the current value set by the current setting unit 12 in the time zone in which the ON times of the currents adjusted by the PWM circuits 20 and 30 overlap. Even in such a case, fluctuations in the average value of the current output to other loads can be prevented.

  8 and 9 are different in that the current set by the current setting unit 12 is different between the time zone in which the ON times of the currents adjusted by the PWM circuits 20 and 30 overlap and the time zone in which they do not overlap. Although common, it is not necessary to change the on / off duty ratio of the current output to the LED load 2 in the example of FIG. 8, but the on / off duty of the current output to the LED load 2 in the example of FIG. It is necessary to change the ratio.

(Embodiment 3)
FIG. 10 is a block diagram illustrating a configuration example of a lighting device including the power supply device 120 according to the third embodiment. The difference from the second embodiment is that switch circuits 61 and 62 are provided instead of the PWM circuits 20 and 30. That is, the power supply device 120 according to the third embodiment includes switch circuits 61 and 62 for turning on / off currents output to the LED loads 1 and 2 connected in parallel to the constant current circuit 10, and includes a plurality of LED loads. Are not dimming, but can be turned on / off individually.

  The receiving unit 40 has a function as a receiving unit that receives a signal for turning off the current output to the LED loads 1 and 2.

  When receiving a signal for turning off the current output to one load, the control unit 50 has a function as a current maintaining unit that maintains an average value of currents output to other loads before and after the reception.

  That is, for example, when the receiving unit 40 receives a signal for turning off the current (average value) output to the LED load 1, the control unit 50 controls the switch circuit 61 to output current to the LED load 1. And the current value set by the current setting unit 12 is changed to a value smaller than the value set before receiving the signal so that the average value of the current output to the LED load 2 does not fluctuate. To.

  Even when the control unit 50 turns off the current output to one LED load, the average value of the current output to other LED loads is maintained. Even when the current output to the load is changed, fluctuations in the average value of the current output to the other LED loads can be prevented.

  More specifically, it is assumed that the rated currents of the LED loads 1 and 2 are set to 1A, and the current supplied by the constant current circuit 10 is set to 2A. When the current output to the LED load 1 is turned off, the current set value is changed from 2A to 1A, and the current output to the LED load 1 is turned off. Since the current set value of the current output to the LED load 2 is 1A, 1A can be maintained without change before and after the current output to the LED load 1 is turned off.

  According to the above-described embodiment, when a plurality of LED loads are individually controlled to be turned on / off by one constant current circuit, or when a plurality of LED loads are individually controlled to be dimmed, on / off control or adjustment is performed. It is possible to prevent the brightness of other LED loads not subject to light control from changing unexpectedly.

  When a plurality of LED loads are connected in parallel to one constant current circuit as in the above embodiment, the output voltage of the constant current circuit (power supply circuit) can be lowered. For example, since one LED load includes 8 to 10 LEDs connected in series, a voltage of about 25 to 33 V is applied to one LED load. Therefore, when the LED loads are connected in parallel, the output voltage of the power supply circuit may be about 25 to 33 V. However, if the LED loads are connected in series, the output voltage of the power supply circuit is about It needs to be raised to 50 to 66V. If the output voltage of the power supply circuit becomes high, it is necessary to design the board in consideration of safety and reliability (for example, anti-condensation, migration, etc.), and it is also necessary to secure a clearance according to the Electric Safety Act Therefore, these measures must be taken. However, when a plurality of LED loads are connected in parallel as in the present embodiment, the above-described measures are not necessary.

  In addition, when a plurality of LED loads are connected in parallel to one constant current circuit, even when one LED in the LED load has an open failure, it is possible to avoid a situation where all the lights are not turned on. That is, when a plurality of LED loads are connected in series to one constant current circuit, even if any one of the plurality of LED loads causes an open failure, no current flows through each LED load, and all LEDs Goes off. However, when a plurality of LED loads are connected in parallel to one constant current circuit, even if one LED of the LED load becomes an open failure, the other LED loads other than the LED load have a current. Therefore, a part of the LED loads is turned on, and it is possible to avoid a situation where all the lights are not lit.

  In the above-described embodiment, when the dimming rate of one LED load is changed while the LED loads 1 and 2 are lit, the current output to the other LED load, that is, the brightness of the LED load varies. However, the present invention is not limited to this. When one LED load is turned off and the other LED load is turned on, a signal (light control) for turning on the one LED load is explained. Even if the signal is not a signal for changing the rate, the output current to the other LED loads, that is, the brightness of the other LED loads can be prevented from changing.

  In the above-described embodiment, an example in which an LED is used as a light source has been described. However, the present invention is not limited to an LED, and other light sources such as EL (Electro-Luminescence) may be used. Moreover, in the above-mentioned embodiment, although it was the structure provided with two LED loads, the structure provided with three or more LED loads may be sufficient.

  In the above-described embodiment, the example of the lighting device that supplies the output current of the power supply device to the LED has been described. However, the load of the power supply device is not limited to the light source such as the LED, and a plurality of loads are individually controlled. The present embodiment can be applied not only to the lighting device but also to other electric appliances as long as it has a function to do so.

DESCRIPTION OF SYMBOLS 1, 2 LED load 10 Constant current circuit 11 Output current control circuit 12 Current setting part 20, 30 PWM circuit 40 Reception part 50 Control part 61, 62 Switch circuit

Claims (8)

Provided between a current supply unit that supplies a predetermined current and each of the current supply unit and a plurality of loads connected in parallel to the current supply unit. In a power supply device comprising a plurality of pulse width modulation units that output to and a reception unit that receives a signal for pulse width modulation of a current output to an arbitrary load,
A power supply comprising: a current maintaining unit that maintains a current output to another load before and after the reception when the reception unit receives a signal for pulse width modulation of the current output to the one load apparatus. When the reception unit receives a signal for pulse width modulating the current output to one load, the pulse width modulation unit for pulse width modulating the current output to the one load turns on / off the output current. Adjust the time,
The current maintaining unit is
2. The configuration according to claim 1, wherein each pulse width modulation unit is configured to adjust the on-time of the current output to each load so as not to overlap and maintain the current output to the other load. The power supply described. A current setting unit for setting the predetermined current;
When the reception unit receives a signal for pulse width modulating the current output to one load, the pulse width modulation unit for pulse width modulating the current output to the one load turns on / off the output current. Adjust the time,
The current maintaining unit is
The current setting unit is configured to increase the current value set by the current setting unit and maintain the current output to the other load in a time period in which the ON times adjusted by the respective pulse width modulation units overlap. The power supply device according to claim 1. The current maintaining unit is
When receiving a signal for pulse width modulating the current output to one load in the receiving unit, the pulse width modulating unit other than the pulse width modulating unit for pulse width modulating the current output to the one load 4. The power supply device according to claim 2, wherein the current on / off time is adjusted. In association with the signal received by the reception unit, a storage unit that stores in advance the on / off time of the current output by each pulse width modulation unit,
The current maintaining unit is
5. The ON / OFF time of the current output from each pulse width modulation unit is adjusted in accordance with the signal received by the reception unit. 6. The power supply device according to item. Provided between a current supply unit for supplying a predetermined current and each of the current supply unit and a plurality of loads connected in parallel to the current supply unit, and for turning on / off the current from the current supply unit In a power supply device including a plurality of switch units that output a current to each load and a reception unit that receives a signal for turning on / off a current output to an arbitrary load,
A power supply comprising: a current maintaining unit that maintains a current output to another load before and after the reception when the reception unit receives a signal for turning on / off a current output to the one load apparatus. A current setting unit for setting the predetermined current;
The current maintaining unit is
When the signal for turning off the current output to one load is received by the receiving unit, the current setting unit sets a current value smaller than the current value set before receiving the signal to the other load. The power supply device according to claim 6, wherein the power supply device is configured to maintain a current to be output.   An illumination device comprising: the power supply device according to any one of claims 1 to 7; and a light source that outputs a current from the power supply device.

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