JP2014022105A - Power supply device, and illuminating device - Google Patents

Abstract

Provided are a power supply device and a lighting device that can prevent an excessive current from flowing to other light sources even when a disconnection occurs in some light sources and the current stops flowing.
A power supply apparatus includes a drive circuit, a control unit, and detection circuits for detecting abnormalities in the LED modules, and driving that flows in the LED modules. FET21, FET22 etc. which turn on / off an electric current are provided. The detection circuits 41 to 44 detect whether or not the LED modules 201 to 204 are non-conductive in a state where no current is output to the LED modules 201 to 204. The control unit 30 controls the drive circuit 20 to output a correction current when any of the detection circuits 41 to 44 detects non-conduction of the LED modules 201 to 204.
[Selection] Figure 1

Description

  The present invention relates to a power supply device that outputs a driving current to a plurality of light sources connected in parallel 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 general, an LED can obtain a required brightness by flowing a predetermined current. Therefore, in a lighting device using an LED as a light source, a power supply device including a constant current circuit is used to drive the LED. ing.

  For example, an LED lighting circuit is disclosed in which a DC power source is driven to be lit at a constant current for an LED module in which a plurality of LED load circuits composed of a plurality of series of LEDs are connected in parallel (Patent Document 1). reference). In each LED load circuit, a PTC thermistor having a characteristic that the resistance value increases as the ambient temperature rises is inserted in series.

JP 2012-9350 A

  According to the LED lighting circuit described in Patent Document 1, if any LED or LED load circuit (load) is disconnected (open), a current exceeding the rated current flows to the remaining LED load circuit, and the temperature rises. Then, the resistance value of the PTC thermistor operates so as to increase, and a current that is equal to or lower than the rated current or equal to or higher than the rated current and equal to or lower than the absolute maximum rated current flows.

  However, in the LED lighting circuit of Patent Document 1, if any one of the LEDs or the LED load circuit (load) is disconnected (open), the remaining other time until the resistance value of the PTC thermistor increases. The LED load circuit (load) has a problem that the current that has flowed through the LED load circuit in which the disconnection has occurred flows, and an excessive current flows through the remaining LED load circuit. In addition, when the excessive current exceeds the maximum rated current, there is a possibility that problems such as smoke generation may occur due to heat generated by the overcurrent.

  The present invention has been made in view of such circumstances, and a power supply device capable of preventing an excessive current from flowing to another light source even when a disconnection occurs in some of the light sources and the current does not flow. An object of the present invention is to provide a lighting device including the power supply device.

  A power supply device according to the present invention includes a power supply unit that outputs a predetermined drive current that turns on a light source unit in which a plurality of light sources are connected in parallel. In the power supply unit, the light source unit has a current value that does not light the light source unit. A detection unit that detects non-conduction of the light source in an output state, and the power source unit has a correction current that is smaller than the predetermined drive current when the detection unit detects non-conduction of any of the light sources; The light source unit is turned on by outputting to the light source unit.

  In the present invention, the power supply unit outputs a predetermined driving current for lighting a light source unit in which a plurality of light sources are connected in parallel. For example, if the parallel number of light sources connected in parallel is 4, and the predetermined drive current output from the power supply unit is I, a current of I / 4 flows through each load. The detection unit detects non-conduction of the light source in a state where a current having a value that does not light the light source unit is output to the light source unit. The non-conduction of the light source is, for example, an event such as disconnection (open) inside the light source or disconnection (open) in a circuit connecting the light source, and current is supplied to any one of the plurality of light sources constituting the light source unit. It does not flow. The power supply unit outputs a correction current smaller than a predetermined drive current when the detection unit detects non-conduction of any one of the light sources.

  For example, it is assumed that when all four light sources connected in parallel are normal, the power supply unit outputs a drive current I, and a current having a value of I / 4 flows through each light source. When detecting non-conduction (for example, disconnection) of one light source, the power supply unit outputs a correction current I ′ (<I) smaller than the drive current I to turn on the light source. As a result, a current having a value of I ′ / 3 smaller than I / 3 can be passed to the other three light sources other than the light source detected as non-conducting. Even when non-conduction occurs and current stops flowing, overcurrent can be prevented from flowing to other light sources. In addition, since the non-conduction of the light source is detected in a state where a current value that does not light the light source is output, an excess current does not flow to a normal light source even for a moment.

  In the power supply device according to the present invention, when the non-conduction of the light source is detected by the detection unit, the control for controlling the correction current output from the power supply unit to be adjusted according to the parallel number of the light sources that are conducting It is characterized by providing a part.

  In the present invention, when the detection unit detects the non-conduction of the light source, the control unit controls the correction current output from the power source unit to be adjusted according to the parallel number of the light sources that are conducting. For example, assume that the parallel number N is 4, a predetermined drive current output from the power supply unit is I, and a current of I / 4 flows through each light source. When it is detected that one of the four light sources is non-conductive (for example, disconnection), the power supply unit outputs a current having a value of I × (N−1) / N. Here, (N-1) is the number of parallel light sources that are conducting. Thus, the other three light sources except the light source detected as non-conducting have {I × (N−1) / N} × 1/3, that is, N = 4, A current flows and a current having a value when the light source is normal can be flown, and an excessive current can be prevented from flowing to a normal light source.

  The power supply device according to the present invention is characterized in that the control unit controls the detection unit to detect non-conduction of the light source in a state where the light source unit is turned off.

  In the present invention, the control unit controls the detection unit to detect non-conduction of the light source while the light source unit is turned off. In other words, when non-conduction of the light source is detected, adjustment is made so that the drive current output from the power supply unit is reduced, and the adjusted correction current is output to the light source unit, so that an excess current flows through a normal light source even for a moment. The situation can be prevented.

  In the power supply device according to the present invention, the detection unit includes a plurality of resistors connected in series to the plurality of light sources, and detects the non-conduction of each light source by determining the presence or absence of a current flowing through the resistors. It is characterized by being.

  In the present invention, the detection unit includes a plurality of resistors connected in series to each of the plurality of light sources, and detects the non-conduction of each light source by determining the presence or absence of a current flowing through each resistor. That is, a current that does not light the light source is supplied to each resistor through the light source. When no current flows through the resistor, it can be detected that the light source is non-conductive (disconnected). . Thereby, non-conduction of the light source can be detected with a simple configuration.

  The power supply device according to the present invention includes an opening / closing element in series with the resistor, and the control unit is configured to close the opening / closing element when the detection unit detects non-conduction of the light source. To do.

  In the present invention, the switching element is provided in series with the resistor, and the control unit closes the switching element when the detection unit detects non-conduction of the light source. That is, when the non-conduction of the light source is detected, the switching element is closed, and when the non-conduction of the light source is not detected, the opening / closing element is opened to prevent the current from constantly flowing through the resistor. Since the current is allowed to flow through the resistor only when necessary when detecting non-conduction, wasteful power consumption can be suppressed.

  In the power supply device according to the present invention, the power supply unit outputs a drive current having a predetermined frequency having an intermittent period in which lighting and non-lighting of the light source are alternately performed. Control is performed to detect non-conduction of the light source during the non-lighting period of the light source.

  In the present invention, the power supply unit outputs a drive current having a predetermined frequency having an intermittent period in which lighting and non-lighting of the light source occur alternately. That is, the power supply unit intermittently outputs a drive current based on a PWM control signal that is alternately repeated at a predetermined frequency having an intermittent period in which lighting and non-lighting of a light source are alternately generated by PWM control, for example. The control unit controls the detection unit to detect non-conduction of the light source during the non-lighting period of the light source. As a result, even when the light source is turned on, it is possible to detect the non-conduction of the light source using the period when the drive current does not flow intermittently, that is, the non-lighting period of the light source. Even when the light source is turned on when the light source is turned on in an alternating state, it is possible to prevent a situation in which excessive current flows evenly for a normal light source.

  An illumination device according to the present invention includes the power supply device according to any one of the above-described inventions.

  In the present invention, it is possible to provide an illumination device that can prevent an excessive current from flowing to other light sources even when non-conduction occurs in some of the light sources.

  According to the present invention, it is possible to prevent excessive current from flowing to other light sources even when a disconnection occurs in some light sources and the current stops flowing.

It is a block diagram which shows an example of a structure of the illuminating device of this Embodiment. It is explanatory drawing which shows typically an example of operation | movement of the power supply device of this Embodiment. It is explanatory drawing which shows an example of the electric current which flows into each LED module at the time of the lighting start by the power supply device of this Embodiment. It is explanatory drawing which shows an example of the electric current setting by the power supply device of this Embodiment. It is a circuit diagram which shows the other example of a structure of a detection circuit. It is explanatory drawing which shows an example of the detection method of the non-conduction of the LED module at the time of color matching of the power supply device of this Embodiment.

  Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a block diagram illustrating an example of the configuration of the lighting device of the present embodiment. As shown in FIG. 1, the lighting device includes a power source device 100, a light source unit in which LED modules 201, 202, 203, and 204 as a plurality of light sources are connected in parallel. That is, the light source unit has a configuration in which four LED modules 201 to 204 having a parallel number N of 4 are connected in parallel.

  The LED modules 201, 202 form an LED group in which a plurality of LEDs 2, 2,. The LED modules 203 and 204 form an LED group in which a plurality of LEDs 3, 3... 3 are connected in series.

  The LED 2 is, for example, a daylight white LED, and the LED 3 is, for example, a light bulb color LED. By providing LEDs with different emission colors, it is possible to adjust the emission color of the light source. Note that LEDs of the same color can be used for the LEDs 2 and 3.

  In the present embodiment, the non-conduction of the light source, that is, the non-conduction of the LED modules 201 to 204, for example, disconnects (opens) any of the LEDs constituting the LED module or connects the LEDs to each other. This is a state where a circuit (wiring) is disconnected (opened) or the like, and is a non-conducting state where a current of a value necessary for lighting the LEDs of some of the LED modules 201 to 204 does not flow.

  When a forward current If having a predetermined value (for example, a current having a predetermined value) flows, each of the LEDs 2 and 3 generates a forward voltage Vf having a predetermined value. When the number of LEDs 2 and 3 in the LED modules 201 to 204 in series is M, the total value VF of the forward voltages of the LEDs 2 and 3 of the LED modules 201 to 204 is VF = M × Vf. For example, when Vf = about 3.5V and M = 10, VF is about 35V. The number of LEDs and the forward voltage Vf are examples, and are not limited to these.

  The power supply device 100 includes a rectifier circuit 10, a drive circuit 20 serving as a power supply unit, a control unit 30 including a microcomputer, and detection circuits 41 and 42 serving as detection units that detect non-conduction of each of the LED modules 201 to 204. 43, 44, FET 21 for turning on / off a predetermined value of current flowing in the LED modules 201, 202, FET 22 for turning on / off a predetermined value of current flowing in the LED modules 203, 204, and resistors 61, 62, 63, 64 , Diodes 71, 72, 73, 74 and the like.

  Between the input terminals A1A2 of the power supply apparatus 100, a commercial power supply 1 such as AC100V or AC200V is connected. Further, the LED module 201 is connected between the output terminals B1B2 of the power supply device 100, the LED module 202 is connected between the output terminals B1B3, the LED module 203 is connected between the output terminals B1B4, and the LED module 204 is connected between the output terminals B1B5. Is done.

  The voltage rectified by the rectifier circuit 10 is supplied to the drive circuit 20.

  The drive circuit 20 includes a constant current circuit, and outputs a voltage having a predetermined value (for example, about 35V) and a drive current having a predetermined value. The predetermined drive current is a total value of forward currents (predetermined values of current) flowing through the LED modules 201 to 204, that is, a current flowing through the entire light source unit. For example, if the forward current (predetermined value) of each LED module 201-204 is I / 4, the parallel number N of the LED modules 201-204 is 4, so the predetermined drive output by the drive circuit 20 The current is I (4 × I / 4).

  That is, the drive circuit 20 outputs a predetermined drive current for lighting a light source unit in which a plurality of LED modules 201 to 204 are connected in parallel with an arbitrary parallel number. For example, assuming that the parallel number is 4 and the predetermined drive current output from the drive circuit 20 is I, a current having a value of I / 4 flows through each LED module 201 to 204.

  In the present embodiment, when the LED modules 201 to 204 are normal (all LEDs are in a conductive state, that is, a non-conductive state), the current output from the drive circuit 20 to the entire light source unit is obtained. This is called a drive current. In addition, when any of the LEDs of the LED modules 201 to 204 is non-conductive, that is, after detecting non-conduction, a current that the drive circuit 20 outputs to the entire light source unit is referred to as a correction current as described later. Note that the drive current and the correction current are currents of values necessary for lighting the LED modules 201 to 204.

  The LED modules 201 and 202 are connected to the drain of the FET 21 via diodes 71 and 72, and the source of the FET 21 is connected to a reference level such as a ground level. The gate of the FET 21 is connected to the terminal D 1 of the control unit 30. By turning on or off the FET 21 by outputting a signal for turning on / off the FET 21 from the terminal D1 of the control unit 30 to the gate of the FET 21, the current flowing through the LED modules 201 and 202 is turned on or off. Can do.

  The LED modules 203 and 204 are connected to the drain of the FET 22 via the diodes 73 and 74, and the source of the FET 22 is connected to the reference level. The gate of the FET 22 is connected to the terminal D2 of the control unit 30. By turning on or off the FET 22 by outputting a signal for turning on / off the FET 22 from the terminal D2 of the control unit 30 to the gate of the FET 22, the current flowing through the LED modules 203 and 204 is turned on or off. Can do.

  A detection circuit 41 is connected in series to the LED module 201, a detection circuit 42 is connected in series to the LED module 202, and a detection circuit 43 is connected in series to the LED module 203. The detection circuit 44 is connected to the LED module 204 in series. The detection circuits 41 and 42 are connected in parallel to the FET 21 and connected in series to the LED modules 201 and 202 regardless of whether the FET 21 is on or off. Similarly, the detection circuits 43 and 44 are connected in parallel to the FET 22 and connected in series to the LED modules 203 and 204 regardless of whether the FET 22 is on or off.

  The detection circuit 41 includes resistors 411, 412, and 413 connected in series, and a capacitor 414 connected in parallel to the resistor 413. Similarly, the detection circuit 42 includes resistors 421, 422, and 423 connected in series, and a capacitor 424 connected in parallel to the resistor 423. The detection circuit 43 includes resistors 431, 432, and 433 connected in series, and a capacitor 434 connected in parallel to the resistor 433. The detection circuit 44 includes resistors 441, 442, and 443 connected in series, and a capacitor 444 connected in parallel to the resistor 443.

  A detection terminal M1 of the control unit 30 is connected to a connection node between the resistors 412 and 413 through a resistor 61. Similarly, the detection terminal M2 of the control unit 30 is connected to the connection node between the resistors 422 and 423 via the resistor 62. A detection terminal M3 of the control unit 30 is connected to a connection node between the resistors 432 and 433 via a resistor 63. A detection terminal M4 of the control unit 30 is connected to a connection node between the resistors 442 and 443 through a resistor 64.

  The resistance values of the resistors 411, 412, 421, 422, 431, 432, 441, and 442 are, for example, 120 kΩ. The resistance values of the resistors 413, 423, 433, and 443 are, for example, 18 kΩ. The resistance values of the resistors 61 to 64 are, for example, 4.7 kΩ.

  The drive circuit 20 is configured to output a voltage of about 30 to 36 V from the output terminal Vout when an AC voltage is applied from the commercial power supply 1. For example, by turning on a power switch provided on the wall, the drive circuit 20 can start operation and output a voltage to the output terminal Vout.

  Further, the control unit 30 acquires a lighting start signal of the light source unit (LED modules 201 to 204) from a remote operation terminal (not shown) such as a remote control. The control unit 30 lights the light source modules 201 to 204 by acquiring the lighting start signal to turn the FETs 21 and 22 from off to on, or from the off to on / off repeatedly.

  When the drive circuit 20 is operating and the FETs 21 and 22 are off, the LED modules 201 to 204 are turned off. However, the voltage at the output terminal Vout of the drive circuit 20 is applied to the detection circuits 41 to 44 via the LED modules 201 to 204 by standby power, and the LED modules 201 to 204 are connected to the respective series resistors of the detection circuits 41 to 44. The current of a value that is less than the drive current for driving the LED modules 201 to 204 does not light.

  That is, in a state where the LED modules 201 to 204 are turned off (that is, a state where the drive circuit 20 does not output a drive current to the LED modules 201 to 204), the LED module 201 is not non-conductive (not disconnected). In this case, a voltage (for example, about 2.5 V) obtained by dividing the voltage of the output terminal Vout of the drive circuit by the resistors 411 and 412 and the resistor 413 is output to the detection terminal M1 of the control unit 30.

  On the other hand, in the state where the LED modules 201 to 204 are turned off, when the LED module 201 is non-conductive (disconnected), the voltage at the output terminal Vout of the drive circuit is not applied to the detection circuit 41. The detection terminal M1 of the control unit 30 is at a reference level (for example, 0V). Therefore, when the voltage value of the detection terminal M1 of the control unit 30 is higher than a predetermined threshold (for example, 1V), the LED module 201 can be detected as normal, and the detection terminal M1 of the control unit 30 can be detected. When the voltage value is lower than a predetermined threshold value (for example, 1 V), it can be detected that the LED module 201 is non-conductive.

  That is, in the detection circuit 41, the LED module 201 is non-conductive in a state where no drive current is output to the LED module 201, that is, in a state where a current having a value that does not light the LED module 201 is passed through the LED module 201. Whether or not it is monitored (monitored). The LED module 201 being non-conductive is, for example, an event such as a disconnection (open) in the LED module 201 or a disconnection (open) in a circuit connecting the LED module 201, and a current is supplied to the LED module 201. It does not flow. The configurations of the detection circuits 42, 43, and 44 are the same as those of the detection circuit 41 and operate in the same manner, so that the description thereof is omitted.

  When the control unit 30 detects the non-conduction (disconnection) of the LED modules 201 to 204 in any of the detection circuits 41 to 44, when the lighting start signal is acquired from the remote control, that is, the light source unit is turned off. When the lighting state is controlled, the correction current output to the entire light source unit composed of the LED modules 201 to 204 is less than the drive current output to the entire light source unit when all the LED modules 201 to 204 are normal. Adjust so that

  And when the drive circuit 20 detects the non-conduction of the LED modules 201 to 204 by the detection circuits 41 to 44 when the light source unit is turned off, the correction is less than the predetermined drive current when it is turned on next time. Output current. For example, when all four LED modules 201 to 204 connected in parallel are normal, the drive circuit 20 outputs a drive current I, and a current of I / 4 flows through each LED module 201 to 204. Suppose. When it is detected that one LED module is non-conductive (for example, disconnection or the like), the drive circuit 20 outputs a correction current I ′ (<I) smaller than the drive current I. As a result, a current having a value of I ′ / 3 smaller than I / 3 can be passed to the other three normal LED modules other than the LED module detected to be non-conductive. It is possible to prevent an overcurrent having a value of I / 3 from flowing through. In addition, when the LED modules 201 to 204 are monitored for non-conduction in a state where no drive current flows to the LED modules 201 to 204 and non-conduction (disconnection) is detected, a predetermined drive is performed when the LED modules 201 to 204 are turned on next time. Since a correction current I ′ smaller than the current I is supplied to the light source unit, an excess current having a value of I / 3 does not flow even for a moment in a normal LED module.

  FIG. 2 is an explanatory diagram schematically showing an example of the operation of the power supply apparatus 100 of the present embodiment. As shown in FIG. 2A, it is assumed that the control unit 30 acquires a lighting start signal from a remote controller or the like at time t. As shown in FIG. 2B, at the time before time t, the LED modules 201 to 204 are in the extinguished state, and in this extinguished state, the control unit 30 outputs the voltages output from the detection circuits 41 to 44 to the detection terminals M1 to M1. Monitored with M4.

  Then, as shown in FIG. 2C, at time t, the control unit 30 determines whether any of the LED modules 201 to 204 is non-conductive based on the voltage output from the detection circuits 41 to 44, If it is determined to be non-conductive, current setting (adjustment) is performed so that the drive circuit 20 outputs a correction current. Further, when it is determined that it is not non-conductive, the control unit 30 sets the current so that the drive circuit 20 outputs a predetermined drive current.

  As illustrated in FIG. 2D, the drive circuit 20 outputs the correction current set by the control unit 30.

  FIG. 3 is an explanatory diagram illustrating an example of a current flowing through each LED module at the start of lighting by the power supply device 100 according to the present embodiment. FIG. 4 is an explanatory diagram illustrating an example of a current setting performed by the power supply device 100 according to the present embodiment. FIG. When the non-conduction of the LED modules 201 to 204 is detected by the detection circuits 41 to 44, the control unit 30 controls the predetermined drive current output from the drive circuit 20 to decrease according to the parallel number N.

  For example, as described above, the parallel number N is set to 4, the predetermined drive current output from the drive circuit 20 is set to I, and each LED module 201 to 204 when all the LED modules are normally conducted includes Assume that a current of I / 4 flows. When it is detected that one of the four LED modules 201 to 204, for example, the LED module 204 is non-conducting (for example, disconnection), the drive circuit 20 controls I × (N− 1) A correction current of / N is output to the light source unit. Here, (N-1) is the parallel number of LED modules that are conducting. In the example of FIG. 3, the drive circuit 20 outputs a correction current of I × (4-1) / 4 = I × 3/4. Therefore, the remaining normal LED modules 201 to 203 are indicated by solid lines. A current having an I / 4 value comparable to the initial current value flows.

  On the other hand, in the conventional example that does not depend on the present embodiment (comparative example shown by a broken line in FIG. 3), when the LED module 204 is disconnected (open), the conventional DC power supply supplies a predetermined drive current I to the LED module. Therefore, the remaining LED modules 201 to 203 are added to the current that has flowed in the broken LED module 204, and the remaining LED modules 201 to 203 are excessive. Current I / 3 (> I / 4) flows.

  According to the present embodiment, as shown in FIG. 4, the other three LED modules 201 to 203 other than the LED module 204 detected to be non-conductive have {I × (N−1) / N } × 1/3, that is, N = 4, the current of I / 4 flows, and the current of the LED module can flow substantially the same value as when the LED module is normal, and the normal LED modules 201 to 203 are excessive. Current can be prevented from flowing.

  As described above, the control unit 30 controls the detection circuits 41 to 44 to detect any non-conduction among the LED modules 201 to 204 before the drive circuit 20 outputs a drive current. That is, when any of the LED modules is detected to be non-conductive, the correction current output from the drive circuit 20 is smaller than the drive current when all of the LED modules 201 to 204 are conductive. Since adjustment is performed and the corrected current after adjustment is output to the light source unit composed of the remaining normal LED modules, it is possible to prevent a situation in which excessive current flows through the normal LED modules even for a moment.

  Further, as described above, the drive circuit 20 does not output a predetermined drive current to the LED modules 201 to 204, and the detection circuit 41 has a current smaller than a predetermined drive current such as a current due to standby power, for example. It flows to ~ 44. The current smaller than the drive current is, for example, a current smaller than a current necessary for the LED modules 201 to 204 to operate (light on). The detection circuits 41 to 44 include a plurality of resistors connected in series to each of the plurality of LED modules 201 to 204, and detect the non-conduction of the LED modules 201 to 204 by determining the presence / absence of a current flowing through each resistor. To do. For example, in the case of the detection circuit 41, a current having a value that does not cause the LED module 201 to operate (lights up) through the LED module 201 is passed through each of the resistors 411, 412, and 413. When no current flows through 413, it can be detected that the LED module 201 is non-conductive (disconnected). The same applies to the other detection circuits 42 to 43. Thereby, the non-conduction of the LED module can be detected with a simple configuration.

  In the example of FIG. 1, the reason why the diodes 71 to 74 are provided is that the non-conduction of the LED modules 201 to 204 is accurately detected by the detection circuits 41 to 44, respectively. For example, since the diode 71 is provided to prevent a small current flowing through the LED module 202 from flowing into the detection circuit 41, the detection circuit 41 can accurately detect the non-conduction of the LED module 201.

  In the example of FIG. 1, the resistors 411 and 412 are connected in series in the detection circuit 41, but the resistors 411 and 412 can be a single resistor. However, by connecting a plurality of resistors 411 and 412 in series, even if one resistor is short-circuited, a small current can flow through the detection circuit 41 via the LED module 201. Conductivity can be detected. Further, it is possible to protect the control unit 30 by preventing the voltage output from the drive circuit 20 from being applied to the detection terminals M1 to M4 of the control unit 30. The same applies to the other detection circuits 42 to 44.

  Further, by connecting each of the capacitors 414 to 444 to the resistors 413 to 443 in parallel, noise that enters the detection terminals M1 to M4 of the control unit 30 can be reduced.

  In the example of FIG. 1, the LED modules 201 and 202 having the daytime white LED 2 are controlled to be turned on and off by the FET 21, and the LED modules 203 and 204 having the light bulb color LED 3 are controlled to be turned on and off by the FET 22. However, the present invention is not limited to this, and a configuration in which an FET is provided corresponding to each LED module may be used. As a result, even if the FET fails, the number of LED modules that are turned off can be minimized, and the deterioration of the lighting function of the entire lighting device can be suppressed.

  FIG. 5 is a circuit diagram showing another example of the configuration of the detection circuit 41. FIG. 5A is an extraction of the detection circuit 41 of FIG. 1, and has the same configuration as the example of FIG. FIG. 5B shows an example in which a transistor 415 as an opening / closing element is interposed between resistors 412 and 413, and FIG. 5C shows an example in which a transistor 415 is interposed between a resistor 413 and a reference level. The base of the transistor 415 is connected to the control unit 30 via the resistor 416.

  As shown in FIGS. 5B and 5C, a transistor 415 is provided in series with the resistor 413 of the detection circuit 41. When the control unit 30 detects whether the LED module 201 is non-conductive with the detection circuit 41, the transistor Turn on 415 and close the circuit. That is, when the non-conduction of the LED module 201 is detected, the transistor 415 is turned on to close the electric circuit, and when the non-conduction of the LED module 201 is not detected, the transistor is turned off to open the electric circuit, The current is prevented from flowing through the resistors 411, 412, and 413, and the current is passed through the resistors 411 to 413 only when it is necessary to detect the non-conduction of the LED module 201. be able to. The same applies to the other detection circuits 42 to 44.

  FIG. 6 is an explanatory diagram showing an example of a detection method of non-conduction of the LED module during the color matching of the power supply apparatus 100 of the present embodiment. As described above, since the LED modules 201 and 202 have the daytime white LED 2 and the LED modules 203 and 204 have the light bulb color LED 3, the ratio of the average value of the current flowing through the LED modules 201 to 204 is changed. Thus, the color can be adjusted between the neutral white color and the light bulb color.

  The drive circuit 20 has, for the LED modules 201 to 204, a predetermined cycle T having an intermittent period in which a period in which current flows and a period in which no current flows alternately, that is, an intermittent period in which lighting and non-lighting of light sources are alternately performed. A drive current having a predetermined frequency f = 1 / T is output to the entire light source unit. The ratio of the average value of the current flowing through the LED modules 201 to 204 can be changed by shortening or lengthening the period during which the driving current flows for the period T.

  In the example of FIG. 6, a period in which current flows through the LED modules 201 and 202 corresponds to a period in which current does not flow through the LED modules 203 and 204. In addition, a period in which no current flows through the LED modules 201 and 202 corresponds to a period in which current flows through the LED modules 203 and 204. Note that the relationship between the period in which the drive current flows and the period in which the drive current does not flow is not limited to the example in FIG. 6, and there is a period in which no current flows in any of the LED modules 201 to 204. Good.

  As described above, the drive circuit 20 outputs a drive current having a predetermined frequency having an intermittent period. That is, the drive circuit 20 intermittently outputs a drive current based on a PWM control signal in which a period in which the drive current flows and a period in which the drive current does not flow are alternately repeated at a predetermined frequency by PWM control, for example.

  As shown in FIG. 6, the control unit 30 should monitor whether or not the LED modules 201 to 204 are non-conductive during a period in which the detection circuits 41 to 44 are not in the LED module during the intermittent period. Control. For example, open (disconnection) monitoring of the LED modules 201 and 202 is performed in a period in which the current of the LED modules 201 and 202 is not flowing. Similarly, open (disconnection) monitoring of the LED modules 203 and 204 is performed in a period in which the current of the LED modules 203 and 204 is not flowing. When non-conduction of the LED module is detected, a correction drive having a current value smaller than a predetermined drive current is output so that an excessive current does not flow through the remaining normal LED modules.

  Accordingly, even when the LED modules 201 to 204 are driven, it is possible to detect the non-conduction of the light source using a period in which the driving current does not flow intermittently, and the non-conduction of the light source during the driving of the light source Even when this occurs, it is possible to prevent a situation in which an excess current flows through a normal light source even for a moment.

  According to the present embodiment, for example, when a non-conduction of the light source (for example, a state in which the drive current does not flow to the light source due to disconnection and the light source is not turned on) is detected before the light source is turned on (while the light source is turned off) Since the correction current is actually output after the correction current output from the (power supply unit) is set to be smaller than the predetermined drive current, excessive current will flow to the remaining light sources other than the light source where non-conduction is detected even for a moment. Can be prevented. In addition, generation of heat generation, smoke generation, and the like due to excessive current flow can be prevented.

  Further, the timing for detecting the non-conduction of the light source is not limited before the light source is turned on. That is, when a driving current having an intermittent period in which no current flows to the light source, such as when the toning function is activated, non-conduction of the light source can be detected during the intermittent period. Therefore, it is possible to prevent excessive current from flowing through the remaining normal light sources.

  In the above-described embodiment, the example in which the LED is used as the light source of the power supply device has been described. However, the light source is not limited to the LED, and any other light source such as EL (Electro-Luminescence) can be used as long as it is a current-driven light source. It can also be applied to.

2, 3 LED
20 Drive circuit (power supply unit)
21, 22 FET (power supply)
30 Control unit 41, 42, 43, 44 Detection circuit (detection unit)
411, 412, 413 Resistor 421, 422, 423 Resistor 431, 432, 433 Resistor 441, 442, 443 Resistor 415 Transistor (switching element)
201, 202, 203, 204 LED module

Claims (7)

In a power supply device including a power supply unit that outputs a predetermined drive current for lighting a light source unit in which a plurality of light sources are connected in parallel,
A detection unit for detecting non-conduction of the light source in a state where a current of a value at which the light source unit does not light is output to the light source unit;
The power supply unit is
When the non-conduction of one of the light sources is detected by the detection unit, a correction current smaller than the predetermined drive current is output to the light source unit to turn on the light source unit. Power supply.   When the non-conduction of the light source is detected by the detection unit, a control unit is provided that controls to adjust a correction current output from the power source unit according to the parallel number of the light sources that are conducting. Item 2. The power supply device according to Item 1. The controller is
The power supply device according to claim 2, wherein the detection unit is controlled to detect non-conduction of the light source in a state where the light source unit is turned off. The detector is
A plurality of resistors connected in series to each of the plurality of light sources,
4. The power supply device according to claim 2, wherein the non-conduction of each light source is detected by determining the presence / absence of a current flowing through the resistor. A switching element is provided in series with the resistor,
The controller is
The power supply device according to claim 4, wherein when the non-conduction of the light source is detected by the detection unit, the opening / closing element is closed. The power supply unit is
A drive current having a predetermined frequency having an intermittent period in which lighting and non-lighting of the light source are alternately generated is output,
The controller is
The power source according to any one of claims 2 to 5, wherein the detection unit is controlled to detect non-conduction of the light source during a non-lighting period of the light source. apparatus.   An illumination device comprising the power supply device according to any one of claims 1 to 6.

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