JP2007234414A - Power supply device for lighting, and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply device for lighting capable of suppressing flow of an excessive current in mounting a light emitter, and a luminaire using the same. <P>SOLUTION: The power supply device is provided with connection terminals 203, 204 for connecting the light emitter 3, a power supply part 21 for supplying a current for light emission, of which a current value is previously set so as to emit light from the light emitter 3, to the light emitter 3 through the connection terminals 203, 204, a resistance R1 and a determination part 205 for determining whether the light emitter 3 is connected to the connection terminals 203, 204, and a control part 22 for outputting the current for light emission between the connection terminals 203, 204 by the power supply part 21 when the determination part 205 determines that the light emitter 3 is connected, and prohibiting an output of the current for light emission between the connection terminals 203, 204 by the power supply part 21 when it is determined that the light emitter 3 is not connected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting power supply device that emits light from a light emitter by constant current control, and a lighting fixture using the same.

2. Description of the Related Art Conventionally, in an LED lighting device that emits light emitting diodes (LEDs) that are light emitters, constant current control is performed in which a constant direct current is supplied to the LEDs to light them. In such an LED lighting apparatus, one or a plurality of LEDs serving as a load are connected in series. Therefore, the lighting power supply device that supplies the current for light emission to the LED detects the load current flowing through the LED load, and is suitable for light emission regardless of the number of LEDs serving as the load and the variation in the forward voltage of the LED. Constant current control is performed to adjust the output voltage so that a constant direct current flows through the LED (see, for example, Patent Document 1).
JP 2003-59676 A

  By the way, in the lighting power supply device as described above, for example, when the LED is removed from the lighting fixture for replacement, or when the LED is detached from the lighting power supply device due to vibration, it is detected when no load is applied. As shown in FIG. 12, the output voltage increases to the maximum output voltage of the lighting power supply device in an attempt to increase the load current. When the LED is connected to the lighting power supply device in this state, as shown in FIG. 13, a target current value suitable for light emission is obtained in a period Tx from when the LED is connected until the load current I is stabilized by constant current control. Since an excessive current exceeding the current flows to the LED, there is a disadvantage that flashing may occur or the LED may be destroyed.

  In particular, the specifications are such that the number of LEDs that can be connected is wide, for example, specifications that allow the number of LEDs to be changed between 1 to 10 lights, and specifications that can cope with variations in forward voltage of LEDs. In the lighting power supply device, since the maximum output voltage is increased, the smaller the number of LEDs mounted in series and the smaller the forward voltage, the larger the current flowing through the LEDs. For example, in the case of a power supply device that can increase or decrease an LED having a forward voltage of 4 V between 1 to 10 lamps, the output is 40 V + α in a no-load state. When less than 10 LEDs are connected in this state, a DC voltage exceeding 40V is applied immediately after connection, and the output voltage is gradually lowered according to the constant current control operation, and finally reaches the target level for constant current control. Stabilize. During the period until the constant current control is stabilized, the LED is in an overvoltage and overcurrent state, causing flashing and destruction of the LED.

  In addition, when such a lighting fixture is used by being attached to an item with large vibration such as an automobile or a train, the connection between the LED load and the lighting power supply device may be intermittently caused by the vibration. There was an inconvenience that a flash was generated and flickered.

  The present invention is an invention made in view of such a problem, and an illumination power supply device capable of suppressing an excessive current from flowing when a light emitter is attached, and a lighting fixture using the same The purpose is to provide.

  In order to achieve the above-described object, a lighting power supply apparatus according to the first means of the present invention includes first and second connection terminals for connecting a light emitter, and the first and second connection terminals. And whether the light emitter is connected to the first and second connection terminals and a power source for supplying a light emission current whose current value is set in advance to cause the light emitter to emit light. When the light emitter detection unit and the light emitter detector determine that the light emitter is connected, the light source current between the first and second connection terminals is determined by the power source unit. And when it is determined that the light emitter is not connected, the voltage applied between the first and second connection terminals by the power supply unit is the voltage for flowing the light emission current through the light emitter. And a control unit that is limited to the following: .

  In the illumination power supply device described above, the light emitter detection unit uses a mechanical switch whose contact is opened and closed according to whether the light emitter is attached to the first and second connection terminals. A determination result indicating whether or not the light emitter is connected to the first and second connection terminals according to an open / close state of a target switch is shown.

  In the illumination power supply device described above, the light emitter detection unit is output from a current detection unit that outputs a detection voltage corresponding to a current flowing between the first and second connection terminals, and the current detection unit. A determination unit that determines whether or not the light emitter is connected to the first and second connection terminals according to whether or not a detection voltage exceeds a preset first threshold voltage; When the determination unit determines that the light emitter is not connected, the control unit detects a light emitter that is lower than a target voltage that is a voltage for allowing the light emission current to flow through the light emitter by the power supply unit. A voltage is applied between the first and second connection terminals.

  In the illumination power supply device described above, when the determination unit determines that the light emitter is connected by the determination unit, the control unit outputs a detection voltage output from the current detection unit, and the determination unit When it is determined that the light emitter is not connected by the first reference voltage, which is a detection voltage output from the current detection unit when the light emission current flows between the first and second connection terminals. A switching unit that outputs a high second reference voltage; and if the voltage output from the switching unit is higher than the first reference voltage, the output voltage from the power supply unit is reduced, and the voltage output from the switching unit is And a power supply control unit that increases the output voltage of the power supply unit if it is lower than one reference voltage.

  Moreover, in the above-described illumination power supply device, when the current detection unit determines that the light emitter is not connected by the determination unit, the current determination unit determines that the light emitter is connected by the determination unit. The detection voltage obtained with respect to the current is increased as compared with the case.

  In the illumination power supply device described above, the current detection unit is a resistor that outputs a voltage drop caused by a current flowing between the first and second connection terminals as the detection voltage. A short circuit switch that short-circuits both ends of the second resistor when the determination unit determines that the light emitter is connected to the second resistor. Is connected.

  Further, in the illumination power supply device described above, the determination unit has an output voltage between the first and second connection terminals by the power supply unit exceeding a second threshold voltage higher than the light emitter detection voltage, and When the detection voltage output from the current detection unit does not exceed the first threshold voltage, it is determined that the light emitter is not connected to the first and second connection terminals.

  Further, in the illumination power supply device described above, when the control unit determines that the light emitter is connected by the light emitter detection unit, the power supply unit gradually increases the output current to the light emission current. It is characterized by increasing.

  In the illumination power supply device described above, the control unit determines that the light emitter is not connected by the light emitter detector, and then the light emission by the power source for a preset time. It is characterized in that the output of the electric current is continued.

  And the lighting fixture which concerns on the 2nd means of this invention is equipped with a light-emitting body and the power supply device for illumination for making the said light-emitting body light-emit, The said power supply device for illumination is the illumination in any one of the above-mentioned It is characterized by being a power supply device for a vehicle.

  In the illumination power supply device and the lighting fixture having such a configuration, the light emitter detection unit determines whether or not the light emitter is connected to the first and second connection terminals. When the light emitter detection unit determines that the light emitter is connected, the control unit causes the light emitter connected to the first and second connection terminals to emit light from the power source unit. When a light emission current having a preset current value is supplied and the light emitter detection unit determines that the light emitter is not connected, the control unit supplies the first and second connection terminals between the first and second connection terminals. The applied voltage is limited to a voltage equal to or lower than a voltage for causing the light emitting current to flow through the light emitter. As a result, when a light emitter is not connected to the first and second connection terminals, an excessive voltage is applied between the first and second connection terminals by the power supply unit in an attempt to flow a light emission current. When the light emitter is attached to the first and second connection terminals, the current flowing through the light emitter is limited to the light emission current or less, so that excessive current flows through the light emitter. be able to.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a block diagram illustrating an example of a configuration of an illumination power supply device according to the first embodiment of the present invention and a lighting fixture using the illumination power supply device. The luminaire 1 shown in FIG. 1 is configured by connecting a light emitter 3 to an illumination power supply device 2. The light emitter 3 is configured by connecting, for example, two LEDs in series. The light emitter 3 may be a single LED. Moreover, the light-emitting body 3 should just be light-emitted according to the flowing electric current, and is not restricted to LED. The illumination power supply device 2 includes a power supply unit 21, a control unit 22, for example, input terminals 201 and 202 that receive a commercial AC voltage Vac, and connection terminals 203 and 204 (first and second connection terminals) to which the light emitter 3 is connected. ), A resistor R1 (current detection unit), and a determination unit 205.

  The power supply unit 21 rectifies the AC voltage Vac received at the input terminals 201 and 202, and outputs it to the smoothing capacitor C1, and the primary winding n1 of the transformer T1 connected in parallel with the capacitor C1. And the transistor Tr1, a diode D1 whose anode is connected to one end of the secondary winding n2 of the transformer T1, and whose cathode is connected to the connection terminal 203, the cathode of the diode D1, and the secondary winding n2 And a smoothing capacitor C2 connected between the ends. The other end of the secondary winding n2 is connected to the connection terminal 204 via the resistor R1. The transistor Tr1 is turned on / off according to a control signal from the control unit 22 so that an output voltage according to the pulse width of the control signal is applied to the light emitter 3 via the connection terminals 203 and 204. It has become.

  The power supply unit 21 may be configured to generate power for light emission of the light emitter 3 based on DC power supplied from a DC voltage source such as a battery. Further, as a power supply system, an insulation type configuration is shown through a transformer, and a flyback system circuit is shown, but the insulation and circuit system of the power supply unit 21 are not particularly limited.

  Since the load current IL flowing through the light emitter 3 by the output voltage of the power supply unit 21 flows through the resistor R1, the voltage drop due to the resistor R1, that is, the detected voltage VR becomes a voltage corresponding to the load current IL.

  The determination unit 205 is a circuit unit that determines whether or not the light emitter 3 is connected to the connection terminals 203 and 204 based on the detection voltage VR, and is configured using, for example, a comparator. The detection voltage VR is set in advance. If it is higher than the first threshold voltage Vth1, the signal indicating that the light emitter 3 is connected is output to the control unit 22, and if it is lower, the signal indicating that the light emitter 3 is not connected is output to the control unit 22. . In this case, the resistor R1 and the determination unit 205 correspond to an example of a light emitter detection unit.

  The control unit 22 includes a changeover switch SW1 (switching unit), first and second reference voltage sources 206 and 207, a comparator 208, and a PWM (Pulse Width Modulation) circuit 209. The first reference voltage source 206 is configured to cause the light emission current ILs to flow through the resistor R1 when the load current IL becomes a light emission current ILs set in advance as a current value for causing the light emitter 3 to emit light appropriately. The first reference voltage V1 that is equal to the detection voltage VR obtained by the above is output. The second reference voltage source 207 outputs a second reference voltage V2 that is higher than the first reference voltage V1. The first reference voltage V1 and the second reference voltage V2 are set to have a relationship of V1 << V2.

  The change-over switch SW1 is, for example, a two-contact change-over switch. When a signal indicating that the light emitter 3 is connected is output from the determination unit 205, the detection switch VR is output to the comparator 208 as the signal Vs. When a signal indicating that the light emitter 3 is not connected is output from 205, the second reference voltage V2 output from the second reference voltage source 207 is output to the comparator 208 as the signal Vs. The changeover switch SW1 may be a switch having a mechanical contact, or may be configured by a semiconductor switch such as a transistor.

  The comparator 208 compares the output signal Vs of the changeover switch SW1 with the first reference voltage V1 output from the first reference voltage source 206, and if the signal Vs exceeds the first reference voltage V1, the signal S1 Is output to the PWM circuit 209 at a high level, and if the signal Vs is equal to or lower than the first reference voltage V1, the signal S1 is output to the PWM circuit 209 at a low level.

  The PWM circuit 209 is a circuit unit that adjusts the output voltage of the power supply unit 21 by PWM control by changing the on-pulse width of the PWM signal S2 output to the base of the transistor Tr1 according to the signal S1. The PWM circuit 209 reduces the on-pulse width of the PWM signal S2 by reducing the on-pulse width of the PWM signal S2 when the signal S1 becomes high level, and decreases the on-pulse width of the PWM signal S2 when the signal S1 becomes low level. The output voltage of the power supply unit 21 is increased by enlarging. Further, even when the output voltage of the power supply unit 21 is reduced most, the PWM circuit 209 generates a light emitter detection voltage Vd lower than the target voltage Vtg for flowing the light emission current ILs to the light emitter 3 at least. Have been to maintain.

  In this case, the comparator 208 and the PWM circuit 209 correspond to an example of a power supply control unit.

  Next, operation | movement of the lighting fixture 1 comprised as mentioned above is demonstrated. First, in a state where the light emitter 3 is connected to the connection terminals 203 and 204, the load current IL flows through the resistor R1, and the detection voltage VR exceeds the first threshold voltage Vth1. Then, a signal indicating that the light emitter 3 is connected to the changeover switch SW1 is output from the determination unit 205, and the detection voltage VR is output to the comparator 208 as the signal Vs by the changeover switch SW1.

  Then, if the detection voltage VR exceeds the first reference voltage V1, the signal S1 is set to a high level by the comparator 208, the on-pulse width of the PWM signal S2 is reduced by the PWM circuit 209, and the output voltage of the power supply unit 21 is Will be reduced. On the other hand, if the detection voltage VR is equal to or lower than the first reference voltage V1, the signal S1 is set to a low level by the comparator 208, the on-pulse width of the PWM signal S2 is expanded by the PWM circuit 209, and the output voltage of the power supply unit 21 increases. As a result, constant current control is performed so that the detection voltage VR becomes the first reference voltage V1, that is, the load current IL flowing through the light emitter 3 is equal to the light emission current ILs, and the light emitter 3 is Lights properly.

  2 and 3 are explanatory diagrams for explaining the operation of the illumination power supply device 2 when the light emitter 3 is connected in a no-load state where the light emitter 3 is not connected to the connection terminals 203 and 204. FIG. is there. 2 shows the output voltage V output to the connection terminals 203 and 204, and FIG. 3 shows the load current IL flowing through the light emitter 3.

  In a state where the light emitter 3 is not connected to the connection terminals 203 and 204, no current flows through the resistor R1, and thus the detection voltage VR is lower than the first threshold voltage Vth1. Then, a signal indicating that the light emitter 3 is not connected is output from the determination unit 205 to the changeover switch SW1, and the second reference voltage V2 is output as the signal Vs to the comparator 208 by the changeover switch SW1.

  Then, since the first reference voltage V1 and the second reference voltage V2 are set to have a relationship of V1 << V2, the signal S1 is set to the high level by the comparator 208, and the PWM circuit 209 turns on the PWM signal S2. As a result of the width being reduced and the output voltage of the power supply unit 21 being continuously reduced, the output voltage of the power supply unit 21 is changed to the light emitter detection voltage Vd, and the voltage applied between the connection terminals 203 and 204 emits light to the light emitter 3. The voltage is limited to be equal to or lower than the voltage for flowing the working current ILs.

  This suppresses the output voltage from rising to the maximum output voltage of the illumination power supply device in the no-load state as in the illumination power supply device according to the background art.

  When the light emitter 3 is connected to the connection terminals 203 and 204, a minute detection current Id less than or equal to the light emission current ILs flows through the light emitter 3 according to the light emitter detection voltage Vd as the load current IL. The detection current Id flows through the resistor R1, and the detection voltage VR exceeds the first threshold voltage Vth1. Then, a signal indicating that the light emitter 3 is connected to the changeover switch SW1 is output from the determination unit 205, and the detection voltage VR is output to the comparator 208 as the signal Vs by the changeover switch SW1.

  In this case, the light emitter detection voltage Vd is set so that the detection current Id has a current value that does not cause flashing or destruction even when the light emitter 3 is connected.

  Then, since the detection voltage VR becomes equal to or lower than the first reference voltage V1, the signal S1 is set to the low level by the comparator 208, the on-pulse width of the PWM signal S2 is expanded by the PWM circuit 209, and the output voltage of the power supply unit 21 increases. As a result, the output voltage V rises until the detection voltage VR becomes the first reference voltage V1, that is, until the output voltage between the connection terminals 203 and 204 becomes the target voltage Vtg. On the other hand, the load current IL flowing through the light emitter 3 increases to the light emission current ILs as the output voltage V rises and stabilizes, and constant current control is performed, so that the light emitter 3 emits light appropriately.

  Thereby, in the no-load state, the light emitter detection voltage Vd lower than the target voltage Vtg for flowing the light emission current ILs to the light emitter 3 is applied between the connection terminals 203 and 204 by constant voltage control. When the light emitter 3 is attached to the connection terminals 203 and 204, it is possible to suppress an excessive current from flowing, and as a result, it is possible to reduce the possibility of flashing or LED destruction. Can do.

  Further, even when the light emitter 3 is detached after starting light emission of the light emitter 3 by constant current control, similarly, for detecting the light emitter lower than the target voltage Vtg for supplying the light emission current ILs to the light emitter 3. Since the voltage Vd is applied between the connection terminals 203 and 204 by constant voltage control, it is possible to prevent an excessive current from flowing when the light emitter 3 is attached again. As a result, a flash is generated. Or the risk that the LED will be destroyed.

  In addition, the resistor R1, the comparator 208, the first reference voltage source 206, and the PWM circuit 209 are control circuits for causing the power supply unit 21 to perform constant current control, and include a determination unit 205, a changeover switch SW1, and By adding the second reference voltage source 207, it is possible to suppress an excessive current from flowing when the light emitter 3 is attached to the connection terminals 203 and 204. It is possible to reduce the risk that the LED will be destroyed.

  Instead of using the changeover switch SW1 and the second reference voltage source 207, for example, a signal indicating that the light emitter 3 is not connected is output from the determination unit 205 using a control circuit such as a microcomputer or a logic circuit. In this case, the light emitting body detection voltage Vd may be output from the power supply unit 21 by the PWM circuit 209.

  For example, as shown in FIG. 4, in the illumination power supply device 2a, a series circuit of a resistor R2 (first resistor) and a resistor R3 (second resistor) is used as a current detection unit instead of the resistor R1. At the same time, when the signal indicating that the light emitter 3 is connected is output from the determination unit 205 to the resistor R3, both ends of the resistor R3 are short-circuited, and the light emitter 3 is not connected from the determination unit 205. A short-circuit switch SW2 that is turned off when a signal to that effect is output may be connected.

  Thereby, when it is determined by the determination unit 205 that the light emitter 3 is connected, the short-circuit switch SW2 is turned on, the resistor R3 is short-circuited, the resistance value of the current detection unit is decreased, and the power loss in the current detection unit On the other hand, when the determination unit 205 determines that the light emitter 3 is not connected, the short-circuit switch SW2 is turned off and the resistance value of the current detection unit is increased. The detection voltage obtained for the current flowing through the current detection unit is increased as compared with the case where it is determined that is connected. Then, the illumination power supply device 2a shown in FIG. 4 is equivalent to the illumination power supply device 2 even if the light emitter detection voltage Vd is set to a lower voltage than the illumination power supply device 2 shown in FIG. Detection current Id can be obtained, and the determination unit 205 can detect the connection of the light emitter 3. That is, in the illumination power supply device 2a shown in FIG. 4, the output voltage of the power supply unit 21 at the time of no load can be reduced as compared with the case of the illumination power supply device 2 shown in FIG. Loss can be reduced.

  Further, for example, like the illumination power supply device 2b shown in FIG. 5, the determination unit 205b has a second threshold voltage Vth2 in which the output voltage to the connection terminals 203 and 204 by the power supply unit 21 is higher than the light emitter detection voltage Vd. If the detection voltage VR output from the resistor R1 is less than or equal to the first threshold voltage Vth1, it may be determined that the light emitter 3 is not connected. Accordingly, when the light emitter 3 is connected to the connection terminals 203 and 204 and the light emitter 3 is disconnected after the voltage supply to the light emitter 3 is started, it is reliably detected that the light emitter 3 is not connected. Can be improved.

  Further, for example, when the light emitter is determined to be connected by the light emitter detector, the controller 22 performs so-called soft start control in which the power source 21 gradually increases the output current to the light emission current ILs. You may do it. Specifically, for example, a switch SW3 and a capacitor C3 are connected in parallel with the first reference voltage source 206 as in the illumination power supply device 2c shown in FIG. When the signal indicating that the light emitter 3 is not connected is output from the determination unit 205, the switch SW3 is turned on to discharge the capacitor C3, and the signal indicating that the light emitter 3 is connected is output from the determination unit 205. When output, the switch SW3 may be turned off to charge the capacitor C3 with the first reference voltage V1, and the charging voltage of the capacitor C3 may be input to the comparator 208.

  As a result, when the light emitter 3 is connected to the connection terminals 203 and 204, the output voltage of the power supply unit 21 gradually increases in accordance with the increase in the charging voltage of the capacitor C3, and the load current IL flowing through the light emitter 3 is reduced. A so-called soft start control that gradually increases can be performed. In this case, the larger the capacitance of the capacitor C3 is set, the slower the output voltage rise rate when the light emitter 3 is connected. Therefore, by appropriately setting the capacitance of the capacitor C3, The output voltage can be increased within the range of the voltage output performance of the power supply unit 21.

  Further, for example, as in the illumination power supply device 2d shown in FIG. 7, the peak hold for holding the signal level of the signal Vs output from the changeover switch SW1 and outputting it to the comparator 208 for a preset time set. A circuit 210 may be provided. FIG. 8 is a circuit diagram showing an example of the configuration of the peak hold circuit 210. The peak hold circuit 210 shown in FIG. 8 includes operational amplifiers 211 and 212, a diode D2, a capacitor C4, and a resistor R4. Then, the detection voltage VR generated in the resistor R1 is input to the non-inverting input terminal of the operational amplifier 211 as a signal Vs via a selector switch SW1 (not shown), and the output voltage of the operational amplifier 211 is not applied to the operational amplifier 212 via the diode D2. Output to the inverting input terminal.

  The cathode of the diode D2 is connected to the ground via a capacitor C4, and a resistor R4 is connected in parallel with the capacitor C4. Further, the signal Vs1 output from the operational amplifier 212 is output to the comparator 208 and also output to the inverting input terminals of the operational amplifiers 211 and 212.

  As a result, even if the signal Vs changes, the signal level of the signal Vs1 input to the comparator 208 is maintained for a set time set by the discharge time constant of the capacitor C4 and the resistor R4. When the illumination power supply device 2d is used in an environment with a lot of vibration, such as when the illumination power supply device 2d is mounted on the vehicle, the connection between the light emitter 3 and the illumination power supply device 2d is intermittently disconnected due to vibration. Even if it is within the set time, the signal level of the signal Vs1 is maintained, and the output of the light emission current ILs is continued without changing the output voltage of the power supply unit 21. It is reduced that the brightness of 3 fluctuates or flickers.

  8 is not limited to the example in which the signal Vs representing the load current IL is held in the analog circuit as in the peak hold circuit 210 shown in FIG. 8, for example, a predetermined set time of the signal Vs by software processing using a microcomputer. You may make it ignore the short time fluctuation in the inside. Further, the output voltage of the power supply unit 21 may be stored and held within a set time.

(Second Embodiment)
Next, a lighting power supply device according to a second embodiment of the present invention and a lighting fixture using the same will be described. FIG. 9 is a block diagram showing an example of a configuration of an illumination power supply device 2e according to the second embodiment of the present invention and a lighting fixture 1e using the illumination power supply device 2e. The lighting fixture 1e shown in FIG. 9 differs from the lighting fixture 1 shown in FIG. 1 in that the lighting power supply device 2e includes a push switch SW4 that is a mechanical push button switch instead of the determination unit 205.

  The push switch SW4 is a mechanical switch whose contacts are opened and closed depending on whether or not the light emitter 3 is attached to the connection terminals 203 and 204. The push switch SW4 emits light to the connection terminals 203 and 204 according to the open / close state of the push switch SW4. A signal indicating the determination result of whether or not the body 3 is connected is output to the changeover switch SW1.

  Specifically, for example, as shown in FIG. 10, the illumination power supply device 2 e includes a connector 213 including connection terminals 203 and 204, and a push switch SW <b> 4 is disposed next to the connector 213. Then, the light emitter 3 is configured by an LED having lead terminals 301 and 302 connected to the connection terminals 203 and 204 by inserting the light emitter 3 into the connector 213, and the light emitter 3 is connected to the connector 213 on one lead terminal 302. A pressing member 303 is provided for pressing the push switch SW4 when inserted into the.

  Accordingly, when the light emitter 3 is inserted into the connector 213, that is, when the light emitter 3 is connected to the connection terminals 203 and 204, the push switch SW4 is pressed by the pressing member 303 to turn on, and the light emitter 3 is disconnected from the connector 213. When the light emitter 3 is disconnected, that is, when the light emitter 3 is not connected to the connection terminals 203 and 204, the push switch SW4 is turned off.

  FIG. 11 is a circuit diagram illustrating an example of a connection method between the push switch SW4 and the changeover switch SW1. The changeover switch SW1 shown in FIG. 11 is a relay switch that includes a drive coil L1 that drives a contact that switches between the detection voltage VR and the second reference voltage V2, and one end of the drive coil L1 is connected via a push switch SW4. Connected to the power supply, the other end of the drive coil L1 is connected to the ground.

  Accordingly, when the light emitter 3 is attached to the connector 213 and the push switch SW4 is turned on, a current flows through the drive coil L1, the changeover switch SW1 is switched to the detection voltage VR side, and the detection voltage VR is used as the signal Vs as the comparator 208. On the other hand, when the light emitter 3 is disconnected from the connector 213 and the push switch SW4 is turned off, no current flows through the drive coil L1, the changeover switch SW1 is switched to the second reference voltage V2 side, and the second reference voltage V2 is set. The signal Vs is output to the comparator 208.

  Further, when the signal S1 becomes high level, the PWM circuit 209e reduces the on-pulse width of the PWM signal S2 to reduce the output voltage of the power supply unit 21, and finally, without maintaining the light emitter detection voltage Vd. The output voltage to the connection terminals 203 and 204 of the power supply unit 21 is equal to or lower than the voltage for flowing the light emission current ILs to the light emitter 3, that is, only a current that does not cause flashing or destruction even when applied to the light emitter 3. Less than a certain voltage, for example substantially zero. Other configurations and operations are the same as those of the lighting fixture 1 shown in FIG.

  Thereby, like the lighting fixture 1 shown in FIG. 1, when attaching a light-emitting body to the connection terminals 203 and 204, it can suppress that an excessive electric current flows, and also the power supply part 21 of the time of no load is sufficient. Since the output voltage can be made substantially zero, the power loss in the power supply unit 21 can be reduced.

It is a circuit diagram which shows an example of a structure of the power supply device for illumination which concerns on the 1st Embodiment of this invention, and a lighting fixture using the same. It is a graph which shows the output voltage output to the connection terminal in the power supply device for illumination shown in FIG. It is a graph which shows the load current which flows through the light-emitting body in the power supply device for illumination shown in FIG. It is a circuit diagram which shows another example of the power supply device for illumination which concerns on the 1st Embodiment of this invention, and a lighting fixture. It is a circuit diagram which shows another example of the power supply device for illumination which concerns on the 1st Embodiment of this invention, and a lighting fixture. It is a circuit diagram which shows another example of the power supply device for illumination which concerns on the 1st Embodiment of this invention, and a lighting fixture. It is a circuit diagram which shows another example of the power supply device for illumination which concerns on the 1st Embodiment of this invention, and a lighting fixture. FIG. 8 is a circuit diagram illustrating an example of a peak hold circuit illustrated in FIG. 7. It is a circuit diagram which shows an example of a structure of the power supply device for illumination which concerns on the 2nd Embodiment of this invention, and a lighting fixture using the same. It is explanatory drawing which shows an example of a structure of the light-emitting body and push switch which are shown in FIG. FIG. 10 is a circuit diagram illustrating an example of connection between the push switch and the changeover switch illustrated in FIG. 9. It is a graph which shows the output voltage output to the load in the power supply device for illumination which concerns on background art. It is a graph which shows the load current which flows through the light-emitting body in the power supply device for illumination which concerns on background art.

Explanation of symbols

1, 1a, 1b, 1c, 1d, 1e Lighting fixtures 2, 2a, 2b, 2c, 2d, 2e Lighting power supply device 3 Light emitter 21 Power supply unit 22 Control unit 201, 202 Input terminal 203, 204 Connection terminal 205, 205b Determination unit 206 First reference voltage source 207 Second reference voltage source 208 Comparator 209, 209e PWM circuit 210 Peak hold circuit 211, 212 Operational amplifier 213 Connector 301 Lead terminal 302 Lead terminal 303 Press member C1, C2, C3, C4 Capacitor D1 , D2 Diode DB1 Diode bridge R1, R2, R3, R4 Resistor SW1 changeover switch SW2 Short-circuit switch SW3 Switch SW4 Push switch T1 Transformer Tr1 Transistor

Claims (10)

First and second connection terminals for connecting light emitters;
A power supply unit for supplying a current for light emission whose current value is set in advance to cause the light emitter to emit light to the light emitter via the first and second connection terminals;
A light emitter detector for determining whether or not the light emitter is connected to the first and second connection terminals;
When the light emitter detection unit determines that the light emitter is connected, the power source outputs the light emission current between the first and second connection terminals, and the light emitter is connected. A control unit that limits an applied voltage between the first and second connection terminals by the power supply unit to a voltage equal to or lower than a voltage for flowing the light emission current to the light emitter when it is determined that the power supply unit does not. A power supply device for lighting. The light emitter detection unit uses a mechanical switch whose contact is opened and closed according to whether or not the light emitter is attached to the first and second connection terminals. The lighting power supply device according to claim 1, further comprising: a determination result indicating whether or not the light emitter is connected to the second connection terminal. The light emitter detector is
A current detection unit that outputs a detection voltage corresponding to a current flowing between the first and second connection terminals;
It is determined whether or not the light emitter is connected to the first and second connection terminals according to whether or not the detection voltage output from the current detection unit exceeds a preset first threshold voltage. And a determination unit for
When the determination unit determines that the light emitter is not connected, the control unit detects a light emitter that is lower than a target voltage that is a voltage for allowing the light emission current to flow through the light emitter by the power supply unit. The lighting power supply device according to claim 1, wherein a working voltage is applied between the first and second connection terminals. The controller is
When the determination unit determines that the light emitter is connected, outputs a detection voltage output from the current detection unit, and when the determination unit determines that the light emitter is not connected, A switching unit that outputs a second reference voltage that is higher than a first reference voltage that is a detection voltage output from the current detection unit when the light emission current flows between the first and second connection terminals;
If the voltage output from the switching unit is higher than the first reference voltage, the output voltage from the power supply unit is reduced. If the voltage output from the switching unit is lower than the first reference voltage, the output voltage from the power supply unit. The illumination power supply device according to claim 3, further comprising: a power supply control unit that increases the power consumption. The current detection unit obtains the current when the determination unit determines that the light emitter is not connected than when the determination unit determines that the light emitter is connected. The illumination power supply device according to claim 4, wherein the detected voltage to be increased is increased. The current detection unit is a resistor that outputs a voltage drop caused by a current flowing between the first and second connection terminals as the detection voltage,
The resistor is a series circuit of first and second resistors,
The short circuit switch which short-circuits the both ends of the said 2nd resistor is connected to the said 2nd resistor, when the determination part determines with the said light-emitting body being connected. 5. The illumination power supply device according to 5. The determination unit has a detection voltage output from the current detection unit, in which an output voltage between the first and second connection terminals by the power supply unit exceeds a second threshold voltage higher than the light emitter detection voltage. When it does not exceed the first threshold voltage, it is determined that the light emitter is not connected to the first and second connection terminals. The illumination device according to claim 3, Power supply. The control unit, when it is determined by the light emitter detection unit that the light emitter is connected, causes the power supply unit to gradually increase the output current to the light emission current. The power supply apparatus for illumination as described. The control unit continues the output of the light emission current by the power supply unit for a preset time after the light emitter detection unit determines that the light emitter is not connected. The illumination power supply device according to claim 1 or 8. A light emitter;
An illumination power supply device for causing the light emitter to emit light,
The illumination power supply device according to any one of claims 1 to 9, wherein the illumination power supply device is an illumination fixture.

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