JP5642006B2 - Lighting device and lighting fixture provided with the same - Google Patents

Description

  The present invention relates to a lighting device that can be lit in both an AC power source and a DC power source, and a lighting fixture including the lighting device.

  There has been proposed a two-wire wiring type separate power source emergency lighting device that uses an AC power source as a power source when the discharge lamp is lit in the normal state, and uses a DC power source in the event of a power outage or the like (for example, Patent Document 1 and Patent Document 2).

  Among these, FIG. 4 in Patent Document 1 shows a power supply-separated emergency light lighting circuit in which a commercial power supply (AC power supply) is input as a power supply in a normal state and a DC power supply (DC power supply) is input in an emergency. The “discharge lamp 23” as a load is lit at high frequency by an inverter circuit including a “switching element Q5”. The power supply voltage in this circuit is the voltage of the “capacitor C4” and is affected by the peak voltage of the AC voltage and the average voltage of the DC voltage. However, since the composite harmonic countermeasure circuit is configured by LC (no symbol), the peak voltage itself does not occur when AC power is input.

  FIG. 2 in Patent Document 2 is a power supply-separated type emergency lamp lighting circuit in which commercial power (AC power) is input as a power source during normal times and DC power (DC power) is input in an emergency, as in Patent Document 1. “Load 13” is connected to the end of “Output unit 17”. The power supply voltage in this circuit is the voltage of the “smoothing capacitor C2” and is affected by the peak voltage of the AC voltage and the average voltage of the DC voltage, as in Patent Document 1.

Japanese Patent Application Laid-Open No. 07-85879 (see page 8, FIG. 4) Japanese Patent Laid-Open No. 10-241868 (see page 5, FIG. 2)

  However, the conventional emergency lighting device with a separate power supply has the circuit configuration as described above, and has a configuration in which an AC power source and a DC power source are input as power sources. Even so, the voltage generated in the capacitor is about 141% when using AC power, such as DC141 [V] when AC100 [V] and DC100 [V] when DC100 [V]. Only the voltage is input. On the other hand, in the main circuit, control for maintaining the light source as a load at a specific output without being affected by the power source is performed to obtain the performance as an emergency light.

  On the other hand, the control power source for controlling the circuit is supplied from a fluctuating power source or a part of the main circuit, but this is not a control target as in the lighting control of the lighting device (load). For this reason, there is a problem in that power supply capacity needs to be designed in consideration of fluctuations in the power supply, and extra power is generated accordingly.

  In addition, if parts are shared with models other than the power supply type, there is a problem that the power supply voltage becomes insufficient when DC power is input.

  The present invention has been made to solve the above-described problems, and provides a stable control power supply even when an emergency DC power supply is input by a simple circuit. The purpose is to make it easy to share parts.

  A lighting device according to the present invention includes a rectifying / smoothing circuit that rectifies and smoothes a power supply voltage, and a constant current circuit that constitutes a flyback switching power supply that drives a light source as a load from the output voltage of the rectifying / smoothing circuit with a constant current; A secondary winding that is installed in the constant current circuit, converts the output voltage of the rectifying and smoothing circuit and supplies a current to the light source, and a tertiary winding that is reverse to the secondary winding. A power supply voltage connected to a transformer to be transmitted, a control power generation circuit that generates a control power from an output voltage of the tertiary winding, an output side of the secondary winding and an output side of the tertiary winding; And a power supply auxiliary circuit for supplying a current from the output side of the secondary winding to the output side of the tertiary winding when the voltage becomes less than a predetermined voltage.

  According to the present invention, even when the power supply voltage is less than the predetermined voltage and the control power supply is insufficient, the current is supplied from the output side of the secondary winding to the output side of the tertiary winding by the function of the control power supply auxiliary circuit. Therefore, the shortage of the input voltage of the control power generation circuit can be compensated, and the control power can be secured stably.

It is a circuit diagram of the lighting device according to Embodiment 1 of the present invention. It is a figure which shows the example of the relationship between the power supply voltage (voltage of the power supply 41) and the output voltage of the tertiary winding output circuit 12 in the lighting device which concerns on Embodiment 1 of this invention. It is a circuit diagram of the lighting device which concerns on Embodiment 2 of this invention. It is a circuit diagram of the lighting device which concerns on Embodiment 3 of this invention. It is a circuit diagram of the lighting device which concerns on Embodiment 4 of this invention. It is a figure which shows the example of the combination of the detection result of each detection circuit for determining the ON / OFF state of the control switch 27 in the lighting device which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
(Configuration of lighting device)
FIG. 1 is a circuit diagram of a lighting device according to Embodiment 1 of the present invention.
As shown in FIG. 1, the lighting device according to the present embodiment uses a rectifying / smoothing circuit 1 that rectifies and smoothes a voltage supplied from a power supply 41, and a DC voltage output from the rectifying / smoothing circuit 1. A DCDC conversion circuit 3 for driving the LED module 2 as a load at a constant current is provided. Further, as will be described later, the lighting device further includes a control power generation circuit 5 that generates a control voltage based on an output voltage from a tertiary winding output circuit 12 included in the DCDC conversion circuit 3, and a secondary winding output. A control power supply auxiliary circuit 6 is provided for flowing the output current from the circuit 11 to the tertiary winding output circuit 12 side.

  The power source 41 supplies an AC voltage as an AC power source (commercial power source) in a normal state, and supplies a DC voltage as a DC power source in an emergency. In this emergency, the power supply 41 supplies a DC voltage by, for example, an emergency storage battery in the emergency.

  The rectifying / smoothing circuit 1 includes a diode bridge 1a that rectifies when an AC voltage is supplied from a power supply 41, and a smoothing capacitor 1b that smoothes the full-wave rectified voltage of the rectified diode bridge 1a.

  The DCDC conversion circuit 3 is a flyback switching power supply, and includes an output transformer 4, a control IC 7, a current control circuit 8, a current detection resistor 9, a photocoupler 10, a secondary winding output circuit 11, and a tertiary winding output circuit. 12, the LED module 2 as a load is driven at a constant current. Among these, the photocoupler 10 includes a photodiode 10a and a phototransistor 10b. The secondary winding output circuit 11 includes a secondary winding of the output transformer 4, a rectifier diode 11a, and a capacitor 11b. The tertiary winding output circuit 12 includes a tertiary winding of the output transformer 4, A rectifier diode 12a and a capacitor 12b are included.

  In the DCDC converter circuit 3, a series circuit of the output transformer 4 and the control IC 7 is connected in parallel to the smoothing capacitor 1b. A series circuit of the rectifier diode 11 a and the capacitor 11 b is connected in parallel to the secondary winding of the output transformer 4. A series circuit of the rectifier diode 12 a and the capacitor 12 b is connected in parallel to the tertiary winding of the output transformer 4. Also, the opposite side of the capacitor 11b on the side where the rectifier diode 11a is connected and the opposite side of the capacitor 12b on the side where the rectifier diode 12a is connected are connected and grounded. That is, the capacitor 11b and the capacitor 12b constitute a series circuit. Further, the connection portion between the rectifier diode 11 a and the capacitor 11 b in the secondary winding output circuit 11 is connected to the LED module 2. The other connection portion of the LED module 2 is connected to the current control circuit 8, and the connection portion between the LED module 2 and the current control circuit 8 is grounded via the current detection resistor 9. Yes. The anode side of the photodiode 10a is connected to the current control circuit 8, and the cathode side is grounded. The collector side of the phototransistor 10b is connected to the control IC 7, and the emitter side is connected to the connection between the control IC 7 and the smoothing capacitor 1b.

  The control power generation circuit 5 includes a transistor 16, a Zener diode 17, a bias resistor 18, and a smoothing capacitor 19.

  In the control power generation circuit 5, the transistor 16 is connected to the collector side, the bias resistor 18, the Zener diode 17, the smoothing capacitor 19, and the emitter side of the transistor 16. Further, the connection portion between the transistor 16 and the bias resistor 18 is connected to the connection portion between the rectifier diode 12 a and the capacitor 12 b in the tertiary winding output circuit 12. Further, the connection portion between the bias resistor 18 and the Zener diode 17 is connected to the base side of the transistor 16. Further, the connection portion between the Zener diode 17 and the smoothing capacitor 19 is grounded. The voltage on the emitter side of the transistor 16 constitutes the control power supply Vcc.

  The control power auxiliary circuit 6 includes a diode 13, a Zener diode 14, and a current limiting resistor 15.

In the control power supply auxiliary circuit 6, a series circuit is configured in the order of a diode 13, a Zener diode 14, and a current limiting resistor 15. The other end of the diode 13 is connected to a connection portion between the rectifier diode 11 a and the capacitor 11 b in the secondary winding output circuit 11. Further, the other end of the current limiting resistor 15 is connected to a connection portion between the rectifier diode 12 a and the capacitor 12 b in the tertiary winding output circuit 12.
In the control power supply auxiliary circuit 6, the series circuit is configured in the order of the diode 13, the Zener diode 14, and the current limiting resistor 15. However, the order is not limited to this order, and the connection is made in any order. It is good also as what is done.

  The DCDC converter circuit 3 corresponds to the “constant current circuit” of the present invention.

(Operation of lighting device)
Next, the basic operation of the lighting device according to the present embodiment will be described with reference to FIG.

  The secondary winding output circuit 11 outputs a voltage for driving the LED module 2 as a load, and this output voltage is stabilized by the capacitor 11b. As will be described later, the output of the secondary winding output circuit 11 is controlled by the operation of the control IC 7 that controls the current flowing in the primary winding of the output transformer 4, and the output current to the LED module 2 as a load is controlled. Is controlled to a constant current. Further, the output voltage of the secondary winding output circuit 11 is determined by a voltage generated when the LED module 2 is driven at a constant current, and varies with a certain range depending on variations, temperatures, and the like.

  The tertiary winding output circuit 12 includes a tertiary winding which is a winding opposite to the secondary winding. When the secondary winding output circuit 11 is controlled by the flyback method, the power supply voltage is set. Outputs a proportional voltage.

  As described above, the DCDC conversion circuit 3 drives the LED module 2 that is a load at a constant current. Specifically, when a current flows through the LED module 2, a current also flows through the current detection resistor 9. When the current control circuit 8 detects that a current flows through the current detection resistor 9, the photodiode 10 a of the photocoupler 10. Current is passed through. When a current flows through the photodiode 10a, the collector and the emitter in the phototransistor 10b are electrically connected. The control IC 7 detects the conduction between the collector and the emitter in the phototransistor 10b, controls the current flowing in the primary winding of the output transformer 4, and realizes constant current driving of the LED module 2.

  The control power supply generation circuit 5 generates the control power supply Vcc based on the output voltage of the tertiary winding output circuit 12. Specifically, the voltage of the control power supply Vcc is a voltage that is lower than the Zener voltage generated by the Zener diode 17 by the base-emitter voltage Vbe due to the current flowing from the base of the transistor 16 to the emitter. The smoothing capacitor 19 smoothes and stabilizes the voltage of the control power supply Vcc. Further, the voltage of the control power supply Vcc is constant by the Zener diode 17 even if the output voltage of the tertiary winding output 12 fluctuates as long as the output voltage of the tertiary winding output 12 is not less than a predetermined output limit value. The voltage is generated by the voltage generation function. However, when the output voltage of the tertiary winding output 12 becomes less than the output limit value, the voltage of the control power supply Vcc decreases accordingly.

  As will be described later, the control power supply auxiliary circuit 6 supplies current from the secondary winding output circuit 11 to the tertiary winding output circuit 12 when the voltage output of the tertiary winding output circuit 12 decreases. is there. Specifically, when the potential difference between the secondary winding output circuit 11 and the tertiary winding output circuit 12 exceeds the total value of the forward voltage of the diode 13 and the Zener voltage of the Zener diode 14, 2 A current is supplied from the secondary winding output circuit 11 to the tertiary winding output circuit 12.

FIG. 2 is a diagram showing an example of the relationship between the power supply voltage (voltage of the power supply 41) and the output voltage of the tertiary winding output circuit 12 in the lighting device according to Embodiment 1 of the present invention.
The output voltage of the tertiary winding output circuit 12 varies in proportion to the input power supply voltage (the voltage of the power supply 41) as described above, and the AC voltage of the power supply 41 that normally operates as an AC power supply is AC100V. In this case, the relationship between the voltage Vac output from the rectifying / smoothing circuit 1 and the voltage Vdc output from the rectifying / smoothing circuit 1 when the DC voltage of the power supply 41 that operates as a DC power supply in an emergency is DC 100V is expressed by the following equation (1). It is expressed as

Vac = Vop = √2 × Vdc≈1.41 × Vdc (1)
(Vop: Maximum voltage value of AC voltage of AC100V (≈141V))

As shown in the above formula (1), the output voltage of the rectifying / smoothing circuit 1 when the power source 41 is an AC power source is a voltage approximately 1.41 times the output voltage of the rectifying / smoothing circuit 1 when the power source 41 is a DC power source. It becomes. Conversely, the output voltage of the rectifying / smoothing circuit 1 when the power supply 41 is a DC power supply is approximately 0.7 times the output voltage of the rectifying / smoothing circuit 1 when it is an AC power supply. The input voltage to 5 is insufficient. FIG. 2 shows a region where the output voltage of the tertiary winding output circuit 12 is insufficient (that is, the voltage of the control power supply Vcc is insufficient) when the power supply 41 is a DC power supply. This corresponds to the case of the power supply voltage of the DC power supply when it is below the limit value.
Note that the above-described voltage Vac has been described in the case of AC100V, and the voltage Vdc has been described in the case of DC100V. However, the voltage Vac is not limited to these voltages, and other voltages satisfy the relationship of the above formula (1). Needless to say.

  At this time, the output design of the output transformer 4 needs to be newly designed so that the output voltage of the tertiary winding output circuit 12 is not insufficient when the power supply 41 is a DC power supply. In contrast, the voltage is too high, and unnecessary power consumption occurs.

  However, in the lighting device according to the present embodiment, the output transformer 4 is not changed, the control power supply auxiliary circuit 6 is provided, and the Zener voltage Vz of the Zener diode 14 is set as shown in the following formula (2), for example. To do.

  Vz = (Output voltage of secondary winding output circuit 11 at AC 90 V) − (Output voltage of tertiary winding output circuit 12) (2)

By setting the Zener voltage Vz of the Zener diode 14 in this way, when the power supply 41 is AC 90 V or higher (the output voltage of the rectifying and smoothing circuit 1 is about 127 V from the equation (1)), the control power auxiliary circuit 6 When the power supply 41 is DC 100 V, for example, the shortage of input voltage to the control power generation circuit 5 can be compensated for when the power supply 41 is DC 100 V.
In the above formula (2), “AC90V” is used as an example. For example, when the output voltage of the tertiary winding output circuit 12 is less than the output limit value and the voltage of the control power supply Vcc is lowered. In this case, the Zener voltage Vz of the Zener diode 14 may be set so that the control power supply auxiliary circuit 6 becomes conductive.

(Effect of Embodiment 1)
As in the above configuration and operation, even if the input voltage to the control power generation circuit 5 that generates the control power supply Vcc (that is, the output voltage of the tertiary winding output circuit 12) decreases, the control power auxiliary circuit 6 By the function, current can be supplied from the secondary winding output circuit 11 to the tertiary winding output circuit 12, and the shortage of the input voltage of the control power generation circuit 5 can be compensated, and the control power supply Vcc can be stabilized. Can be secured.

  In addition, it becomes easy to share parts with models other than the separate power supply type in which the power supply is separately provided in normal and emergency situations.

  As shown in FIG. 1, the LED module 2 is connected as a load. However, the present invention is not limited to this, and an incandescent bulb, a discharge lamp, an organic EL, or other light source may be used.

Embodiment 2. FIG.
The lighting device according to the present embodiment will be described focusing on differences in configuration and operation of the lighting device according to the first embodiment.

(Configuration of lighting device)
FIG. 3 is a circuit diagram of a lighting device according to Embodiment 2 of the present invention.
As shown in FIG. 3, the lighting device according to the present embodiment further detects voltage in the ACDC detection circuit 21, the microcomputer 26, and the rectifying / smoothing circuit 1, as compared with the lighting device according to the first embodiment. A circuit 20 is provided. In addition, the control power supply auxiliary circuit 6 includes a control switch 27 having a configuration in which the diode 13, the Zener diode 14, and the current limiting resistor 15 are connected in series.
As shown in FIG. 3, in the control power supply auxiliary circuit 6, a diode 13, a Zener diode 14, a current limiting resistor 15, and a control switch 27 are connected in this order to form a series circuit. 27 may be installed in any position of this series circuit.

  The voltage detection circuit 20 includes voltage dividing resistors 22a and 22b, a comparator 23, a reference voltage power supply 24, and a photocoupler 25, and detects that the output voltage of the rectifying and smoothing circuit 1 has dropped below a predetermined voltage. Is. Among these, the photocoupler 25 includes a photodiode 25a and a phototransistor 25b.

  In the voltage detection circuit 20, one end of the voltage dividing resistor 22a is connected to the positive side of the output of the rectifying and smoothing circuit 1, and the other end is connected to the voltage dividing resistor 22b. The other end of the voltage dividing resistor 22b is connected to the negative side of the output of the rectifying and smoothing circuit 1. Further, the connection part between the voltage dividing resistor 22 a and the voltage dividing resistor 22 b is connected to the non-inverting input part of the comparator 23. A reference voltage power supply 24 is connected to the inverting input side of the comparator 23. In addition, the photodiode 25a of the photocoupler 25 is connected to the output unit of the comparator 23. When the output voltage of the comparator 23 outputs a positive voltage, a current flows through the photodiode 25a. The collector side of the phototransistor 25b of the photocoupler 25 is connected to the microcomputer 26, and the emitter side is grounded.

  The ACDC detection circuit 21 includes a diode 28, a current limiting resistor 29, a smoothing capacitor 30, and a photocoupler 31, and detects whether the voltage supplied from the power supply 41 is an AC voltage or a DC voltage. Among these, the photocoupler 31 includes a photodiode 31a and a phototransistor 31b.

  In the ACDC detection circuit 21, the diode 28, the current limiting resistor 29, the photodiode 31 a of the photocoupler 31, and the negative electrode side of the power source 41 are connected in this order from the positive side of the power source 41. Also, smoothing capacitors 30 are connected to both ends of the photodiode 31a. The collector side of the phototransistor 31b of the photocoupler 31 is connected to the microcomputer 26, and the emitter side is grounded.

  The control switch 27 is electrically connected to the microcomputer 26 and performs an ON / OFF operation (opening / closing operation) according to a control signal of the microcomputer 26.

  The microcomputer 26 corresponds to the “control device” of the present invention.

(Operation of lighting device)
Next, the basic operation of the lighting device according to the present embodiment will be described with reference to FIG.

  In the voltage detection circuit 20, the output voltage of the rectifying and smoothing circuit 1 is divided by the voltage dividing resistor 22 a and the voltage dividing resistor 22 b, and the divided voltage and the reference voltage supplied from the reference voltage power supply 24 are the comparators. 23 for comparison. When the divided voltage is higher than the reference voltage, the comparator 23 outputs a positive voltage, and current flows through the photodiode 25a due to the positive voltage. When a current flows through the photodiode 25a, the collector and the emitter in the phototransistor 25b are conducted. The microcomputer 26 can determine whether or not the output voltage of the rectifying / smoothing circuit 1 is lower than a predetermined voltage based on the reference voltage of the reference voltage power supply 24, depending on whether or not the phototransistor 25b is turned on. .

  As described above, the ACDC detection circuit 21 detects whether the voltage supplied from the power supply 41 is an AC voltage or a DC voltage. Specifically, when a current flows through the photodiode 31a of the photocoupler 31, the collector and the emitter in the phototransistor 31b become conductive. The microcomputer 26 can determine whether the voltage supplied from the power source 41 is an AC voltage or a DC voltage depending on whether or not the phototransistor 31b is conductive.

  Based on the detection results of the voltage detection circuit 20 and the ACDC detection circuit 21, the microcomputer 26 reduces the voltage of the power supply 41 (that is, the output voltage of the rectifying and smoothing circuit 1) below a predetermined voltage when the power supply 41 is a DC power supply. If they occur, or if they occur simultaneously, the control switch 27 of the control power supply auxiliary circuit 6 is turned on to supply current from the secondary winding output circuit 11 to the tertiary winding output circuit 12. Further, the ON operation condition of the control switch 27 can be set by appropriately combining the detection results of the voltage detection circuit 20 and the ACDC detection circuit 21.

(Effect of Embodiment 2)
As in the above configuration and operation, the control power supply Vcc of the control power supply generation circuit 5 is stabilized even when the power supply 41 is switched to the DC power supply or when the output voltage of the rectifying / smoothing circuit 1 drops below a predetermined voltage. Can be secured.

Embodiment 3 FIG.
The lighting device according to the present embodiment will be described focusing on differences in configuration and operation of the lighting device according to the first embodiment.

(Configuration of lighting device)
FIG. 4 is a circuit diagram of a lighting device according to Embodiment 3 of the present invention.
As shown in FIG. 4, the lighting device according to the present embodiment further includes a control power source determination circuit 32 as compared with the lighting device according to the first embodiment, and is included in the control power source auxiliary circuit 6. Includes a control switch 27 in a configuration in which the diode 13, the Zener diode 14, and the current limiting resistor 15 are connected in series.
As shown in FIG. 4, in the control power supply auxiliary circuit 6, a diode 13, a Zener diode 14, a current limiting resistor 15, and a control switch 27 are connected in this order to form a series circuit. 27 may be installed in any position of this series circuit.

  The control power supply determination circuit 32 includes a reference voltage power supply 33 and a comparator 34, and detects that the output voltage of the tertiary winding output circuit 12 has dropped below a predetermined voltage.

  In the control power supply determination circuit 32, the non-inverting input part of the comparator 34 is connected to the connection part of the rectifier diode 12 a and the capacitor 12 b that can detect the output voltage of the tertiary winding output circuit 12. A reference voltage power supply 33 is connected to the inverting input section of the comparator 34. The output section of the comparator 34 is electrically connected to the control switch 27 and controls its ON / OFF operation.

(Operation of lighting device)
Next, the basic operation of the lighting device according to the present embodiment will be described with reference to FIG.

  The comparator 34 compares the output voltage of the tertiary winding output circuit 12 with the reference voltage of the reference voltage power supply 33, and when the output voltage of the tertiary winding output circuit 12 falls below the reference voltage, The control switch 27 of the control power supply auxiliary circuit 6 is turned on to supply current from the secondary winding output circuit 11 to the tertiary winding output circuit 12.

(Effect of Embodiment 3)
Even when the output voltage of the tertiary winding output circuit 12 drops below a predetermined voltage (reference voltage of the reference voltage power supply 33) for some reason as in the above configuration and operation, the control of the control power supply generation circuit 5 is controlled. The power supply Vcc can be secured stably.

Embodiment 4 FIG.
The lighting device according to the present embodiment will be described focusing on the differences in configuration and operation of the lighting device according to the second embodiment.

(Configuration of lighting device)
FIG. 5 is a circuit diagram of a lighting device according to Embodiment 4 of the present invention.
As shown in FIG. 5, the lighting device according to the present embodiment further includes an LED abnormality detection circuit 35 as compared with the lighting device according to the second embodiment, and is included in the control power supply auxiliary circuit 6. Includes a control switch 27 in a configuration in which the diode 13, the Zener diode 14, and the current limiting resistor 15 are connected in series.

  The LED abnormality detection circuit 35 includes a comparator 36 and a reference voltage power source 37. The LED abnormality detection circuit 35 compares the voltage applied to the LED module 2 with the reference voltage, and is normally lit or short-circuited or opened. This is to detect whether or not an abnormality has occurred.

  In the LED abnormality detection circuit 35, a reference voltage power source 37 is connected to a non-inversion output portion of the comparator 36. Further, the inverted output portion of the comparator 36 is connected to the positive electrode side of the LED module 2. The output unit of the comparator 36 is connected to the microcomputer 26.

  The LED abnormality detection circuit 35 corresponds to the “illumination abnormality detection circuit” of the present invention.

(Operation of lighting device)
FIG. 6 is a diagram illustrating an example of combinations of detection results of the detection circuits for determining the ON / OFF state of the control switch 27 in the lighting device according to Embodiment 4 of the present invention. Hereinafter, the basic operation of the lighting device according to the present embodiment will be described with reference to FIGS. 5 and 6.

  The comparator 36 compares the generated voltage of the LED module 2 with the reference voltage, detects whether the LED module 2 is normally lit, or has an abnormality such as a short circuit or an open state, and the detection result Is output to the microcomputer 26. The microcomputer 26 turns on / off the control switch 27 based on the combination of detection results of the LED abnormality detection circuit 35, the voltage detection circuit 20, and the ACDC detection circuit 21 as shown in FIG. As shown in FIG. 6, in the microcomputer 26, for example, the ACDC detection circuit 21 detects that the power supply 41 is a DC power supply, and the voltage detection circuit 20 reduces the voltage of the power supply 41 to be lower than a predetermined value. Is detected, and when the LED abnormality detection circuit 35 detects that the generated voltage of the LED module 2 is normal, the control switch 27 is turned on. As a result, current is supplied from the secondary winding output circuit 11 to the tertiary winding output circuit 12, and the shortage of the input voltage of the control power generation circuit 5 can be compensated. Further, when the microcomputer 26 detects that the LED module 2 has a short circuit abnormality by the LED abnormality detection circuit 35, the microcomputer 26 turns off the control switch 27 because the output voltage of the secondary winding output circuit 11 has decreased. Let On the other hand, when the LED abnormality detection circuit 35 detects that the LED module 2 is in the open state, the microcomputer 26 turns on because the output voltage of the secondary winding output circuit 11 is sufficiently generated. As described above, the microcomputer 26 performs the ON / OFF operation of the control switch 27 of the control power supply auxiliary circuit 6 according to the state of the entire circuit.

(Effect of Embodiment 4)
As described above, the microcomputer 26 turns on the control switch 27 according to the state of the entire circuit of the lighting device based on the detection results of the LED abnormality detection circuit 35, the voltage detection circuit 20, and the ACDC detection circuit 21. Since the / OFF operation is performed, the control power supply Vcc of the control power supply generation circuit 5 can be secured stably.

  1 rectifying and smoothing circuit, 1a diode bridge, 1b smoothing capacitor, 2 LED module, 3 DCDC conversion circuit, 4 output transformer, 5 control power generation circuit, 6 control power supply auxiliary circuit, 7 control IC, 8 current control circuit, 9 current detection Resistor, 10 Photocoupler, 10a Photodiode, 10b Phototransistor, 11 Secondary winding output circuit, 11a Rectifier diode, 11b Capacitor, 12 Tertiary winding output circuit, 12a Rectifier diode, 12b Capacitor, 13 Diode, 14 Zener diode , 15 current limiting resistor, 16 transistor, 17 Zener diode, 18 bias resistor, 19 smoothing capacitor, 20 voltage detection circuit, 21 ACDC detection circuit, 22a, 22b voltage dividing resistor, 23 comparator 24 Reference voltage power supply, 25 Photocoupler, 25a Photodiode, 25b Phototransistor, 26 Microcomputer, 27 Control switch, 28 Diode, 29 Current limiting resistor, 30 Smoothing capacitor, 31 Photocoupler, 31a Photodiode, 31b Phototransistor, 32 control power supply determination circuit, 33 reference voltage power supply, 34 comparator, 35 LED abnormality detection circuit, 36 comparator, 37 reference voltage power supply, 41 power supply.

Claims (10)

A rectifying / smoothing circuit for rectifying and smoothing a power supply voltage;
A constant current circuit constituting a flyback type switching power supply for driving a light source as a load at a constant current from an output voltage of the rectifying and smoothing circuit;
Installed in the constant current circuit, converts the output voltage of the rectifying and smoothing circuit, and supplies the secondary winding for supplying current to the light source, and the tertiary winding reverse to the secondary winding. With a transformer
A control power generation circuit for generating a control power from the output voltage of the tertiary winding;
When the output side of the secondary winding and the output side of the tertiary winding are connected and the power supply voltage becomes less than a predetermined voltage, the output of the tertiary winding is output from the output side of the secondary winding. Control power supply auxiliary circuit for supplying current to the side,
A lighting device comprising: When the difference between the output voltage of the secondary winding and the output voltage of the tertiary winding becomes a predetermined value or more, the control power supply auxiliary circuit starts from the output side of the secondary winding to the tertiary winding. The lighting device according to claim 1, wherein a current is supplied to the output side of the lighting device. The control power supply auxiliary circuit supplies current from the output side of the secondary winding to the output side of the tertiary winding when the output voltage of the tertiary winding becomes less than a predetermined output limit value. The lighting device according to claim 1, wherein: A voltage detection circuit for detecting whether the output voltage of the rectifying and smoothing circuit is less than a predetermined voltage;
An ACDC detection circuit for detecting whether the power supply voltage is an AC voltage or a DC voltage;
A control switch which is provided in the control power supply auxiliary circuit and which conducts or cuts off between the output side of the secondary winding and the output side of the tertiary winding;
A control device for controlling the control switch to a conductive state or a cut-off state based on detection results of the voltage detection circuit and the ACDC detection circuit;
The lighting device according to any one of claims 1 to 3, further comprising: When the voltage detection circuit detects that the output voltage of the rectifying and smoothing circuit is less than a predetermined voltage, or when the power supply voltage is a DC voltage, the control switch The lighting device according to claim 4, wherein the lighting device is in a conductive state. A control switch which is provided in the control power supply auxiliary circuit and which conducts or cuts off between the output side of the secondary winding and the output side of the tertiary winding;
Detecting whether or not the output voltage of the tertiary winding is less than a predetermined voltage, and if the output voltage is less than the predetermined voltage, a control power supply determination circuit for turning on the control switch;
The lighting device according to any one of claims 1 to 3, further comprising: An illumination abnormality detection circuit that compares the applied voltage of the light source with a reference voltage and transmits the comparison result to the control device,
The control device controls the control switch to a conductive state or a cut-off state based on detection results of the illumination abnormality detection circuit, the voltage detection circuit, and the ACDC detection circuit. 5. The lighting device according to 5. The illumination abnormality detection circuit detects that the light source is in a normal state, a short-circuit state, or an open state based on a result of comparing an applied voltage of the light source with a reference voltage,
When the illumination abnormality detection circuit detects that the light source is in a short-circuit state, the control device turns off the control switch, and detects that the light source is in an open state. The lighting device according to claim 7, wherein the lighting device is made conductive. The lighting device according to any one of claims 1 to 8,
An instrument body for housing the lighting device;
A lighting fixture characterized by comprising: The lighting device according to any one of claims 1 to 8,
A display panel that emits light when the light source is turned on by the lighting device;
An instrument body to which the lighting device and the display panel are attached;
A lighting fixture characterized by comprising:

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