JP3678279B2 - Power supply device, discharge lamp lighting device and lighting fixture - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of a startup circuit of a power supply device that supplies power for lighting a discharge lamp, a discharge lighting device using the power supply device, and a lighting fixture using the discharge lighting device.
[Prior art]
FIG. 1 is a circuit diagram showing a first conventional configuration example of a discharge lamp lighting device using a conventional power supply device (half-bridge method). When the power is turned on, AC power is supplied from the commercial power source 1 to the rectifier circuit 3 via the filter 2 for preventing high frequency leakage. Thus, the AC power is rectified by the rectifier circuit 3, smoothed by the capacitor C to be a DC power, and applied to the resistors R1 and R2 and the transistor Tr1.
[0002]
Initially, a charging current flows through the capacitors C1 and C2 of the main circuit via the resistor R2, and a charging current flows through the capacitor C3 via the resistor R1. When the potential of the capacitor C3 rises, the trigger diode TD is turned on, a voltage is generated at the gate of the transistor Tr2, and the transistor Tr2 is turned on. When the transistor Tr2 is turned on, the discharge currents of the capacitors C1 and C2 flow through the inductor L, the supersaturated transformer CT, and the transistor Tr2. At this time, the transistor Tr2 is turned on by the voltage generated at the secondary side CT22 of the supersaturated transformer CT. The current continues to flow. However, after a while, the supersaturated transformer CT is saturated, no voltage is generated on the secondary side CT22, and the transistor Tr2 is turned off.
[0003]
When the transistor Tr2 is turned off, a current flowing from the inductor L to the capacitors C1 and C2 is generated, resetting the supersaturated transformer CT and generating a voltage at the secondary CT21 to turn on the transistor Tr1. Thereby, a direct current flows through the transistor Tr1 to the supersaturated transformer CT, the inductor L, and the capacitor C1 side. Due to this current, the secondary side CT21 of the supersaturated transformer CT continues to generate voltage, and the transistor Tr1 is kept on.
[0004]
After that, when the supersaturated transformer CT is saturated, the generated voltage of the secondary side CT21 disappears, so that the transistor Tr1 is turned off. Next, since a current flows from the capacitors C1 and C2 to the inductor L and the supersaturated transformer CT, the supersaturated transformer CT is reset and a voltage is generated at the secondary CT22 to turn on the transistor Tr2. Thereafter, by repeating the above operation, the transistors Tr1 and Tr2 are switched, and a high-frequency high-frequency voltage is applied to the discharge lamp 4 to light the discharge lamp 4.
[0005]
In the conventional circuit, as noted above, when the power is turned on, to start the Tr2, by supplying current from the trigger diode TD to the gate of the transistor Tr2, but are on the transistor Tr2, which in the trigger Since expensive elements such as the diode TD are used, there is a problem that the cost of the circuit becomes high.
[0006]
FIG. 2 is a circuit diagram showing a second configuration example of a discharge lamp lighting device using a conventional power supply device (full bridge method) .
[0007]
FIG. 3 is a circuit diagram showing a third configuration example of a discharge lamp lighting device using a conventional power supply device (one-stone self-excited type).
[0008]
2 and FIG. 3, the transistor Tr2 is turned on by supplying current from the trigger diode TD to the gate of the transistor Tr2 to start the transistor Tr2 when the power is turned on. Since expensive elements such as the trigger diode TD are used, there is a problem that the cost of the circuit becomes high.
[Problems to be solved by the invention]
In the discharge lamp lighting apparatus using a conventional power supply device as described above, to boot the boot target transistor due to the use of expensive elements such as trigger diode, it is a disadvantage that the cost of the circuit is increased there were.
[0009]
The present invention has been made to solve the above problems, and provides a power supply device capable of reducing the cost of a circuit, a discharge lamp lighting device using the power supply device , or a lighting fixture incorporating the discharge lamp lighting device. The purpose is to do.
[0010]
[Means for Solving the Problems]
A power supply device of the present invention includes a DC power supply; a switching circuit that has a set of MOS-FETs connected in series with the DC power supply in parallel and switches the output from the DC power supply at a high frequency to output a high-frequency voltage. A resonance circuit for generating a high voltage by resonating the switching current output from the switching circuit; detecting a high-frequency output on the primary side, and applying 2 to the control terminal of each MOS • FET constituting the switching circuit Feedback means for supplying a positive feedback control signal for turning on / off the MOS FET from the secondary side; between one end of the DC power supply and the gate of one of the MOS FETs in the set of MOS FETs A first starting impedance connected to and supplied with a direct current from the direct current power source; connected between a gate and a source of the one MOS • FET, A starting capacitor that is charged by the direct current supplied from the start-impedance; second connected without passing through the resonant circuit between the DC power supply and the other end to the source of the one MOS · FET of And a starting impedance.
[0011]
A discharge lamp lighting device according to the present invention includes the power supply device according to claim 1; and a discharge lamp that is lit by a high-frequency voltage output from the power supply device.
[0012]
A lighting fixture of the present invention comprises the discharge lamp lighting device according to claim 2; and a lighting fixture main body.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings .
[0013]
FIG. 4 is a circuit diagram showing the configuration of the first embodiment of the present invention. 1 is a commercial power source, 2 is a filter for preventing high frequency components from leaking to the commercial power source 1 side, 3 is a rectifier circuit comprising a diode bridge, 4 is a discharge lamp such as a fluorescent lamp, and C is a rectifier current smoothing capacitor, C1, C2 capacitor (first capacitor) constituting a resonant circuit of the main circuit, the capacitor C 8 of the transistor Tr1 side to charge the direct current during startup, C8 of transistor Tr2 side supersaturated transformer CT Is a capacitor (second capacitor) for increasing the impedance on the secondary side, CT is a supersaturated transformer for switching the transistors Tr1 and Tr2, and CT21 is a supersaturation for supplying a control voltage to the gate (control terminal) of the transistor Tr1. The secondary side of the transformer CT, CT22 is the gate of the transistor Tr2 (control terminal) ) Is a secondary side of a supersaturated transformer CT that supplies a control voltage to L), L is an inductor that constitutes a resonance circuit of the main circuit, R6 and R7 are resistances for starting assistance (first and second resistors), and transistors Tr1 and Tr2 are A transistor (switching element or first and second transistors) for switching a direct current supplied from the rectifier circuit 3 is usually a MOS / FET. The remaining part excluding the discharge lamp 4 constitutes the power supply device of the present invention. Here, the rectifier circuit 3 and the capacitor C constitute a DC power source, the transistors Tr1 and Tr2 constitute a switching circuit, and the supersaturated transformer CT, the inductor L, and the capacitors C1 and C2 constitute a resonance circuit. The capacitor C8 may be anything as long as it provides an impedance such as a resistor.
[0014]
Next, the operation of the present embodiment will be described. When the power is turned on, the direct current from the rectifier circuit 2 is supplied to the transistor Tr1 and the resistor R6. Since the capacitor C8 in series with the secondary side CT21 supersaturated transformer CT is inserted, the impedance on the secondary side CT21 is high, the control voltage is applied through a resistor R6 to the gate of the transistor Tr1. As a result, the drain and source of the transistor Tr1 become somewhat conductive, and a direct current passes through the transistor Tr1, the primary side of the supersaturated transformer CT, and the inductor L, and charges the capacitors C1 and C2. When the potential of the capacitor C1, C2 is increased, the potential in FIG point A rises as shown in FIG. 5 (A). Here, since the capacitor C8 is inserted in series with the secondary side CT22 of the supersaturated transformer CT, the impedance of the secondary side CT22 is high, and the resistor R7 is connected to the gate of the transistor Tr2 as the potential at the point A rises. A control voltage will be applied through.
[0015]
Therefore, when the gate potential of the transistor Tr2 rises through the resistor R7 and rises to the saturation potential, the transistor Tr2 is turned on, and the discharge current of the capacitors C1 and C2 passes through the primary side of the supersaturated transformer CT and the inductor L to It flows to Tr2. At this time, a voltage is generated at CT22 on the secondary side of the supersaturated transformer CT and the gate potential of the transistor Tr2 is maintained, so that the transistor Tr2 is kept on and the current continues to flow. Further, FIG. 5 (B) is a drain current waveforms of the transistor Tr2 with respect to the potential change of the point A.
[0016]
However, after a while, the supersaturated transformer CT is saturated, no voltage is generated in the CT22 on the secondary side, and the transistor Tr2 is turned off. When the transistor Tr2 is turned off, a current flowing from the inductor L to the capacitors C1 and C2 is generated, resetting the supersaturated transformer CT and generating a voltage at the secondary CT22 to turn on the transistor Tr1. Thereby, a direct current flows through the transistor Tr1 to the supersaturated transformer CT, the inductor L, and the capacitor C1 side. Due to this current, the secondary side CT21 of the supersaturated transformer CT continues to generate voltage, and the transistor Tr1 is kept on.
[0017]
After that, when the supersaturated transformer CT is saturated, the voltage generated by the CT21 on the secondary side disappears, so that the transistor Tr1 is turned off. Next, since a discharge current flows from the capacitors C1 and C2 to the primary side of the inductor L and the supersaturated transformer CT, the supersaturated transformer CT is reset and a voltage is generated at the secondary side CT22 to turn on the transistor Tr2. To do. Thereafter, by repeating the above operation, the transistor Tr1 and the transistor Tr2 are switched, a high-frequency high-frequency voltage is applied to the discharge lamp 4, and the discharge lamp 4 is turned on.
[0018]
According to the present embodiment, even if a trigger diode, a capacitor, a current supply diode, and the like for starting the transistor Tr2 are omitted, the transistor Tr2 is started with a simple circuit configuration using the resistors R6 and R7. Switching of the transistors Tr1 and Tr2 can be started. As a result, the cost of the circuit can be reduced, and the mounting can be facilitated as the circuit scale is reduced.
[0019]
As shown in FIG. 6 , even when the resistor R7 is connected to the resistor R6 and the gate control voltage of the transistor Tr2 is supplied through the resistor R6, the same operation as that of the first embodiment shown in FIG. 4 is obtained. Can have a similar effect.
[0020]
FIG. 7 is a circuit diagram showing the configuration of the second embodiment of the present invention. This example differs from the configuration of the first embodiment shown in FIG. 4 only in the vertical position of the main circuit, and the operation and effect are the same as those of the first embodiment.
[0021]
FIG. 8 is a circuit diagram showing the configuration of the third embodiment of the present invention. This example is a circuit construction called a clean bridge subjected to harmonic countermeasure, the configuration and operation related to starting of the transistor Tr1 is the same as the first embodiment shown in FIG. 4, to obtain the same effect Can do. In this example, a charging current is supplied to the capacitor C9 from the rectifier circuit 3 side, so that an input current to the circuit is secured even in a period where the rectified voltage output from the rectifier circuit 3 is low, and the harmonics of the input current are obtained. Ingredients can be reduced.
[0022]
FIG. 9 is a circuit diagram showing the configuration of the fourth embodiment of the present invention. This example is the configuration of the first embodiment shown in FIG. 4, in place of the supersaturation transformer CT, but adopts a circuit configuration using a ballast choke Bch, configuration and operation related to starting of the transistor Tr1 Is the same as in the first embodiment, and the same effect can be obtained.
[0023]
FIG. 10 is a circuit diagram showing the configuration of the fifth embodiment of the present invention. This example differs from the configuration of the fourth embodiment shown in FIG. 9 only in the vertical position of the main circuit, and the operation and effect are the same as those of the tenth embodiment.
[0024]
FIG. 11 is a circuit diagram showing the configuration of the sixth embodiment of the present invention. This example is a circuit construction called a clean bridge subjected to harmonic countermeasure, the configuration and operation related to starting of the transistor Tr1 is the same as in the fourth embodiment shown in FIG. 9, to obtain the same effect Can do.
[0025]
FIG. 12 is a circuit diagram showing the configuration of the seventh embodiment of the present invention. In this example, the gate circuits of the transistors Tr1 and Tr2 have a circuit composed of a Zener diode ZD, a diode D1, and a resistor R9, and the voltage applied to the gate from the secondary side Bch21, 22 of the ballast choke Bch by this circuit. The power supplied to the discharge lamp 4 is increased by making the rise and fall of the transistor steep and wide, increasing the on-time of the transistors Tr1 and Tr2, and lowering the switching frequency. but other circuit configuration and operation are the same effect similar to the embodiment of the first embodiment shown in FIG.
[0026]
FIG. 13 is a circuit diagram showing the configuration of the eighth embodiment of the present invention. This example differs from the configuration of the seventh embodiment shown in FIG. 12 only in the upper and lower positions of the main circuit, and the operation and effect are the same as those of the seventh embodiment.
[0027]
FIG. 14 is a circuit diagram showing the configuration of the ninth embodiment of the present invention. This example has a circuit configuration called a clean bridge with a countermeasure against harmonics, but the configuration and operation related to activation of the transistor Tr1 are the same as those of the seventh embodiment shown in FIG. Can do.
[0028]
FIG. 15 is a circuit diagram showing the configuration of the tenth embodiment of the present invention. In this example, the inverter circuit constituting the power supply device is configured by a full bridge. An impedance Z1 is connected between the gate of the transistor Tr1 and the DC power supply line, and an impedance Z2 is connected between the gate of the transistor Tr2 and the transistor Tr2 side of the supersaturated transformer CT. As a result, when the power is turned on, a control voltage is applied to the gate of the transistor Tr1 through the impedance Z1, so that the drain and source of the transistor Tr1 are somewhat conductive, and a direct current is applied to the transistor Tr1, the supersaturated transformer CT, The capacitor C2 is charged through the inductor L, the capacitor C2, and the resistor R4. When the potential of the capacitor C2 rises, the gate potential of the transistor Tr2 rises through the impedance Z2, and when it rises to the saturation potential, the transistor Tr2 is turned on and the transistors Tr1 to Tr4 start switching. Also in this example, since expensive components such as the trigger diode TD are not used for starting the transistor Tr2, the cost of the circuit can be reduced, and the mounting can be facilitated as the circuit scale is reduced. .
[0029]
FIG. 16 is a circuit diagram showing the configuration of the eleventh embodiment of the present invention. In this example, the inverter circuit constituting the power supply device is configured by a full bridge. An impedance Z1 (first impedance) is connected between the gate of the transistor Tr3 and the DC power supply line, and an impedance Z2 (second impedance) is connected between the gate of the transistor Tr4 and the source of the transistor Tr3. . Thus, when the power supply is turned on, a control voltage is applied to the gate of the transistor Tr3 through the impedance Z1, so that the drain and source of the transistor Tr3 are somewhat conductive, and a direct current is applied to the transistor Tr3, the capacitor C2, and the inductor. The capacitor C2 is charged through L, the supersaturated transformer CT, and the resistor R4. When the potential of the capacitor C1 rises, the gate potential of the transistor Tr4 rises through the impedance Z2, and when it rises to the saturation potential, the transistor Tr4 is turned on and the transistors Tr1 to Tr4 start switching. In this example as well, since expensive components such as the trigger diode TD are not used for starting the transistor Tr4, the cost of the circuit can be reduced, and the mounting can be facilitated as the circuit scale is reduced. it can.
[0030]
FIG. 17 is a partially broken sectional view showing an embodiment of a lighting fixture of the present invention. 11 mouthpiece 12 cover forming the fixture body, the glove 13 to cover the discharge lamp 4 (luminous tube), 14 is a printed circuit board, wherein, the discharge lamp lighting power supply circuit described in FIGS 16 It is installed. When the base 11 is screwed into a socket (not shown) and the commercial power supply is turned on, the power supply device operates to supply a high voltage to the discharge lamp 4 and light it.
[0031]
【The invention's effect】
As described above, according to the power supply device of the first aspect of the present invention, it is only necessary to provide a start-up capacitor charged via an impedance from a DC power source between the gate and source of two switching elements connected in series. The switching element can be started up without using expensive parts such as a trigger diode, and the cost of the circuit can be reduced.
[0032]
According to the discharge lamp lighting device of the second aspect, the discharge lamp can be reliably started or the cost of the device can be reduced.
[0033]
According to the lighting fixture of Claim 3, a discharge lamp can be started reliably or the cost of a fixture can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a first conventional configuration example of a conventional discharge lamp lighting device.
FIG. 2 is a circuit diagram showing a second conventional configuration example of a conventional discharge lamp lighting device.
FIG. 3 is a circuit diagram showing a third conventional configuration example of a conventional discharge lamp lighting device .
FIG. 4 is a circuit diagram showing the configuration of the first embodiment of the present invention.
5 is a waveform diagram showing a voltage waveform and a potential at a point A shown in FIG. 4 and an example of a drain current waveform of a transistor Tr2.
FIG. 6 is a circuit diagram showing an example of the first embodiment of the present invention.
FIG. 7 is a circuit diagram showing a configuration of a second embodiment of the present invention.
FIG. 8 is a circuit diagram showing a configuration of a third embodiment of the present invention.
FIG. 9 is a circuit diagram showing a configuration of a fourth embodiment of the present invention.
FIG. 10 is a circuit diagram showing a configuration of a fifth embodiment of the present invention.
FIG. 11 is a circuit diagram showing a configuration of a sixth embodiment of the present invention.
FIG. 12 is a circuit diagram showing a configuration of a seventh embodiment of the present invention.
FIG. 13 is a circuit diagram showing a configuration of an eighth embodiment of the present invention.
FIG. 14 is a circuit diagram showing a configuration of a ninth embodiment of the present invention.
FIG. 15 is a circuit diagram showing a configuration of a tenth embodiment of the present invention.
FIG. 16 is a circuit diagram showing a configuration of an eleventh embodiment of the present invention.
FIG. 17 is a fragmentary cross-sectional view showing an embodiment of a lighting fixture of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Commercial power supply 2 ... High frequency leak prevention filter 3 ... Rectifier circuit (DC power supply)
4. Discharge lamp (discharge lamp lighting device)
12 ... Cover (lighting fixture body)
13 ... Glove (lighting fixture body)
14 ... printed circuit board,
Bch ... Ballast choke C ... Rectifier current smoothing capacitor (DC power supply)
C1, C2, ... capacitors (resonance circuit)
C 8 ... Capacitor (starting capacitor)
C4 ... Capacitor CT ... Saturable transformer D ... Diode L ... Inductor (resonant circuit)
R1 ... Current introduction resistor R2 ... Start-up auxiliary resistor R5 ... Resistance R6, R7 ... Start-up resistor (first and second resistors)
TD: Trigger diode (trigger element)
Tr1, Tr2 ... transistors (switching elements or first and second transistors)
Z1, Z2 ... impedance

Claims (3)

DC power supply;
A switching circuit having a set of MOS FETs connected in series with the DC power supply in parallel, and switching the output from the DC power supply at a high frequency to output a high frequency voltage;
A resonance circuit for generating a high voltage by resonating the switching current output from the switching circuit;
Feedback means for detecting a high-frequency output on the primary side and supplying a positive feedback control signal for turning on / off the MOS • FET from the secondary side to the control terminal of each MOS • FET constituting the switching circuit;
A first starting impedance connected between one end of the DC power source and the gate of one of the pair of MOS • FETs and supplied with a DC current from the DC power source;
A starting capacitor connected between the gate and source of the one MOS-FET and charged by a direct current supplied from the first starting impedance;
A second starting impedance connected between the other end of the DC power source and the source of the one MOS • FET without passing through the resonance circuit ;
A power supply device comprising: A power supply device according to claim 1;
A discharge lamp that is lit by a high-frequency voltage output from the power supply device;
A discharge lamp lighting device comprising: A discharge lamp lighting device according to claim 2;
A lighting fixture body;
The lighting fixture characterized by comprising.

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