JPS63244599A - Discharge lamp lighter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a discharge lamp lighting device, for example, a high-frequency fluorescent lamp lighting device that is energized by a DC power source and is dimmable, and is capable of preventing insufficient preheating at the time of startup. This relates to a method for reliably starting the engine.

[Prior Art] Conventionally, in a high frequency fluorescent lamp lighting device that operates using a DC power source such as a dry cell battery, it has been possible to operate in a dimming mode in order to extend the life of the dry cell battery. In such a lighting device, the heater of the discharge lamp is preheated for a predetermined time after the power is turned on, and the electrodes of the discharge lamp are short-circuited to prevent lighting, and after the predetermined time has elapsed, the heater of the discharge lamp is short-circuited to prevent lighting. The discharge lamp was lit by releasing the short-circuit condition.

[Problems to be Solved by the Invention] However, in such a conventional type, when the dimming mode is set, the discharge lamp does not function properly in both the preheating state after the power is turned on and the lighting state after a predetermined period of time has elapsed. Since the drive circuit operates in a dimming mode, the heater is insufficiently preheated in the preheating state, which puts a heavy burden on the discharge lamp at startup, shortening the lamp life. Further, during lighting, the starting voltage may not be sufficiently high and the discharge lamp may not be lit properly.

In view of the problems in the conventional type described above, the purpose of the present invention is to
In a discharge lamp lighting device, even in dimming mode, sufficient preheating is performed after the power is turned on, thereby extending the lamp life, and a sufficiently high starting voltage is applied to the discharge lamp to ensure proper lighting. The goal is to ensure that the work is carried out accordingly.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the discharge lamp lighting device according to the present invention, for example, as shown in FIG. 1, a first timer 2, a second timer 4, A driver 6 forming an inverter, a driver transistor 8, a step-up transformer 10, a discharge lamp 12 such as a fluorescent lamp, and a switch 14 connected between electrodes of the discharge lamp 12 are provided. Note that 16 is a DC power source such as a dry battery. Further, the first timer 2 mainly controls the operating time of the switch 14, and the second timer 4 controls the output level of the inverter.

[Function] In the above configuration, as shown in FIG. 2, for example, the operating time of the second timer 4 is set longer than the operating time of the first timer 2. And DC TllR16
When the switch 1 is turned on during the operation time of the first timer 2,
4 is turned on, the electrodes of the discharge lamp 12 are short-circuited, and lighting of the discharge lamp 12 is prevented. Further, during the operating time specified by the timer 4 in section 2 after the power is turned on, the inverter is controlled to operate, for example, at maximum output, that is, in a full light state. Therefore, during the time specified by the first timer 2, the discharge lamp 12 is preheated in the maximum output state of the inverter. When the time specified by the first timer 2 ends, the switch 14 is turned off and the discharge lamp 12 is started and lit. At this time,
Since the inverter is still in the maximum output state, the starting voltage applied to the discharge lamp 12 is sufficiently high, so that the discharge lamp 12 is reliably started. When the time specified by the second timer 4 ends, the output of the inverter decreases if, for example, a high-level dimming command signal is applied to the dimming input terminal 18, that is, in the dimming mode. After that, the light is controlled to be dimmed. Note that in order to reduce the output of the inverter, for example, the base bias current of the driver transistor 8 may be reduced, or the on-time of the driver transistor 8 may be shortened. In this way, according to the present invention, sufficient preheating is performed after the power is turned on, and then a high starting voltage is applied.
The lamp life of the discharge lamp 12 is not shortened, and the lamp can be started reliably. As shown by dotted lines in FIGS. 1 and 2, after the specified time of the first timer and until the timer of Section 2 operates, the output of the inverter is kept within the range necessary for starting the discharge lamp 12. It can also be lowered slightly.

Control of the inverter in this case is performed by both the first timer 2 and the second timer 4.

[Example] Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 3 shows the configuration of a discharge lamp lighting device according to an embodiment of the present invention. The device shown in the figure includes transistors Ql, Q2 .
..., QB, diode DI, D2゜・, D6, '7
x f 9'i;t)' Z D 1 ,
Z D 2.

ZD3, step-up transformer T1, inductor L1, resistor R1
, R2, -, R13, capacitor CI, C2,...
It is composed of C7 etc. The transistor Q1, step-up transformer T1, capacitor c5, resistor R13, etc. form a self-excited high frequency inverter. A discharge lamp 12 is connected to the secondary coil N2 of the step-up transformer T1 via a capacitor C7.
are connected to the discharge lamp 12, and a diode D3. D4. D5. D6, transistor Q2, and resistor R4 constitute a switch that short-circuits the electrodes of the discharge lamp 12. Transistor Q8, Zener diode ZD1, resistor R2, capacitor C2 form a first timer 2a, and transistor Q5, Zener diode ZD2, diode D1, resistor R6, capacitor 03, etc. form a second timer 4a. There is. The switch S1 connected to the input side of the device shown in Fig. 3 is a power switch for supplying power E to each part of the circuit, the switch S2 is a switch for setting the dimming mode, and Fl is a temperature fuse. be.

In the discharge lamp lighting device of FIG. 3, the power switch S1
is turned on, the first timer 2a is activated by the DC power supply E.
At , capacitor C2 is gradually charged via resistor R2. When the voltage of capacitor C2 is below a predetermined value, transistor Q8 is turned off, and therefore transistor Q2 is turned on. For this reason, the diode D3. D4.
Both D5 and D6 become conductive, and the power supplied from the secondary coil N2 of the step-up transformer T1 is applied to each heater of the discharge lamp 12, and each heater is preheated, but lighting of the discharge lamp 12 is prevented. ing. In this case, even if dimmer switch S2 is turned on, the voltage across capacitor C3 is not high enough to turn on transistor Q5 via Zener diode ZD2. Therefore, transistor Q5 is turned off, transistor Q6 is turned on, and transistor Q3 is also turned on. As a result, DC type 11iXE is applied to the base of transistor Q1 via temperature fuse F1, transistor Q3, resistor R5, transistor Q4, etc., and transistor Q1 self-oscillates with sufficient base current supplied to the step-up transformer. Power at the maximum output level is supplied to the heater of the discharge lamp 12 from the secondary coil N2 of T1.

In this state, when the voltage of the capacitor C2 of the first timer 2a exceeds a predetermined value, the transistor Q8 is turned on and the transistor Q2 is turned off. This causes diode D3. D4. The switch circuit having D5 and D6 is turned off, preheating of the discharge lamp 12 is stopped, and a high voltage is applied between the electrodes of the discharge lamp 12, that is, between the heaters, and the discharge lamp 12 is started. If the dimmer switch S2 is turned on, then after a predetermined period of time has elapsed, the voltage of the capacitor C3 of the second timer 4a becomes high and the transistor Q5 is turned on. As a result, transistor Q6
and the QB cuts off.

Therefore, the base of the inverter driver transistor Q1 is connected to the power supply E through resistors R7 and R5 and the transistor Q4.
Since the current is supplied through , the base current is lower than in the all-light state described above.

That is, the output of the inverter decreases, and the discharge lamp 12 lights up in a dimmed state. In addition, a transistor Q4 inserted in the base circuit of the driver transistor Q1, a transistor Q7 connected to this transistor Q4, and a Zener diode Z
A circuit consisting of D3, capacitor c4, and resistors RIO, R11, and R12 is a circuit for stopping oscillation of the inverter when the voltage of DC power supply E decreases.

FIG. 4 shows a circuit configuration of a discharge lamp lighting device according to another embodiment of the present invention. The device shown in the figure has a transistor Q21
．． Q22. ..., Q30, diode D21. D22
．． ..., D27, Zener diode ZD21. ZD
22. ZD23, step-up transformer T2, inductor L2,
Resistor R21, R22゜..., R34, capacitor C2
1, C22, . . . , C31, and a pulse width modulation integrated circuit IC1. Also connected to the circuit of FIG. 4 are a discharge lamp 12, a temperature fuse F1, a DC power source E, a power switch S1, and a dimmer switch S2. Further, the transistor Q23, the Zener diode ZD21, the resistor R23, and the capacitor C22 constitute the first timer 2b, and the transistors Q26. Q29, Zener diode ZD23, resistor R29, capacitor C
24 and the like form a second timer 4b.

In the device shown in FIG. 4, when the power switch S1 is turned on, DC power E is supplied to each circuit, and in particular, in the first timer 2b, the capacitor C22 is supplied through the resistor R23.
is gradually charged, and in the second timer 4b, if the dimming switch S2 is on, the capacitor C24 is gradually charged via the resistor R29. The first timer 2b is activated for a predetermined time after the power switch S1 is turned on.
Since the voltage of capacitor C22 is not high, transistor Q23 is turned off. Therefore, transistor Q2
4 is turned on, and Q27 is also turned on. As a result, the DC power supply E is connected to the inductor L2, the temperature fuse F1, the turned-on transistor Q27, the resistor R21, and the transistor 028.
is applied to the base of driver transistor Q21 via. Therefore, the transistor Q21 is supplied with a sufficient base current, and the transistor Q21 and the step-up transformer T
2. The inverter including the capacitor C30, resistor R28, etc. operates at maximum output to preheat the heater of the discharge lamp 12. At this time, the transistor Q22 is on, and the diodes D24°..., D27 are all conductive, so that lighting of the discharge lamp 12 is prevented, and a sufficiently large preheating current is supplied to each heater. Ru. Furthermore,
At this time, the voltage of the capacitor C24 of the second timer 4b is not high enough to turn on the transistor Q26, so
The transistor Q26 is off, so the transistor Q2
9 is also in the off state. For this reason, integrated circuit ICI
The output terminal P1 of the transistor Q30 becomes a low level.
Since the transistor Q30 is off, the transistor Q30 has no effect on the operation of the inverter driver transistor Q21.

Next, after a predetermined period has elapsed, the capacitor C of the first timer 2b
When the voltage across transistor Q22 increases and transistor Q23 turns on, both transistors Q24 and Q27 turn off, and resistor R26 is inserted into the base circuit of driver transistor Q21 of the inverter, so that the output level of the inverter decreases slightly. At the same time, transistor Q2
2 is also turned off, and each diode D24.2 connected to the discharge lamp 12 is turned off. ..., D27 is turned off. This results in
The discharge lamp 12 is started.

After a predetermined period has passed after the transistor 023 of the first timer 2b is turned on, if the dimmer switch S2 is turned on, the capacitor C of the second timer 4b is
24 rises, transistor Q26 is turned on, and therefore transistor Q29 is also turned on. As a result, power is supplied to the integrated circuit ICI, a pulse having a predetermined duty cycle is output to the output terminal P1, and the transistor Q30 is turned on and off by this pulse.

When transistor Q30 is turned on, driver transistor Q21 is cut off and oscillation is stopped, so that the inverter reduces its output in accordance with the duty cycle of transistor Q30, so that discharge lamp 12 is lit at a dimming level.

[Effects of the Invention] As described above, according to the present invention, even if the discharge lamp lighting device is in the dimming mode, the inverter supplies large preheating power to the discharge lamp for a predetermined time after the power is turned on, similar to that in the full-light mode. Since the discharge lamp can be supplied with heat, the discharge lamp can be completely preheated and the lamp life can be extended. Further, even after preheating is completed, a sufficiently large starting voltage can be supplied even in the dimming mode, so that the discharge lamp can be started reliably.

[Brief explanation of the drawing]

1 is a block circuit diagram schematically showing a discharge lamp lighting device according to an embodiment of the present invention; FIG. 2 is a waveform diagram for explaining the operation of the device shown in FIG. 1;
3 and 4 are electrical circuit diagrams showing the circuit configuration of a discharge lamp lighting device according to an embodiment of the present invention, respectively. 2.2a, 2b: first timer, 4.4a, 4b = second
timer, 6: driver, 8: driver transistor,
10. TI, T2: Step-up transformer, 12: Discharge lamp, 14
: Switch, 16: DC power supply, Ql, Q2. ..., Q
8. Q21. Q22. ..., Q30: transistor,
Di, D2. ..., D6. D21, D22.・・・
・, D27: Diode, ZDI. ZD2. ZD3. ZD21. ZD22. ZD23: Zener diode, Ll, L2 inductor, C1, C
2,..., C7, C21, C22,... C31: Capacitor, R1, R2,..., R13°R
21, R22,..., R34: Resistor, Sl: Power switch, S2: Dimmer switch.

Claims (1)

[Scope of Claims] 1. Inverter means having a driver transistor and a step-up transformer, a discharge lamp connected to the secondary side of the step-up transformer of the inverter means, a switch element for short-circuiting between electrodes of the discharge lamp; A first timer that defines the operating time of the switch element, and a second timer that controls the operation of the driver transistor of the inverter means, the operating time of the second timer being the operating time of the first timer. A discharge lamp lighting device characterized by being set longer than . 2. After turning on the power, the switch element is turned on for a period of time specified by the first timer, and the second
The discharge lamp lighting device according to claim 1, wherein the inverter means is brought into a dimming state after a time specified by a timer. 3. The discharge lamp lighting device according to claim 2, wherein the inverter means is brought into a full-light state for a time specified by the second timer after power is turned on. 4. After turning on the power, the inverter means is kept in a full light state for a time specified by the first timer, and after the time specified by the first timer elapses, only for a time specified by the second timer. The discharge lamp lighting device according to claim 2, wherein the inverter means is set to a medium light state with an output level lower than a full light state. 5. The discharge lamp lighting device according to claim 4, wherein the dimming state is set by adjusting a base bias current of a driver transistor of the inverter means. 6. The discharge lamp lighting device according to any one of claims 1 to 5, wherein the dimming state is set by adjusting an on/off time ratio of a driver transistor of the inverter means. 7. The discharge lamp lighting device according to any one of claims 1 to 5, wherein the dimming state is set by adjusting a base bias current of a driver transistor of the inverter means.