JPS59132595A - Device for firing discharge lamp in high frequency - 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 [Technical Field] The present invention relates to a high frequency lighting device for a 1/-1 fc discharge lamp using a transducer.

[Background technology]

FIG. 1 is a circuit diagram of a discharge lamp high-frequency lighting device using a conventional self-excited push-pull type transistor inverter. In the circuit shown in FIG. 1, the power supply voltage of the AC '1 source VS is full-wave rectified by the diode bridge DB, smoothed by the cosidiser C1, and then supplied to the transmission inverter A. 1-5.7 The resistor A is composed of an oscillation transistor OT, transistors Q1 and Q2, resonance 00% bias resistors R1 and R2, a starting resistor R3, a constant current choke L□, and the like. The rectifying and smoothing circuit consisting of the tie motor D1 and the shift resistor C2 operates after the start of the shift resistor A.
This supplies the base bias of Q2. The leakage flux type oscillation transformer OT is commonly used, and the second type is
A discharge lamp F is connected to the next side via a current limiting reactor L2. A switch SW is connected to both ends of this current limiting reactor L2. When the switch SW is closed, the discharge lamp F is fully lit, and when the switch SW is open, the discharge lamp F is dimmed and lit by the current limiting reactor L. However, in such a conventional example, there is a problem in that the discharge becomes unstable at low temperatures, and a peculiar flicker called so-called resig flicker occurs in which light runs from one end of the discharge lamp F to the other end.

[Purpose of the invention]

The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a high-frequency lighting device for emitting lights that can prevent flickering that occurs at low temperatures. .

[Disclosure of the invention]

The configuration of the present invention will be described below with reference to illustrated embodiments. Second
The figure shows a circuit diagram of an embodiment of the present invention, and parts having the same functions as those of the conventional example in FIG. In this embodiment, a pulsating current-voltage obtained by full-wave rectification of the power supply voltage of the AC power source Vs by the tie switches D2 and D3 is generated across the resistor R1. This resistance R4,! - A series circuit of resistance R3 and thermistor Th is connected between the resistor R3 and the thermistor Th. Here, the thermistor Th has a positive characteristic, and therefore the resistance value of the thermistor Th becomes high at room temperature to high temperature, and the transistor A is generated by the same operation as in the conventional example in Fig. 1. - When you shake it, all the lanterns F will light up. At the time of starting the transistor A, a base bias is supplied to the bases of the transistors Q1 and Q2 via the starting resistor R3, but after the start of oscillation, a bias is supplied from the transistor D1 and the transistor A base bias is also supplied to the bases of the transistors Q1 and Q2 by the output of the rectifying and smoothing circuit.

Next, when the temperature becomes low, the resistance value of the thermistor Th decreases, so the base bias of the transistors Q□ and Q20 decreases, and the oscillation of the transistor transistor 3A stops.
Since a pulsating current voltage obtained by full-wave rectification of the power supply voltage of
The base bias necessary to maintain 2K oscillation is supplied, and the transistor A oscillates. KS3
Figures (a) to (4) show the support f7- of each part at such low temperatures.
FIG. 3 Ca) shows the voltage across the resistor R1, and FIG. 3 Φ) shows the four-voltage waveform at the connection point between the resistor island and the thermistor Th. Further, FIG. 3(e) shows the voltage VCE applied to the cap emitter of the transistor Q (or Q2), and FIG. 3(d) shows the applied voltage Va applied to both ends of the discharge lamp F. As is clear from the above figures, when one voltage v2 is higher than the voltage VBE (ON) required to turn on the transistors Q1 and Q2, the transistor A output oscillates, and the voltage v2 becomes the voltage VBE (ON).
When K is lower than 0 (ON), transistor isciverter A stops oscillating. In this way, the oscillation of transistor isciverter A is intermittently stopped in synchronization with the zero-crossing point of the AC power supply voltage. By doing so, it is possible to prevent the so-called "flickering" in which light runs from one end of the discharge lamp F to the other end at low temperatures. Fig. 4 shows another embodiment of the present invention. This is a series circuit including a thermistor Th and resistors R6 and h, and a dimming switch SW is connected in parallel. In this embodiment, when the switch SW is turned on, the voltage V2 applied to the base of the transistor Q3 for bias control decreases, resulting in a dimmed lighting state. That is, during the period in which the pulsating current voltage obtained by the diodes D2 and D3 exceeds a predetermined reference voltage, the traction switch inverter A oscillates, but when the pulsating current voltage is lower than the predetermined reference voltage, the traction switch inverter A oscillates. stops oscillation, and therefore the discharge lamp F enters the dimming lighting state. I also turned off the switch SW. ! -'@, as in the embodiment circuit of FIG. 2, is fully lit at room temperature to high temperature, and at low temperature, t! of the AC power supply voltage (as shown in FIG. 3(d)). Oscillation to the transducer is stopped in synchronization with the Q cross point to prevent resig flickering that occurs at low temperatures.

〔Effect of the invention〕

As described above, the present invention provides a high-frequency lighting device for a discharge lamp in which a transducer for lighting a discharge lamp at high frequency is driven by a voltage obtained by distorting the commercial power supply voltage.
Rectifying means generates a pulsating voltage by full-wave rectification of the commercial power supply voltage, which is superimposed on the base bias of the oscillating transistor of the transducer, and a rectifying means generates a pulsating voltage by full-wave rectification of the commercial power supply voltage. It is equipped with a temperature-sensitive element that lowers the base bias of the oscillating transistor to below the base bias required to maintain the oscillation of the transistor inverter during periods when the current and voltage are low, so it can be used at low temperatures. In this case, the oscillation of the trans-distributor oscillation stops intermittently in synchronization with the zero point of the AC power supply voltage. This has the advantage that so-called flickering, which occurs when light runs from one end of an electric lamp to the other, does not occur.

[Brief explanation of the drawing]

Fig. 4 is a circuit diagram of another embodiment of the same as above. Th is a thermistor, F is a discharge lamp, VS is an AC power supply, DB is a tie auto bridge, D2, D are diodes, and A is a transistor. Vata, Ql, and Q2 are transisisters. Agent Patent Attorney Ishi 1) Chief Seven Procedures Amendment (Voluntary) February 20, 1980 Peaceful Application No. 4937 of 1988 2, Title of Invention Discharge Lamp High Frequency Lighting Device 3, Comparison with Case of Person Who Makes Amendment Related Patent applicant Location: 1048 Kadoma, Kadoma City, Osaka Prefecture Name (583) Denji Matsushita [Co., Ltd. Representative: Iku Kobayashi 4, Agent: 5, Date of amendment order: 6, Number of inventions increased by amendment Correction: We will correct r Qx, Qz J in Patent Application No. t'B5874937 No. 1, page 5, line 10 of the specification of this application to "Q3". 2. "VB" on page 5, line 10 and line 12 of the same page.
I will correct E(ON) J to rVB303,
Figures 2 and 3 of the attached drawings have been corrected as shown in the attached sheet. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Claims] (1) In a discharge lamp high-frequency lighting device in which the transistor sciverter for lighting the discharge lamp at high frequency is driven by voltage regulation that rectifies the commercial power supply voltage, the base bias of the transistor for oscillation of the transistor sciverter is used. rectifying means for generating a pulsating voltage superimposed on the commercial power source voltage by full-wave rectification; a period during which the pulsating voltage is low at low temperatures by detecting ambient temperature
A temperature-sensitive element is provided inside the oscillating transisister to lower the base bias of the oscillating transistor to a level below that required to maintain the oscillation of the transistor. : A discharge lamp high frequency lighting device characterized by: