JPS5835896A - Device for firing discharge lamp - 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 The present invention relates to a device for lighting a discharge lamp, such as a fluorescent lamp.

When a semiconductor switching element such as a triac is used to control turning on and off of a lamp, it has the advantage of not generating sparks when conducting, but has the problem of large heat loss.

An object of the present invention is to provide a discharge lamp lighting device that reduces heat loss of semiconductor switching elements.

FIG. 1 is an electrical circuit diagram of an embodiment of the present invention. Discharge lamps such as fluorescent lamps have a pair of filaments (poles 2 and 3).
is provided. A lighting tube 6 is connected between each terminal 4.5 of the filament electrode 2.3. This glow lighting tube 6 is equipped with a noise prevention capacitor 7.
are connected in parallel GC. The capacitance of the noise prevention capacitor is set at 0.06 μA according to Japanese Industrial Standards. The other terminal 8.9 of the filament electrode 2 is connected to a commercial AC power source 14 via a choke 10, a switch 11 as a semiconductor switching element, and a primary coil 13 of a current transformer 12.
It is connected to the. (Relay 15 has relay 15 for relay 11.
relay switches 16 are connected in parallel.

The relay switch 16 of the relay 15 is connected to the relay fill 17.
conducts only during the period when is energized.

The voltage across triac 11 and relay switch 16 is applied to diode 20 via line 19 in control circuit 18 for rectification, and applied to smoothing capacitor 22 via resistor 21 . The output from the secondary coil 23 of the current transformer 12 is rectified by a diode 24 and given to the smoothing capacitor 22. By the output from smoothing capacitor 22 via line 25.26,
Toggle 7 lip 70 knob 27 is energized. A series circuit consisting of a relay coil 17 and a transistor 28 is connected between lines 25 and 26.

The 7-lip 70 knob 27 alternates between stable states each time a push button 29, which is manually operated and has a light operating feel, is operated. The output of the 7-rip 70 tube 27 is applied from line 30 via a timer 31 to the pacing of transistor 28. ? The signal is applied to the gate of the iris register 32.

As the thyristor 32 becomes conductive, the current from the full-wave rectifier circuit 33 is applied to the gate of the triac 11, causing the triac 11 to fire and become conductive.

Referring to FIG. 2, when the push button 29 is turned on at time tl as shown in FIG.
derives a high level signal on line 30 as shown in FIG. 2(2). Therefore, the thyristor 32 becomes conductive and the triac 11 becomes conductive, thereby lighting the discharge lamp 1. Therefore, the secondary coil of current transformer 12 /I/23
A voltage is induced in and the control circuit 18 is energized by the electric power. At time t2, when a predetermined time limit W has elapsed from time t1, the timer 31 operates as shown in FIG.
A high-level signal is derived as shown in FIG. 2 to make the transistor 28 conductive. This excites the relay fill 17 and keeps the relay switch 16 conductive.

Therefore, after time t2, the triac 11
Since the current flowing through the triac 11 is almost zero, the triac 11 does not generate heat and cause large heat loss.

When the push button 29 is operated again at time t3, the 7-lip 70 knob 27 brings the line 30 to a low level, which causes the timer 31 to cut off the transistor 28. In this way, the triac 11 is cut off, the relay coil 17 is demagnetized, and the relay switch 16 is cut off.

When the triac 11 and relay switch 16 are cut off, current from the AC power source 14 flows through the choke 10.
A current flows through the filament electrode 2, the noise prevention capacitor 7, the filament electrode 3, the line 19, the diode 20, and the resistor 21, and the output from the smoothing capacitor 22 keeps the 7 lip 70 knob 27 energized and on standby. in a state.

When the triac 11 is conducting and when the relay switch 16 is conducting, the discharge current of the discharge lamp l flows to the primary coil 13 of the current transformer 12, thereby causing the 2
The vehicle force induced in the next coil 23 energizes the 7 lip 70 knob 27 and enables the relay coil 17 to be excited.

In the illustrated embodiment, the circuit parts on the right side of FIG. 1 from the terminals 34, 35 (i.e., the triac 11, the current transformer 12, and the control circuit 18) can be made into a unit and incorporated in place of a conventional wave switch or the like. It has the excellent advantage of being extremely easy to wire.

As described above, according to the present invention, the relay coil is excited after the semiconductor switching element is made conductive when lighting the discharge lamp, and the relay switch connected in parallel to the semiconductor switching element is made conductive. It becomes possible to reduce heat loss of the switching element. The control circuit for controlling this semiconductor switching element can be constantly energized and put into a standby state by a current through a noise prevention capacitor connected in parallel with the glow bulb, and therefore the discharge lamp There is no need to perform complicated wiring work to energize the control circuit when the light is turned off. After ignition of the discharge lamp, a relatively large force from the current transformer energizes the control circuit and allows the relay fill to be energized.

[Brief explanation of drawings]

FIG. 1 is an electric circuit diagram of an embodiment of the present invention, and FIG. 2 is a waveform diagram for explaining its operation. 1... Discharge lamp, 2, 3... Filament electrode, 6...
・・Glo-1 lighting tube, 7・・Noise prevention capacitor, 1
0...Choke, 11...Triac, 12...
・Current transformer, 14... AC power supply, 15... Relay, 1
6...Relay switch, 17...Relay fill, 1
8... Control circuit, 20.24... Diode, 22
...Smoothing capacitor, 27...Toggle 7 Lip 7
0 knob, 28..., transistor, 29...push button, 3
1...Timer agent Patent attorney Kei Nishi

Claims (1)

[Claims] A noise prevention capacitor is connected in parallel to the glow tube connected between one terminal of each of the ME electrodes (a pair of filament electrodes), and the other terminal of each filament electrode is connected to a choke and a semiconductor switching element. The semiconductor switching element is connected to an AC power supply via a current transformer, and a relay or relay switch is connected in parallel to the semiconductor switching element to form a parallel circuit, which is controlled by the voltage across the parallel circuit and the output of the current transformer. A discharge lamp lighting device characterized in that the circuit is energized with power, and the control circuit excites the relay coil of the relay to make the relay switch conductive after the semiconductor switching element is made conductive.