JPS59119699A - Dimmer - 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 dimming device for a preheating start type fluorescent lamp.

When dimming using a preheating start type fluorescent lamp, since the electrodes of the preheating start type fluorescent lamp are not always preheated, the period of rest of the current flowing through the fluorescent lamp becomes longer. The restrike voltage increases, and eventually a stable discharge cannot be maintained and the battery goes out.

FIG. 1 is a circuit diagram (Japanese Patent Application Laid-Open No. 57-11498) showing a conventional example of a dimming device for a preheating start type fluorescent lamp, in which a power source 1 is connected to a choke coil 2. Preheating start type fluorescent lamp 3. A bidirectional three-terminal thyristor 7 and a resistor 6 connected in parallel thereto are connected in series to form a closed circuit, and a diode 9 is connected in antiparallel to the gate of the bidirectional three-terminal thyristor 7.
．． 10 is connected in the same direction as the thyristor 11, and the ignition pulse generating circuit 13 and the resistor 12 are connected to the thyristor 11.
The conduction control means and the gold wave rectifier 14 are connected to each other. The resistor 8 is a resistor for adjusting the gate signal of the bidirectional three-terminal thyristor 7, and the resistor 5 is a resistor for limiting the current passing through the thyristor 11. In addition, preheating start type fluorescent lamp 6
A starting device such as a glow starter 4 is connected in parallel to the non-power supply side terminal of. In the above conventional example, while the bidirectional three-terminal thyristor 7 is not conducting, a small lamp current flows through the resistor 6 to prevent the re-ignition power of the preheating start type fluorescent lamp 3 from rising and turning off. Preventing. , an arbitrary tW synchronized with the power supply frequency VC by the Q arc pulse generation circuit 131C.
%KJ= ri +, (+) Power source 1. Choke coil 2.
Preheating start type arc coffin light lamp 3% resistance 8, diode 9. A current flows through the thyristor 11 and the full-wave rectifier 14, and a conductive signal line 2 enters between the gate and cathode of the bidirectional three-terminal thyristor 7, thereby ensuring conduction of the bidirectional 54i child thyristor 7 to perform dimming operation. . A pulse signal for conduction is output from the ignition pulse generation circuit 16, but since the fluorescent lamp circuit is inductive, it is necessary to keep the gate current flowing until the bidirectional three-terminal thyristor 7t becomes conductive. In order to maintain conduction of the thyristor 11, a relatively large holding current is supplied through the resistor 5, which has the disadvantage that the loss in the resistor 5 is large.

In order to eliminate the above-mentioned drawbacks and obtain a dimming device with low loss, the present invention uses an impedance element that allows a small amount of lamp current to flow during the lighting period of a preheat-start type fluorescent lamp to prevent a rise in the restriking voltage. It is characterized in that it also has the function of supplying gate current to a bidirectional three-terminal thyristor.

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a circuit diagram showing a dimmer device for a preheating start type fluorescent lamp according to the present invention, and FIG. 3 is an operating waveform diagram of the dimmer device.
(a) shows the voltage across the choke coil 27, the preheating start type fluorescent lamp 3, and the lamp current of the preheating start type fluorescent lamp B, and I'b) shows the base drive voltage of the gate signal generation circuit 20 for the transistor 19. , (C) show the AC side voltage waveforms of the full-wave rectifier 14, respectively. As shown in Figure 2, a choke coil 2 and a preheating start type fluorescent lamp 3
and the series circuit of the main current control device A are connected to the power supply 1. The main current control device A has a bidirectional three-terminal thyristor 7 connected between its power supply side terminals a and b, and one end of a resistor 15, which is an impedance element, is connected to one end of the bidirectional three-terminal thyristor 7. , the other end of the resistor 15 is the trigger element 1
6 to the gate of the bidirectional three-terminal thyristor 7, and between the connection point of the resistor 15 and the trigger element 16 and the other end of the bidirectional three-terminal thyristor 7, a resistor 18 and a current switch are connected. A parallel circuit consisting of a transistor 9 and a gate signal generation circuit 20 that generates a signal to cut off the current flowing through the transistor 9 in synchronization with the power supply frequency is connected via a full-wave rectifier 14. A diode 17 and a capacitor 21 supply power to the gate signal generation circuit 20 by the voltage drop across the resistor 18 when the bidirectional three-terminal thyristor 7 is non-conducting. In some cases, the capacitor 21 becomes unnecessary. Note that the value of the resistor 18 is set so that its terminal voltage is below the breakover voltage of the trigger element 16. In addition, the transistor 1
If a gate turn-off syringe 4 is used instead of 9, the full-wave rectifier 14ij can be omitted.

In the above circuit, as shown in the waveform envelope in Figure 3, the lamp N current xl is delayed by the phase angle θ from the voltage Vo across the preheating start type fluorescent lamp 3 and the choke coil 2 due to the choke coil 2, and is delayed by the phase angle θ due to the choke coil 2. At the time when the cycle current ends, the gate signal generating circuit 20 generates the base drive voltage shown in FIG. A small lamp current limited by the power supply 1, choke coil 2. Preheating start type fluorescent tube 3, resistor 15,
Full wave rectifier 14. Resistance 18% Flows like the transistor 19 and full wave rectifier 14 to prevent the re-ignition voltage of the preheating start type fluorescent lamp 3 from rising. Further, at time t, when the base current of the transistor 19 is cut off and the transistor 19≠ becomes non-conductive, the alternating current (Ill voltage) of the full-wave rectifier 14 is
The voltage rises rapidly as shown at 1J(Q), reaches the breakover voltage of the trigger element 16, and the trigger element 16 becomes conductive.

Then, fc≠2 flows through the resistor 15, and f? Since the current flows through the trigger element 16, the gate and cathode of the bidirectional 34-terminal thyristor 7, the bidirectional 3-terminal thyristor 7 is reliably conductive, and the preheat-start type fluorescent pump B is activated.
The lamp current T required for revision is applied and the lamp is dimmed until time t11. At time tIl when the lamp current 1 finishes flowing, the gate signal generating circuit 20 supplies the base current again to the transistor 19, and the above two operations are repeated. As described above, Mn1f passes current through the bidirectional three-terminal thyristor 7-74 (C) through the resistor 15 to maintain conduction of the preheating start type fluorescent lamp 6, and when the bidirectional three-terminal thyristor 7 starts conduction, the resistor 15 supplies the gate current of the two-way three-channel circuit.

As described above, the present invention supplies a small amount of lamp current when the bidirectional three-terminal thyristor is non-conducting during the lighting down time of the preheating start type 1 type fluorescent lamp, thereby increasing the restriking voltage of the preheating start type fluorescent lamp. This is because the impedance element that prevents the increase in impedance has the function of supplying the gate current of the bidirectional three-terminal thyristor.

In the conventional example shown in FIG. 1, a relatively large holding current is passed through the thyristor 11 of the current switch to keep it conductive during the lighting period, so the loss occurring in the resistor 5 is eliminated, and a low-loss dimming device # can be obtained. can. In addition, in the light control device according to the present invention, the main current control device, which is the part that operates the light control, is composed of two terminals, so when installing the light control device on a wall or the like and controlling the light by remote control, wiring is required compared to the conventional method. It is advantageous because the number of pieces is small.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional dimmer device for a preheating start type fluorescent lamp, FIG. 2 is a circuit diagram showing a dimmer device for a preheating start type fluorescent lamp according to the present invention, and FIGS. 3(a) and (b). )-(c)
FIG. 2 is a waveform diagram showing voltages and currents at various parts for explaining the operation of the light control device. 1... Power supply, 2... Choke coil, 3... Preheating start type fluorescent lamp, 7... Bidirectional filter terminal thyristor. 15...Resistance which is an impedance element -16...
Trigger element, 19...Transistor serving as a current switch, 20...Gate signal generation circuit, A...Main current control device. Agent Patent Attorney Usui 1) Toshiyuki Figure 2 Figure 3

Claims (1)

[Claims] A light control device comprising a series circuit of a φ yoke coil, a preheating start type fluorescent lamp, and a main current control device connected to a power source,
The main current control device is a bidirectional three-terminal thyristor connected between its power supply side terminals. an impedance element having one end connected to one end of the bidirectional three-terminal thyristor and the other end connected to the gate of the bidirectional three-terminal thyristor via a trigger element, and a connection point between the impedance element and the trigger element; A current switch connected between the other end of the bidirectional 3-terminal thyristor and a power supply 'j of the current switch in synchronization with the power supply frequency.
1. A light control device comprising a signal generation circuit that emits a signal to turn off the light.