JPS584436B2 - Keikoutoushidosouchi - Google Patents

Description

[Detailed description of the invention] The present invention is directed to a fluorescent lamp starting device.

Generally, in order to start and light a fluorescent lamp, it is necessary to preheat the fluorescent lamp filament and apply a high voltage between the fluorescent lamp electrodes.

The present invention uses an oscillation circuit using a thyristor (for example, SCR) for generating high voltage and a thyristor (for example, SSS) for flowing preheating current, and kicks the fluorescent lamp at every cycle and half cycle of one cycle until the fluorescent lamp lights up. In a fluorescent lamp starter that operates to generate voltage and supply preheating current during the other half cycle, and then stops its operation after the fluorescent lamp is turned on, the operation of the starter after the fluorescent lamp is turned on. The purpose is to ensure that the system stops.

As shown in Figure 1, the conventional fluorescent lamp starting device has a ballast L.
The filament f1 on the non-power side of the fluorescent lamp F connected in series with
- f2, a thyristor Q1 (e.g. SCR) which generates a high kick voltage in cooperation with the ballast L, its bias resistors R1, R2 and a resistor R connected in series with the cathode of Q1.
An oscillation circuit A consisting of a 3A capacitor C, a preheating circuit B consisting of a diode D supplying a preheating current to the filament of a fluorescent lamp, and a thyristor Q2 (for example, SSS) are connected, and the power supply voltage E is In one half cycle, oscillation circuit A operates to generate a high-voltage kick voltage, and in the other half cycle, preheating circuit B operates to supply preheating current.

In order to perform the above operation, in the preheating state before the fluorescent lamp lights up, Q1 must be set at a voltage below the peak voltage of the power supply voltage E.
Bias resistors R1 and R2 are set so that Q2 is turned on, and VBO is set so that Q2 is turned on. After fluorescent lamp F is turned on, Qt and Q are set.
It is necessary to set the VBO of bias resistors R1, R2, and Q2 so that 2 does not fire. In particular, for thyristors such as SCRs, where it is difficult to design gate sensitivity stably, bias resistors R, , R2 must be set to be stable. It was difficult to take it.

The present invention has been proposed to improve the above-mentioned drawbacks.

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

As shown in FIG. 2, the present invention also provides an oscillation circuit A composed of thyristors Ql, Rl, R2, C, and R3 shown in FIG.
thyristor Q2 of preheating circuit B, which also consists of diode D and thyristor Q2, is connected in series with resistor R2 of
Apply voltage to bias resistors R2 and R1 via Q1
The oscillation circuit A operates to generate a high-voltage kick voltage, and in the other half cycle, a preheating current is supplied via the diode D1 and the thyristor Q2.

FIG. 3 shows another embodiment of the present invention, and its structure will be explained as follows: filament f1 on the non-power side of the fluorescent lamp F;
A series connection of the oscillation circuit A shown in Figure 1 and a thyristor Q2 that flows a preheating current is connected between -f2, and a diode D is connected in antiparallel to the oscillation circuit A.
A preheating circuit B is formed.

The operation of the circuit of the present invention shown in FIG. 2 during preheating before lighting the fluorescent lamp will be explained with reference to FIG.

In Figure 4, e is the instantaneous voltage of power supply E, Q1 is the voltage between the anode and cathode of thyristor Q1, Q2 is the voltage across thyristor Q2, i is the filament current, and vo is the terminal voltage AvF of capacitor C. This is the tube voltage of fluorescent lamp F.

Current time t.

Assume that the filament gf2 side is in a positive cycle.

When the filament preheating current i that has been flowing through L-f1D-Q2-f2 becomes zero at time t1, the power supply voltage at that phase. e is applied between filaments f2-f1.

That voltage is the breakover voltage VB of thyristor Q2.
At time t2 when O is reached, thyristor Q2 is turned on,
The gate signal of the thyristor Q1 is applied through the bias resistor R2, and the thyristor Q1 becomes conductive between point and arc, and the charging current of the capacitor C flows through f2-Q1-C-f1-L, charging the capacitor C and its terminal. The voltage vc increases as shown in the figure.

At time t3, the charging voltage of the capacitor C increases, and the thyristor Q is cut on to reverse bias the gate cathode of the thyristor Q1.

At that time, the anode current of the thyristor Q1 that has been flowing so far decreases rapidly, so a kick voltage of Ldi/dt is generated in the ballast L, and a pulsed high voltage VF is applied to the fluorescent lamp F.

At time t4, the power supply voltage phase is reversed, and the filament f1 side becomes a positive cycle.

When the power supply voltage reaches VBO of thyristor Q2 at time t5, Q2 is turned on and the preheating current becomes L-f1-D-Q2-f.
Flows through 2.

At time t6, the electric charge charged in the capacitor C is completely discharged via R3.

At time t7, the filament f2 side becomes a positive cycle again, and at this time, the preheating current is still flowing due to the delay of L.

Time t below. The subsequent operations will be repeated.

In the same way, to explain the feat when lighting the fluorescent lamp with reference to FIG. 5, at current time t0, the filament gf2 side enters a positive cycle, and at time t1, the fluorescent lamp lighting voltage phase is reversed, and f2
side becomes positive, and the lighting voltage peak value VFP of the fluorescent lamp is applied to the thyristor Q2.

If VBO of thyristor Q2 is set above VFP, thyristor Q2 will not fire, and therefore thyristor Q1 will not fire.

At time t2, the filament f1 side enters a positive cycle,
At time t3, the fluorescent lamp lighting voltage phase is reversed, and the f1 side becomes positive.

However, the fluorescent lamp lighting voltage peak value VFP at that time is VBO
If it is below, thyristor Q2 will not fire.

That is, neither kick voltage nor preheating current is supplied when the fluorescent fish lamp is used.

As explained above, thyristor Q1 is connected in series with the gate resistance R2 of thyristor Q1, and the V of thyristor Q2 is
By setting BO to the peak value of the fluorescent lamp lighting voltage vF, < VBo and the peak value EP of the power supply voltage E, a high voltage pulse voltage and a preheating current are supplied during preheating before lighting the fluorescent lamp, and the fluorescent lamp During lighting, the operation of the starter can be stopped regardless of the gate sensitivity of the thyristor Q1, which increases the degree of freedom of the thyristor Q1 and facilitates industrial production of the starter.

[Brief explanation of drawings]

FIG. 1 shows a conventional fluorescent lamp starter, FIG. 2 shows a fluorescent lamp starter according to the present invention, FIG. 3 shows another embodiment of the present invention, and FIG. 4 e-V
F is a preheater, and FIG. 5 shows voltage or current waveforms at various parts during lighting. F... Fluorescent lamp, f1, f2... Filament, L.
... Ballast, E... Power supply, QltQ2... Thyristor, R1, R2, Ra... Resistor, C... Capacitor, A... Oscillation circuit, B... Preheating circuit.

Claims (1)

[Claims] 1. Between the filaments on the non-power side of a fluorescent lamp in which a ballast is inserted in series, an oscillation circuit that uses a thyristor to generate a kick voltage to the ballast when the thyristor is turned on and off during one half cycle of the power supply, and the other half are installed. In a fluorescent lamp lighting circuit connected to a starter consisting of a preheating circuit that scoops a thyristor that passes a preheating current in the cycle, one end of a resistor voltage divider circuit that provides a gate firing signal for the thyristor of the vibration-absorbing circuit is connected. The thyristor of the oscillation circuit is connected to the non-power supply side terminal of the filament via the thyristor of the preheating circuit, and when the thyristor of the preheating circuit flakes over, the voltage applied to the resistive voltage divider circuit causes the thyristor of the oscillation circuit to fire and conduct. Fluorescent light starting device.