JPS60143596A - Electronic fluorescent lamp starter circuit - 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 of the Invention] This invention relates to an electronic fluorescent lamp starter circuit.

[Prior art]

In general, a fluorescent lamp starter circuit attempts to instantly light the fluorescent lamp by quickly generating a discharge within the fluorescent lamp. As an example of this fluorescent lamp starter circuit, conventionally, a glow lamp is connected in parallel with a fluorescent lamp, and the filament of the fluorescent lamp is preheated by the action of the glow lamp, and a lighting pulse is applied to the fluorescent lamp. Some devices are designed to quickly generate electrical discharge within the tube. However, in this glow lamp type circuit, it is necessary to set a sufficiently long time for the glow lamp to apply a lighting pulse, taking into account manufacturing variations in fluorescent lamps. There was a problem that it took 2 to 3 seconds.

There is also a conventional starter circuit of the rabbit starter type, in which a high voltage is constantly applied to the filament using a step-up coil that is separate from the ballast or built into the ballast. . This type of circuit has the advantage that it takes less than one second for the fluorescent lamp to turn on compared to the above-mentioned glow lamp type, but if a booster coil is provided separately from the ballast, Since the boost coil is large, it requires a large installation space, and on the other hand, if the boost coil was built into the ballast, the ballast would have to have special specifications, which would increase costs. .

Recently, in order to solve the above-mentioned problems, various small and inexpensive instant lighting electronic fluorescent lamp starter circuits using electronic circuits have been proposed. One has already been developed and applied for (see Utility Model Application No. 7720/1983).

[Summary of the invention]

This invention was made under such circumstances, and consists of a lighting pulse generation circuit using a small booster coil, a capacitor, and a triac, and this tritic is controlled by the same trigger circuit as the trigger circuit of the filament preheating Cyrisk. The object of the present invention is to provide an instant-on type electronic fluorescent lamp starter circuit with a completely new configuration.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an electronic fluorescent lamp starter circuit according to one embodiment of the invention. In the figure, 1 is an AC power supply, 2 is a power switch, 3 is a fluorescent lamp ballast, 4 is a fluorescent lamp, 5 and 6 are filament electrodes, 7 is a cyrisk, and 8 is a rectifier that blocks lighting pulses that occur with negative polarity. The diode 9 is constituted by a thyristor 7 and a rectifier diode 8, and is a filament preheating circuit that facilitates discharge of the fluorescent lamp by preheating the filament electrodes 5 and 6 and producing thermoelectrons.

10 is a capacitor for generating lighting pulses; 11 is a step-up coil with an intermediate tap that boosts the voltage of the capacitor 10 and generates lighting pulses for the fluorescent lamp; 12 is a booster coil that charges the capacitor 10 during the positive half cycle of the power supply 1; Power status 1
13 is a resistor that limits the charging current to the capacitor 10, and 14 is a resistor that causes the charged charge of the polarity shown in the capacitor 10 to flow to the boost coil 11 immediately after the filament current finishes flowing. The triac 15 is a diode that causes the triac 14 to be triggered only when the trigger current has a negative polarity, and the numeral 16 is a fluorescent lamp lighting pulse generation circuit constructed as described above.

Furthermore, 1, 7, and 18 are resistors for detecting fluorescent lamp tube voltage, 19 is a bidirectional trigger element, and 20 is a resistor for stably operating the circuit over a wide range of voltage and temperature fluctuations by absorbing spike voltage after the fluorescent lamp is turned on. Thyristor 7 and triac 14
The trigger capacitor 21 is configured as described above and is a tube voltage detection/trigger circuit that detects the tube voltage of the fluorescent lamp 4 and triggers the thyristor 7 and triac 14. Note that the capacitor 20 does not necessarily need to be provided.

Next, circuit operation will be explained.

When the power switch 1 is turned on, the commercial voltage boosted by the ballast 3 is applied to the tube voltage detection/trigger circuit 21 via the ballast 3. In the case of a 40W fluorescent lamp, the tube voltage is approximately 230
When the voltage becomes V, the voltage across the voltage dividing resistor 18 reaches the switching voltage of the bidirectional trigger element 19, and the bidirectional trigger element 19 turns on to trigger the thyristor 7 (see Fig. 2 (bl)). When turned on,
From power supply 1 to ballast 3. A filament preheating current (see FIG. 2(C)) flows through the path of the filament 6, the diode 8° thyristor 7, and the filament 5, thereby preheating the filaments 5 and 6.

Due to the inductance of the ballast 3, this filament preheating current becomes zero at approximately 90 degrees from the phase of the power supply voltage (see Figure 2 fal fcl), and when the filament preheating current becomes zero, the power supply voltage becomes almost a negative half. The cycle has reached its peak, and immediately after the preheating current, almost the peak voltage of the power supply voltage boosted by the ballast 3 is applied to the tube voltage detection/trigger circuit 21. Therefore, a voltage higher than the switching voltage of the bidirectional trigger element 19 is applied to the resistor 18 in the opposite direction to that described above, and the bidirectional trigger element 19 turns on to trigger the triac 14 in a negative manner (see FIG. 2(b)). . When the triac 14 is turned on by this trigger signal (see Figure 2 + d), the capacitor 10, which was charged in the direction shown during the positive half cycle of the power supply 1, discharges its charge through the boost coil 11, and the boost voltage is A negative high voltage pulse of approximately 1 to 1.5 kV is generated at both ends of the coil 11. This voltage is applied to both ends of the fluorescent lamp every cycle as shown in TQI in FIG.

In this way, the preheating of the filament 5.6 and the application of the negative high voltage pulse are repeated for 0.5 to 0.8 seconds, and when the filament 5.6 reaches a temperature at which it emits enough thermoelectrons necessary for discharge, Electric discharge occurs within the tube of the fluorescent lamp 4, which causes the fluorescent lamp 4 to light up. After lighting, the tube voltage is several tens of volts.
(see FIG. 2 (8)). Therefore, in the tube voltage detection trigger circuit 21, the voltage across the resistor 18 is always lower than the switching voltage of the bidirectional trigger element 19. Both the CYRISC 7 and the TRIAC 14 are turned off, and the starter circuit stops operating.

The apparatus of this embodiment as described above provides the following effects. That is, ■ Use a small, small-capacity general tritic whose T2 terminal is sufficient and can be triggered by a negative gate signal in the negative lighting pulse generation circuit, and connect a capacitor charged with the polarity of the positive half cycle of the power supply to the negative polarity. Since the discharge is performed during a half cycle, it is possible to manufacture a negative lighting pulse generation circuit using an ultra-small step-up transformer.

■ The trigger circuits for both the filament preheating circuit and the lighting pulse generation circuit are shared, making it possible to downsize and reduce costs.

■ Since a bidirectional trigger element is used in the tube voltage detection/trigger circuit, miniaturization can also be achieved.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications and changes are possible. For example, the tube voltage detection/trigger circuit and the filament preheating circuit may have different configurations from those of the above-mentioned embodiments.

〔Effect of the invention〕

As described above, according to the present invention, the lighting pulse generation circuit is composed of a small booster coil, a capacitor, and a tritic, and the tritic and the filament preheating cyrisk are controlled by the same trigger circuit. This has the effect of providing a compact and inexpensive instant-start type electronic fluorescent lamp starter circuit with a completely new configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electronic fluorescent lamp starter circuit according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of the circuit. Trigger pulse, filament preheating current. Waveform diagram of triac current and fluorescent tube voltage. ■... AC power supply, 3... Ballast, 4... Fluorescent lamp, 5.6... Filament, 7... Cyrisk, 9... Filament preheating circuit, 10... Capacitor, 11... Boost coil, 12... Rectifier diode, 14... Triac, 16... Lighting pulse generation circuit, 21 ...Tube voltage detection/trigger circuit. Agent Masuo Oiwa 0

Claims (1)

[Claims] +11 A ballast connected to an AC power supply, a fluorescent lamp connected in parallel to the ballast, a series body of a rectifier diode, a step-up coil with an intermediate tap, and a tritic, and the step-up coil. and a primary coil and a capacitor connected in parallel to the triac, which is connected in parallel to the fluorescent lamp, and when the triac is triggered, applies a lighting pulse to the filament of the fluorescent lamp by discharging the charge in the capacitor. A lighting pulse generating circuit, a filament preheating circuit connected in parallel to the fluorescent lamp and preheating the filament when the circuit's cyrisk is triggered, and a filament preheating circuit that detects the tube voltage of the fluorescent lamp and detects that the tube voltage is correct. and a tube voltage detection/trigger circuit that triggers the sirisk of the filament preheating circuit when the voltage is higher than the set voltage, and triggers the triac of the lighting pulse generation circuit when the tube voltage is lower than the negative set voltage. Electronic fluorescent lamp starter circuit. (2) The tube voltage detection/trigger circuit includes a series resistor connected in parallel to the fluorescent lamp to detect the tube voltage, one end of which is connected to the connection point of the resistor, and the other end of which is connected to the triac and SIRISK. Claim 1 comprising a bidirectional trigger element connected to the
Electronic fluorescent lamp starter circuit as described in Section.