CN201063924Y - Ignition starting equipment of ballast - Google Patents

Abstract

The utility model relates to a firing circuit for high strength gas discharge lamps (HID) and electronic energy-saving lamps, in particular to a ballast initial-firing circuit. The utility model comprises a switch tube, a resistor, a capacitor and a transformer, wherein, one end of a transformer primary side is connected with the switch tube, and the other end of the transformer primary side is connected with the capacitor, and the three form a discharge circuit; the resistor is serially connected with the capacitor into a charging circuit; a transformer secondary side is connected with a light source. The utility model solves the technical problem that the prior firing circuit is uncontrollable in firing pulse, can guarantee the safe and reliable initial firing of HID or electronic energy-saving lamps, and can adapt to the starting needs of different light sources through the control of a single chip microcomputer.

Description

Ballast ignition start device

Technical field

The utility model relates to a kind of ballast ignition start device that is used for high-intensity gas discharge lamp (HID), electronic energy-saving lamp.

Background technology

In the use of HID and electronic energy-saving lamp, light source all needs a relative higher voltage pulse (amplitude is looked Different Light and difference) to activate its inner material and produces arc light in initial start stage, after arc light forms by the time, just finishes the ignition trigger stage.What existing firing circuit adopted is the former change windings in series of transformer avalanche diode, the secondary winding connects the structure of light source, its operation principle is: the BUS voltage on former limit is obtained by sinusoidal wave rectification, in each cycle, when BUS voltage was higher than 240V, avalanche diode was breakdown, and electric current flows through the former limit of transformer winding, generate high-voltage pulse at the secondary winding, thereby light the light source of series connection with it.Because avalanche diode is uncontrollable device, could avalanche breakdown when its reverse bias voltage must be greater than its rated value, can't control amplitude, pulsewidth and the duration of high-voltage pulse, so whole firing circuit is uncontrollable.And this firing circuit have again the igniting overlong time shortcoming, can have a strong impact on light source life.

The utility model content

Technical problem to be solved in the utility model provides the ballast ignition start device of amplitude, pulsewidth and the duration of the fiery pulse of a kind of may command electricity.It can guarantee HID or the safe and reliable ignition trigger of electronic energy-saving lamp, and can adapt to various light source startup needs by the control of single-chip microcomputer.

The technical scheme that the utility model adopted: ballast ignition start device comprises switching tube VT1, resistance R 1, R2, capacitor C 4, transformer T1.The former limit of transformer T1 one end connects switching tube VT1, and the other end connects capacitor C 4, and the three constitutes discharge loop, and resistance R 1, R2 and capacitor C 4 are connected into a charging circuit and are connected between DC power supply and the ground, and transformer T1 secondary connects light source LAMP.

The advantage that the utility model had is:

1. fail safe

Whether the utility model adopts transformer as boosting device, according to different needs, can select former secondary to isolate, and strengthens fail safe.

2. controllability

In the utility model, the drive signal of switching tube VT1 is sent by control circuit, the core of control circuit is single-chip microcomputer or DSP (digital processing unit), send the DRP control signal by it, and control circuit can be adjusted spark rate, pulse duration, ignition duration and sparking mode according to different light sources.Therefore this firing circuit just can adapt to different qualities, reaches optimum IGNITION CONTROL purpose.

3. reliability

Among the present invention, the effect of C4 is a storage power, and its appearance value has determined energy delivered size between burn period, can adapt to the different demands of different fluorescent tubes for the ignition energy size.

Description of drawings

Fig. 1 is the utility model circuit diagram

Embodiment

Below in conjunction with accompanying drawing the utility model is further described

Fig. 1 is a circuit diagram of the present utility model.Ballast ignition start device comprises switching tube VT1, resistance R 1, R2, capacitor C 4, transformer T1.The former limit of transformer T1 one end connects switching tube VT1, and the other end connects capacitor C 4, and the three constitutes discharge loop, and resistance R 1, R2 and capacitor C 4 are connected into a charging circuit and are connected between DC power supply and the ground, and transformer T1 secondary connects light source LAMP.

T1 is an ignition transformer, is used to produce high-voltage pulse; VT1 is the switching tube of control ignition, and drive signal DRP is produced by single-chip microcomputer, is used for driving metal-oxide-semiconductor VT1, according to the Single Chip Microcomputer (SCM) program algorithm, and frequency, pulsewidth, duration and ignition mode that can control ignition.The R3 cross-over connection is used for protecting the metal-oxide-semiconductor open circuit situation in G, the S of MOS end.D1, D2 are clamp diodes, are used for preventing that the drain voltage of MOS is too high or low excessively, and this drain voltage will be by pincers at BUS current potential or earth potential.R1, R2 and C4 constitute the loop, and BUS voltage charges to C4 by resistance R 1, R2, and the resistance that changes R1, R2 can be controlled charge constant and charging current size.C2, C3 are electrochemical capacitors, make shunt capacitance here and use, and C1 is a high-frequency filter capacitor, absorbs the high frequency burr of major loop.

Its operation principle is as follows:

When DRP when low, VT1 turn-offs, BUS voltage charges to C4 by R1, R2, charge constant is

τ＝(R1+R2)*C4

Electric current can be calculated by following formula

$(R1+R2)*\frac{\mathrm{di}}{\mathrm{dt}}+i=C4*V_{\mathrm{BUS}}$

Wherein dt is by switching tube turn-off time decision, and charging current is directly proportional with BUS voltage, appearance value and pulsewidth as can be seen from the above equation, is inversely proportional to resistance, interior between at this moment C4 is charged to BUS voltage.

As DRP when being high, VT1 is open-minded, and C4 voltage is added in winding two ends, the former limit of transformer T1, and its value equals BUS voltage, and the time is the pulse duration of DRP signal, produces high pressure by being coupling in the secondary winding, and its value is V _BUS* N2/N1.

Because BUS voltage is stable direct current, so the mid-point voltage of C2 and C3 also is stable, the high pressure that the T1 secondary produces is added on the LAMP by major loop, triggers light source and starts.

Claims (1)

1. ballast ignition start device, comprise switching tube VT1, resistance R 1, R2, capacitor C 4, transformer T1, it is characterized in that: the former limit of transformer T1 one end connects switching tube VT1, the other end connects capacitor C 4, the three constitutes discharge loop, resistance R 1, R2 and capacitor C 4 are connected into a charging circuit and are connected between DC power supply and the ground, and transformer T1 secondary connects light source LAMP.

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