CN105472854A - Ignition device of capacitive resonance charging type high-pressure gas discharge lamp - Google Patents

Abstract

The invention discloses an ignition device of a capacitive resonance charging type high-pressure gas discharge lamp, wherein no spark gap discharge exists and an auxiliary power supply can be saved. The ignition device of the capacitive resonance charging type high-pressure gas discharge lamp has advantages of low electromagnetic interference, high system stability, no easy saturation of a magnetic core, easy ignition to a high-pressure gas discharge lamp, etc.

Description

Ignition device for capacitor resonant rechargeable high-pressure gas discharge lamp

technical field

The invention designs an ignition device of a capacitor resonance charging type high-pressure gas discharge lamp, which belongs to the ignition device of a high-pressure gas discharge lamp in a laser power supply and an illumination power supply system.

Background technique

For the laser power supply, the final object of action is the gas pump lamp, which provides pumping energy for the laser through the discharge of the gas pump lamp. The ignition working state of the gas pump lamp is divided into three stages: 1-glow, 2-pre-combustion and 3-high voltage arc discharge, which is a relatively complicated unsteady gas discharge process in each stage.

In the traditional ignition system, as shown in Figure 1a, b, and Figure 2, the circuit in Figure a is an external trigger type, which is unreliable to ignite, and the discharge lamp cannot be cooled by water, and is not suitable for high-pressure discharge lamps. The circuit in Figure b is ignited The voltage is connected across the electrodes of the lamp 9 . Therefore, a high-voltage isolation relay 8 must be added between the main discharge circuit and the lamp, which often contains a pre-ignition power supply 6 in this circuit. Circuit diagram 2 is the ignition circuit of the most widely used high-pressure gas discharge lamp at present. After the capacitor 1 is charged, the thyristor SCR2 is turned on, the spark gap 4 is connected in parallel with the secondary of the pulse transformer 3, the energy of the accumulator 5 is discharged to the primary of the transformer 3, and the secondary generates a pulse voltage of more than 10,000 volts. Under the action of this voltage, the spark gap 4 is broken down. According to the principle of series resonance, a pulse voltage with an amplitude of U will be obtained on the inductance 4 and capacitor 2. After being boosted by the transformer 5, as long as the nU value is greater than the lamp’s Gas breakdown voltage Uj, the internal gas of the lamp is broken down to form an ionization channel, and the neutral gas discharge lamp becomes a conductor. Since the energy of the ignition voltage is very small, the voltage at both ends of the lamp has not dropped below the main The voltage U0 provided by the electric circuit cannot ignite the main power immediately after the breakdown, so there must be a pre-ignition voltage source 6, and the output voltage of the power supply is called the ignition voltage. The function of this voltage is that when the gas of the discharge lamp is broken down, the discharge current of the lamp will increase, and the voltage at both ends of the lamp will drop further. When the voltage at both ends of the lamp drops below the main power supply voltage U ₀ , U ₀ Participate in the discharge, so that the lamp can be continuously ignited to form a stable arc discharge. Therefore, the pre-ignition voltage source must provide enough power to make the voltage at both ends of the lamp drop below the value of the main power supply voltage U ₀ . The discharge lamp U ₀ of high pressure is less than 70v, and the ignition current is greater than 10 amps, so the pre-ignition power supply 6 must provide power greater than 700w in a short time.

In the above-mentioned ignition system, there are the following problems: 1. Due to the existence of the spark gap 3, the gap of the spark gap should be adjusted at any time for different lamps. The electromagnetic interference generated during spark gap discharge is extremely large, and oxygen smell is generated during ignition. 2. The magnetic core of the transformer is easily saturated, and it is not easy to ignite high-pressure lamps (such as krypton lamps). 3. There must be an auxiliary that can provide enough energy in a short time Power supply 6. Based on the above reasons, we have invented a new type of ignition device that can overcome the above-mentioned problems of the traditional ignition system. The circuit is simple and low in cost, and the ignition is reliable.

Contents of the invention

The object of the present invention is to provide an ignition device for a high-pressure gas discharge lamp that does not require a spark gap 3 and does not require a pre-ignition power source 6 .

In order to achieve the above object, the present invention adopts the following technical scheme: as shown in Figure 2, it includes an inverter transformer (8), an output capacitor (1), a high-voltage energy storage capacitor (2) and a discharge thyristor (3). Transformer (4), resonant charging capacitor (5), discharge lamp (6); inverter transformer (8) has two sets of output taps, connected to output capacitor (1) via rectifier (9) (10) and isolation diode (11) ) and the high-voltage energy storage capacitor (2), the high-voltage energy storage (2) is connected to the anode of the discharge thyristor (3), and the cathode of the discharge thyristor (3) is connected to the input terminal of the ignition step-up transformer (4). The taps at the two turns of the autotransformer near the input end are connected to one end of the resonant capacitor (5), and the other end of the resonant capacitor (5) is grounded; the output end of the step-up transformer (4) is connected to the anode of the discharge lamp (6) , the cathode of the discharge lamp is grounded;

The two sets of output voltages of the main inverter transformer (8) charge the output capacitor (1) and the high-voltage energy storage capacitor (2) to a certain voltage respectively. The voltage obtained on the output capacitor (1) is E ₀ , and the voltage obtained on the high-voltage capacitor is U ₀ ;

When the discharge thyristor (3) is turned on by the driving signal, the voltage on the high-voltage energy storage capacitor (2) is charged to the resonant capacitor (5) through the primary coil 1 and terminal 2 of the step-up autotransformer (4), and the charging current is at The high-voltage end of the step-up transformer induces a high-voltage pulse, and the high-voltage pulse causes the lamp to break down; when the resonant capacitor (5) is charged, due to the resonant charging, it is charged to , which is the boost coefficient. 2>>1. As the voltage of the pre-ignition power supply; after the resonant capacitor (5) is broken down, the voltage further discharges to the lamp (6), so that the voltage at both ends of the lamp (6) continues to drop until it is lower than the voltage on the output capacitor (1) Discharge voltage E ₀ , at this time, the output capacitor discharges to the lamp, completing the ignition process of the high-pressure discharge lamp.

The ignition device of the capacitor resonance charge according to the present invention essentially adopts the resonant charging process of the resonance capacitor to form the pre-ignition voltage. At the same time, the high-voltage pulse formed in the resonant charging process is combined to ignite the gas discharge lamp.

The high-voltage winding of the main power inverter transformer (8) provides initial energy for the high-voltage accumulator (2), which saves the additional high-power pre-ignition power supply. The step-up autotransformer (4) is composed of a ring ferrite magnetic Core wound, it provides a high voltage ignition pulse, saving the spark gap.

The ignition device of the capacitor resonance rechargeable high-pressure gas discharge lamp of the present invention saves the spark gap and the pre-ignition power supply, greatly reduces the interference, reduces the weight and reduces the cost. It can be widely used in laser power supply and high pressure lamp power supply.

Description of drawings

Figure 1 is a schematic diagram of a conventional ignition circuit;

Fig. 2 is the structural representation of the circuit of the present invention;

Fig. 3 is a schematic circuit diagram of the present invention.

detailed description

Embodiment 1 An ignition device for a capacitive resonance rechargeable high-pressure gas discharge lamp.

The specific implementation process of the capacitor resonant rechargeable high-pressure gas discharge lamp ignition device of the present invention is described in detail in conjunction with accompanying drawings 2 and 3 as follows:

The composition structure of the present invention is described with reference to the structure Fig. 2 . As can be seen from the structural diagram of the ignition device of the capacitor resonant charging type high-pressure gas discharge lamp of the present invention, the present invention comprises a high-voltage capacitor energy storage network, a discharge network, an auto-coupling step-up transformer ignition circuit, and a resonant capacitor energy storage network. Their connection relationship is as follows: one end of the capacitor of the high-voltage energy storage network is connected to the anode of the discharge switch thyristor in the discharge network, the cathode of the thyristor is connected to the input end of the auto-coupling step-up transformer, and the tap of the autotransformer is connected to one end of the resonant capacitor , the other end of the resonant capacitor is grounded. The high-voltage output terminal of the self-coupled step-up transformer is connected to the anode of the gas discharge lamp, and the cathode of the other end of the lamp is grounded. When the ignition drive signal is applied to the control pole of the discharge thyristor, the thyristor is turned on, and the voltage on the energy storage is charged to the resonant capacitor through the coil of the step-up transformer, and the resonant capacitor is charged to the voltage , The charging current generates a pulse high voltage at the high voltage end of the step-up autotransformer, which causes the discharge lamp to break down. At the same time, the voltage on the resonant capacitor is also discharged to the lamp, so that the voltage at both ends of the discharge lamp drops below the main power supply voltage, and the main power supply discharges to the lamp to complete the lighting process.

It can be seen from the electrical schematic diagram 3 of the capacitor resonant charging type high-pressure gas discharge lamp ignition device that the high-voltage energy storage network is composed of the main inverter transformer and the high-voltage rectifier bridge V1 (). Composed of current limiting resistor R1 (10K/2W) and high voltage energy storage capacitor C1 (30μ/1400V). The high-voltage AC voltage of the secondary high-voltage winding of the main transformer is rectified into a DC voltage by the rectifier bridge V1, and the voltage is charged to the high-voltage energy storage capacitor C1 through the current-limiting resistor R1, and a certain voltage is obtained on the high-voltage energy storage. This voltage will be used for ignition and to charge the resonant capacitor C2 (2μ/1600V).

The discharge network in Figure 3 is composed of the discharge thyristor V2 (MFC100/16E), the driving signal source S1 (BT-33) of the thyristor and the protection absorption circuit R2 (50Ω/5W) C3 (0.1μ/1600V) of the thyristor V2. The anode of the thyristor V2 is connected to the positive high-voltage terminal of the high-voltage energy storage capacitor C1, and the cathode of the thyristor V2 is connected to the input terminal 1 of the step-up ignition transformer T1 (MXO-120X80). The driving signal generated by the signal driving source of the thyristor V2 is applied to the control pole of the discharge thyristor to turn it on. After the thyristor V2 is turned on, the voltage on the high-voltage energy storage C1 is added to the input terminal 1 of the step-up transformer T1 through the thyristor V2.

The resonant capacitor network in Fig. 3 is composed of a resonant capacitor C2 and a breaker F (1A). One end of the resonant capacitor C2 is connected to the tap 2 end of the step-up autotransformer T1, the other end of the resonant capacitor C2 is connected to one end of the fuse F, and the other end of the fuse F is grounded. When the discharge thyristor V2 is turned on, the high-voltage energy storage capacitor C1 discharges to the resonant capacitor C2 through the primary of the transformer T1, instead of directly discharging to the primary of the transformer. During the discharge process, the inductance L of the primary coil of the transformer T1 and the resonant capacitor C2 form a resonant charge. After charging, the voltage obtained on the capacitor C2 is U _C . Under the first-order approximation, the Q value of the transformer inductance is greater than 20.

The charging process of the resonant capacitor C2 is a cosine charging process, and the current is not very large. The charging current forms an ignition high-voltage pulse U at the high-voltage end of the step-up transformer, and the high-voltage pulse breaks down the discharge lamp. Since the high-voltage pulse is single-frequency and has no spark gap, the interference released is small.

The voltage U on the resonant capacitor C2 participates in the discharge to the lamp after the lamp is broken down, so that the voltage at both ends of the lamp further drops, and plays the role of pre-ignition power supply. Therefore, the ignition device can save the pre-ignition power supply. In this installation, the energy of the accumulator can be discharged directly to the lamp, which saves the high-voltage discharge isolation relay and simplifies the discharge circuit. Therefore, this circuit can save the auxiliary power supply 6 in the circuit diagram 2 and reduce the cost.

The invention has no spark gap discharge, saves the auxiliary power supply, has the characteristics of small electromagnetic interference, stable system, difficult saturation of the magnetic core, and easy ignition of high-pressure lamps.

Claims (5)

1. An ignition device for a capacitor resonance rechargeable high-pressure gas discharge lamp, characterized in that it includes an inverter transformer (8), an output capacitor (1), a high-voltage energy storage capacitor (2) and a discharge thyristor (3). voltage autotransformer (4), resonant charging capacitor (5), and discharge lamp (6). 2. According to claim 1, the inverter transformer (8) has two sets of output taps, which are connected to the output capacitor (1) and the The high-voltage energy storage capacitor (2), the high-voltage energy storage (2) is connected to the anode of the discharge thyristor (3), and the cathode of the discharge thyristor (3) is connected to the ignition step-up transformer (4 ), the taps are connected to one end of the resonant capacitor (5) at two turns of the step-up autotransformer close to the input end, and the other end of the resonant capacitor (5) is grounded. The output end of the step-up transformer (4) is connected to the anode of the discharge lamp (6), and the cathode of the discharge lamp is grounded. 3. According to claim 1, the two sets of output voltages of the main inverter transformer (8) respectively charge the output capacitor (1) and the high-voltage energy storage capacitor (2) to a certain voltage. The voltage obtained on the output capacitor (1) is E ₀ , and the voltage obtained on the high voltage capacitor is U ₀ . 4. According to claim 1, when the discharge thyristor (3) is turned on by the driving signal, the voltage on the high-voltage energy storage capacitor (2) passes through the primary coil 1 of the step-up autotransformer (4), Terminal 2 charges the resonant capacitor (5), and the charging current induces a high-voltage pulse at the high-voltage terminal of the step-up transformer, and the high-voltage pulse causes the lamp to break down. 5. According to claim 1, when the resonant capacitor (5) is charged, due to the resonant charging, it is charged to, is the boost coefficient. 2>>1. As the voltage of the pre-ignition power supply. After the resonant capacitor (5) is broken down, the voltage further discharges to the lamp (6), so that the voltage across the lamp (6) continues to drop until it is lower than the discharge voltage E ₀ on the output capacitor (1) , at this time The output capacitor discharges to the lamp to complete the ignition process of the high pressure discharge lamp.