Industrial electronic igniter

The industrial electronic igniter introduced in this example has the characteristics of high ignition energy and low production cost, and can be used for starting ignition when burning fuel or gas in industrial oil furnaces and chemical and petroleum fields.
Circuit Operation Principle The industrial electronic igniter circuit consists of a power supply circuit, a starting ignition control circuit, and a boost ignition circuit, as shown in Figure 8-149.

The power circuit is composed of a power switch S1, a fuse FU, a step-down capacitor Cl, a bleeder resistor R1, a rectifier diode VD1, a Zener diode VS, and a filter capacitor C2.
The starting ignition control circuit is composed of an ignition control button S2, a resistor R5-R7, a NAND gate integrated circuit IC (D1-D4), a thyristor VT, an intermediate relay KA, and capacitors C4, C5.
The boost ignition circuit is composed of a step-up transformer T, a rectifier diode VD2-VD5, a capacitor C3, a resistor R2-R4, a discharge tube, an inductor L, and a spark plug.
Turn on the power switch S1, AC 220V voltage through Cl step-down, VS voltage regulation, VS voltage regulation, VD1 rectification and C2 filtering, provide 6V DC working voltage for the IC.
When the ignition control button S2 is pressed, C5 starts to charge, NAND gate D3 outputs å‚€ level, Dl and D2 output high level, so that VT is triggered to conduct, KA energizes and pulls, and its normally open contact turns on boost The operating power of the ignition circuit. After the AC 220V voltage is rectified by T boost and VD2-VD5, C3 is charged through R2. When the voltage across C3 reaches the breakdown voltage of the discharge tube, the discharge tube breaks down, and the electric energy stored on C3 is applied to the spark plug through the discharge tube and the inductor L, and a spark is generated through the spark plug to ignite the fuel or gas.
When C5 is fully charged (about 12s), NAND gate D3 outputs a high level, Dl and D2 output a low level, VT is turned off when the AC voltage crosses zero, KA is released, and the working power of the boost ignition circuit is cut off.
Component selection
Rl, R3, R5-R7 select 1/4W metal film resistor for use; R2 selects 5OW wirewound resistor for use; R4 selects lOW wirewound resistor for use.
Cl selects a CBB capacitor with a withstand voltage of 630V; C2 and C4, C5 select aluminum electrolytic capacitors with a withstand voltage of 16V; C3 selects a high-pressure oil-impregnated paper capacitor with a withstand voltage of 3kV.
VDl selects 1N4007 type silicon rectifier diode; VD2-VD5 selects 2CL55C or 2DL56 type 3kV rectifier bridge stack, and can also be replaced by 3R1N4007 series.
VS selects 1N4735 (1W, 6.2V) type Zener diode.
VT selects the bidirectional thyristor of lA, 400V.
IC selects CD401l or CC401l, MCl4011 type four NAND gate integrated circuits.
T is made of U-shaped core with a cross-sectional area of ​​4Ommx2Omm and high-strength enameled wire: Wl winding is wound around 800匝 with φ0.72mm enameled wire, and WZ winding is wound with φ0.25mm enameled wire around 8000匝.
L is made by winding an enamel wire of φ1.6 mm around a medium-wave magnetic bar of φ10 mm x I2O.
The discharge tube is selected from the R-l2 type vacuum discharge tube.
KA selects an intermediate relay with a coil voltage of 220V AC.
S1 selects SA, 220V bipolar switch; S2 selects small moving button.