Flame-ignitor

Description: The spark generated by the circuit is suitable for a gas ignitor. Capacitor C1 is charged through R1 and D1 towards peak line voltage. Concurrently, C2 is being charged at a slower rate through R5. When the charge on C2 is sufficient to trigger the Programmable Unijunction Transistor (PUT), the Silicon Controlled Rectifier (SCR) is activated, providing a rapid discharge path for C1 through the transformer primary. The SCR is triggered approximately 20 times per second with the specified component values. Additionally, the L14G3 functions as a flame sensor. Once ignition is achieved and detected by the photodetector, the low voltage at Vc8 prevents further triggering of the SCR.

The described circuit operates as a gas ignitor, utilizing a combination of capacitors, resistors, and diodes to create a high-voltage spark necessary for ignition. The charging of capacitor C1 occurs rapidly through resistor R1 and diode D1, allowing it to reach peak line voltage efficiently. Simultaneously, capacitor C2 is charged more slowly through resistor R5, creating a delay that enables the system to regulate the ignition process.

The key component in this circuit is the Programmable Unijunction Transistor (PUT), which acts as a control element. Once the voltage across capacitor C2 reaches a predetermined threshold, the PUT triggers the SCR. This action creates a low-resistance path for the discharge of capacitor C1, allowing the energy stored in C1 to flow through the primary winding of the transformer, generating a high-voltage spark necessary for igniting gas.

The triggering frequency of the SCR, approximately 20 times per second, indicates a repetitive cycle of charging and discharging that maintains consistent ignition capability. The use of L14G3 as a flame sensor enhances the safety and reliability of the system. When the photodetector senses successful ignition, it generates a low voltage at Vc8. This low voltage effectively disables further SCR triggering, preventing unnecessary discharge and potential hazards associated with continuous sparking.

Overall, this circuit design is an efficient and effective solution for gas ignition applications, combining rapid spark generation with safety features to ensure reliable operation. The careful selection of components and their values plays a crucial role in achieving the desired performance and functionality of the ignitor system.The spark developed by the circuit is suitable for a gas ignitor. Capacitor Cl is charged through Rl and Dl toward peak line voltage. C2 is simultaneously being charged at a slower rate through R5. When the charge on C2 is sufficient.to trigger the PUT, the SCR is triggered on, providing a rapid discharge path for Cl through the transformer primary. The SCR is triggered about 20 times per second with the component values shown. The Ll4G3 serves as a flame sensor. When ignition is achieved and sensed by the photodetector, the low Vc8 prevents further SCR triggering.