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The circuit on the 16th floor is correct! The power requirement of the potentiometer in this circuit is much lower than that of the original poster's circuit! In theory, the withstand voltage of the capacitor does not need to be very high, 100V is enough! According to your current situation, it may be caused by the trigger diode or R1 being open! The thyristor may also be damaged? Check it carefully! !

刘兴光

I checked it, it seems to be fine! :faint:

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Have you connected the pins of the thyristor correctly?

刘兴光

The third leg is the control leg.

zhutx

The conclusion after component testing should be clear and straightforward. "Seems" means that you don't understand it. In fact, you don't need to use a meter to measure the voltage change. You can directly connect a 25W incandescent lamp to the place where the soldering iron is connected to see the adjustment effect. To measure the thyristor, you need to use the RX10 or RX1 resistance range of the pointer multimeter. A digital meter cannot measure the triggering process.

刘兴光

The problem has been solved, thank you everyone, but I tried it with an incandescent lamp, but it went out as soon as I plugged it in :(

刘兴光

I don't know why, but I think it's probably because the incandescent lamps are connected in series!

刘兴光

Did the incandescent lamp act as a safety device? :puzzle:

zhutx

If you are connected to a 380V power supply, the incandescent lamp will definitely act as a safety.