This simple circuit uses an SCR to lock the alarm once triggered. The circuit is from an English documentation. R1 can be from 1 to 4k7, transistor one BC548 and trimpot R2 100k. It is convenient to connect a 10k resistor in series with the trimpot.
This simple circuit uses an SCR to lock the alarm once triggered. The circuit is from an English documentation. R1 can be from 1 to 4k7, transistor one BC548 and trimpot R2 100k. It is convenient to connect a 10k resistor in series with the trimpot.
