Found in a 1947 publication, this circuit uses 4 parallel/push-pull tuber in the output stage. The circuit employs dual power supply with two rectifier tubes.
Vz determines the trigger point for this protection circuit. The SCR doesn’t need to be mounted on a...
Varicap or varactor is the basic component used in this circuit of an American 80's documentation. The...
In this alarm R1 and R2 can be 10k. The SCR is any 106 Series SCR and V1 is an oscillator buzzer....