This circuit was found in a 1967 General Electric documentation. The components are from that time. The load depends on the SCRs used.
The sensor for this alarm is an LDR and it consists of an oscillator that goes into action when...
This circuit was found in American documentation from the 90's. The transformer is of the high...
The circuit shown is a white noise generator using a zener diode as a source of noise. The...