We found this circuit in a 90's Popular Electronics. The circuit produces a loud sound if S2 is not pressed to reset.
This Siliconix circuit was found in a 1980s documentation. The coil consists of 18 turns of 22...
This circuit is suggested by RCA and is based on a dedicated integrated circuit that is the...
This circuit consists of a constant current source for charging 12 V batteries. The charge is...