This circuit for 12 V relays was found in the July 1992 Radio Electronics magazine. The circuit is set at R6.
This circuit, when it picks up a sound, emits a beep and records for a while the sounds picked up by a...
This old common analog telephone circuit was found in 1967 American documentation. The circuit uses...
This 4-transistor timer was found in the April 1975 issue of Radio Electronics magazine. It uses...