This circuit was found in the November 1992 issue of Radio Electronics magazine. The circuit has an amplification stage for the relay. The relay is rated at 12 V.
This PA or Public Address amplifier with a few watts of power was found in the March 1986 Radio...
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This circuit is a telephone line simulator and can be used for internal communications. It is...