This CMOS 4001 oscillator alternately turns the relay on and off at times set by R2. The circuit is from Electronics Now magazine, June 1995.
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...