The RCA integrated circuit used in this control is uncommon today. The circuit is from an Electronics Now from July 1995. The sensor determines the value of the adjustment potentiometer.
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...