This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The maximum current is 170 mA. and the integrated circuit is the MAX655 from Maxim.
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...