This circuit was found in the October 1989 issue of Radio Electronics magazine. It drives an auxiliary relay with the call signal for a possible louder bell.
This circuit was originally designed to monitor the temperature of a vehicle. The integrated...
This circuit was obtained in a Popular Electronics of the 90s. It warns when the indicator lamp is...
This amplifier circuit with two transistors was found in a Mullard transistor manual from 1960. The...