Capacitive Relay (T1527E)

Found in Popular Electronics from August 1956 this sensitive two-tube relay is powered directly from the mains power supply.

Telephone Dialer (CB5979E)
This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference,...
AC to DC Converter (CB5098E)
This circuit was obtained from an American 80's documentation. The operational ones can be...
741 Logarithmic Amplifier (CB25723E)
This logarithmic gain operating configuration was found in the June 1994 Electronics Now magazine. The...