Suggested for the control of photographic enlargers, this 1967 General Electric circuit uses still common components. The circuit directly controls a lamp for exposing negatives.
Found in a 1967 RCA manual this circuit applies only to incandescent lamps up to 240 W. The...
This excellent wireless microphone circuit for the varicap-modulated FM band came out in...
This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in...