This circuit was obtained from an American 80's documentation. The balanced mixer can be shown in CB4234. The circuit is for controlling RF signals in a modulation system.
A touch in this circuit turns-on the lamp or the relay. Power supply is according the lamp or...
Found in a Popular Electronics from the 90's, this circuit uses integrated from that time, today...
This isolated shield for triac was found in old European documentation. The resistor R1, in fact,...