From an audio signal, this circuit gets two signals of the same amplitude and opposite phases. This setting is widely used in bridge amplifiers (BTL). Transistors may be commonly used as BC series.
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,...