This circuit is from an1966 General Electric documentation. The Triac can be equivalent to 6 A or more, mounted on a good heatsink. Any diac can be used.
This circuit produces a warning signal with the programmed current that can reach 4 A. The circuit is...
Found in an old American documentation this FM modulator makes use of a varactor diode. The...
This circuit was obtained in Motorola documentation from 1969. The transistors are from the time...