Found in an old Popular Electronics this circuit is still current. The SCR can be of the 106 series and the relay according to the voltage used in the supply. The voltage can be 12 V.
This circuit reinforces the treble, working as a booster for instruments or home theater. The...
A fourth version of a non-retriggerable monostable is shown in Figure. It is triggered by the...
This circuit was found in Radio Electronics from May 1965. The SCRs and transistors are from that...