Circuits similar to this can be found in this section. This is from 1967 General Electric documentation. The main SCR must be fitted with a heat sink.
The purpose of this circuit is to add millivolt scales to a common multimeter. Used transistors are...
This simple circuit connects in external battery to a load when the AC Power line fails. S1 can be...
This conventional team from a 1992 publication has 10 fixed times selected by a key. The times are...