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.
This circuit is intended to trigger an alarm when the input voltage exceeds one value and to...
This circuit, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
This circuit was found in Delco documentation from 1966. The components are from that time....