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 project is to monitor remote loads. The windings are made in a burnt...
The scale of this scale uses LEDs, and its accuracy depends on the number of LEDs. We found this...
We find this circuit in an American documentation from the 80's. The circuit has the coil given by the...