Suggested by General Electric in a 1965 document, this circuit can accept a greater number of sensors. When anyone opens the SCR it fires powering the load.
This circuit is from 1968 General Electric documentation. It can certainly be adapted for any...
This tester from a 1960 magazine is only for capacitors with insulation voltages above 200 V (110...
Found in a 1991 publication this circuit can be assembled with more modern components. We can use...