We found this circuit in a 1965 Electronic Design. Transistors are still common but admit equivalents for some of them. The circuit drains a current of only 4 mA.
When the temperature rises above the value adjusted by P1 the relay triggers on. The rated voltage for the...
This circuit was found in a 1968’s publication and uses germanium transistors. Equivalents can be...
This bistable or flip-flop is triggered by a negative pulse applied to the collector of the...