This circuit shows how to add a 1st regulator to a source that already has a step for this purpose. The circuit was found in an American power supply documentation.
We found this active crossover in a Radio Electronics magazine from June 1961. Note the different...
Found in Popular Electronics from the 90s, this circuit serves to indicate the output level of a...
If you are on an old PC that you use for experiments, control or other applications, this circuit is...