Found in a 90’s 73 magazine for radio amateurs, this circuit provides a few milliamps of output with -15 V from a 3 V input, when the consumption will be 10 mA.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...