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.
This circuit is from an old publication from the 70s, but it can be implemented with modern diacs...
This circuit is from a 1950 documentation, being one of the first to use the then discovered...
This circuit provides a linear charging for the capacitor. Time interval is adjusted by P1. The...