This power source was found in a 1969’ Electronics World. The version is too sophisticated by the current it supplies and can be implemented with modern transistors.
This circuit was obtained in an old American publication from 1978. It can be assembled with a...
Decade counters, such as the 4017, can be cascaded as sourcing signals with the frequency divided...
This circuit uses a dual-gate MOSFET, a rare component today. We found it in American...