We found this circuit in a 1986 documentation. It uses only LEDs, batteries, resistors and the power supply which can consist of 4 batteries or a 9V battery. The basic circuit uses two-color LEDs.
This DC / DC converter was found in an American 1980s documentation. It provides a negative...
This low drift or offset circuit is from an 80's documentation. The configuration can be made with...
The integrated circuit used in this project is not common today, but it can be implemented with more...