This low power circuit was obtained from an American 80's documentation. The circuit indicates the voltage of a battery being trimmed by the trigger point. The transistors can be the BC549.
The more sensitive the instrument used the better the sensitivity of the indicated meter. We...
Based on the 4017 integrated circuit, this circuit of a European 303 Circuits from the 90s,...
The integrated circuit used in this project is unusual and it includes internal transistors that...