Found in a Philips publication from the 1970s, this circuit uses a DO040, which is difficult to obtain today. The circuit is powered by 12 V on pins indicated in the diagram.
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...