This car battery monitor was featured in the January 1988 issue of Radio Electronics magazine. The circuit uses common transistors and has 3 levels of indication made with common LEDs.
We found this circuit in a 1986 documentation. It is based on TTL integrated circuits that can be...
This circuit was obtained from a 1968 Philips publication. The transistors are of the time. Dual...
This project, found in a 1981 documentation, consists of an interesting adaptation of the test...