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.
Quadrature Generator for Transistor and SCR Testing This circuit was found in US 1980s...
This circuit, with output currents up to 500 mA, can stabilize or regulate the output voltage of a...
This circuit that uses only transistors that are still common was found in a 1995 documentation. The TIP41...