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.
This circuit is the factory version of the LM386 low-power amplifier. The sound quality is...
This circuit with transistors of the time was found in the magazine Radio Electroinics of June of...
This circuit charges a battery to power a flashlight at night. The circuit is from an English...