This circuit is from an 80's Electronic Engineering. The base is a common operating and 4 single integrated voltage comparators. The circuit directly drives 4 indicator LEDs.
The drive levels of this shield are opposite to the previous one. The photo-transistor can be of...
This circuit was found in a Radio Electronics of July 1984. It consists of the traditional 1 A...
This flasher or neon signal powered by batteries was found in old documentation. The transformer must...