This circuit was found in Radio Electronics from the 90s. Q3 must have a heatsink and R10 fixes the output voltage.
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...