5 LED Log Scale with U257B (CB25442E)

The circuit was found in the February 1992 Radio Electronics magazine. The scale can be changed by changing R2 and R3.

12 V x 5 A Regulator SFC2812 (CB19502E)
The integrated circuit used in this regulator is from the 1980s, so it is difficult to obtain...
Passage Alarm (CB18109E)
The pass-through alarm we present uses an infrared (IR) emitter as a sensor. When cutting the...
240W Inverter (CB21768E)
Found in a documentation for radio amateurs from 1977, this circuit is intended to power equipment from...