This circuit was obtained from a 1970s RCA. The circuit uses LDRs as sensors. The resistors depend on the A / D converter used. The circuit can be used as a shield.
This circuit, from a documentation of the 90s, uses unusual operations today, but the...
This circuit is from a Radio Electronics from May 1994. In it we have the way to connect three 4017...
This circuit is from the 70's by A. Fanzeres. We kept the original text. It has already been said...