Unlike the previous circuit, the output of this one goes high in the window voltage range. The circuit is from Radio Electronics from June 1986 and is based on the CA3140.
This circuit was found in a 90s Popular Electronics. The components are from the era. R3 must be...
This circuit is from the magazine La Radio per Tutti of 1926. The primary and secondary coil have...
The sensor for this circuit, found in a 1992 publication, is a phototransistor. The power is...