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.
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an...
This circuit can use both separate LEDs and a common cathode display when one segment indicates...