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, found in a 1986 documentation, uses an optical sensor to count pulses and, in its...
This circuit, found in a 1997 publication, activates a lamp or a monitoring camera when the bell...
We found this circuit in an English publication in 1981. It can be improved by exchanging T1 for a...