This CMOS integrated alarm was found in the July 1992 Radio Electronics magazine. The circuit has a small power stage and its sensitivity is adjusted at R5.
We have here a very interesting project found in a 1982 publication. By the operation of the...
We found this circuit in an old American manual. The formulas allow the gain to be calculated as a...
This circuit is from the time when cars used contact breakers. This 80's version measures the dwell...