We found this transistorized circuit in a 1985 documentation. The circuit can operate with voltages from 9 to 12 V and the adjustment of the operating point or input sensitivity is done in P1.
This circuit is from the 1993 Motorola Linear Interface ICs. Equivalent operating may be used and...
Through the TTL output this circuit can be used as a shield. The sensor is a platinum probe, and...
This alarm with sensors in series and parallel was found in the 1995 Encyclopedia of Electronic...