Found in an Electronic Design from the 90s, this circuit uses high voltage operationals of the time to excite a piezoelectric motor in a bridge circuit.
This circuit, with an operational amplifier, was found in the Motorola Dataar Linear of 1990. The...
In the fist circuit the alarm triggers on when any sensor is CUT. In the second circuit the alarm...
This circuit for a digital module was found in the September 1989 Radio Electronics magazine. The...