The sensor is S1 in this alarm that we found in a Radio Electronics magazine from May 1971. Several sensors can be used in series. The SCR supports equivalents from the 106 series.
We found this circuit, which should only be used with incandescent lamps. In the Motorola Linear...
We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency...
This pulse-synchronized oscillator was found in a Mullard manual from 1960. The transistors are...