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 can use high value electrolytic capacitors in alternating current circuits with the...
Using only one integrated circuit this control was found in an 80's Electronic Engineering. The circuit...
This source of constant current was obtained in an American documentation of 1973. The transistors can be...