This shield circuit is from a 1968s Motorola documentation. The relay is according to the supply voltage. R1 can be reduced to lower trigger voltages.
The integrated circuit used is not common today. The circuit is from the SGS linear integrated circuits...
This circuit includes the power supply from the power grid. We found it in Radio Electronics from...
This circuit was found in the April 1998 issue of Electronics Now magazine. The circuit uses...