We found this circuit in the October 1996 Electronics Now magazine. The circuit uses LDRs as sensors and drives relays. The relays must have voltages according to the power supply.
In the figure we have a typical polarization circuit for MOSFETs with a high impedance...
Equivalent transistors, like the BC548 and BC558 pair can be used in this circuit that we find in an...
The circuit presented is from an old magazine having been translated and published in a national...