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.
Found in documentation from the 1970s, this circuit uses an oscillator and a display to warn of...
This circuit indicates whether a cable or wire is energized by simply approaching its antenna. The...
Using bipolar, FETs and unijunction this long-lasting timer can reach 10 hours with good quality...