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.
This circuit was found in old documentation. PUTs are uncommon components today. The circuit...
This circuit was obtained in a 1991 Electronics Handbook. The publication no longer exists, but...
This crystal oscillator generates a 20 MHz signal. Equivalent transistors such as BF494 and 2N2222...