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 uses a JFET CA3140 operational amplifier to convert a low frequency sinusoidal signal...
This circuit is from the National Semiconductor Audio Handbook. The amplifier operates with 6 V...
This simple amplifier was found in a Radio Electronics magazine from July 1970. The transistors are...