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 show another timer, this one is simpler because it uses only one of the four...
This instrumentation circuit is from the June 1986 issue of Radio Electronics magazine. Equivalent...
This two-transistor amplifier has good gain but delivers a fraction of a watt of power. The...