This long interval timer was found in the September 1976 issue of Radio Electronics magazine. The output can be used to control a relay. The circuit achieves timings of up to 14 hours.
This simple circuit controls the signal amplitude through a photoresistor optical coupler. The...
In the figure we have the way to obtain the Exclusive-OR function with 1 transistor. The circuit...
This circuit uses as an indicator a common micrometer type VU with 200 uA of full-scale current. The...