We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
We found this circuit in a 2005 Linear Technology manual. The resistor is calculated for the...
The frequency of this circuit is determined by the 100 uF capacitors. These components can be...
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....