We found this circuit in an old RCA publication. The components are of the time, admitting equivalents. The circuit is triggered in two ways using LDRs.
We found this circuit in an English documentation from 1995. With it it is possible to measure a...
This circuit is from an ancient American documentation. The coil is frequency dependent and the...
We have here a simple signaling circuit for two common incandescent lamps, which is used for...