Few realize how close an optical coupler resembles a relay. It is so close, in fact, that one can be wired as a Run-Stop latch circuit. One advantage over the relay is that it may be turned off via a ...

For some of us, there are few sounds more satisfying than the deep resonant “thunk” of a high quality toggle switch slamming into position. There isn’t an overabundance of visceral experiences when ...

This intelligent electronic lock circuit is built using transistors only. To open this electronic lock, one has to press tactile switches S1 through S4 sequentially. For deception you may annotate ...