A very simple but highly efficient combination lock circuit is shown in the figure. Any type of on/off switches can be used, varying from commercially available inexpensive types to more sophisticated ...

Photocouplers optically links, via transparent isolating material, a light emitter and a photodetector. Used as an interface between circuits with different ground potentials, photocouplers replace ...

Looking at some anecdotal stories as well as some reasonably valid survey data, it seems that STEM-related subjects are getting serious interest from students at all age levels; STEM stands for ...