Relays are electromechanical devices that use a magnetic solenoid to actual a switch. When current is passed through the solenoid coil, it produces a magnetic field. The magnetic field is strengthened ...

UNTIL a few months ago the literature on the subject of electricity meters was entirely confined to articles in text-books on electrical engineer- ing, and the advent of a book dealing exclusively ...

Testing products designed to operate from ac power is not as simple as one might think. Consider a factory with the straight-forward need to manufacture and test the heating element for a toaster.