(Amperometric relay) It can be of maximum current (Maximum curent relay) and minimum current (Minimun curent relay)). DC relay which has two coils wound on the same magnetic core; the coils are powered separately; in this relay ampere turn (the product of the number of turns of a coil due to the current flowing through it) of one and the other coil generally have the same characteristics and contribute to generating the flow to excite the relay. It is generally used to check whether or not the supply of specific devices is present. See Relay FS
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