The difference between DC relay and AC relay

The principle of the DC relay and the AC relay is the same as that of the electromagnetic principle, but the power supply of the DC relay must be a direct current. DC relay coil DC resistance is very large, the coil current is equal to the voltage divided by the DC resistance of the coil, so the coil is thin and a lot of turns.

AC relay coil number corresponding less, because in addition to limit the current in AC circuit coil resistance outside the limited current size is the size of coil inductance, and alternating current frequency is proportional to the inductance XL, if AC relay connected to the DC circuit in the DC frequency is equal to zero so the coil inductance XL=0, the resistance is small so the coil will heat and burning. Instead of DC relay connected to the AC power supply when the coil resistance and inductance will cause great big coil pull not, so not interchangeable. AC relay manufacturers