Select "220V AC Cooling Fan" relay _ relay rated working voltage relay rated working voltage selection is one of the main technical parameters of the relay. When using a relay, you should first consider where the circuit (ie, where the relay coil circuit) operating voltage, rated working voltage of the circuit where the relay should be equal to the operating voltage. General "220V AC Cooling Fan" where the circuit voltage relay rated working voltage of 0.86. Note where the work piece circuit voltage must not exceed the rated working voltage relay, or the relay coil burnt. In addition, "220V AC Cooling Fan" some integrated circuits, such as NE555 circuit can directly drive a relay to work, and some integrated circuits, such as COMS circuit output current is small, and needs only a transistor amplifier circuit to drive a relay, which should consider the transistor output current should be greater than the rated operating current relay.