What is a relay?

Relay is an electronic control device, which has a control system ( also known as the input loop ) and the control system series ( also known as the output circuit ), which is usually applied to automatic control circuits, is actually a kind of " automatic switch " that uses a small current to control a larger current. So in the circuit plays the role of automatic adjustment, security protection, conversion circuit, etc, commonly used in the shape of the relay as shown in bottom.

First, the classification of relays is generally divided into DC electromagnetic relay, AC electromagnetic relay, reed relay, intermediate relay and solid state relay five .

( 1 ) Starting relay, intermediate relay, step relay, overload relay, time-limited relay and temperature relay are divided according to purpose.

( 2 ) According to the power, the relay with power below 25 W is called a small power relay, and the relay with power in the range of 25 to 100 W is called middle power relay, the relay with a power above 100 W is called a high power relay.

( 3 ) According to the time of relay, the relay with less than 50ms action time is called fast relay, and the relay with action time of 50 ms ~ 1s is called standard relay a relay with an action time greater than 1 s is called a delay relay.

( 4 )As long as there is a certain voltage on both ends of the coil, a certain current will flow in the coil, so the electromagnetic effect can be generated, and the armature will be attracted by the electromagnetic force the pulling force of the return spring is overcome to attract the iron core, so that the movable contact of the armature is connected with the static contact ( normally open contact ). When the coil is cut off, the electromagnetic suction will also disappear, the armature will return to the original position in the spring reaction force, so that the moving contact with the original static contact closed contact ) suction. Thus, the purpose of conducting and cutting off the circuit is achieved. For the " normally open " and " normally closed " contacts of relays, it is possible to distinguish : static contacts that are disconnected when the relay coil is not energized, it's called a " normally open contact "; the stationary contact is called " normally closed contact ".

If you want to know more, our website has product specifications for relays, you can go to Allicdata Electronics Limited to get more information