The definition of the relayRelay is when the input (or motivation) to satisfy certain specified conditions, can be in one or more electrical output circuit due to jump in a device.@ relay the predicate should be limited to between the input circuit and output circuit which has the function of a single relay relay component.(2) relay this predicate bag hand to complete the set all the necessary part of containing the input part, drive part and output part.(3) to used for protection and automatic control, should be combined with a relay function name, so that the qualitative relay. In this case, the function of according to regulations (made by standard or regulation), relay can include a auxiliary relay, to complete the required function. For example: differential relay, impedance relay, tripped relay.
1, the general working principle of the electromagnetic relayTo 1 structure as an example, when the coil leads to add voltage or current on both ends of the foot, the coil excitation current flux, flux, yoke iron, through core armature and the work of the air gap magnetic circuit, electromagnetic suction and work in the air gap. When the excitation current rising to a certain value, the electromagnetic absorption torque will overcome the moment of spring to rotate the armature, drive the drive to promote dynamic spring, realizing the contact closure; When the excitation current decreases to a certain value, the dynamic spring counter torque is greater than the electromagnetic torque armature return to original state, off contact.2, the working principle of the magnetic stick relayAs shown in figure 2, the relay contact state retention is produced by the armature part two magnetic steel, magnetic steel produced by the magnetic flux through the right armature - a yoke ferromagnetic yoke very a ferromagnetic core - left a armature magnetic steel form closed loops, the armature and yoke iron electrode produce suction, as shown, left armature extension of the arm by driving chip on double-layer thrust, make produce enough between dynamic and static contact stress, can make its reliable load flow.When you need to make the relay contact disconnected, need to impose a sufficient width pulse voltage on coil, the flux produced by the pulse voltage and magnetic flux in the opposite direction, on the pole will generate the same polarity as the magnetic steel, according to the principle of the same magnetic field, the armature and the yoke ferromagnetic electrode can generate thrust, when the magnetic circuit to produce synthetic moment of reed to the size of the torque, dynamic spring after the movement, the armature part around the axis of rotation, the relay will present the off state in figure 3. If you want to return to the closed, must exert on coil instead of an impulse, otherwise, the relay contact state will last forever.
