Finder intermediate relayIt is used in relay protection and automatic control system to increase the number and capacity of contacts and transmit intermediate signals in the control circuit. There are mainly two kinds of delay methods for finder intermediate relay, namely, power on delay and power off delay. The installation methods are mainly divided into fixed type, protruding type, embedded type and guide rail type. Generally, there is no main contact, because the overload capacity is relatively small. Therefore, it uses all auxiliary contacts, with a large number.
Finder intermediate relay is a relay, which is composed of fixed iron core, moving iron core, spring, moving contact, static contact, coil, wiring terminal and shell. When the coil is energized, the moving iron core moves and closes under the action of electromagnetic force, and the moving contact moves to separate the normally closed contact and close the normally open contact; When the coil is powered off, the moving iron core will bring the moving contact to reset under the action of the spring.
Finder intermediate relay often exists in industrial control circuit and current control circuit of household appliances. For different control circuits, the function of finder intermediate relay is different. Their common functions in the circuit are as follows.
Function 1: replace small contactor
The contact of finder intermediate relay has a certain load capacity. When the load capacity is relatively small, it can be used to replace small contactors, such as the control of electric rolling gate and some small household appliances. This can not only achieve the purpose of control, but also save space and make the control part of electrical appliances more refined.
Function 2: increase the number of contacts
In the circuit control system, adding a finder intermediate relay to the circuit will not only not change the control form, increase the number of contacts, but also facilitate maintenance.
Function 3: increase contact capacity
Although the contact capacity of finder intermediate relay is not very large, it also has a certain load capacity, and the current required for driving is very small. Finder intermediate relay can be used to expand the contact capacity. In the control circuit, the finder intermediate relay is used to control other loads in order to expand the control capacity.
Function 4: conversion contact type
In the industrial control circuit, a finder intermediate relay can be connected in parallel on the coil of the original contactor, and the normally closed contact of the finder intermediate relay is used to control the corresponding components. By changing the contact type, the normally closed contact of the contactor can be used to achieve the control purpose.
Function 5: as a switch
In some control circuits, the on-off of some electrical components is often controlled by the opening and closing of their contacts. For example, in the automatic degaussing circuit commonly used in color TV sets or displays, the triode controls the on-off of the finder intermediate relay, so as to control the on-off function of the degaussing coil.
Function 6: switching voltage
In the industrial control circuit, the voltage in the control circuit is DC24V, while the coil voltage of the solenoid valve is AC220V. Installing a finder intermediate relay can separate DC and AC, high voltage and low voltage, which is convenient for future maintenance and safe use.
Function 7: remove interference in the circuit
In industrial control or computer control circuits, although there are various interference suppression measures, the interference phenomenon still exists more or less. Adding a finder intermediate relay inside can achieve the purpose of removing interference.