What are the general occasions in which intermediate relays are used?

Intermediate relaysThere are two types of power sources used in solenoid coils: DC and AC. in relay protection with automatic control system.

, which is used to expand the number of control contacts and increase the capacity of contacts. In the control circuit, it is used to transmit signals (transmit signals to several control elements at the same time) and control multiple lines at the same time. Specifically, intermediate relays are used in the following ways.

When selecting intermediate relays, the main consideration is the rated voltage of the contacts.

and current should be equal to or greater than the voltage and current of the connected circuit, the type and number of contacts should meet the requirements of the circuit, and the winding voltage should be the same as the voltage of the connected circuit.

Structure. An intermediate relay is essentially a voltage relay, but it has a larger number of contacts and a smaller capacity, and it is an electrical appliance used as a control switch.

The structure and principle of the intermediate relay with the AC contactor.

It is basically the same, and the main difference with the contactor is that the main contact of the contactor can pass through a large current; The number of contact groups of intermediate relays is large, and there is no main and auxiliary division, and the current allowed to pass through each group of contacts is the same, and its rated current.

About 5a. Intermediate relays are typically used to transmit signals and control multiple circuits simultaneously, but they can also be used to directly control small volume motors or other electrical actuators. The structure and working principle of the intermediate relay are basically the same as those of the AC contactor, and the main difference with the AC contactor is that the number of contacts is larger, and the contact capacity is smaller.

When selecting intermediate relays, the voltage level is mainly considered.

and the number of contacts.

When the number of contacts of the control circuit does not meet the requirements of the control circuit, the corresponding intermediate relay can be selected to meet the requirements of the control circuit.

The working principle and function of the intermediate relay are as follows:

The coil is energized, and the moving iron core moves and engages under the action of electromagnetic force, driving the action of the moving contact, so that the normally closed contact is separated and the normally open contact is closed; The coil is de-energized, the moving iron core drives the moving contact to reset under the action of the spring, and the working principle of the relay is that when a certain input quantity (such as voltage, current, temperature, speed, pressure, etc.) reaches a predetermined value, it will act to change the working state of the control circuit, so as to achieve the established purpose of control or protection.

In this process, the intermediate relay mainly plays the role of transmitting signals.

The intermediate relay is a relay, and its principle is the same as that of the AC contactor, which is composed of a fixed iron core, a moving iron core, a spring, a moving contact, a static contact, a coil, a terminal block and a shell. The coil is energized, and the moving iron core moves and engages under the action of electromagnetic force, driving the action of the moving contact, so that the normally closed contact is separated and the normally open contact is closed; The coil is de-energized, and the moving iron core drives the moving contact to reset under the action of the spring.

The working role of the intermediate relay:

In the industrial control circuit and the current household appliance control circuit, there are often intermediate relays, for different control circuits, the role of intermediate relays is different, and the role of the first road is common as follows

1. Replace small contactors.

The contacts of the intermediate relay have a certain load capacity, and when the load capacity is relatively small, it can be used to replace the use of small contactors, such as electric roller shutters and the control of some small household appliances. The advantage of this is that it can not only play the purpose of control, but also save space, so that the control part of the electrical appliance is more exquisite.

2. Increase the number of contacts.

This is the most common use of intermediate relays, for example, when the contact of a contactor in a circuit control system needs to control multiple contactors or other components, an intermediate relay is added to the circuit.

3. Increase contact capacity.

Although the contact capacity of the intermediate relay is not very large, it also has a certain load capacity, and the current required for its drive is very small, so the contact capacity can be expanded with the intermediate relay. For example, it is generally not possible to directly use the output of inductive switches and transistors to control electrical components with relatively large loads. Instead, an intermediate relay is used in the control line to control other loads through the intermediate relay to achieve the purpose of expanding the control capacity.

The intermediate relay transmits the intermediate signal in the control circuit, and is a multi-purpose automatic telecontrol appliance in the relay protection and automatic control system. There is good electrical isolation, so that the controller and the controlled party have no electrical connection, and achieve the purpose of safe control.

The structure of an intermediate relay.

1. The coil is installed"u"On the shaped magnet, there is a movable armature on the magnet, and two rows of contact shrapnel are mounted on both sides of the magnet. In the non-operating state, the contact shrapnel lifts the armature upwards to maintain a certain gap between the armature and the conductor.

When the electromagnetic torque between the air gaps exceeds the reaction torque, the armature is attracted to the guide magnet, and at the same time, the armature presses the contact shrapnel, so that the normally closed contact is disconnected and the normally open contact is closed, and the relay work is completed. When the electromagnetic torque is reduced to a certain value, the contact and armature will return to the initial position due to the reaction torque of the contact shrapnel, and prepare for the next work.

2. This relay"u"The shape of the conductor adopts a double-core structure, that is, coils can be installed on both side posts. For DZY, DZL and DZJ types, only one coil is installed, while for DZB, DZS, DZK types, it can be installed on another core to maintain the coil or delay damping sheet, etc. As a result, relays with very different coil types all share a single conductor.

3. The principle of intermediate relay is the same as that of AC contactor, which is composed of fixed iron core, moving iron core, spring, moving contact, static contact, coil, terminal and shell.

The intermediate relay plays the role of signal amplification and control in the circuit. Due to reliability, contact life, etc., there may be some problems with the direct control power supply of some circuits, so intermediate relays are needed to achieve control. Intermediate relays can amplify the signal and improve the responsive beam capability of the control circuit.

At the same time, the intermediate relay can convert the control signal into a signal that can control the high-current device, so that the control of the high-power load device can be realized. Therefore, the role of intermediate relays in the circuit is very important, and they are widely used in high and low voltage electrical automation systems, robots, intelligent buildings, automatic control instruments, CNC machine tools, Chunkuan aerospace and other fields.

1. At the electrocution position of the intermediate relay, it has the function of carrying load. If the load capacity required by electrical appliances is small, you can use small contactors instead, such as small household appliances and electric roller shutters. In this case, the small contactor not only provides better control, but also saves more space.

2. The intermediate relay can not only be used to connect the components, but also be connected to other intermediate relays, so that the number of connection points can become more and more troubles can be solved in life. In addition, the capacity of the relay can be expanded by connecting another intermediate relay to ensure proper use.

3. In many control circuits, intermediate relays will be used to achieve the on-off and disconnection of electrical appliances, such as indoor use of color TVs, and its triode can well control the intermediate relays, so as to control the on-on and disconnection of the internal degaussing coil. In addition, the intermediate relay can also effectively shield some interference and ensure normal work.

A relay is a device that is often used as a switch in a circuit. According to the type of control voltage required by its coil, it can be divided into AC relay and DC relay. The specifications of the relay are expressed by the coil control voltage and the contact current, and the load current is usually less than 10A, and the circuit can be directly turned on or off with the contact of the relay.

If the load current is too high, it can be used as an indirect control device.

In the first-class air conditioning control system, the relay is often used as the switch of the power supply circuit such as the pressure neutralization and shrinking machine, the fan motor, the water pump, and the four-way valve. When in use, one end of the relay control coil is connected with the power supply, and the other end is connected with the output end of the control unit, and the potential difference between the two ends of the relay control coil is generated through the output control signal of the control component, and the electromagnetic force is generated by the current circuit lifting slag. Under the action of electromagnetic force and the inherent elastic force of the relay reed, the relay contact is engaged or released, so as to turn on or off the circuit of the electrical load power supply to control the operation or stop of the relevant barrier equipment.