What are the general functions of relays?

Relays are mainly embodied in:

1) Expand the control range: for example, when the control signal of the multi-contact relay reaches a certain value, it can be changed, interrupted and connected to multiple circuits at the same time according to the different forms of the contact group.

2) Amplification: For example, sensitive relays, intermediate relays, etc., can control very high-power circuits with a very small control quantity.

3) Comprehensive signal: For example, when a plurality of control signals are input into a multi-winding relay in the prescribed form, the predetermined control effect is achieved after comparative synthesis.

4) Automatic, remote control, monitoring: For example, the relay on the automatic device, together with other electrical appliances, can form a program control circuit, so as to achieve automatic operation.

Yuan Ze relay, at present, is mainly the production and research and development of this kind of relay!!

Relay is just a general term, generally commonly used relays are divided into time relays, speed relays, temperature relays, current relays, voltage relays and intermediate relays, etc., the role of each relay such as time relay is mainly to control the role of time, the role of speed relay is to monitor speed, temperature relay is to monitor temperature, current relay is to monitor current, voltage relay is to monitor voltage, and intermediate relay when contactors and other controller contacts are not enough to increase the role of contact.

Control electric shock. Relay (English name: relay) is an electrical control device, which is an electrical appliance that makes a predetermined step change of the controlled quantity in the electrical output circuit when the change of the input quantity (excitation quantity) reaches the specified requirements.

The relay has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop). Usually used in the control circuit of automation, it is actually a kind of "automatic switch" that uses a small current to control the operation of a large current. Therefore, it plays the role of automatic adjustment, safety protection, and conversion circuit in the circuit.

Relays generally have an induction mechanism (input part) that can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); There is an actuator (output part) that can realize "on" and "off" control of the controlled circuit; Between the input and output parts of the relay, there is also an intermediate mechanism (drive part) that couples and isolates the input quantity, processes the function, and drives the output part.

The life of the relay determines the life of the meter to some extent, and the performance of the device is very important to the operation of the smart prepaid energy meter. There are many domestic and foreign relay manufacturers, the production scale is quite different, the technical level is very different, and the performance parameters are very different, therefore, the electric energy meter manufacturers must have a complete set of detection devices when the relay is detected and selected, so as to ensure the quality of the electric meter.

According to the test requirements of relay performance parameters, the test items can be divided into two categories, one is the test items without load current, such as action value, contact contact resistance, and mechanical life; The second is the test items with load current, such as contact voltage, electrical life, and overload capacity.

A relay is a device that is 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 air conditioning control system, the relay is often used as the switch of the power circuit of the compressor, fan motor, water pump, four-way valve and so on. 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 electromagnetic force is generated by the potential difference between the two ends of the relay control coil and the current loop is generated through the output control signal of the control component. Under the action of electromagnetic force and the inherent elastic force of the relay reed, the relay contacts are 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 related equipment.

Relays are an umbrella term.

What he means is that with a small amount of power and current, a device (electric motor or electromagnet) is driven to drive a load component (such as a switch or contact piece) to carry a large current.

For example, our switches only need a 12V control relay, which can help us turn on and off UHV lines with millions of volts and currents of up to thousands or even tens of thousands of amperes.

No matter where you are, if you want to keep the controller or device from danger, it is best to use a relay, let us touch the safe side, let the relay touch the dangerous side, we just control the relay action, the relay will help us connect some lines that we don't want to touch in person.

Relays are an umbrella term.

It is also divided into contactors (relays that are specially used to control on-off and load a large current, but do not act quickly).

Intermediate relay (relatively fast, generally the small ones of the long see are like this).

Time relays (used to control time movements, such as street lights automatically turning on at night) and many, many more. You can get something new by combining a device and a relay, such as a time relay by combining a clock and a relay. Come from.

The current relay is BAI

The size or presence of the current DU is used to control the electric shock, but DAO is less used and is used in a special current sensing device;

Voltage relay is to use the small current in the electromagnetic coil to control the larger current of electric shock, used for small current control of large current or electrical isolation, voltage relay applications, horn relays on the car, electronic control unit fuel injection main relay, starting relay, oil pump relay, air conditioning relay, fan relay lamp are voltage relays, AC contactors for industrial control are also relays - but there are multiple sets of normally open and normally closed electric shock or stroke electric shock --- is also a voltage relay.

Sometimes relays can also be used to change the trigger polarity of the control end, and multiple relays can also be used to form logic circuits - but now digital chips are generally used, and relays can also be combined with capacitors to form monostable delay circuits and unsteady oscillation circuit lights.

It is equivalent to the function of circuit switch, and it is a component that controls large current with a small current.

The understanding of intermediate relay is the knowledge that every maintenance electrician must know, the intermediate relay can only be used in the secondary circuit, and its contacts can only pass through small currents, so it can only be used to increase the number of auxiliary contacts and the capacity of use.

The relay is an automatic switching element with isolation function, which is widely used in remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment, and is one of the most important control components.

Relays generally have an induction mechanism (input part) that can reflect certain input variables (such as current, voltage, power, impedance, frequency, temperature, pressure, speed, light, etc.); There is an actuator (output part) that can realize "on" and "off" control of the controlled circuit;

To put it simply, it is a controlled electrical switch, which is like a switch, such as rotating, toggling, self-locking, etc., with multiple contacts and single contacts.

The switch must be manually or electrically controlled, but it must be controlled at close range, and the relay is different, and the control of long-distance electrical appliances can be realized!

It can be used to control the on/off of high-voltage electricity from a long distance to prevent high-voltage electricity from harming the human body.

Control high voltage with low voltage.

The main role and working principle of thermal relays.

The role of the roader:

1.Normally, the no-load and load currents in the high-voltage circuit are switched on and off.

2.In the event of a system failure, it can cooperate with the protection device and automatic device to quickly cut off the fault current and prevent the accident from expanding, so as to ensure the safe operation of the system.

In fact, the circuit breaker is a kind of switch, and the difference between it and other ordinary switches is mainly in: 1The applicable voltage level is higher than 2Arc extinguishing medium and method, there are vacuum, less oil, more oil and sulfur hexafluoride and so on 3Strong arc extinguishing ability and good effect.

Under normal circumstances, there is no lubrication problem in the circuit breaker itself, and it is often its operating mechanism that needs to be lubricated.

Thermal Relay Role:

The function of the thermal relay is to automatically cut off the power supply when the motor is overloaded, and the structure of the thermal relay is composed of two metal sheets with different expansion coefficients, and when the current is too large, the expansion coefficient is large and expands first, which plays the role of cutting off the power supply. There are manual reset and automatic reset after the thermal relay action.

Fuse function:

When the circuit is faulty or abnormal, it is accompanied by the continuous increase of current, and the increased current may damage some important or valuable devices in the circuit, and may also burn the circuit or even cause a fire. If the fuse is correctly placed in the circuit, the fuse will fuse itself to cut off the current when the current rises abnormally to a certain height and a certain time, so as to protect the safe operation of the circuit.

If the circuit breaker is installed in the circuit, the fuse can not be used, and the thermal relay needs to be used in conjunction with the AC contactor, because the contact on the thermal relay is disconnected and cut off the control loop when overloaded, and the fuse is generally used for the control loop at present.

Protects circuits and controls large currents with small currents.

The main role and working principle of thermal relays.

The role of the relay in the electrical circuit is to play an automatic adjustment role in the circuit

Safety protection, conversion of electric circuit and other functions.

1. Relay (English name: relay) is an electrical control device, which is an electrical appliance that makes a predetermined step change of the controlled quantity in the electrical output circuit when the change of the input quantity (excitation quantity) reaches the specified requirements.

2. It has an interactive relationship between the control system (also known as the input loop) and the controlled system (also known as the output loop).

3. It is usually used in the control circuit of automation, and it is actually a kind of "automatic switch" that uses a small current to control the operation of a large current.

The principle of the relay is the switch, which plays the role of power-off and energization. There are many varieties, and the principle is the same. There is a difference in the specific role played in the circuit:

Overheat (current overload) protection, electric shock protection, circuit rectification, travel switch, start-up protection, etc.

1.Instead of 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.

3.Increase contact capacity.

We know that 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.

4.Convert the contact type.

In the industrial control circuit, it often happens that the control requirement needs to use the normally closed contact of the contactor to achieve the control purpose, but the normally closed contact of the contactor itself has been used up and the control task cannot be completed. At this time, an intermediate relay can be connected in parallel with the original contactor coil, and the normally closed contact of the intermediate relay can be used to control the corresponding components, and the contact type can be converted to achieve the required control purpose.

Relay 5Used as a switch.

In some control circuits, the on/off of some electrical components often use intermediate relays to control the opening and closing of their contacts, such as automatic degaussing circuits commonly found in color TVs or displays, and the triode controls the on/off of intermediate relays, so as to control the on/off of degaussing coils.

6.Conversion voltage.

7.Eliminate interference in the circuit.

In industrial control or computer control circuits, although there are various interference suppression measures, interference phenomena still exist to a greater or lesser extent.

Eagle relay solution.

A relay is a device that uses the effect of electric current to close or disconnect a circuit, and is used for automatic protection and automatic control. In most cases, a relay is an electromagnet whose armature can close or break one or more contact points. When an electric current passes through the windings of an electromagnet, the armature is attracted to the electromagnet and thus changes the state of the contact.

A relay is a device that uses the on/off of low-voltage and weak-current circuits to indirectly control high-voltage and high-current circuits. Electromagnetic relay is a kind of switch that uses an electromagnet to control the working circuit.

When the protected element of the power system fails, the relay protection device should be able to automatically, quickly and selectively remove the faulty component from the power system, so as to ensure that the fault-free part quickly recovers normal operation and prevents the faulty element from continuing to suffer damage. reduce the scope of power outages; By the early 90s, the development, production and application of integrated circuits and large-scale integrated circuit protection were in a dominant position, and the era of computer relay protection for intelligent information processing is currently being studied.