What is a voltage relay, what is it used for, and what is its principle?

It is a relay that acts when the voltage in the circuit reaches a predetermined value. Its structure is basically the same as that of a current relay, except that the number of turns of the solenoid coil is large, and it must be connected in parallel with the power supply when used. It is widely used in loss of voltage (voltage to zero) and undervoltage (low voltage) protection.

The so-called loss of voltage and undervoltage protection means that when the power supply voltage drops too much or the power is temporarily cut off for some reason, the motor is automatically disconnected from the power supply; When the power supply voltage is restored, if the start button is not repressed, the motor cannot start by itself. If it is not controlled by relay, but directly controlled by the knife switch, because the switch is not pulled in time when the power failure occurs, when the power supply voltage is restored, the motor will start by itself, which may cause an accident. In addition, there is an overvoltage relay, which is a relay that cuts off the power supply due to the attraction of the electromagnet when the circuit voltage exceeds a certain value, and it is used for overvoltage protection (such as protecting silicon tubes and thyristor components).

Relays are mainly used in fuse circuits, what is its function? Today is a long time to see.

When the voltage in the circuit reaches the setting value, the contact of the relay will switch action, which is called a voltage relay. The impedance value of the electromagnetic coil is large, and the coil current is often only a few milliamperes. This relay is connected in parallel in the circuit.

When the current in the circuit reaches the setting value, the contact of the relay will switch action, which is called a current relay. The impedance value of its solenoid coil is very small, and the coil current often reaches 1-5 amperes. This relay is connected in series in the circuit.

Enter the area and get the decoration for free**].

The use of relays in our homes is still very important, which can give the most basic life guarantee for home life, but we should also pay attention to the use of relays to avoid unnecessary trouble. So what is the function and principle of the relay, and the correct use of the relay, do you understand? Now let's take a look.

1. What is the function and principle of the relay?

The function of the relay: it can increase the range of the whole circuit, and achieve the purpose of controlling the high-power circuit, so that it can operate automatically. The principle of relays:

When the input quantity is at a fixed value, the working state can be changed, and the working state can be changed to avoid accidents.

Second, the correct use of relays.

1. When using relays, they should be used according to the instructions as much as possible, and each parameter must be within the specified range, so as to ensure sufficient safety. In addition, the load and use time of the relay cannot be determined, after all, it will change according to the surrounding environment and load.

2. If you are going to use DC relays indoors, you need to use rectangular waves to perform the work. AC relays, on the other hand, are used indoors and require the use of sine waves to perform the work. If you want the relay to be used better, don't let the relay be impacted, otherwise it is very easy to cause damage to the internal components.

3. In the process of using the relay, it is necessary to ensure that the temperature of the surrounding environment is moderate, the humidity is also moderate, and the air cannot contain more harmful gases, otherwise it will affect the use of the relay. In the case of polarized relays, the voltage properties of the coil should be taken into account to ensure that they can be used properly.

As for the function and principle of relays, as well as the correct use of relays, I will introduce them here, do you understand them? The function of the relay is quite good, but before using it, you must know the relevant knowledge, so that there will be no trouble when using it.

Do the math how much it will cost you to renovate your home

The working principle of the relay is that when an input quantity (such as voltage, current, temperature, speed, pressure, etc.) reaches a predetermined value, it will be made to 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 relay mainly plays the role of transmitting signals.

The role of the relay:

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 specified form, the predetermined control effect is achieved after comparative synthesis.

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

It refers to the voltage required by the coil when the relay is working normally. Depending on the type of relay, DC voltage is generally used, but AC relays can be AC voltage.

There are three ways to connect the relay:

1. The two contacts are disconnected when the dynamic (normally open) (H-type) coil is not energized, and the two contacts are closed after the power is on.

2. The two contacts are closed when the dynamic breaking type (normally closed) (D type) coil is not energized, and the two contacts are disconnected after being energized.

3. Conversion type (Z type) This is the contact group type. This type of contact group has a total of three contact beam points, i.e. a moving contact in the middle and a static contact at the top and bottom. When the coil is not energized, the moving contact and one of the static contacts are disconnected and the other is closed, and after the coil is energized, the moving contact will move, so that the original disconnected will be closed, and the original closed will be disconnected, so as to achieve the purpose of conversion.

Such a set of contacts is called a conversion contact. I don't care.

When the relay is working, the electromagnet is energized, and the armature is sucked down to make D and E come into contact, and the working circuit is closed. When the electromagnet loses its magnetism when it is de-energized, the spring pulls the armature up and cuts off the working circuit. Therefore, the relay is a switch that uses an electromagnet to control the on/off of the working circuit.