To control various often very powerful circuits and mechanisms using low-current electrical signals or other factors of influence (heat, light, mechanics), special devices are used. They are different in power and design, but their meaning is one thing - to turn on or off the electric circuit when a control signal is received. The 220V relay also serves to protect the network.
What is an electrical relay
In an electrical relay, one electrical signal controls another electrical signal. In this case, there is no place for changing the parameters of the latter, but only its switching. The signals can be completely different in form, shape and power, but one thing is important - as soon as the current begins to flow in the control circuit, the switching circuit is activated, connecting or disconnecting the load. When the control current disappears, the system returns to its original state.
An electric relay is a kind of amplifier if, for example, a weak signal commutes a strong one, and at the same time they are similar in form and type of voltage. You can also consider such a device as a converter, if the signals differ from each other in the form of voltage.
Operating principle
You can clearly see the effect of the relay on the example of electromagnetic. Such a mechanism contains a winding with a steel core and a group of contacts that move movably, closing and breaking the circuit. A control current is supplied to the core coil. This current, according to the law of electromagnetic induction, creates a magnetic field in the core, which attracts a contact group, and it closes or opens an electric circuit, depending on the type of relay.
Types of Relays
The described devices are classified according to several parameters. For example, based on the type of voltage, an AC or DC relay is isolated. Structurally, such devices differ from each other only in the type of core, and more precisely, in their material. Permanent relays are characterized by a core made of electrical steel, and they are of two types:
- Neutral
- Polarized.
The former differ from the latter in that they can function in any direction of the current passing through the relay.
If we consider the kind of control signal and the corresponding design of the device, then the latter are divided into:
- Electromagnetic, which contains an electric magnet that switches contacts.
- Solid state. The switching circuit is assembled on thyristors.
- Thermostats based on thermostat.
- Delay relay 220V.
- Optical, where the control signal is the luminous flux.
Voltage monitoring relay
To control electrical networks, or rather voltage parameters, 220V relays are developed. They are designed to protect household electrical appliances from sudden surges. The basis of such devices is a special quick response microcontroller. It monitors the voltage level in the network. If for any reason there are voltage deviations up or down from the permissible limit, then a control signal is sent to the device, which disconnects the network from consumers.
The response threshold of the 220V relay is in the range of 170-250 volts. This is a generally accepted standard. And when the network is disconnected, the voltage level control in it continues. When the voltage returns to within acceptable limits, a time delay system is triggered, after which power is again supplied to the devices.
Such devices are usually installed at the input of the circuit after the meter and the circuit breaker. The power of the device must be with a margin to withstand surges when the load circuit breaks.
Time delay relay 220V
A device whose purpose of functioning is to create conditions where the devices of an electric circuit operate in a certain sequence mode is called a time relay. For example, if you need to create a load on mode not instantly upon the arrival of a control signal, but after a set period, use a certain system. The following types of equipment are distinguished:
- Time relay 220V electronic type. They can provide temporary exposure within fractions of a second and up to several thousand hours. They can be programmed. The energy consumption of such devices is negligible, and the dimensions are small.
- With a deceleration time on an electromagnet for DC power circuits. The circuit is based on two electromagnetic coils in which magnetic fluxes simultaneously occur, directed in the opposite direction and thus weaken each other for the duration of the operation delay.
- Devices where the response time is slowed down by a pneumatic process. Exposure can be between 0.40-180.00 seconds. The pneumatic damper is delayed by adjusting the air intake.
- Devices on the anchor mechanism or clockwork.
Intermediate relay 220V
Such a device is considered an auxiliary device and is used in various automatic circuits, as well as in control. The purpose of the intermediate relay is the disconnect function in the contact circuits of individual groups. It can also simultaneously turn on one circuit and turn off the other.
The switching circuits of the 220V intermediate relay are of two types:
- By the principle of a shunt. In this case, all the supply voltage is supplied to the relay coil.
- By serial type. Here, the winding of the mechanism with the coil of the switch is connected in series.
In the relay circuit, depending on its design, up to three windings on the coils may be present.