How voltage relays work
How voltage relays work
The electromagnetic relay is generally composed of an iron core, a coil, an armature, and a contact spring. Just apply a certain voltage across the coil, a certain current will flow in the coil, which will produce an electromagnetic effect, and the armature will restrain the tension of the return spring to be attracted to the core by the electromagnetic force absorption, thereby driving the armature. The moving contact and the static contact (normally open contact) are attracted.
When the coil is de-energized, the electromagnetic suction force also disappears, and the armature will return to the original position under the reaction force of the spring, so that the moving contact will attract the original static contact (normally closed contact).
This attracts and releases, thus achieving the purpose of conducting and cutting in the circuit. Regarding the "normally open, normally closed" contact of the relay, it can be distinguished as follows: The static contact that is in the open state when the relay coil is not energized is called the "normally open contact"; the static contact in the on state is called It is "normally closed contact".
A voltage relay is an electronic control device. It has a control system (also known as an input circuit) and a controlled system (also known as an output circuit). It is usually used in automatic control circuits. In practice, it uses less current to control A type of "automatic switch" for high current.
Therefore, it plays the role of automatic conditioning, safe maintenance, and switching circuits in the circuit. It is mainly used in the relay maintenance installation of generators, transformers and transmission lines, as a starting element for over-voltage maintenance or low-voltage blocking.
Low voltage relay is a kind of automatic control electrical appliances that act according to specific input signals. There are many types of low voltage relays, including intermediate relays, thermal relays, time relays and other types.
As a control element, in summary, the relay has the following functions:
1. Extended control range: For example, when a multi-contact relay control signal reaches a certain value, it can simultaneously switch, disconnect, and connect multiple circuits in different ways of the contact group.
2. Amplification: For example, flexible relays, intermediate relays, etc., can control very large power circuits with a very small amount of control.
3. Comprehensive signal: For example, when multiple control signals are input to a multi-winding relay in a regular way, the analog signal is compared to achieve a predetermined control effect.
4, automatic, remote control, monitoring: For example, the relays installed automatically can form program control lines together with other electrical appliances, thereby completing the automatic operation