RELAY

Aviation relays are an electrical or electronic device (key) designed to close or open an electrical circuit in case of given changes in electrical or non-electrical input influences.

The main parts of the electromagnetic relay: electromagnet, armature and switch. An electromagnet is an electric wire wound on a yoke made of a ferromagnetic soft magnetic material. An anchor is usually a plate of magnetic material that acts on the contacts through pushers.

Aviation relays handle high output and low input. They also perform various logical operations, create multifunctional relay devices, fix deviations of a certain parameter, and are a memory device.

Relay classification:

Relays with:
- Normally closed contacts;
- Normally open contacts;
- Changeover contacts.

Relays are distinguished by the type of control signal:
- Direct current;
- Neutral relays: the polarity of the control signal does not matter, only the presence / absence of the signal is recorded. Example: relay type NMSh;
- Polarized relays: sensitive to the polarity of the control signal, switch when it is changed. Example: relay type KSh;
- Combined relays: react both to the presence / absence of a control signal and to its polarity. Example: relay type KMSh;
- Alternating current.

According to the permissible contact load.

By response time.

By type of execution:
- Electromechanical relays;
- Electromagnetic relays (the electromagnet winding is stationary relative to the core);
- Reed relays;
- Magnetoelectric relays (electromagnet winding with contacts is movable relative to the core);
- Thermal relay (bimetallic);
- Electrodynamic relays;
- Ferrodynamic relays;
- Induction relays;
- Static relays;
- Ferromagnetic relays;
- Ionic relays;
- Solid state relays.

Controlled value:
- Voltage relay;
- Current relay;
- Power relay;
- Pneumatic pressure switch;
- Insulation monitoring relay.

Special types of electromagnetic devices:
- Stepper finder.
- Residual current device.
- Circuit breaker.
- Time relay.
- Electromechanical counter.