1. Definition of relay: a type of automatic control device that causes a jump-change in the output when the input quantity (electricity, magnetism, sound, light, heat) reaches a certain value.
1. The working principle and characteristics of relays:When the input quantity (such as voltage, current, temperature, etc.) reaches a specified value, it controls the output circuit to be turned on or off. Relays can be divided into two categories: electrical (such as current, voltage, frequency, power, etc.) relays and non-electrical (such as temperature, pressure, speed, etc.) relays.
They have the advantages of fast action, stable operation, long service life, and small size. They are widely used in power protection, automation, motion control, remote control, measurement, communication, and other devices.Relays are a type of electronic control device that has a control system (also known as an input circuit) and a controlled system (also known as an output circuit). They are usually applied in automatic control circuits.
They are actually a kind of “automatic switch” that uses a small current to control a larger current. Therefore, they play a role in automatic adjustment, safety protection, and circuit switching in the circuit.1. The working principle and characteristics of electromagnetic relays:Electromagnetic relays generally consist of iron cores, coils, armatures, and contact springs. As long as a certain voltage is applied to the two ends of the coil, a certain current will flow through the coil, generating an electromagnetic effect.
The armature will be attracted to the iron core by the electromagnetic force, overcoming the pull force of the return spring, and thus bringing the dynamic contact of the armature and the stationary contact (normally open contact) together. When the coil is de-energized, the electromagnetic force disappears, and the armature returns to its original position under the action of the return spring, making the dynamic contact and the original stationary contact (normally closed contact) together.
In this way, through the action of attraction and release, the circuit can be turned on and off. For the “normally open, normally closed” contacts of the relay, they can be distinguished in this way: the stationary contact in the disconnected state when the relay coil is not energized is called the ”normally open contact”
Post time: Jun-01-2023