Simple understanding - the principles and characteristics of various relays:

Electromagnetic relay: An electronic control device that has a control system (also known as an input loop) and a controlled system (also known as an output loop) and is usually used in automatic control circuits. It actually uses a small current. Lower voltage to control larger current. An automatic switch with higher voltage. Therefore, it plays the role of automatic regulation, safety protection and conversion circuit in the circuit. The thermal sensitive reed relay is a new type of thermal switch which uses thermal sensitive magnetic material to detect and control the temperature. Thermosensitive dry spring relay is composed of inductive magnetic ring, constant magnetic ring, dry reed tube, heat conduction mounting sheet, plastic substrate and other accessories. The thermo sensitive reed relay does not need coil excitation, but the magnetic drive switch generated by the constant magnetic ring acts. Whether the constant magnetic ring can provide magnetic force to the reed pipe is determined by the temperature control characteristic of the temperature sensitive magnetic ring.

Solid State Relay (SSR) is a contactless switch composed of microelectronic circuits, discrete electronic devices and power electronic power devices. The isolation between the control end and the load side is realized by isolation devices. The input of solid state relay is controlled by tiny control signal to directly drive large current load.

GL88S electronic overload relay

Principle characteristics:

1, the working principle and characteristics of electromagnetic relay (Electromagnetic relay)

Electromagnetic relay is generally composed of electromagnet, armature, spring, contact and so on. Its working circuit consists of low-voltage control circuit and high-voltage working circuit. Electromagnetic relay can also realize remote control and automatic control. As long as a certain voltage is applied at both ends of the coil, a certain current will flow through the coil, which will produce electromagnetic effect. The armature will overcome the pulling force of the return spring to the core under the action of electromagnetic attraction, thus driving the armature's dynamic contact and static contact (usually open contact) to engage. When the coil is cut off, the electromagnetic attraction disappears, and the armature returns to its original position in the spring reaction force, releasing the moving contact and the original static contact (normally closed contact). In this way, it can be absorbed and released so as to achieve the purpose of conducting and cutting in the circuit. For the "normally open and normally closed" contacts of relays, it can be distinguished as follows: static contacts in the state of disconnection when the relay coil is not energized are called "normally open contacts"; static contacts in the state of switching on are called "normally closed contacts". [1]

2, the working principle and characteristics of Thermal reed relay.

The thermo sensitive reed relay is a new type of thermal switch which uses thermal sensitive magnetic material to detect and control the temperature. It consists of a temperature-sensitive magnetic ring, a constant magnetic ring, a dry reed tube, a heat conductive mounting sheet, a plastic substrate and other accessories. The thermo sensitive reed relay does not need coil excitation, but the magnetic drive switch generated by the constant magnetic ring acts. Whether the constant magnetic ring can provide magnetic force to the reed pipe is determined by the temperature control characteristic of the temperature sensitive magnetic ring.

3, the working principle and characteristics of SSR:Solid-state relay.

Solid-state relay is a kind of four-terminal device with two terminals as input and two terminals as output. In the middle, isolation devices are used to isolate the input and output. Solid state relay

Solid state relay can be divided into AC and DC type according to the type of load power. According to switch type, it can be divided into normally open and normally closed type. According to the isolation type can be divided into mixed type, transformer isolation type and photoelectric isolation type, photoelectric isolation type is the most.

Solid-state relay is a branch of relay products. Semiconductor devices are used instead of traditional coils. It does not need to rely on the movement of mechanical parts to control the switch opening and closing. It effectively improves the reliability and service life. As the coil is no longer used, so it will not encounter electromagnetic interference and contact "spark" and other issues, in terms of safety has also been greatly improved. Solid state relay has smaller power and is more suitable for high-grade products, which is in line with national energy conservation and environmental protection requirements.

Simple understanding - the principles and characteristics of various relays: