In the field of electrical engineering, relays play an indispensable role as an important control element.
Electromagnetic relays and solid-state relays are two common types of relays.
The relay information network will introduce the differences and comparisons of these two types of relays in detail.
Electromagnetic relay is an electronic control device, which is actually a kind of "automatic switch" that uses the on/off of low voltage and weak current circuits to control high voltage and strong current.
It plays the role of automatic adjustment, safety protection, conversion circuit and so on in the circuit. It is composed of an iron core, coil, armature, contact reed, etc., and is a relay with mechanical contacts.
A solid-state relay is a contactless switching element composed entirely of solid-state electronics.
It uses the electrical, magnetic and optical characteristics of electronic components to complete the isolation of input and output, and uses the switching characteristics of high-power transistors, power MOSFETs, unidirectional thyristors or bidirectional thyristors and other devices to achieve the purpose of turning on and disconnecting the controlled circuit without contact and spark. It is a static electronic switch with no mechanical contacts.
Although electromagnetic relays are widely used, in some special occasions, solid state relays have obvious advantages.
For example, in industrial control, solid state relays are more suitable for use in hazardous environments such as flammable and explosive because electromagnetic relays generate sparks during operation, which can cause hazards such as ** or fire.
In addition, in terms of electronic control and some special environments, there are many applications of solid state relays.
Reliability: The reliability of electromagnetic relays is high, and the self-locking and interlocking are more convenient, and they are suitable for complex control circuits. Solid state relays, on the other hand, have relatively low reliability, but fast switching speed and long life.
Control power: The control power of electromagnetic relay is large, and it is suitable for high-current circuits. Solid state relays, on the other hand, have less control power and are suitable for low-current circuits.
Stability: The stability of the solid state relay is good, and it is suitable for use in harsh environmental conditions such as mines, gas, and tunnels. The stability of electromagnetic relays is relatively poor, and the coil is easy to oxidize in a humid environment, and the contacts are frequently worn.
Safety: Electromagnetic relays are not suitable for use in hazardous environments such as flammable and explosive, because sparks will be generated during operation. Solid state relays, on the other hand, are more suitable for use in these environments.
Cost: The cost of electromagnetic relays is relatively low, but measures such as heat dissipation and thermal grease are required to maintain stable operation. Whereas, solid state relays are more costly, but have higher reliability and stability.
To sum up, electromagnetic relays and solid-state relays have their own characteristics and application scenarios. The selection needs to be evaluated and selected according to specific needs.
By understanding the differences and comparisons between these two types of relays, we can better understand their working principles and application ranges, so as to provide more accurate choices and references for our circuit design.
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