Overview Of The Difference Between Optocoupler Relays And Ordinary Relays

Both optocoupler relays and ordinary relays are electrical sensor elements that can convert electrical energy into mechanical energy and realize various switch controls and protection controls. However, the biggest difference between optocoupler relays and ordinary relays is that the input circuit and the output circuit are connected through photoelectric conversion devices instead of physical contact. This article will explain the difference between optocoupler relays and ordinary relays from the aspects of structure, working principle and scope of application.

Structure and working principle of optocoupler relays:

The structure of optocoupler relays consists of photoelectric conversion devices, output relays, etc. When an electrical signal is input to the input circuit, it drives the photoelectric conversion device to convert the electrical signal into an optical signal, and then another photoelectric conversion device converts the optical signal into an electrical signal at the output end to make the output relay work. Therefore, the input and output of the optocoupler relay are isolated and contactless.

Structure and working principle of ordinary relays:

The structure of ordinary relays consists of coils, iron cores, switch contacts, etc. When the coil is turned on, the current in the coil will generate an electromagnetic field, causing the iron core to attract and move up and down, thereby changing the state of the switch contacts and realizing the switching of input and output. Therefore, the input and output of ordinary relays are transmitted through the contact of physical switches.

Features of optocoupler relays:

Strong isolation

The input and output circuits of optocoupler relays are photoelectrically coupled, without physical contact, which can effectively isolate external interference and ensure the stability and reliability of electrical control.

Strong anti-interference ability

The input part of the optocoupler relay adopts photoelectric isolation, which avoids problems such as interference caused by grounding and reverse coupling of interference source voltage, and can effectively resist strong electromagnetic interference.

Long life

The optocoupler relay has no physical contact, avoids problems such as contact burnout, and has a longer service life.

Small size and light weight

The optocoupler relay adopts photoelectric coupling technology to isolate the input circuit and the output circuit, and the input and output parts use semiconductor devices, which makes the entire device smaller and lighter.

Features of ordinary relays:

The input and output are based on physics and are relatively simple and easy to use.

When the relay is in working state, problems such as electromagnetic wave interference and contact wear caused by mechanical switching may occur, affecting the life and reliability.

Most ordinary relays have relatively low sensitivity and low response speed, and have a narrow range of application. It is difficult to accept higher frequencies and more complex control systems.

In general, although both optocoupler relays and ordinary relays can complete electrical control functions, their working principles, characteristics and applicable scopes are quite different. In actual electrical control applications, it is necessary to comprehensively consider and select appropriate relays based on specific control requirements and environmental conditions.