Difference between optical relay and ordinary relay

Structure and working principle
Optocoupler relay: The structure consists of photoelectric conversion devices, output relays, etc. When there is an electrical input in the input circuit, the driving photoelectric conversion device converts the electrical signal into an optical signal, and the output terminal then converts the optical signal into an electrical signal by another photoelectric conversion device, causing the output relay to work. Its input and output are isolated and non-contact
Ordinary relay: The structure consists of coils, iron cores, switch contacts, etc. When the coil is connected, the current in the coil generates an electromagnetic field, which attracts the iron core to move up and down, changes the state of the switch contacts, and achieves the switching of input and output through the contact of the physical switch.
Technical Parameter
Rated voltage: The rated voltage of optocoupler relays varies depending on the specific model; The rated voltage range of ordinary relays is relatively wide, usually ranging from 5V to 380V, and can adapt to various electrical environments
Contact type: Both types of contacts have forms such as single pole single throw, double pole double throw, etc. Ordinary relays can also choose normally open or normally closed contacts
Working frequency: The optocoupler relay has a fast response speed and can adapt to higher frequencies; The working frequency of ordinary relays is relatively low, usually below 1Hz, which is suitable for circuit control with low switching frequency requirements.
Power load capacity: The power load capacity of the optocoupler relay is relatively small; Ordinary relays have power load capacities ranging from several hundred watts to several thousand watts depending on their design, making them more widely applicable.
Packaging method
Optocoupler relay: Due to the use of optoelectronic coupling technology, the input and output parts use electronic devices, resulting in a smaller overall volume and lighter weight.
Ordinary relay: The packaging is relatively simple, usually using standard rectangular or square shells, which are more sturdy and durable, suitable for long-term use in the industrial field
advantages and disadvantages
Optocoupler relay:
Advantages: Isolation between input and output is achieved through optical signal transmission, without direct current or voltage connection, which can prevent interference in the input signal from being transmitted to the output terminal, enhancing the safety and stability of the circuit; No mechanical moving parts, no noise or vibration will be generated; Fast response speed of 23.
Disadvantages: Limited power load capacity, cost may be relatively high
Ordinary relay:
Advantages: Simple structure, high reliability, wide applicability, generally low production cost, suitable for large-scale production and application; Equipment with strong power load capacity and the ability to control large currents and voltages, suitable for complex industrial applications.
Disadvantages: relatively slow response speed; There will be certain noise and vibration during the suction and release process; Electromagnetic interference and contact wear caused by mechanical switching may occur during working conditions, affecting the lifespan and reliability.
Application scenarios
Optocoupler relay: commonly used in application scenarios that require electrical isolation, fast response, and low noise requirements, such as precision measuring instruments, communication equipment, etc
Ordinary relays: more commonly used in automated production lines, HVAC systems, as well as various general circuit switches and electrical control devices