Solid State Relays
Solid State Relay Definition
Solid state relays (SSRs), unlike mechanical relays, are defined to switch load by carrying signals in electronic circuits.
※These are also called non-contact relays and semiconductor relays.
Solid State Relay Features
Unlike contact relays, these relays do not have a mechanical drive unit, but are composed of electronic components such as semiconductors.
Unlike contact relays, these relays do not have a mechanical operating unit, but are composed of electronic components such as semiconductors.
As for features of Omron’s solid-state relays (SSRs), we have wide range of products, such as integrated with heat sink type, separate with heat sink type, and the same types with plug-in relay, that are compatible with the types of loads and the customer's use environment (installation method and space restrictions) .
Solid State Relay Types
|Types||Loading current||Points||Typical relays||Model|
|SSRs integrated with heat sinks||~ 150 A||The integrated heat sink enables a slim design. These relays are mainly installed in control panels.||G3PH, G3PA, G3PE, etc.|
|SSRs with separate heat sinks||~ 90 A||Separate installation of heat sinks allows the customers to select heat sinks to match the housings of the devices they use. These relays are mainly built into the devices.||G3NA, G3NB, etc.|
|SSRs of same shape with the relay||~ 5 A (10 A)||These relays have the same shape as plug-in relays and the same sockets can be used. They are usually built into control panels and used for I/O applications for programmable controllers and other devices.||G3F (D), G3H (D), G3R-I/O, G3RZ, etc.
*G9H hybrid-power relay
|PCB-mounted SSRs||~ 5 A||SSRs with terminal structure for mounting to PCBs.||G3MC, G3M, G3S, G3DZ, etc.|
Solid State Relay Diagram
- The input device (switch) is turned ON.
- Current flows to the input circuits, the photocoupler operates, and an electric signal is transferred to the trigger circuit in the output circuits.
- The switching element in the output circuit turns ON.
- When the switching element turns ON, load current flows and the lamp turns ON.
- The input device (switch) is turned OFF.
- When the photocoupler turns OFF, the trigger circuit in the output circuits turns OFF, which turns OFF the switching element.
- When the switching element turns OFF, the lamp turns OFF.
Solid State Relay Application Examples
Basic Structure （Case of temperature control)
The SSR receives voltage pulses (such as DC12V) from a temperature controller to turn on/off the load circuits.
To select a product, information of the input voltage and input current of SSR is required.