Solid State Relays

Solid state relays, or SSRs, are electrical switching devices that serve the same purpose as electromechanical relays but without the moving parts, hence the name 'solid state'. By having no moving parts, SSRs tend to have a longer operational lifetime as they are not subjected to wear and tear.

Solid state relays can switch faster than their electromechanical counterparts. They use the electrical and optical properties of semiconductors to perform the switching functions. SSRs operate by using a small control signal to enable a larger load current or voltage. They come in various configurations to suit different requirements, such as minimum and maximum load voltages and currents. Common types include DC input voltage and AC input voltage, each tailored for specific load control needs.

Where Are Solid State Relays Used?

SSRs are used across a wide range of industrial settings, including industrial control, robotics, and medical equipment. Due to their highly diverse nature, SSRs are crucial in managing power delivery for applications requiring precision and reliability.

• Industrial Control Systems: SSRs are commonly used in automated manufacturing processes where precise control of high-power machinery is essential. For example, they regulate the operation of motors in conveyor belts and control heating elements in plastic injection moulding machines, ensuring consistent product quality.
• Robotic Systems: In robotics, SSRs are utilised to control the movement and operation of robotic arms used in assembly lines. Their fast switching capabilities allow for precise timing and movement, critical in high-speed automation and intricate assembly tasks.
• Medical Equipment: SSRs play a crucial role in various medical devices, such as imaging equipment and surgical tools. They help in managing the power supply meticulously, ensuring the safety and effectiveness of medical procedures.
• Lighting and Heating Systems: In both commercial and industrial settings, SSRs are used to control lighting and heating systems. For instance, they manage the lighting in large office buildings and control temperature in greenhouses, optimising conditions for plant growth.
• Data Acquisition Systems: SSRs are also essential in data acquisition systems where they help in the collection and transfer of data without interference, critical in sectors like meteorology and geophysical monitoring.

What Are the Advantages of an SSR?

The main advantages of SSR relay over conventional electromechanical relays include having no moving parts to wear out, thereby eliminating contact bounce issues. SSRs can switch both ON and OFF much faster than a mechanical relay’s armature can move. They also offer zero voltage turn-on and zero current turn-off, which helps to eliminate electrical noise and transients. For more information, please refer to our comprehensive guide to solid state relays.

Types of Solid State Relay Mount

Solid state relays are available with a variety of mounting solutions, each suited to different industrial and electrical systems. Here's a brief overview:

• Solid State Relay PCB Mounts: Designed for direct mounting to printed circuit boards (PCBs), ideal for integration into motherboards and various PCBs, either via push-in pin fittings or soldering.
• Solid State Relay DIN Rail Mounts: These are suitable for standard DIN rail setups, commonly used alongside other control equipment within PCL racks and enclosures.
• Solid State Relay Panel and Chassis Mounts: Commonly used for attachment to industrial panels, hatches, or heatsinks. Chassis-mount versions offer flexibility and are typically fixed through the SSR base or body with screws.
• Solid State Relay Heatsink Mounts: Allow for the attachment of a heatsink to provide cooling, crucial for high-power applications.
• Solid State Relay Plug-in Mounts: Emphasise quick and convenient plug-and-play functionality, typically used for direct PCB insertion.

Buying Solid State Relays: Ordering & Delivery Information for Australia

RS is dedicated to delivering your solid state relays swiftly and reliably across Australia. We stock a comprehensive range of SSRs from leading brands like Celduc, Sensata/Crydom, Omron, Phoenix Contact, and more. Whether you require DIN rail-mounted relays, power monitoring relays, or any other related products, our delivery services are designed to meet your needs. For detailed delivery information and services, please refer to our Delivery Information page.