What is a solid state relay?

What is a Solid State Relay?

A solid state relay (SSR) is an electronic switching device that allows the control of high-power signals using low-power signals, without the moving parts found in traditional mechanical relays. SSRs are designed to be highly reliable and durable, making them ideal for demanding applications. At Delcon, we specialise in the design and manufacturing of solid state interface relays that are known for their longevity and ability to handle high-voltage equipment and inductive loads without performance degradation.

How does a Solid State Relay Work?

A solid state relay operates by using electronic components to switch on or off the circuit. This is achieved through semiconductor devices like thyristors, triacs, or transistors, which control the load current. When a control voltage is applied to the input terminals of an SSR, it triggers the semiconductor switching elements to conduct electricity, allowing current to flow through the load. Once the control signal is removed, the relay returns to its non-conducting state.

Unlike mechanical relays, solid state relays do not have moving parts. This absence of mechanical components results in faster operation, reduced wear and tear, and a longer lifespan. For instance, Delcon relays have a mean time to failure (MTTF) of over 15 years, ensuring that they last as long as your automation system, eliminating the need for frequent replacements.

Advantages of Using Solid State Relays

Solid state relays offer a plethora of advantages over their mechanical counterparts, making them the preferred choice for various industrial applications. Here are some key benefits:

• Longevity: With no moving parts, SSRs provide a longer operational life, as seen in Delcon relays which often exceed 15 years in lifespan.
• Reliability and Durability: SSRs are less prone to failures caused by mechanical wear, ensuring continuous operation without interruptions.
• Noise-Free Operation: The absence of mechanical contacts means that SSRs operate silently, which is beneficial in noise-sensitive environments.
• Fast Switching: SSRs can switch on and off much faster than mechanical relays, improving the efficiency of systems that require rapid switching.
• Resistance to Shock and Vibration: Without moving parts, SSRs are more resistant to physical shocks and vibrations, making them suitable for harsh industrial environments.
• High-Voltage and Inductive Load Handling: SSRs like Delcon relays can manage high voltage and inductive loads without degradation, ensuring consistent performance.

Applications of Solid State Relays

Solid state relays are versatile and are utilised in a wide range of applications across various industries. Their reliability and performance make them ideal for challenging environments. Here are some common applications:

• Industrial Automation: SSRs are used in controlling motors, heaters, and other industrial equipment, providing precise and reliable switching.
• Railway Systems: Given their robustness and ability to handle high-load conditions, SSRs are extensively used in railway signalling and control systems.
• HVAC Systems: In heating, ventilation, and air conditioning systems, SSRs ensure efficient and silent operation.
• Lighting Controls: SSRs are used in dimming and lighting control systems due to their fast and silent switching capabilities.
• Telecommunications: SSRs provide reliable switching in telecommunication networks, where continuous operation is critical.

Delcon relays stand out for their ability to meet the specific needs of these applications, offering durability and performance that align with the demands of these sectors.

Comparing Solid State Relays and Mechanical Relays

While both solid state relays and mechanical relays serve the purpose of controlling circuits, they differ significantly in functionality and performance. Here's a comparison:

• Operation: Mechanical relays use a coil to create a magnetic field that moves contacts to open or close a circuit, while SSRs use semiconductor components with no moving parts.
• Switching Speed: SSRs can switch much faster than mechanical relays, which is crucial for applications requiring rapid response times.
• Durability: Mechanical relays suffer from wear and tear due to moving parts, whereas SSRs offer longer service life and reliability.
• Maintenance: SSRs require less maintenance due to their solid-state nature, resulting in reduced downtime and operational costs.
• Cost: Although SSRs might have a higher initial cost, their longer lifespan and lower maintenance needs make them more economical in the long run.

At Delcon, we are committed to providing high-quality solid state relays that ensure superior performance and reliability, making them a cost-effective choice over traditional mechanical relays. With our solid state relays, you gain the advantage of reduced maintenance costs and improved system efficiency, making them an integral component of modern industrial automation systems.

Explore Delcon’s range of solid state relays and discover how our solutions can optimize your industrial systems. Contact us today for expert guidance tailored to your needs.