Thyristor Power Controllers, also known as Power Regulators are devices that control the power delivery. They are designed to vary the AC voltage across resistive and inductive loads. The primary controlling device is a back to back connected Silicon Rectifier (SCR) or Thyristor. They are coupled with the triggering electronics from Libratherm which provide gate cathode triggering pulses proportional to the control signal. This controls the conduction angle of the thyristor which controls the average AC voltage across the load. Regulating the AC voltage controls the AC current drawn by the load and thereby controls the power delivered to the load.

The thyristor power controller can accurately and consistently control the process proportional to the control signal. They provide a smooth way of controlling the power delivered to the load. Unlike Contactors, thyristors don’t have any electromechanical movement which may cause arcing/sparking and carbon formation. They gradually deliver power to the load and prevent electrical surges, and transients, thereby enhancing the operational life of the load. Libratherm offers Thyristor Power Controllers ranging from 10A to 1000A load. Select models have a built-in current limit and current trip feature which safeguards against overload damages. They can be paired with Libratherm PID Controllers and Ramp Soak Controllers for precise temperature control for various applications.

Some of the applications where Libratherm Power Controllers are successfully implemented:

• Aluminium Melting Furnaces
• Holding Furnaces
• Air Handling Units
• Dehumidifiers
• Boilers
• Hot Air Generators and Hot Air Dryers
• Very high temperature furnaces built using Silicon Carbide/MoSi2 heating elements
• Microwave dryers
• Multi-zone Drying and Curing Ovens
• Heat Transfer Printing Machines
• Food grains/Paper and Printing drying ovens made using Quartz tube Medium wave IR and Ceramic coated IR heaters
• Pet bottles Pre Forms preheating tunnel ovens made using IR heaters
• Plastic Injection moulding requiring multi-zone heating for manifold moulds
• Plastic Pipes and Sheets extrusion
• Metal sheets welding systems