Engineering
Crow Bar
The hard crowbar assembly has three main circuit components. A bod-firing panel which measures the high voltage input and generates a thyristor firing pulse if the voltage exceeds a present threshold. A current detector assembly which detects the current through the thyristor and if a current is detected above 100A switches 2 110V relay contacts. A thyristor assembly which when fired shorts the anode and cathode to discharge the filter capacitors.
The crowbar and thyristor firing panel are designed to detect the voltage across a thyristor and fire the crowbar to protect the thyristor if the voltage exceeds a preset threshold . The thyristor firing panel provides electronically controlled firing of the thyristor allowing safe working on the supply .
The signal interface panel provides a 1500V dc isolation interface between the electronic control system and the electrical control equipment (relays ,solenoids , motors) . It processes analogue , and digital signals . The panel is manufactured using the latest surface mount technology.
