What does holding current in an SCR refer to?

Holding current in an SCR (Silicon Controlled Rectifier) is defined as the minimum current that must flow through the device to keep it in the 'on' or conducting state after it has been triggered on. When the SCR is turned on, it enters a state where it can conduct current, but as the load current drops, it will eventually fall below this holding current level. If it drops below this threshold, the SCR will turn off.

Understanding holding current is crucial for designing circuits that utilize SCRs, especially in applications where power levels fluctuate. It ensures that once the SCR is activated, it remains in the conducting state until the current through it decreases below this specified minimum, at which point the SCR will naturally turn off. This concept is essential for reliable operation and ensures that the SCR functions correctly within its designed specifications.