Varian MLC HD Secondary Feedback PCB part 100025100-04 REV. C For Sale

The Varian HD120 Secondary response Assembly is a specialized Printed Circuit Board (PCB) and hardware component used in the Varian TrueBeam STx and Edge radiotherapy linear accelerators. It functions as a critical safety and monitoring layer for the high-definition Multi-Leaf Collimator (HD120 MLC) system.System Function & PurposeVarian’s MLC systems use dual-validation technology to verify exact mechanical positioning before and during radiation delivery:Primary response: The system drives and tracks leaves using individual motors and primary encoders.Secondary response: The secondary response assembly reads position data independently (often via an optical camera/reflector system or secondary mechanical sensors) to verify the leaves are positioned exactly where the treatment planning system demands.Interlock Prevention: If a mismatch occurs between the primary drive command and the secondary response reading, the board triggers a beam interlock (such as an MLC or HW fault) to avoid misadministrations.