Transportation VRS Thrumold Series
The Thrumold Series VRS (Variable Reluctance Speed) sensors are designed to detect engine timing and transmission speed by determining the speed and position of rotating shafts in heavy-duty, off-road, and construction vehicles, providing information to help improve engine combustion process efficiency. These passive VRS sensors are simple, rugged devices that do not require an external voltage source for operation. A permanent magnet in the sensor establishes a fixed magnetic field.
The approach and passing of a ferrous metal target near the sensor’s pole piece (sensing area) changes the flux of the magnetic field, dynamically changing its strength. This change in magnetic field strength induces a current into a coil winding which is attached to the output terminals.