Railway vehicle wheel detector utilizing magnetic differential bridge
AssigneeUnion Switch & Signal Inc.
InventorHeinz Gilcher
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Abstract
A differential magnetic wheel detector is disclosed which identifies the presence and direction of a railway vehicle. The wheel detector includes a primary winding, a secondary winding and signal processing circuitry. The primary winding is excited by a source of AC energy to produce a magnetic flux in the wheel of the railway vehicle. The secondary winding senses a change in voltage induced by the magnetic flux in the railway wheel. The secondary winding includes two coils in a differential bridge which prevents external factors from interfering with the sensing of the wheel. The signal processing device transforms the voltage change into a signal identifying the presence and direction of the railway vehicle.
Claims16
A railway vehicle detector device for sensing a passing railway vehicle wheel traveling along an elongated rail, said device comprising:
- (a) means for supplying alternating current energy having a preselected frequency;
- (b) primary winding means excitable by said alternating current energy for producing a time-varying magnetic transmission flux;
- (c) secondary winding means including first and second receiver coils arranged in a differential bridge configuration for producing a differential voltage change as said wheel is traveling adjacent said detector due to a magnetic coupling with said primary winding means;
- and
- (d) processing means for receiving said differential voltage change and responsively producing an output signal indicative of the presence and direction of movement of said wheel.
Dependencies are inferred from the claim text.