Browse Prior Art Database

Motor Malfunction Detection

IP.com Disclosure Number: IPCOM000084570D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Buhler, OR: AUTHOR

Abstract

The device as shown schematically detects an open motor, light motor load or load terminal short to ground defect.

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Motor Malfunction Detection

The device as shown schematically detects an open motor, light motor load or load terminal short to ground defect.

The philosophy of detection is that if the output voltage exceeds a certain threshold, a corresponding current greater than some threshold value must be drawn by the load. Failure to detect or sense such a threshold current with an output voltage can be caused by either an open motor or a shorted current sense resistor.

The scheme incorporates a motor 12 which is driven by a power amplifier 10. Output voltage threshold detector 14 is positioned within the high-terminal side of motor 12. Likewise, a load current threshold detector 16 is positioned within the low-side terminal of motor 12.

In operation, if the magnitude of the output voltage exceeds a predetermined threshold level and the magnitude of the load current is less than a predetermined threshold, the AND circuit 18 is activated. The output from AND circuit 18 is delayed by delay circuit 20 and then latch 22 is set, thereby signifying a motor malfunction. Delay circuit 20 is incorporated in the device to avoid false triggering of latch 22 due to the electrical time constant.

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