Patent ID: 8587246
Filing Date: 2013-11-19
Classification: F02D,G01R,H02P,Y02T

Abstract:
1. A system for estimating electric current flowing in a motor control circuit in the event of an error condition, comprising: an error condition detection circuit coupled to the motor control circuit that reports an error condition when actual motor operation deviates from a predetermined desired motor operation; a data storage register storing an overcurrent threshold data value indicative of a motor overcurrent threshold, the data storage register being initialized to a value corresponding to a predetermined upper current limit; an overcurrent threshold comparator coupled to the motor control circuit that senses motor current, reads the threshold data value, compares the motor current with the threshold data value, and sets an overcurrent flag when the motor current exceeds the motor overcurrent threshold; and a current interrogation processor coupled to monitor the reported error condition and the overcurrent flag and programmed to operate in response to the reported error condition to iteratively read the overcurrent flag and decrement the overcurrent threshold data value by a predetermined decrement amount until the overcurrent flag becomes set by the overcurrent threshold comparator, the current interrogation processor being further programmed to report the overcurrent threshold data value extant at the time the overcurrent flag becomes set as an estimate of electric current flowing in the event of an error condition.