The InnovationQ application will be updated on Sunday, May 31st from 10am-noon ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

Current-Sampling Transformer Circuit

IP.com Disclosure Number: IPCOM000042843D
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04

Publishing Venue


Related People

Commander, RD Ramage, JG [+details]


A current-sampling transformer circuit is described for use with a bridge-driven motor. The transformer is pulsed at high frequency, gives high voltage isolation between a sensing circuit and the motor drive circuit, and senses both DC and AC motor current. A current source is pulsed into the primary of the transformer, and the secondary of the transformer is connected through a diode to a sensing resistor through which the motor current passes. Two applications of this circuit are described to prevent motor-switching transients affecting the accuracy of DC measurement or damaging the transformer: the first injects current into the primary and the second shorts the primary both during the off period of motor drive. Fig.