Invention Grant
- Patent Title: Sensing motor current
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Application No.: US17663624Application Date: 2022-05-16
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Publication No.: US11747368B2Publication Date: 2023-09-05
- Inventor: Paul Christopher Roberts , Edward John Mottram
- Applicant: CMR SURGICAL LIMITED
- Applicant Address: GB Cambridge
- Assignee: CMR SURGICAL LIMITED
- Current Assignee: CMR SURGICAL LIMITED
- Current Assignee Address: GB Cambridge
- Agency: Lando & Anastasi, LLP
- Priority: GB 20524 2016.12.02
- Main IPC: G01R15/20
- IPC: G01R15/20 ; H02P6/28 ; G01R19/32 ; G01R33/00 ; G01R35/00

Abstract:
A circuit for sensing the driving current of a motor, the circuit comprising: a driver configured to generate a driving current for each phase of a multiple-phase motor, the instantaneous sum of all the driving currents being zero; a current sensor for each phase of the multiple-phase motor, each current sensor configured to measure the driving current of that phase and comprising a plurality of current sensor elements arranged with respect to each other such that each current sensor element has the same magnitude of driving current systematic error due to magnetic fields external to the driving current to be measured; and a controller configured to, for each phase of the multiple-phase motor, generate an estimate of the driving current of that phase to be the measured driving current of that phase minus 1/n of the total of the measured driving currents for all phases, n being the number of phases of the multiple-phase motor.
Public/Granted literature
- US20220276284A1 SENSING MOTOR CURRENT Public/Granted day:2022-09-01
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