Invention Grant
- Patent Title: Short circuit protection for a BLDC motor
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Application No.: US17694249Application Date: 2022-03-14
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Publication No.: US11929698B2Publication Date: 2024-03-12
- Inventor: Michael T. Rajzer , Jason Genz
- Applicant: Snap-on Incorporated
- Applicant Address: US WI Kenosha
- Assignee: Snap-on Incorporated
- Current Assignee: Snap-on Incorporated
- Current Assignee Address: US WI Kenosha
- Agency: Seyfarth Shaw LLP
- Main IPC: G01R31/34
- IPC: G01R31/34 ; B25B21/00 ; H02K7/14 ; H02P29/024

Abstract:
The present invention relates to switching element protection of a BLDC motor, such as used with a power tool. The present invention checks each switching element of a power stage individually for a short circuit when a trigger of the tool is actuated. Each switching element is turned ON for a period of time (such as 1-5 microseconds, for example), current flowing through the half-bridge or the full power stage is measured, and that switching element is turned OFF. When the current is greater than or equal to a threshold (such as 5 A, for example), the controller stops and indicates a fault condition. By testing each switching element in order, the controller is able to determine whether the shorted switching element is the opposite one in the half-bridge being tested.
Public/Granted literature
- US20220311372A1 SHORT CIRCUIT PROTECTION FOR A BLDC MOTOR Public/Granted day:2022-09-29
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