Control and protection methodologies for a motor control module
First Claim
1. A method of estimating tool motor temperature of a tool motor in a corded power tool, comprising:
- comparing a motor current value representing an estimate of what temperature the tool'"'"'s motor will be after a given time period has elapsed, assuming constant current, to a temperature register value representing an estimate of the motor temperature at a present point in time, andupdating the temperature register value based on the comparison so that the temperature register value equals the motor current value after the given time period has elapsed wherein upon tool startup, an initial temperature register value is determined byretrieving stored temperature data at the previous tool shutdown from a memory of a controller in the tool, the stored temperature data including a latest temperature register value at the last tool shutdown and a latest controller temperature at the last shutdown, after a given delay upon tool startup, determining controller temperature at startup, andcomparing the determined controller temperature at startup to the stored controller temperature to determine the initial temperature register value.
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Abstract
A motor control module designed to control operation of a plurality of different motors in a plurality of different tools a power tool uses an electronic clutch in the module in conjunction with a mechanical clutch in the tool to protect the tool against an overload event. The module is adapted to implement methods to provide aural and/or tactile feedback to a tool user as a warning of an impending or current fault condition in the tool. The module can prevent power from inadvertently turning on either after an overload event has cleared with the tool plugged in and its power switch on, or after plugging in the tool within the power switch on. The control module is adapted to provide torque control for the power tool, to estimate tool motor temperature and to inform a tool user when a servicing need in the tool is required.
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Citations
7 Claims
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1. A method of estimating tool motor temperature of a tool motor in a corded power tool, comprising:
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comparing a motor current value representing an estimate of what temperature the tool'"'"'s motor will be after a given time period has elapsed, assuming constant current, to a temperature register value representing an estimate of the motor temperature at a present point in time, and updating the temperature register value based on the comparison so that the temperature register value equals the motor current value after the given time period has elapsed wherein upon tool startup, an initial temperature register value is determined by retrieving stored temperature data at the previous tool shutdown from a memory of a controller in the tool, the stored temperature data including a latest temperature register value at the last tool shutdown and a latest controller temperature at the last shutdown, after a given delay upon tool startup, determining controller temperature at startup, and comparing the determined controller temperature at startup to the stored controller temperature to determine the initial temperature register value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification