MOTOR CURRENT DETECTION DEVICE, MOTOR CONTROL DEVICE, AND ELECTRIC TOOL

摘要

PROBLEM TO BE SOLVED: To allow for appropriate detection of average current and instantaneous current flowing from a battery to a brushless motor with respective simple configurations.

SOLUTION: A motor current detection device comprises: a current detection resistor R0 which detects current flowing from a battery to a brushless motor; first filter means 42 for extracting a current component (average current) of a frequency band lower than or equal to a first cutoff frequency fc1 from the current detected by the current detection resistor R0; and second filter means 43 for extracting a current component (instantaneous current) of a frequency band lower than or equal to a second cutoff frequency fc2 higher than the first cutoff frequency fc1 from the current detected by the current detection resistor R0. Irrespective of such a simple configuration, a highly-efficient and high-output brushless motor can appropriately detect the average current and instantaneous current to be detected for circuit protection.

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