| 摘要 |
<p>PURPOSE:To prevent a motor and a power element section from being damaged, by detecting the temperatures of power elements with the use of the turn-on resistance of the power element, and by controlling current running through a motor to decrease it to a value within a predetermined range. CONSTITUTION:A power element turn-on resistance calculating means 9c measures a power element turn-on resistance with the use of a across voltage and currents running through power elements 9h1-9h4 for controlling current running through a motor 13, which currents are detected by a current sensor 9i when the power elements 9h1-9h4 are turned on. Thus measured power element turn-on resistance is made to correspond to a power element temperature so that a power element excessive temperature judging means 9d determines an excessive temperature condition of the power elements. If the power elements are in an excessive temperature condition, a motor current determining means 9c decrease the motor current.</p> |
