| 摘要 |
PROBLEM TO BE SOLVED: To detect disconnection of a thermistor for detecting temperature even at an extremely low temperature. SOLUTION: An electromagnetic retarder is equipped with a thermistor for detecting the temperature of the retarder, and a circuit for controlling an exciting current carried to an exciting coil of the retarder based on the temperature detected by the thermistor. The retarder is composed in such a manner that a magnetic pole core equipped with a plurality of magnetic poles magnetized by the exciting current and an eddy-current cylinder installed oppositely to the magnetic poles are rotated relatively to generate an eddy current in the eddy-current cylinder to obtain a braking force. This system is constituted of a control unit for referring, adding, subtracting or integrating fundamental values of temperature characteristics of the retarder memorized in an integration element table, based on an operation or non-operation signal of the retarder, a braking intensity (H/L) signal and a vehicular speed signal, for estimating a temperature rise of the retarder at the braking time, for taking a temperature detection signal during a period when the integrated value is over a prescribed value, and for determining the truth or falsehood of thermistor disconnection detection.
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