Mitsuba Corporation

Mikihito Shimoyama

Toshiyuki Amagasa

Takeshi Ikeda

Yuichi Yanagita

Katsuhiro Tanino

Tomoyuki Ogawa

Takayuki Kawakura

Naohiko Shiga

Yasuhiro Nagahara

Hideaki Hakoda

A motor speed, duty, and power source voltage are detected (steps Sto S). Referring to a load point map, a load point value is obtained (steps Sand S). The load point map is created with the motor speed, duty, and power source voltage taken as parameters, and is corrected in accordance with atmospheric temperature of the motor. After the load point value is obtained, the value is accumulated (step S). The accumulated point value and a predetermined threshold value are compared with each other (step S). If the accumulated point value exceeds the threshold value, an overloaded state is determined and the accumulated point value is stored (step S). Thereafter, the motor is stopped.

Motor control method and motor controller

Various component parts of a driver circuit for drive sources such as electric motors and clutches, such as relays and FETs as well as the drive sources can be tested by selectively energizing the relays and evaluating the voltage levels of the selected points by using the first and second test voltage detection circuits. This testing process is typically executed before the power up of the drive circuit. The test current is so small that the drive sources would not be inadvertently activated and various components would not be damaged even when there is any faulty component in the driver circuit. When any faulty component is detected in the testing process, the driver circuit may be prevented from being powered up so that any undesired operation of the drive sources or permanent damage to various components owing to such a faulty component may be avoided.

Fault detection circuit for a driver circuit

Growing community of inventors

Kiryu, Japan

Mikihito Shimoyama