| US 7,589,490 B2 | ||
| Motor control system for the PWM control of an electric motor | ||
| Achim Haesters, Pulheim (Germany); Bernd Dienhart, Köln (Germany); Joachim Waschkies, Kürten (Germany); Guido Lindeke, Bergisch Gladbach (Germany); and Cornelius Peter, Buehl (Germany); Angelika Peter, legal representative | ||
| Assigned to Ford Motor Company, Dearborn, Mich. (US) | ||
| Filed on Jun. 19, 2007, as Appl. No. 11/820,271. | ||
| Claims priority of application No. 10 2006 029 332 (DE), filed on Jun. 23, 2006. | ||
| Prior Publication US 2008/0008459 A1, Jan. 10, 2008 | ||
| Int. Cl. H02P 23/00 (2006.01) | ||
| U.S. Cl. 318—811 [318/471; 318/472; 318/565] | 19 Claims |
| 1. A motor control system comprising:
a monitoring circuit for monitoring a PWM control for a DC electric motor, the PWM control including at least a first field
effect transistor that controls a current at the DC electric motor;
the motor control system configured to detect a voltage drop across the first field effect transistor;
a temperature sensor for detecting a temperature of the first field effect transistor; and
a microprocessor for receiving a temperature-related signal from the temperature sensor relating to the temperature of the
first field effect transistor, the microprocessor configured to determine an internal resistance of the first field effect
transistor from the detected temperature thereof and determine a current at the DC electric motor from the internal resistance
of the first field effect transistor and from the voltage drop across the first field effect transistor.
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