Patent ID: 6111379
Filing Date: 2000-08-29
Classification: H02H

Abstract:
A circuit configuration for driving an electrical drive unit, comprising:a control circuit through which a current is supplied to the electrical drive unit, said control circuit having a current bridge and a bridge driver connected to said current bridge; anda temperature evaluation circuit determining from the current supplied to the electrical drive unit a temperature of said current bridge and outputting a temperature-dependent output signal, said temperature evaluation circuit including a squarer, an adder and an RC filter having a time constant equal to a thermal time constant of said control circuit, said temperature evaluation circuit being connected to receive a motor current value of the electrical drive unit, the temperature-dependent output signal being formed by squaring the motor current value with the squarer to form a square of the motor current, integrating the square of the motor current with said RC filter to form an integral, and adder, to the integral a variable dependent on an ambient temperature.