Filter circuit for filtering e.g. disturbing transients from direct current motor, has series connection of capacitors connected in parallel to inputs of filter circuit, and electrical connection between capacitors is grounded

摘要

The circuit (48) has a series connection of capacitors (50, 52) connected in parallel to inputs (12, 14) of the circuit. Entire capacitance of the capacitors is dimensioned such that differential-mode interferences (10) to the inputs are short-circuited. An electrical connection between the capacitors is grounded. A line between a throttle valve (28) and one of the capacitors is selected in a short manner such that admittance from one of the capacitor and line inductor (54) to the valve over frequencies to be filtered is smaller than admittance of the throttle valve. Independent claims are also included for the following: (1) an electric motor comprising a commutator (2) a method for dimensioning a filter circuit for filtering common-mode interferences and differential-mode interferences.