Patent ID: 6775468
Filing Date: 2004-08-10
Classification: H02P

Abstract:
A pump device including an electronically commutating dc motor with a wet-supported permanent magnet-rotor (17) for a dishwasher, wherein said dishwasher is equipped with an operating circuit (13) for the implementing of an operating program in the absence of providing the pump motor (11) with a therewith connected speed control, an auxiliary circuit (20) adapted to a motor housing for said motor being provided with a speed control for said pump motor (11) through a mean motor voltage which is operative in a field current circuit (30), said field current circuit (30) being supplied with current in a type of chopper control through commutator switching sections (34) rotor position-dependently controlled by sensor signals (37), which include avalanche-fixed free-running diodes (33) or configured as avalanche-fixed field effect transistors (FET) forming the switching sections, and an AND-condition which is pulsed through a pulse sequence (23) with a variable keying ratio and which includes a series switch (38) arranged in said field current circuit (30), said sensor signals (37) being connected to a microcontroller (14) for providing an answer-back of rotational speed to effect a rotational speed regulation and therefrom adaptive programming configurations, said microcontroller further receiving an input signal dependent upon the motor current in the form of a measuring voltage (27) which drops off at a current measuring resistance (25) in the field current circuit (30).