METHOD AND DEVICE FOR ADJUSTING THE FREQUENCY OF A DRIVE CURRENT OF AN ELECTRIC MOTOR

• Main Authors: JUNGNICKEL, UWE, VETTER, INGO, KLEMM, TORSTEN
• Format: Patent
• Language: English; French
• Published: 27.01.2015
• Subjects: APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE; CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DENTISTRY; ELECTRICITY; GENERATION; HUMAN NECESSITIES; HYGIENE; MEDICAL OR VETERINARY SCIENCE

A small electric appliance is described which comprises an oscillation-capable mechanism (4), an electric motor (1) to drive the oscillation-capable mechanism (4), wherein the electric motor (1) can be operated with a drive current (10) at a predetermined frequency (f), and a device (3) for adjusting the frequency (f) of the drive current of the electric motor (1). Furthermore, a method for adjusting the frequency (f) of a drive current (10) of an electric motor is described comprising the following steps of - detecting, at a specified time (tmeas), in relation to the period of the drive current, an electric variable (20) generated by the electric motor (1) - determining, at the specified measuring time (tmeas), whether the detected electric variable (20) essentially has a zero-crossing and - changing the frequency (f) of the drive current until the detected electric variable (20) essentially has a zero-crossing at the measuring time (tmeas).