The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 30, 2001
Filed:
Feb. 28, 2000
Roland Dorfer, Keutschach, AT;
U.S. Philips Corporation, New York, NY (US);
Abstract
In a device (,) having a variable-speed motor (,), a single switching device (,) has been provided for influencing the speed of the motor and for generating turn-off voltage transients (SP) on a coil terminal (,) of the motor. The turn-off voltage transients can be applied to a voltage boosting circuit (,) for generating a d.c. control voltage required for driving a control electrode of the single switching device. This d.c. control voltage is supplied to the control electrode of the switching device with the aid of a control pulse generator (,). The d.c. control voltage reaches a higher value than the d.c. supply voltage (V) applied to the device (,). Preferably, the device includes a starting circuit (,), by which a minimum d.c. control voltage, required for the control electrode of the single switching device, can be generated for the first time in order to drive the single switching device into its conductive state.