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:
Sep. 25, 1984
Filed:
Jan. 26, 1983
Abstract
A drive circuit for brushless direct-current motors having a cylinder-like air gap between a permanent magnetic inner or outer rotor and a stator, the stator windings being connected to a supply direct-current source in series with a respective feed transistor. The current flux depends on position signals from a semiconductor control element determining the rotor position, in particular a Hall IC, and on the switching state of a semiconductor switch responding to blocking of the rotor and serving as blocking protection for the stator windings. In order to avoid a thermal overload of the stator windings and of the semiconductor elements contained in the circuit, the semiconductor switch provided as the blocking protection is a transistor. The emitter/collector path of the blocking protection transistor is in series with the stator windings and the feed transistors associated with each of these stator windings, and the base of the blocking protection transistor receives an inductive voltage generated in the stator windings.