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:
Jul. 01, 2014
Filed:
Apr. 02, 2012
Hidekazu Suda, Anjo, JP;
Katsuhito Fujinami, Anjo, JP;
Hidekazu Suda, Anjo, JP;
Katsuhito Fujinami, Anjo, JP;
Makita Corporation, Anjo, JP;
Abstract
A drive device of the present invention includes a pair of drive switches, a first diode, a switching element, a current detection unit, a capacitor, a second diode, and a current control unit. The first diode, the switching element, and the current detection unit are arranged, in this order from one end of an armature in a motor, on a braking current path that is formed of the armature and a field winding in the motor when the pair of drive switches is in a brake position. The second diode is adapted to keep allowing a braking current to flow through the field winding when the switching element is in an off-state by directly connecting a partial path between the switching element and the current detection unit on the braking current path and the other end of the armature.