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:
May. 22, 1984
Filed:
Oct. 22, 1982
John D Markham, Droylsden, GB;
Abstract
A dynamic braking system for a D.C. traction motor which is driven from an asymmetric bridge rectifier having freewheel diodes to permit circulation of motor generated current. The system employs field reversal to ensure a generated (braking) current direction the same as for motoring and this facility permits injection current braking by phasing up the supply bridges when the motor is braking with full excitation. The brake resistance is in two parts one of which forms an uncontrolled arm of the bridge, this part of the resistance being shunted by a thyristor. Part way through an injection braking process the supply bridge is phased down, the resistance bridge arm shorted out and the supply bridge phased up again. Lower losses and greater braking efficiency result.