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:
Apr. 15, 2003
Filed:
Jan. 08, 1998
James E. Chloupek, Plano, TX (US);
Edward N. Jeffrey, Garland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A circuit ( ) for braking a polyphase dc motor ( ) includes a circuit ( ) for producing an output signal indicating that the motor has slowed at least to an actual rotational speed and a braking circuit ( ) to brake the motor ( ) when the output signal indicates that the motor has slowed at least to an actual rotational speed. The circuit ( ) for producing an output signal indicating that the motor ( ) has slowed at least to an actual rotational speed includes a first counter ( ) for counting pulses of a speed signal, which may be a standard tach signal. The first counter ( ) produces a first output when the first counter ( ) reaches a first predetermined pulse count. A second counter ( ) counts clock pulses from a clock generator ( ) to produce a second output when the second counter ( ) reaches a second predetermined pulse count. The first output is connected to restart the first ( ) and second ( ) counters, and the second output provides an indication when the frequency of the speed signal is lower than a desired ratio to the clock pulse frequency.