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:
Aug. 23, 1994
Filed:
Jun. 25, 1991
Norman M Hill, Bothell, WA (US);
Other;
Abstract
The specification describes a controller apparatus for a DC motor and a lamp having a filament electrically connected in parallel with the DC motor, comprising: (a) an output driver circuit for generating a DC power signal, where the DC power signal energizes the DC motor; (b) an AC signal generating circuit for generating an AC power signal; and a high frequency coupling transformer for so adding the AC power signal to the DC power signal that the AC power signal energizes the filament. Preferably, the controller also comprises: (a) a switching circuit for periodically preventing the DC power signal from controlling the DC motor; (b) a speed sensing circuit for determining a speed of the locomotive by measuring a back EMF signal generated by the DC motor during the time that the switching means prevents the DC power signal from controlling the DC motor; and (c) an error correcting circuit for correcting the DC power signal based on the speed of the locomotive.