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. 23, 1989
Filed:
Dec. 28, 1987
Joseph A Volk, Sr, Chesterfield, MO (US);
Joseph A Volk, Jr, Creve Coeur, MO (US);
Beta Raven Inc., Earth City, MO (US);
Abstract
An offset current which is 180.degree. out of phase with the leakage current for a motorized bed circuit is created through the use of an additional transformer winding and series resistor which is connected between the neutral conductor and ground conductor. As the circuit is connected in the reverse polarity condition for testing to UL standards, the offset current is injected into the ground conductor which cancels out a portion of the leakage current from the motors to thereby bring it within testing standards. In the normal connection condition, the injected offset current is additive to the leakage current, although the normal leakage current is much less than the reverse polarity connection leakage current so that the overall leakage current in the normal connection condition remains within test standards.