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. 12, 1977
Filed:
Apr. 30, 1975
Gene J Seider, Bloomington, MN (US);
Michael C Freund, Mendota Heights, MN (US);
Gould Inc., Rolling Meadows, IL (US);
Abstract
A battery charging system for charging a battery from a conventional a.c. power source has a leakage reactance transformer connected between the power source and the battery for reducing the voltage of the power source for application to the battery. The power source is connected directly across the primary winding of the transformer to charge the battery at a high rate until it is charged to about 90% of the final capacity. A voltage sensing circuit is activated when the battery reaches about 80% of the desired final voltage, and this circuit energizes a timing motor which maintains the connection of the source directly across the primary winding of the transformer for a period of one hour, which is the normal time required for the battery charge to be increased from the 80% level to the 90% level. At the end of the 1 hour period, a cam driven by the timing motor operates a switch to connect a resistor, which is external of the transformer, in series with the primary winding of the transformer. This sharply reduces the charging current and the charging of the battery is completed at relatively low current levels which vary over a very narrow range. This 'finish' charging is continued for a 6 hour period determined by the timing motor. At the end of the 6 hour period, additional cams driven by the timing motor disconnect the power source from the transformer to terminate the charging cycle, and de-energize the timing motor. The system is automatically reset for the next charging cycle.