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, 1978
Filed:
Aug. 18, 1976
George William Foster, Bolton, EN;
Chloride Group Limited, London, EN;
Abstract
Automatic battery charging apparatus in which a control signal is generated by subtracting a signal representing a fraction of the mains supply voltage from the battery voltage so that the control signal represents the state of charge of the battery irrespective of variations in the mains voltage. The charge is terminated when the rate of rise of the control signal falls below a predetermined value; this condition is sensed by sampling the output frequency of a voltage controlled oscillator whose frequency is directly proportional to the control signal. In one arrangement the output frequency is fed to an up-down counter for a sampling period (2 minutes) with the counter counting up and then, after an interval of 30 minutes, the output frequency is fed to the counter for a further sampling period (1 minute 55 seconds) with the counter counting down. If the counter fails to return to zero at the end of a down count the charge is terminated.