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US 5,177,427 AGranted
Battery charging system and method for preventing false switching from fast charge to trickle charge
AssigneeH. M. Electronics, Inc.
InventorJulian J. Bugaj
Life of this patent
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Abstract
A battery charging system which prevents false switching from a fast charge mode to a trickle charge mode due to low frequency voltage aberration signals. The battery charging system includes a battery voltage analyzer and a plurality of battery charging and conditioning units for charging different types and kinds of nickel cadmium batteries. Firmware in the microprocessor rejects low frequency aberrations permitting a desired voltage signal to be produced which is indicative of the actual battery potential for charge switching purposes.
Claims10
A method for charging a battery, comprising:
- applying a high charge current to a battery;
- generating continuously a conditioned signal indicative of an instantaneous potential value of said battery;
- converting said conditioned signal into a digital signal indicative of a present potential value of said battery;
- responding to said digital signal by calculating periodically a derived battery potential value indicative of an averaged present potential value of said battery;
- determining whether said averaged present potential value is a peak potential value;
- storing said derived battery potential value when said averaged present potential value is the peak potential value;
- responding to said digital signal by calculating periodically an incremental derived battery potential value relative to the stored peak potential value;
- determining whether said incremental derived battery potential value is at least equal to a predetermined incremental battery potential value;
- starting a timer in response to said incremental derived battery potential value being at least equal to said predetermined incremental battery potential value;
- repeating said steps of generating, converting, responding, determining, storing, responding and determining;
- resetting said timer if said derived battery potential value is the peak potential value;
- resetting said timer in response to said incremental derived potential value having a potential value less than said predetermined incremental battery potential value;
- and
- switching from applying said high charge current to the battery to applying a trickle charge current when said timer completes a predetermined counting sequence.
11 more elements
A battery charging system, comprising:
- a current control circuit for applying one of a fast charge current and a trickle charge current to a battery;
- conditioning means coupled to said battery for generating a digital signal indicative to a present potential value of said battery;
- processor means responsive to said conditioning means for calculating periodically a derived battery potential value indicative of an averaged potential value of said battery;
- said processor means including means for calculating periodically an incremental derived potential value relative to a derived peak potential value of said battery;
- and
- said processor means further including timing means for causing said current control means to decrease said charging current from said fast charge current to said trickle charge current after a predetermined period of time during which said incremental derived potential value does not become less than a predetermined incremental value.
3 more elements
Dependencies are inferred from the claim text.