Battery state of charge indicator operating on bidirectional integrations of terminal voltage
First Claim
1. A battery state of charge indicator comprisingmeans for measuring battery terminal voltage on a continuing basis during both positive and negative voltage excursions with relation to a summed reference value,means including a fixed reference voltage source and a summing means for providing a summed reference value for comparison with said measurement,means for comparing said battery terminal voltage measurement with said summed reference value and for deriving a difference signal value,means responsive to said difference signal value for generating convergence function signals which vary dependent on the magnitude and polarity of said difference signal value,a bidirectional integrator connected to receive said convergence function signals and operable to integrate in one direction for positive convergence function signals and in the other direction for negative convergence function signals to provide an integrated output signal as a measure of the state of charge,said means for providing a summed reference value including feedback means connected from the output of said integrator to said summing means for summation of a predetermined function of the integrated output signal with the fixed reference voltage from said fixed reference voltage source to thereby modify said summed reference value.
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Abstract
Battery terminal voltage is measured on a continuing basis during both positive and negative voltage excursions with relation to a summed reference value to obtain a measured difference. The resultant measured difference causes the generation of convergence function signals which vary dependent upon the magnitude and polarity of the measured difference and a bi-directional integrator is connected to receive the convergence function signals to integrate in either direction dependent upon the polarity of the convergence function signals. A feedback is provided from the integrator to modify the summed reference value and the output of the integrator is indicated as a measure of the state-of-charge.
50 Citations
18 Claims
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1. A battery state of charge indicator comprising
means for measuring battery terminal voltage on a continuing basis during both positive and negative voltage excursions with relation to a summed reference value, means including a fixed reference voltage source and a summing means for providing a summed reference value for comparison with said measurement, means for comparing said battery terminal voltage measurement with said summed reference value and for deriving a difference signal value, means responsive to said difference signal value for generating convergence function signals which vary dependent on the magnitude and polarity of said difference signal value, a bidirectional integrator connected to receive said convergence function signals and operable to integrate in one direction for positive convergence function signals and in the other direction for negative convergence function signals to provide an integrated output signal as a measure of the state of charge, said means for providing a summed reference value including feedback means connected from the output of said integrator to said summing means for summation of a predetermined function of the integrated output signal with the fixed reference voltage from said fixed reference voltage source to thereby modify said summed reference value.
Specification