State of battery charge indicator circuit
First Claim
1. In a circuit for indicating the actual state of charge of a storage battery including means for providing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for providing a third signal proportional to the actual terminal voltage of the battery, means for combining said signals to produce an output signal proportional to the actual state of charge, and converting means for converting the output signal to an indication of the actual state of charge of the battery, the improvement comprising:
- disabling means for preventing the converting means from indicating an increase in the state of charge during use of the battery as a power source.
1 Assignment
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Accused Products
Abstract
An indicator circuit for indicating to the operator of an electrically propelled vehicle the remaining capacity of the vehicle battery. The state of charge information is indicated in digital form for facilitated readout. The circuit is arranged to prevent an increase in the indicated state of charge during use of the battery as a power source, i.e. in a motoring mode. The circuit is arranged to prevent a decrease in the indication of the state of charge during a recharging of the battery. The circuit utilizes a feedback signal from the digital counter portion thereof for comparison with a second signal produced in the control circuit to provide either a count-up signal to the digital counter or a count-down signal to the digital counter in providing the control of the operator indicator. The feedback signal may be converted to an analogue signal for comparison with the produced circuit signal in a comparator to provide the appropriate count-up or count-down signal. A fast count control may be provided for bringing the indicator quickly to the actual state of charge reading upon initiating use of the vehicle in the motoring mode. The circuit is arranged to prevent the indicator from reading out less than zero percent state of charge when the battery is being used as the power source and more than one hundred percent state of charge during the recharging operation.
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Citations
23 Claims
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1. In a circuit for indicating the actual state of charge of a storage battery including means for providing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for providing a third signal proportional to the actual terminal voltage of the battery, means for combining said signals to produce an output signal proportional to the actual state of charge, and converting means for converting the output signal to an indication of the actual state of charge of the battery, the improvement comprising:
disabling means for preventing the converting means from indicating an increase in the state of charge during use of the battery as a power source. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. In a circuit for indicating the actual state of charge of a storage battery including means for providing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for providing a third signal proportional to the actual terminal voltage of the battery, means for combining said signals to produce an output signal proportional to the actual state of charge, and converting means for converting the output signal to an indication of the actual state of charge of the battery, the improvement comprising
disabling means for preventing the converting means from indicating a decrease in the state of charge during a recharging operation.
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10. In a circuit for indicating the actual state of charge of a storage battery including means for producing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for producing a third signal proportional to the actual terminal voltage of the battery, and means for combining said signals to produce an output signal proportional to the actual state of charge, the improvement comprising
converting means for converting the output signal to an indication of the actual state of charge of the battery including means for producing a feedback signal and comparator means for comparing said output signal and said feedback signal to control said actual state of charge indication.
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14. In a circuit for indicating the actual state of charge of a storage battery including means for providing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for providing a third signal proportional to the actual terminal voltage of the battery, means for combining said signals to produce an output signal proportional to the actual state of charge, and converting means for converting the output signal to an indication of the actual state of charge of the battery, the improvement comprising
disabling means for preventing the converting means from indicating a state of charge outside the range of zero to one hundred percent.
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17. In a circuit for indicating the actual state of charge of a storage battery including means for providing a first signal proportional to battery current, means for producing a second signal proportional to the internal resistance of the battery at its actual state of charge, means for providing a third signal proportional to the actual terminal voltage of the battery, and means for combining said signals to produce an output signal proportional to the actual state of charge, the improvement comprising:
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a comparator; means for feeding said output signal to the comparator; digital counter means; and feedback means for providing a feedback signal from the digital counter means to the comparator for comparison therein with said output signal to produce a count-down signal when the feedback signal is less than said output signal and a count-up signal when the feedback signal is greater than said output signal. - View Dependent Claims (18, 19, 20, 21, 22, 23)
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Specification