Remote sensing of remaining battery capacity using on-battery circuitry
First Claim
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1. A method of remote sensing a remaining battery capacity, comprising:
- receiving, at a communications module of a remote charge indicator system and from a reader system of a handheld computing device, an interrogation signal;
responsive to receiving the interrogation signal, closing a switch, wherein closing the switch causes a battery to charge or discharge (i) a first capacitor of a first RC circuit portion and (ii) a second capacitor of a second RC circuit portion;
receiving, at the communications module, a first indication in response to the voltage of the first capacitor reaching a predetermined voltage threshold;
transmitting, to the reader system, the first indication at a first time;
receiving, at the communications module, a second indication in response to the voltage of the second capacitor reaching the predetermined voltage threshold; and
transmitting, to the reader system, the second indication at a second time, wherein the difference between the first time and the second time corresponds to the remaining battery capacity of the battery.
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Abstract
A method of remote sensing a charge includes charging or discharging a first capacitor of a first RC circuit and a second capacitor of a second RC circuit to a predetermined threshold voltage using a power source. When each of the capacitors reach the predetermined threshold voltage, a response signal is provided from a communications module to a handheld computing device comprising a reader system. An amount of time between the response signals is determined. The amount of time is indicative of charge information.
292 Citations
7 Claims
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1. A method of remote sensing a remaining battery capacity, comprising:
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receiving, at a communications module of a remote charge indicator system and from a reader system of a handheld computing device, an interrogation signal; responsive to receiving the interrogation signal, closing a switch, wherein closing the switch causes a battery to charge or discharge (i) a first capacitor of a first RC circuit portion and (ii) a second capacitor of a second RC circuit portion; receiving, at the communications module, a first indication in response to the voltage of the first capacitor reaching a predetermined voltage threshold; transmitting, to the reader system, the first indication at a first time; receiving, at the communications module, a second indication in response to the voltage of the second capacitor reaching the predetermined voltage threshold; and transmitting, to the reader system, the second indication at a second time, wherein the difference between the first time and the second time corresponds to the remaining battery capacity of the battery. - View Dependent Claims (2)
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3. A remote charge indicator system operatively connected to a battery, the remote charge indicator system comprising:
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a communications module comprising an antenna that receives an interrogation signal from a reader system; and a voltage sensing module comprising a switch that closes when the communications module receives the interrogation signal, a first RC circuit portion having a first time constant comprising a first resistor and a first capacitor, and a second RC circuit portion having a second time constant comprising a second resistor and a second capacitor, wherein the first time constant is different than the second time constant, wherein the voltage sensing module provides a pulse as an output signal to the communications module, wherein the pulse begins when the first capacitor is charged or discharged to a predetermined threshold voltage using the battery and ends when the second capacitor is charged or discharged to the predetermined threshold voltage using the battery, and wherein the duration of the pulse corresponds to the voltage of the battery and the remaining battery capacity of the battery. - View Dependent Claims (4, 5)
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6. A method of remote sensing a remaining battery capacity, comprising:
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receiving, at a communications module of a remote charge indicator system and from a reader system of a handheld computing device, an interrogation signal; responsive to receiving the interrogation signal, closing a switch, wherein closing the switch causes a battery to charge or discharge (i) a first capacitor of a first RC circuit portion and (ii) a second capacitor of a second RC circuit portion; receiving, at the communications module, a pulse having a duration that corresponds to a time difference between when the first capacitor reaches a predetermined threshold voltage and when the second capacitor reaches the predetermined threshold; and transmitting, to the reader system, the pulse, wherein the duration of the pulse corresponds to the remaining battery capacity of the battery. - View Dependent Claims (7)
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Specification