The present invention discloses a system for detecting a battery voltage with high precision, of which a RC filter circuit or a PI type circuit is applied to a handheld hardware device for eliminating the effect of a power noise on a battery voltage detector of the handheld device, while an appropriate weight algorithm is used with the software of the handheld device, such that a conditional determination can be added to a remaining battery capacity parameter to compensate the effect of the fluctuated battery voltage caused by the consumed current, so as to detect the battery voltage with a high precision and allow users to determine the using time of the handheld device accurately.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of detecting hardware of a prior art;
FIG. 2 is a schematic view of a RC filter circuit of the present invention; and
FIG. 3 is a schematic view of a PI type circuit in accordance with the present invention.
Claims
1. A system for detecting a battery voltage with high precision, which is applied to a handheld device having a battery and a voltage detection chip for detecting battery voltage of said battery, comprising:
a first capacitor for filtering a high-frequency power noise of said battery voltage, where one end of said first capacitor is connected between said voltage detection chip and said battery;a second capacitor for lowering a larger instant fluctuation of said battery voltage, where one end of said second capacitor is connected between said one end of said first capacitor and said battery; anda resistor for reducing power noises at different frequencies, where said resistor is connected between said one end of said second capacitor and said battery;wherein said first capacitor, said second capacitor and said resistor form a RC filter circuit.
2. The system for detecting a battery voltage with high precision of claim 1, wherein said first capacitor is a small capacitor.
3. The system for detecting a battery voltage with high precision of claim 1, wherein said second capacitor is a large capacitor.
4. The system for detecting a battery voltage with high precision of claim 1, further comprising:
an appropriate weight algorithm for adding a conditional determination to a parameter of a remaining battery capacity detected by said voltage detection chip;an old value being assigned to a previous detected battery capacity when said previous detected battery capacity is non-zero; anda value currently sampled by said voltage detection chip being assigned to said previous detected battery capacity when said previous detected battery capacity is zero.
5. The system for detecting a battery voltage with high precision of claim 4, wherein said conditional determination further comprises an average of three old values and one current value obtained for displaying said remaining battery capacity, where said currently sampled value has a weight of one-quarter.
6. The system for detecting a battery voltage with high precision of claim 4, wherein said conditional determination further comprises a jump of said remaining battery capacity displaying on a display screen of said handheld device, if said display screen has not been turned on for a long time, and is then turned on with said battery voltage having a large difference from that of a previous shutdown.
7. A system for detecting a battery voltage with high precision, which is applied to a handheld device having a battery and a voltage detection chip for detecting battery voltage of said battery, comprising:
a first capacitor of said PI type circuit, where one end of said first capacitor is connected between said voltage detection chip and said battery;a second capacitor for reducing an instant fluctuation of a larger battery voltage provided by said battery, where one end of said second capacitor is connected between said first capacitor and said voltage detection chip;a third capacitor, where one end of said third capacitor is connected between said first capacitor and said battery; andan inductor coupled between said one end of said first capacitor and said one end of said third capacitor;wherein said first capacitor, said inductor and said third capacitor form a PI type circuit capable of eliminating power noises of different frequencies.
8. The system for detecting a battery voltage with high precision of claim 7, wherein said second capacitor is a large capacitor.
9. The system for detecting a battery voltage with high precision of claim 7, further comprising:
an appropriate weight algorithm for adding a conditional determination to a parameter of a remaining battery capacity detected by said voltage detection chip;an old value being assigned to a previous detected battery capacity when said previous detected battery capacity is non-zero; anda value currently sampled by said voltage detection chip being assigned to said previous detected battery capacity when said previous detected battery capacity is zero.
10. The system for detecting a battery voltage with high precision of claim 9, wherein said conditional determination further comprises an average of three old values and one current value for displaying said remaining battery capacity, where said currently sampled value has a weight of one-quarter.
11. The system for detecting a battery voltage with high precision of claim 9, wherein said conditional determination further comprises a jump of said remaining battery capacity displaying on a display screen of said handheld device, if said display screen has not been turned on for a long time, and is then turned on with said battery voltage having a large difference from that of a previous shutdown.
Patent Application
20070145955
