Battery remaining amount warning circuit
First Claim
1. A battery remaining amount warning circuit that detects a voltage drop of a battery in an electronic device, comprising:
- a storage device which stores a current value in each of a plurality of operating modes of the electronic device;
a measuring device which measures a voltage variation of the battery when a first one of the operating modes of the electronic device is changed for a second one of the operating modes of the electronic device;
a calculation device which calculates a DC resistance value of the battery from the voltage variation measured by the measuring device and a difference between the current value in the first operating mode stored in the storage device and the current value in the second operating mode stored in the storage device; and
a warning device which gives a warning when the DC resistance value calculated by the calculation device becomes greater than a predetermined warning level.
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Accused Products
Abstract
The battery remaining amount warning circuit can issue a battery remaining amount warning after battery power is fully used, reduce current consumption, and issue a warning at appropriate timing for various types of battery. A system controller calculates DC resistance value of the battery from a difference between a current value in an operating mode before a change which is stored in the memory and a current value in an operating mode after the change which is stored in the memory and a voltage variation of the battery measured by an A/D converter, and when the calculated DC resistance value becomes greater than a predetermined value, the system controller sends a warning instruction signal to a data LCD.
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Citations
2 Claims
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1. A battery remaining amount warning circuit that detects a voltage drop of a battery in an electronic device, comprising:
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a storage device which stores a current value in each of a plurality of operating modes of the electronic device;
a measuring device which measures a voltage variation of the battery when a first one of the operating modes of the electronic device is changed for a second one of the operating modes of the electronic device;
a calculation device which calculates a DC resistance value of the battery from the voltage variation measured by the measuring device and a difference between the current value in the first operating mode stored in the storage device and the current value in the second operating mode stored in the storage device; and
a warning device which gives a warning when the DC resistance value calculated by the calculation device becomes greater than a predetermined warning level. - View Dependent Claims (2)
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Specification