Method and apparatus for testing batteries
First Claim
1. A circuit for testing the condition of a battery and having a pair of terminals to which a battery is adapted to be connected, said circuit comprising a series circuit of a plurality of resistors and a switching means, said resistors defining first and second junctions, control means for controlling said switching means to connect said resistors between said terminals, and sensing means for sensing the voltage levels at said first and second junctions of said resistors, said sensing means comprising threshold sensing means for producing first and second logic level outputs in response to determined voltages at said first and second junctions, and means for enabling said sensing means to sense the voltages at said first and second junctions, whereby the condition of a battery connected to said terminals is indicated by the voltages sensed at both said first and second junctions at any given time.
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Abstract
A circuit for testing a computer battery without removing it from the computer includes a plurality of serially connected resistors, and a transistor connected to saturate. The voltages at the junctions of the transistors is sensed by a logic device such as a buffer, for application to the data bus of the computer. The transistor may be controlled from the computer via a latch. The resistors have values to produce voltages at two sensed resistor junctions such that the corresponding logic levels applied to the computer are the same, at a first level, when the battery voltage is acceptable, are the same at another logic level when the battery voltage is unacceptable, and are different when the battery voltage is between acceptable and unacceptable voltage values.
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Citations
16 Claims
- 1. A circuit for testing the condition of a battery and having a pair of terminals to which a battery is adapted to be connected, said circuit comprising a series circuit of a plurality of resistors and a switching means, said resistors defining first and second junctions, control means for controlling said switching means to connect said resistors between said terminals, and sensing means for sensing the voltage levels at said first and second junctions of said resistors, said sensing means comprising threshold sensing means for producing first and second logic level outputs in response to determined voltages at said first and second junctions, and means for enabling said sensing means to sense the voltages at said first and second junctions, whereby the condition of a battery connected to said terminals is indicated by the voltages sensed at both said first and second junctions at any given time.
- 10. The method of determining the condition of a battery comprising controlling a transistor to pass saturation current from the battery through first, second and third serially connected resistors, sensing the voltage at a first junction between said first and second resistors with a first threshold device to establish the output level of the first threshold device at a first level when the voltage at said first junction is above a first voltage, and simultaneously sensing the voltage at a second junction between said second and third resistor with a second threshold device to establish the output level of the second threshold device at a second level when the voltage at said second junction is below a second voltage, said second voltage being less than said first voltage.
Specification