Electronic battery tester
AssigneeMidtronics, Inc.
InventorKevin I. Bertness
Life of this patent
Estimating the term…
Abstract
An apparatus for electronically testing or monitoring the condition of a storage battery is provided. The apparatus includes an inductance cancellation circuit for use in a Kelvin probe of an electronic battery tester. The induction cancellation circuit reduces inductive coupling between leads of the Kelvin probe. The apparatus also includes a DC coupled AC amplifier for amplifying an AC response signal of an electronic battery tester. Other aspects include a critically damped band-pass filter a response signal, a DC to DC convertor isolation circuit, operator editable test criteria, a battery temperature sensing element, an automatically adjustable gain stage and the use of an internal reference standard for a self calibration.
Claims42
An apparatus for monitoring the condition of a storage battery, comprising:
- battery test circuitry adapted to couple to the storage battery through a first Kelvin connection and second Kelvin connection;
- first and second electrical leads coupled to a first terminal of the battery test circuitry and adapted to provide the first Kelvin connection to the battery;
- third and fourth electrical leads coupled to a second terminal of the battery test circuitry and adapted to provide the second Kelvin connection to the battery;
- and
- induction cancellation circuitry coupling the first electrical lead to the second electrical lead.
A method of reducing an inductively coupled current in a Kelvin probe of an electronic battery tester, comprising:
- coupling to a sense current carried on a first electrical lead of the Kelvin probe;
- and
- supplying an opposed current in a second electrical lead of the Kelvin probe in response to the sense current, the opposed current flowing in opposition to an inductively coupled current in the second electrical lead.
An apparatus for monitoring the condition of a storage battery, comprising:
- first and second Kelvin connections configured to couple to terminals of the battery;
- an AC test signal source adapted to couple to the terminals of the battery through a first terminal of the first Kelvin connection and a first terminal of the second Kelvin connection and inject an AC test signal therethrough;
- test circuitry adapted to provide battery condition information in response to a battery response signal;
- and
- a DC coupled AC amplifier adapted to couple to the terminals of the battery through a second connection of the first Kelvin connection and a second connection of the second Kelvin connection and provide the battery response signal to the test circuitry as a function of an AC response signal arising in response to the AC test signal between the battery terminals, the battery response signal substantially independent of DC battery voltage.
An apparatus for monitoring the condition of a storage battery, comprising:
- an AC test signal source adapted to couple to terminals of the battery and inject an AC test signal therethrough;
- test circuitry adapted to provide battery condition information in response to a battery response signal;
- and
- a critically damped band-pass filter adapted to couple to the terminals of the battery and provide the battery response signal to the test circuitry as a function of an AC response signal arising in response to the AC test signal between the battery terminals, the battery response signal substantially independent of DC battery voltage.
An apparatus for monitoring the condition of a storage battery, comprising:
- first and second Kelvin connections configured to couple to terminals of the battery;
- an AC test signal source adapted to couple to the terminals of the battery through a first terminal of the first Kelvin connection and a first terminal of the second Kelvin connection and inject an AC test signal therethrough;
- test circuitry adapted to provide battery condition information in response to a battery response signal;
- and
- an adjustable gain stage adapted to couple to the terminals of the battery through a second connection of the first Kelvin connection and a second connection of the second Kelvin connection and provide the battery response signal to the test circuitry as a function of an AC response signal arising in response to the AC test signal between the battery terminals, the adjustable gain stage having a gain input and wherein the amplification gain of the adjustable gain stage is a function of the gain input.
Dependencies are inferred from the claim text.