Battery tester with stacked thermochromic elements
First Claim
1. A battery unit which may be tested by a user to determine the test status thereof, comprising:
- an electrical battery for supplying a test current during the testing, having an anode end with an anode terminal means and cathode end with a cathode terminal means;
a dielectric substrate with a single test site thereon, mounted on the electrical battery;
conductive means on the dielectric substrate and having an anode end for electrically engaging the anode terminal means of the electrical battery, and having a cathode end for electrically engaging the cathode terminal means of the electrical battery;
a resistive heater means formed by a segment of the conductive means proximate the single test site for generating heat in response to the test current flowing therethrough, which raises the temperature of the single test site from an initial temperature to a higher temperature determined by the test status of the battery and the resistive heater means, wherein the segment of the conductive means forming the resistive heater means has a constant width for producing a substantially constant temperature (the test temperature) throughout the entire test site;
at least two thermochromic layers stacked on said substrate at said test site, a first thermochormic layer over a second thermochromic layer, said thermochromic layers being stacked at the test site so that the second thermochromic layer is closer to the test site on the substrate than is the first thermochromic layer, whereby during battery testing the first thermochromic layer is closer to the viewer than the second thermochromic layer,said first thermochromic layer being of a first color which is generally opaque at said initial temperature, and clear at a test temperature (T1) which is greater than the initial temperature thereby revealing the color of the second thermochromic layer to indicate that the battery is at least partially operable;
said second thermochromic layer being of a second color which is generally opaque at said initial temperature and T1, and clear at a test temperature (T2) which is greater than T1 thereby revealing the color of a layer of material therebelow to indicate that the battery is stronger than if only the first thermochromic layer has cleared; and
thermal barrier means between the electrical battery and the dielectric substrate directly under the single test site for minimizing heat flow from the first and second thermochromic layers into the electrical battery during testing.
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Accused Products
Abstract
A thermochromic apparatus for testing dc voltage sources, particularly small, low voltage disposable batteries, employs a very thin resistive heater layer deposited onto a flexible dielectric substrate. A series of thermochromic elements are "stacked" (mounted on top of one another) at a single thermochromic site proximate the resistive heater. During testing current from the battery flows through the resistive layer heats the substrate, causing a series of thermochromic elements mounted on the substrate to undergo visual "temperature events" (such as color changes) at progressively higher temperatures. The thermochromics may be stacked in a series of discrete films, each film containing a dye for one temperature event. Alternatively, the thermochromics may be contained in microcapsules in a common film.
23 Citations
14 Claims
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1. A battery unit which may be tested by a user to determine the test status thereof, comprising:
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an electrical battery for supplying a test current during the testing, having an anode end with an anode terminal means and cathode end with a cathode terminal means; a dielectric substrate with a single test site thereon, mounted on the electrical battery; conductive means on the dielectric substrate and having an anode end for electrically engaging the anode terminal means of the electrical battery, and having a cathode end for electrically engaging the cathode terminal means of the electrical battery; a resistive heater means formed by a segment of the conductive means proximate the single test site for generating heat in response to the test current flowing therethrough, which raises the temperature of the single test site from an initial temperature to a higher temperature determined by the test status of the battery and the resistive heater means, wherein the segment of the conductive means forming the resistive heater means has a constant width for producing a substantially constant temperature (the test temperature) throughout the entire test site; at least two thermochromic layers stacked on said substrate at said test site, a first thermochormic layer over a second thermochromic layer, said thermochromic layers being stacked at the test site so that the second thermochromic layer is closer to the test site on the substrate than is the first thermochromic layer, whereby during battery testing the first thermochromic layer is closer to the viewer than the second thermochromic layer, said first thermochromic layer being of a first color which is generally opaque at said initial temperature, and clear at a test temperature (T1) which is greater than the initial temperature thereby revealing the color of the second thermochromic layer to indicate that the battery is at least partially operable; said second thermochromic layer being of a second color which is generally opaque at said initial temperature and T1, and clear at a test temperature (T2) which is greater than T1 thereby revealing the color of a layer of material therebelow to indicate that the battery is stronger than if only the first thermochromic layer has cleared; and thermal barrier means between the electrical battery and the dielectric substrate directly under the single test site for minimizing heat flow from the first and second thermochromic layers into the electrical battery during testing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification