Wahl Clipper Corporation

Einar Trygstad

Curtis William Fisher

Apparatus indicates a charge on a battery that has a predetermined operating range. The apparatus includes a thermochromatic material for displaying the charge level of the battery, and a resistive heating device, which is in thermal contact with the thermochromatic material, for generating heat for activating the thermochromatic material. A controlling device which is connected to the resistive heating device is also included for controlling the heat generated by the heating device so that the thermochromatic material has sufficient resolution to indicate the charge on the battery over a substantial portion of the thermochromatic material.

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Sterling, IL, United States of America

Einar Trygstad