How to build A Low Cost Negative Voltage Supply To Bias Extended Temperature LCDs

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Submitted by: Bruce Layne
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There are several LCDs available through surplus or traditional commercial channels which allow an extended temperature range. This sounds ideal, as there seems to be nothing for the designer to do, but as usual there's a catch. The extended temperature range LCDs require a negative bias voltage to operate. Without it, there is no contrast and the display is completely blank. This document outlines an easy solution with circuit details and schematic.

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