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Last Post 27 Nov 2007 10:42 AM by  mikea@logicpd.com
LCD 6.4 VGA vs. LCD 10.4 VGA current draw
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mandyliu
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26 Nov 2007 03:37 PM
    Why is it that the smaller LCD 6.4 VGA is drawing twice the amount of current as the LCD 10.4 VGA? I'm seeing 1.3A on the 6.4 VGA vs. 0.73A on the 10.4 VGA.

    The backlight on the 6.4 seems brighter than the 10.4. Perhaps this is the cause for the higher current draw?

    Is there any way to decrease the intensity of the backlight on the LCD 6.4?
    mikea@logicpd.com
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    27 Nov 2007 10:42 AM
    The 6.4" display has two CCFL tubes versus the 10.4" which only has one tube. The inverter on the 6.4" kit takes more power to drive the two tubes.

    Look at the data sheets for the two inverters, you'll see the difference in power:

    6.4" -> ERG K1957
    10.4" -> ERG 8M051972

    (http://www.ergpower.com)

    Both of these inverters have the ability to be driven at lower brightness, but the kits have no connection to those pins. You can use a PWM to drive the 'enable' pins on those inverters, but this would be a custom wire from the SOM kit to the Display kit. (Left open, they are full brightness)

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