Dim second hand digit on bright setting
Moderators: adafruit_support_bill, adafruit

Dim second hand digit on bright setting

by daveacnp on Thu Dec 06, 2012 1:31 pm

Hi,
I recently built the ice tube clock and am pleased with the results aside from one thing. The last digit is very dim, even in the brightest setting. Can you help with this problem. Thanks! daveacnp
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Re: Dim second hand digit on bright setting

by adafruit_support_bill on Thu Dec 06, 2012 2:11 pm

This is described in the FAQ and is due to the way the tube is driven. There is a drop in voltage from one end of the tube to the other, so the last digit or two often appear dim. Some customers have modified the firmware to compensate for this. viewtopic.php?f=41&t=23586
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Re: Dim second hand digit on bright setting

by jarchie on Fri Dec 07, 2012 4:39 pm

Hi daveacnp. Are you interested in modifying the firmware to make the last digit brighter? If so, I'm sure others on this form (including myself) would be willing to help.
--John <www.jarchie.com/email>
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Re: Dim second hand digit on bright setting

by jarchie on Sun Jan 27, 2013 4:41 pm

Hello again. If the dim digit still bothers you, the cause may be insufficient current running through the tube's filament and not the way the tube is driven. There might also be a straightforward solution: Replace R3 with a jumper. R3 is a bit difficult to remove, as it's squeezed between the alarm switch and VFD chip socket. So instead of removing R3, you could also short out R3 by soldering a jumper across R3 on the bottom side of the board, placing the jumper and R3 in parallel.

For a more technical discussion, see viewtopic.php?f=41&t=23586&start=21
--John <www.jarchie.com/email>
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