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Subject: Re: [Homebrew_PCBs] Re: UV LED box

From: DJ Delorie <dj@...>
Date: 2008-06-11

"warrenbrayshaw" <warrenbrayshaw@...> writes:
> I note that your LEDs are laid out with overlap in one axis but none
> in the other.

Not by much, and that was to spread them out to fit the 9x12 area I
wanted to cover. The problem isn't the pattern (although a triangular
grid is much more consistent than a square grid), it's that the LEDs
aren't all perpendicular to the board. It's a much more significant
variable.

> I suggest that you need to have all neighbouring LEDs overlap the
> same amount to obtain a more even coverage.

That's why I'm trying a triangular grid instead of a square grid.
IIRC this was discussed a few weeks ago here.

> All the best with the fine tuning.

Thanks. I think what I'll do is use the test supply to run each LED
one at a time and see where it hits on a third printout where the
board goes. It may just be a few LEDs that are way off. I don't
think I can do better than that with plywood; I'd need a real PCB to
hold them steady enough to be more tweakable, but it would be
expensive to fab out and I'm not yet up to that point with the home
fab.