40mm fan in a 50mm opening?

[lasitter]

50mm is a really odd fan size, and it turns out that there are NO PWM fans available in this size.

That left me with the idea of putting a smaller fan (but enough CFM) in a larger opening, if I could find or devise a step-up-adapter or make one.

Ideas?

Thanks.

[edh]

The extra rotation speed needed to shift air will make it much louder. Probably better to run a 50mm slower than a maxed out 40mm.

You can get PWM-DC adaptors. I have one which is specially made by this company but I'm sure others may be available:
http://www.paqt.co.uk/store/index.php?a ... roductId=5

[lasitter]

[quote]You can get PWM-DC adaptors. I have one which is specially made by this company but I'm sure others may be available:
http://www.paqt.co.uk/store/index.php?a ... roductId=5[/quote]

I've contacted the vendor for a datasheet / added info. It looks like an interesting potential solution.