Lamptron Fanatic fan controller - now 12v/ 5v/ off

[TedShred]

I got an email from Lamptron that they've changed the specs on the FanAtic so that the 3 power settings (it gives out 60W max/ channel) are now 12v/ 5v/ off changed from 12v/ 7v/ off. I asked why they did that and it was something about the 7v option actually drawing it's power from the difference between the 12v. and 5v. outputs on the PSU which was apparently a bad thing. Better to make it the same 5v on the controller. I didn't really understand it, can anyone explain this idea? Does it indeed sound like a good thing? I'm thinkin' the Lamptron guys know what they're doing so I'm guessing "yes."

Oh, the Porsche has nothing to do with this. It's just my drool-car-of-the-moment. http://www.detailingbliss.com/forum/f46/miracle-detail-porsche-965-turbo-mint-7050.html Well, and 99% probably will be the colour of my eventual new Cosmos. (I've ditched Dodge snakeskin or sublime green. Damn this is going slow.)

[Kayin]

7v is made on a fan controller by connecting 12v to 5v. It can put a real drain on there, though, especially if you do a lot of fans that way...

I either use the little Zalman rheostats or solder resistors inline. I don't fsck with that, that's a good way to damage a PSU.

[TedShred]

Okay, that makes sense, thanks.

No doubt the fans would spin a bit slower @ 5v rather than 7v (well, I always have a doubt :D). Do you think the 5v setting would be as useful as 7v, ignoring the benefit to the power situation?

edit: I think this question comes from a review I read on the FanAtic in which the reviewer found that the 7v. setting almost perfectly matched the setting that he found himself using with his own fully adjustable controller. Maybe it doesn't even really have an answer beyond personal preference and trial/ error?

[Bigtime]

If done right, they can just use the 5v rail as vref, create an internal 5v line from 12v input with voltage regulators and then use the internal 5v as ground against the external 12v line. Voila, 7V with no strain on the 5V line! :p

This is probably a cost cutting measure more than anything :mad:

[Kayin]

Yup, but that's cost and complexity they don't wanna do. That kinda attitude pisses me off.

Sure, I 5v a lot of stuff, but it has to do with silence rather than cheapness...