pinkfloyd4ever
500+ Head-Fier
Ok so I know this isn't audio related, but I figured the EE's here would have the best answer. So I've recently started homebrewing (which has pretty much overtaken audio as my main hobby) and I'm building a magnetic stir plate for yeast starters. I've seen two approaches, both of which are based on using a [usually 12VDC] PC fan to spin rare earth magnets. The fan is not really used to move air or cool anything, but simply to spin the magnets. The differences between these 2 designs is in the speed control. Rather than explaining the details myself, I'll let the original designers do that.
1) http://www.stirstarters.com/instructions.html
2) http://www.homebrewtalk.com/f51/my-stirplate-cheap-easy-build-86252/
so which design would you use? The one with just a high wattage rheostat or the one with the pot on the VAdj pin of the LM317? Or anyone have another, simple suggestion?
Btw, I've already got the rare earth magnets from an old HD, a 12V PC fan, and a 12V wallwart, and obviously I know where to get the rest of the parts.
regardless of the electronics design I pick, I definitely plan on using the PVC spacer between the fan and the magnets. I can't see how the ones that don't do so don't burn up their fans after a couple hours of use.
1) http://www.stirstarters.com/instructions.html
2) http://www.homebrewtalk.com/f51/my-stirplate-cheap-easy-build-86252/
so which design would you use? The one with just a high wattage rheostat or the one with the pot on the VAdj pin of the LM317? Or anyone have another, simple suggestion?
Btw, I've already got the rare earth magnets from an old HD, a 12V PC fan, and a 12V wallwart, and obviously I know where to get the rest of the parts.
regardless of the electronics design I pick, I definitely plan on using the PVC spacer between the fan and the magnets. I can't see how the ones that don't do so don't burn up their fans after a couple hours of use.
