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Updated: 32 min 6 sec ago

Re: Venting sealed battery box, run fans continuous or?

8 hours 32 min ago
I like it! Initially thought 2" was too small and the circulation might leave some hydrogen pockets but you're making sure no arcing can be inside. Minimizing the hydrogen buildup with a 1" continuous fan outside normally and one or two 4" fans when th...

Re: Prius Battery

Fri, 12/19/2014 - 22:46
Here's a 12 v battery! 160 pounds of NiMH. All the negatives on one side. Copper sheet to join the two batteries vertically on each side is at the lower left, ready to be cut and drilled.

Re: Efficiency, Delta vs Wye

Fri, 12/19/2014 - 20:19
its basically the same.
In delta, third and 9th harmonics flow round and round in circles, causing no load losses to be higher, but they are canceled out at the terminals--because they got eaten up by the winding resistance.
For WYE, third and 9th harm...

Efficiency, Delta vs Wye

Fri, 12/19/2014 - 19:37
Is the efficiency the same for axial flux alternators?

Efficiancy, delta vs. wye

Fri, 12/19/2014 - 19:35
Is the efficiency the same for axial flux alternators?

Re: Venting sealed battery box, run fans continuous or?

Fri, 12/19/2014 - 17:30
    Code requires nearly all venting to be above the roof line and 2' higher than anything 10' close to it. And if you get strong wind on that side of the house, I pray you have a very strong exhaust fan. I really don't like this.

Re: selecting a resin for my generator

Fri, 12/19/2014 - 14:33
It seems everyone has developed their own method. Mine is using Smooth-on with one layer of fiberglass cloth on each side of the stator and mixing as much chopped fiberglass as I can get into the stator. I vibrate the stator with an electric sander to ...

Re: For Sale - (2) 70' towers

Fri, 12/19/2014 - 14:26
What brand are they? Putting up towers these days requires a PE stamp and engineering drawings in a lot of locations, especially for wind use.

Re: Venting sealed battery box, run fans continuous or?

Fri, 12/19/2014 - 14:24
Piece of 1/2 " hardware cloth inside the end. I figure it will rot from acid fumes every couple of years but it is a cheap replacement. Outside vent, gave it some rise to try and create a chimney effect

[img width=304 height=540]http://i226.photobucket...

Re: ATmega328P for OpenTRV use

Fri, 12/19/2014 - 14:20
Sweet! Keep us posted, I have been following this fro the start

Re: selecting a resin for my generator

Fri, 12/19/2014 - 11:27
This post seems to have re-started after a long time so my opinions have changed, particularly with the magnets. In a damp climate, potting magnets in polyester is a disaster. I think epoxy may be the only option but I am not sure potting in a solid bl...

Re: selecting a resin for my generator

Fri, 12/19/2014 - 09:10
After asking a lot of the same questions, based on feedback here, and researching what I could, I ended up using as a high temp potting/encapsulating epoxy.  It is supposed to be high temp, thermally conductive.  My biggest concern was the cracking tha...

Re: Winpower turbine questions

Fri, 12/19/2014 - 08:58
Scratch that - I see it now.  When I first looked at it I thought the collar/synch plate was on the upwind side.  ~ks

Re: ATmega328P for OpenTRV use

Fri, 12/19/2014 - 08:41
I'm pleased to be able to say that we've got some funding to work on the cheap/easy sensor/actuator part of our technology:

http://techcityuk.wordpress.com/2014/12/18/iot-launchpad-winners/

So, lots more sensor fun coming up over the next year!

Rgds

Da...

Re: Venting sealed battery box, run fans continuous or?

Fri, 12/19/2014 - 08:33
NICE looking setup !!
Not sure how the vent look outside, but I think I'd be worried about the varmits getting into the vent.
I had to put a metal wire mesh on my vent to keep the squirrels and field mice away from the pass-through wires.
Not sure why ...

Re: selecting a resin for my generator

Fri, 12/19/2014 - 07:41
polyester is normally used in a lay up process. thin layers of glass and resin.   when you cast a stator use half the hardener and mix it twice as much as you think is enough. let is cure slowly  to avoid problems
if your bedding your mags in resin, ep...

For Sale - (2) 70' towers

Fri, 12/19/2014 - 03:54
I am selling (2) identical 70' self supporting tilt towers. These are 3 leg bolted angle iron primed and painted and are 4 years old in perfect condition. They are at the same location in Western NY and are currently lowered, I have started partial dis...

Re: selecting a resin for my generator

Fri, 12/19/2014 - 02:06
Aluminum oxide should be fine, it is an insulator so no issues with eddy currents. But the heat problem would be better served by a more open stator design with cooling slots... but then you lose stiffness.

Re: bipolar off grid array

Fri, 12/19/2014 - 01:53
You should run (strings of) panels that point in different directions (or have different shading/exposure) on different controllers, especially MPPT, if the controller is to get maximum energy out of them.

I have east- and west- facing strings of panel...

Re: selecting a resin for my generator

Thu, 12/18/2014 - 22:53
guess ile have to try a small experimental stator buried in  concrete...?????????