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Re: Passive solar tracking

Discussion Board - 5 hours 51 min ago
I've though of using propane.  Much cheaper than (other) liquid refrigerants.  Liquid at reasonable pressure.  Suitable containers and plumbing are easy to come by.

Site it far from the house, though.  You'd need several pounds of it, so a leak would m...

Re: Solyndra PV tube, what to do with it?

Discussion Board - 5 hours 54 min ago
I think that their solar panels sold for about $5 per watt while regular silicon panels were around $2 per watt.

At that price point, they were doomed to fail without some super marketing plan.

Re: Interesting new commercial solar generator

Discussion Board - 6 hours 3 min ago
Quote from: joestue on May 20, 2014, 11:35:28 AM
As for the mirror, it needs to be cheap and made from unobtainium, doesn't rust, doesn't warp, doesn't loose its reflectivity after 5 years...

They call it "silver...

Re: Active or passive solar PV hail protection

Discussion Board - 6 hours 51 min ago
"Hardware cloth" or "welded Wire Fencing".  Think coarse window screen with the wires welded where they cross.

The latter is very strong - like 1/32" steel wire welded together with various hole sizes (like 1" x 2")

Mount this sturdily a foot or to so ...

Re: Solyndra PV tube, what to do with it?

Discussion Board - 7 hours 9 min ago
Quote from: MaryAlana on May 11, 2014, 02:36:00 PMHad to look those up, never looked at the technology, just the fact that it was a failed company due to Chinese competition. Interesting idea...

My townhouse is j...

Re: ATmega328P for OpenTRV use

Discussion Board - Sun, 08/31/2014 - 21:39
If it's still fun, you're still on the right track.

Ever considered a Kickstarter campaign?  In Canada this often gets projects extra press coverage, which doesn't hurt the funding, if you know what I mean.  The media love Kickstarter because you basic...

Re: Out of the blue LED experiments

Discussion Board - Sun, 08/31/2014 - 15:28
Hi

I have a little LED torch while tracing cables at my old work place I dropped it down the side of an RSJ into the void at the back of the wall cladding. I was prepared to leave it there but a week later it was still glowing at the same level as when...

Re: Out of the blue LED experiments

Discussion Board - Sun, 08/31/2014 - 12:26
Quote from: DamonHD on August 30, 2014, 11:10:18 AMMy little LED nightlight went the best part of a year between its last two charges.

http://www.earth.org.uk/LED-homebrew-nightlight.html

It does have a little solar panel in...

Re: Blade theory questions

Discussion Board - Sun, 08/31/2014 - 10:52
That is a good discovery.  It seems to cover the same subject and details, but of course just delivers the math and the program, not the explanation and details that expand the Wilson-Lissaman papers to more than 100 pages.

I was very interested to rea...

Re: bigger pipe = greater pressure = higher flow rate!

Discussion Board - Sun, 08/31/2014 - 08:34
Just put in the next smaller sized nozzle and check your amp meter. If it is close to the output you got before the pipe upgrade you are done. With the larger pipe you should get a bit more power with the same amount of water. You will have to decide i...

Re: Active or passive solar PV hail protection

Discussion Board - Sat, 08/30/2014 - 17:59
Quote from: electrondady1 on August 30, 2014, 06:59:23 AM
i would guess with hail that size you would want  to protect them quickly .
mount them like a door with the panels  hinged along one edge,  maybe just pull a pin and l...

Re: Active or passive solar PV hail protection

Discussion Board - Sat, 08/30/2014 - 14:53
My solar hot air collector has been in use 3 or 4 years and the polcarb has been subjected to 180 degree temps when a friend disconnected the blower power to plug in her laptop. I smelled melting spray foam and tokk the air temp at the outlet of 180, p...

Re: Out of the blue LED experiments

Discussion Board - Sat, 08/30/2014 - 11:10
My little LED nightlight went the best part of a year between its last two charges.

http://www.earth.org.uk/LED-homebrew-nightlight.html

It does have a little solar panel in there, but I'm not at all sure how much difference it makes.

The key improveme...

Re: Out of the blue LED experiments

Discussion Board - Sat, 08/30/2014 - 09:11
I once connected a yellow led to 2 double A alkaline batteries in series just before Thanksgiving .
It was still glowing at Easter.

Out of the blue LED experiments

Discussion Board - Sat, 08/30/2014 - 08:55
Long story short, found in our yard a marker light, kids?


pulled the LED and hooked to 2 junker low capacity batteries 3+ days ago, LED fv unknown, batteries known capacity of only 235mah with a ...

Re: Going Back 100 years

Discussion Board - Sat, 08/30/2014 - 07:10
in your ling go, i think it's, "good on ya"
around here, we say "way to go"
did you use any kind of special welding rod  or hardening technique ?

Re: Active or passive solar PV hail protection

Discussion Board - Sat, 08/30/2014 - 06:59

i would guess with hail that size you would want  to protect them quickly .
mount them like a door with the panels  hinged along one edge,  maybe just pull a pin and let them go edge ways. just a 90 degree rotation down powered by gravity.
_  _  _  _ ...

Going Back 100 years

Discussion Board - Sat, 08/30/2014 - 03:06
G'day Guy's,
                    Well it has been a long time since I posted any of my projects on this forum and after having a private word with a mod I will now explain what I'm going to do.

First my reasons for going back 100 years as people back t...

Re: NEMA L14-30R vs NEMA 14-50R?

Discussion Board - Fri, 08/29/2014 - 18:15
Because the two coils are wound over the top of each other, and on both sides of the rotor, you can pull 50 amps from one coil without burning it out, or 31 amps from both, the heat generated is about same and it is more or less just as evenly spread o...

Re: Active or passive solar PV hail protection

Discussion Board - Fri, 08/29/2014 - 17:58
Frank S,
My solar panels are surrounded by cattle panels made with 1/4" bar. If there is a difference in output, I don't notice it. Bear in mind, I do have 7100 watts of panels. Small differences aren't too noticeable.

Sliding shudders would work if t...
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