Welding helmets (Hobby use)

wrote:


Mine were NEVER good for 45 Watts. That was at the Maximum Power Point of 17V while real-world power is at 12V. I think I saw 32W from them once when they were new.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I had to cut that posting short to go and listen to Lindsay Graham and John McCain speak, then mingle with the audience. The Republicans at least seem to like our NH style of face-to-face campaigning, rent a hall and let anyone in to listen and ask questions, rather than the big-money media circus of larger states. It becomes a good test of mental endurance that weeds many out.
Bush, Graham and Kasich are experienced leaders with solid plans and ideas, "policy wonks", any of which I'd be comfortable with as President. I haven't had a chance to meet Carson, Cruz or Rubio yet, and Jim Webb had to cancel.
Here's a list of the candidates. http://www.politics1.com/p2016.htm You say you want more choices???
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Nov 2015 23:26:46 -0500, "Jim Wilkins"

Sounds good to me.

McCain's out: too religious/hawkish (strange companions) + other things. He's not the man I thought he was when he first ran, so I dumped him back then.
Carson's out: too religious and not nearly tough enough on illegals. Rand wants illegals here? I like the man, but: Out!
Ditto Cruz on the latter. Jindal has now dropped out, and I'm waiting for most of the above to drop, too. I'm waiting until they nominate to see whether or not I'll have to write in my candidate of choice. Not looking forward to it. Hell, if Perot were still eligible, he'd get my nod in a nanosecond. Methinks that was our last chance to take the road which didn't lead directly to Hell. <deep sigh>

No, I said I want --== REAL ==-- choices. <sigh>
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Nov 2015 20:59:19 -0500, "Jim Wilkins"

HUH? Y'mean to tell me that HF uses Searz Watts?
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

They may deliver that power into a large rheostat set to load them to 17V, but you won't get it from a 12V battery using the kit's PWM controller.
Said large (300W) rheostat showed that my monocrystalline panels put out nearly the same power at 18V, 17V and 16V, the current rising as the voltage drops.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I forgot to mention that I checked the HF panels too. The three aluminum-framed ones from the kit I bought in 2011 and two newer plastic-framed ones that have had very little sun exposure all generated 0.5 to 0.6A at 17V, averaging around 9W each. Their reverse leakage is only a few milliAmps at 17V, less than 1/10 that of the old monocrystalline panels. Nevertheless I replaced the shorted blocking diode in my HF controller so battery voltage and possibly high fault current couldn't feed back onto the wires running out to the panels.
McCain on TV News: "You cannot buy a vote in New Hampshire, they have to hear you." He should know since his campaign went broke before he recovered and won the nomination.
I generally like McCain but TV doesn't show his occasional "senior moments".
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sat, 21 Nov 2015 09:32:44 -0500, "Jim Wilkins"

HF monocrystallines, or the new used panels?

Nor his extreme hawk moments. He's too eager to get into ME wars. I'd just as soon pull all our men out (stop the bleeding from our Treasury) and send a few SEALS over some night to take out the bad guys.
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

The current estimate to destroy Daesh from a retired military/scientific advisor and writer whose blog I follow is three divisions and all our A-10s plus SEAD assets. A smaller force could do it but would suffer higher casualties in a longer effort. Rooting them out after firepower forces them to disperse will require a large committment of infantry.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 Nov 2015 07:48:05 -0500, "Jim Wilkins"

Too bad he isn't in charge, eh?
What the brass doesn't seem to "get" is that there will be collateral deaths of innocents during a "war". Dust 'em and get out. Far fewer will die (on both sides) the quicker we do just that.
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

This was his boss, who should have been in charge: http://www.nytimes.com/1995/05/02/obituaries/stefan-t-possony-82-a-scholar-of-international-security-affairs.html https://en.wikipedia.org/wiki/Stefan_Thomas_Possony
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 Nov 2015 09:20:52 -0500, "Jim Wilkins"

I like the guy. Good article about this in the Defense Journal.

WOW, talk about opposite positions in articles. Those 2 don't sound like they're referring to the same guy.
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

They do get it, and it cripples them into inaction. http://www.theguardian.com/world/2015/jul/04/how-britain-and-us-abandoned-srebrenica-massacre-1995 BTW, we still have troops there: https://en.wikipedia.org/wiki/Camp_Bondsteel
Our planes can't attack ISIS oil tankers because their drivers -might- be innocent civilians.
"Good" people do nothing wrong. It doesn't matter if they also do nothing right, even when in command. How often do news helicopters rescue crash victims?
I found two incidents: http://www.cbsnews.com/news/wfor-cbs-miami-crew-helps-locate-crashed-plane-help-rescue-victims/ http://www.wftv.com/news/news/news-helicopter-helps-save-plane-crash-victims-in-/nJgs6/
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

The HF panels are amorphous. I assumed that you knew the difference.
http://www.harborfreight.com/15-watt-12-volt-solar-panel-96418.html "Amorphous crystal panel for superior performance in both bright sun and low light or partial shade"
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 Nov 2015 08:31:32 -0500, "Jim Wilkins"

NON-crystalline silicon? No, I hadn't noticed that.
--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 22 Nov 2015 18:17:29 -0800, the renowned Larry Jaques

Wth is an "amorphous crystal"? They're opposites. Do they mean *poly*crystalline, perhaps?
--sp
--
Best regards,
Spehro Pefhany
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


Do you expect ad copy writers to understand chemistry?
https://en.wikipedia.org/wiki/Amorphous_silicon
Perhaps they are "nanocrystalline." Even glass and rubber may have localized crystalline structure.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 23 Nov 2015 06:43:02 -0500, "Jim Wilkins"

Amorphous silicon is not nanocrystalline, or any other crystalline. It's a non-crystalline allotrope of silicon.
An old friend of mine was working on amorphous silicon solar cells at Harvard back in the '80s. They never achieved the efficiency that was hoped for, but there are some thin-film amorphous silicon cells around, or there were.
--
Ed Huntress

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


A regular crystalline structure has a lower energy and will form spontaneously to the extent allowed by processing conditions which are likely proprietary secrets. http://scitation.aip.org/content/aip/journal/jap/65/5/10.1063/1.342851
https://en.wikipedia.org/wiki/Amorphous_solid "Even amorphous materials have some shortrange order at the atomic length scale due to the nature of chemical bonding .... Even the most advanced structural characterization techniques, such as x-ray diffraction and transmission electron microscopy, have difficulty in distinguishing between amorphous and crystalline structures on these length scales."
I meant the uneducated ad copy writer at Harbor Freight.
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Mon, 23 Nov 2015 11:30:54 -0500, "Jim Wilkins"

The silicon used in thin-film cells typically is doped, or nucleated with hydrogen. These typically wind up being nanocrystalline materials as they're applied to a specific task.
But as-deposited amorphous silicon has no detectable cystal structure, at any scale. The standard diffraction method for detecting amorphous materials may be ambiguous at nanoscales, but there is no *positive* indicator for crystal structure in pure amorpous silicon.
--
Ed Huntress

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload


This disagrees: http://www.sciencedirect.com/science/article/pii/S0168583X11006628 "By high resolution transmission electron microscopy (HRTEM) it was found that the average size of crystals in samples deposited in that way were similar, about 8-9 nm, whereas crystal size distributions were generally broad and varied for different samples."
The crystalline structure may simply have been undetectable with your friend's equipment back in the 1980's.
In the 60's the analysis of crystals by X-Ray diffraction needed a dedicated round room with film or detectors at precisely positionable locations on the walls. Constructive interference from the regularly spaced atoms in crystal structures focuses the X-rays into spots on the wall like a prism. Amorphous material just creates diffuse fog. https://en.wikipedia.org/wiki/X-ray_crystallography
-jsw
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.