Welding helmets (Hobby use)

On Mon, 23 Nov 2015 13:08:10 -0500, "Jim Wilkins"


Ok, I'm certainly not up-to-date on them (or on much else <g>), so I'll defer.
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On Mon, 23 Nov 2015 14:19:25 -0500, Ed Huntress

WAIT a minute. That paper is about hydrogen-doped amorphous/nanocrystalline silicon. It's been known for decades that doping with hydrogen causes amorphous silicon to adopt a nanocrystalline structure.
If that's the evidence, then I think the jury is still out on pure amorphous silicon.
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Yep, there are many observations we can't explain because we can't yet measure well enough at the atomic level, especislly below the surface.
That's why I objected to your blanket statement that amorphous silicon has no nanocrystals, in practical mass production versus by theoretical definition. I suspect the solar panel makers don't waste the time and money to check for them, and I once built semiconductor automatic test equipment for Teradyne and was a lab tech at Unitrode.
https://en.wikipedia.org/wiki/Staebler%E2%80%93Wronski_effect My amorphous Harbor Freight panels will barely reach 0.6A instead of the 0.86A they are rated for. When I bought them I didn't have the test equipment to measure their maximum power point so I don't know if they met spec even then. No one offered a better kit at a local store.
The surplus monocrystalline panels have degraded in reverse leakage current but not output. At noon they were pushing 85W into the battery according to the power meter.
-jsw
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On Monday, November 23, 2015 at 9:41:50 AM UTC-5, Ed Huntress wrote:

I think there are still amorphous solar cells around. The solar cells in calculators were pretty much all amorphous cells. Cheap, not too efficient, but adequate for calculators.
Dan
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On Mon, 23 Nov 2015 11:12:20 -0800 (PST), " snipped-for-privacy@krl.org"

Yes, looking around, I see that's one place where they're still used. There also are a variety of experimental multi-layer thin-film cells that contain a layer of amorphous silicon, and which have much higher efficiency. Sony has made some, and there is a large installation of them at an agriculture station somewhere in NJ.
The problem Sony had with theirs, initially, was relatively short life. I don't know if that's still the case.
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No crystal shape but a crystal. Likely a translation from xxxx to English.
And missed.
Some experimentalist make it out of plastic and other materials.
Martin
On 11/22/2015 11:27 PM, Spehro Pefhany wrote:

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On Sun, 22 Nov 2015 08:31:32 -0500, "Jim Wilkins"

I went out and added a battery to the array and hooked up the inverter. It runs the electric chainsaw just fine, thankfully. It's all boxed back up for the winter now.
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On Sat, 21 Nov 2015 01:15:40 -0500, "Jim Wilkins"

I'm OK with the original PWM ctrl on the HF array, but after reading what MPPT can do with arrays wired at 24v or more, I definitely want one for my larger array when I get it. I'm on the fence between a Taiwanese brand and an Outback, either 60 or 80A models for the possibility of additional panels in the coming years.
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I put them with this temporarily wired meter. (Amazon.com product link shortened)

I heat water for laundry in kettles on the woodstove.
-jsw
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On Thu, 19 Nov 2015 07:26:15 -0500, "Jim Wilkins"

Picked up one of the little $13 AODE aluminum-cased wattmeters you mentioned last time, thanks. It works well.

I can't stand wood heat, but may when the SHTF. Need to buy one of those little guys for $60, JIC. http://tinyurl.com/qdvp8lt
Does anyone _like_ the smell of wood smoke in the house? Then again, having heat would be A Good Thing(tm), if the natural gas goes out. I wonder if they keep generators for the nat gas pumps, and how long they'd last once the pumps quit, if not. Delivery pressure is 1.5psi, so it may last a long while.
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wrote:

Don't trust the least significant digit of the Amps readout. Mine actually resolves to 0.2A and fakes higher sensitivity by dithering the raw value. The wires are too small for its full-scale Amp capacity. Otherwise it's a very handy gadget for checking and reconditioning older batteries. http://www.artecing.com.uy/pdf/guias_megger/New%20-%20BatteryTestingGuide_en_LR.pdf
I've found a DC resistance check while periodically topping off a battery to be a good, quick indication of when it needs attention. I haven't found a good Net reference to this yet, all descriptions of battery impedance testing I've seen are from companies trying to sell fancy equipment for it, just like desulfation.
The Bayite meter is more suited to a fixed installation, with the shunt in the battery cable and the readout at the control panel. I added a DPDT switch to reverse the (fused) shunt sense leads so it can read either charge or discharge current. My inverter is an APC1400 UPS which can draw over 50A continuously, probably too much for the Aode's wires.

A properly installed and operated wood stove doesn't emit smoke into the house, all leaks draw air in. I've learned how to set the draft for complete combustion with little or no visible smoke from the chimney.
That wasn't easy. I have thermocouples on the basement stove with readouts in the kitchen and bedroom and an outdoor mirror plus a night vision camera to observe the chimney top. It's very convenient to know when to tend the stove or the food cooking on it from upstairs.
These are cheap and good enough if you can't find (and fix) surplus lab instruments as I did. (Amazon.com product link shortened)
-jsw
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On Fri, 20 Nov 2015 08:18:34 -0500, "Jim Wilkins"

I guess I'll have to remember to crank the draft wide open to load firewood, but I've never seen a house yet whose wood stove didn't blow smoke into it, regardless of settings. <shrug>

Hah, that's cool! Self-surveilled. Are those remote t-coups?

I have a thermocouple available with my Mastech DVM.
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wrote:

I can't say my stove -never- smoulders, catches and backfires but it's rare. Lighting it may be smoky until the cold draft down the chimney reverses. Burning one sheet of crumpled newspaper in the upper chamber is usually enough to get the air flowing up long enough to light the kindling.
When the stove is up to temperature the draft vacuum runs between 0.08 and 0.15 inches of water, enough to make the air inlet whistle. (Amazon.com product link shortened)
I can remove the cleanout cap in the inside flue pipe without releasing smoke into the house.

I found spools of cheaper thermocouple extension wire at the surplus store and ran them from the stove in the basement to the kitchen and bedroom. http://www.awcwire.com/productspec.aspx?id=pvc-single-pair The X indicates extension wire which matches real thermocouple wire only near room temperature.
The dollar a pound price for regular wire was better than a dollar a foot for real thermocouple wire. Omega charges only a little more for high-quality new wire: http://www.omega.com/pptst/XC_K_TC_WIRE.html
These panel jacks http://www.omega.com/pptst/MPJ.html snap into these wall outlet faceplates with only a little trimming https://www.computercablestore.com/12-port-keystone-faceplate-dual-gang-white-3

If my Tekpower DVM is like it the cold compensation isn't exact and the linearization is incorrect. The PC datalogging program corrects the linearization and shows a difference from the meter's display. The error is only a few degrees C. When I log the house's heating or cooling rates I record a few temperature points and times from the lab instruments for calibration correction. They read within 1 degree C at freezing and boiling regardless of room temperature.
-jsw
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On Sat, 21 Nov 2015 00:49:41 -0500, "Jim Wilkins"

I've always done the wadded paper at the chimney trick to get the smoke drafted up that way from the start.

Har, he even measured it! <g> (Yup, Gadgaholic) I guess my old automotive vacuum gauge won't cut it.

Cool.

For K t-coup wire?!? Seems way heavy.

Ensuring a Kosher and clean setup.

http://tinyurl.com/ofygs9s $4.56 delivered.

I think Tekpower bought them, so they're probably nearly identical.

If and when I get into datalogging (most of the new MPPT controllers have that capability), I'll remember this.
Now that I'm retired, I have all sorts of projects lined up and ready to go, and I'm gaining the time to get around to them. You're NOT helping. <vbg>
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On Saturday, November 21, 2015 at 4:49:43 PM UTC-5, Larry Jaques wrote:

My wood stove has an opening such that I can use a small propane torch to preheat the air in the chimney. So I do that and then close that opening and use the torch to light the kindling. I refill the 16 oz propane tanks from a 20 lb cylinder.
Dan
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Has your refilled cylinder ever leaked? -jsw
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On Sunday, November 22, 2015 at 6:57:11 AM UTC-5, Jim Wilkins wrote:

I have bought a number of small propane torches at garage sales. So when I refill a tank, I put a torch on the tank. So no problem with leaks.
And I do not mess with the relief valve. To refill a cylinder, I put the c ylinder in the freezer and refill after the cylinder is cold. If the tank is completely empty, I may have to cool it and refill it more than once. B est to do this when the cylinder is about 1/4 full. The steel tank does no t have much thermal mass.
But to answer your question, yes I have had refilled cylinders leak.
Dan
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On Sunday, November 22, 2015 at 6:57:11 AM UTC-5, Jim Wilkins wrote:

I have bought a number of small propane torches at garage sales. So when I refill a tank, I put a torch on the tank. So no problem with leaks.
And I do not mess with the relief valve. To refill a cylinder, I put the cylinder in the freezer and refill after the cylinder is cold. If the tank is completely empty, I may have to cool it and refill it more than once. Best to do this when the cylinder is about 1/4 full. The steel tank does not have much thermal mass.
But to answer your question, yes I have had refilled cylinders leak.
Dan =============I bought the adapter fitting and extension hose but haven't used them yet. Now might be a good time since the weather is 50's during the day and 20's at night. I could insulate the big tank with bubble wrap to retain the day's heat and let it fill the small one outdoors overnight.
-jsw
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wrote:

https://en.wikipedia.org/wiki/Compressor_station "A small portion of natural gas from the pipeline is burned to power the turbine."
"Commonly known as "recips," these engines are fueled by natural gas from the pipeline."
I never investigated how reliable or susceptible to sabotage the gas lines may be. Electricity on poles is demonstrably vulnerable but easy to repair. Our ice storms and distracted drivers keep the crews in practice.
My automatic backup is the house's original baseboard electric heat, set to come on at 50F. I have these on the wall thermostat wires to warn me if they turn on or I forget to set the bathroom back after showering. (Amazon.com product link shortened) In an unlit hallway the LED is visible at a much lower current than they list. There's no sharp 'turn-on point", they just get brighter as the current increases.
-jsw
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On Fri, 20 Nov 2015 09:39:10 -0500, "Jim Wilkins"

Bloody mahvelous!

Transformers are far too susceptible to sabotage, too, especially "hidden" behind chain link fences.

I ripped all those out in 2002, less than 2 weeks after I moved in this house. CROM, those suck. 40F floor, 65F in the middle, and 90F at your head when you stand up, all while sucking 4kWh per unit. The 96% efficient HVAC cost me $6k, but it blows the air around and keeps everything mixed so the temp at the floor is the same at the ceiling, more or less. I like to stand under the vent when I come in from outside in the winter. How can you stand baseboard heat, especially when it's not on PV to pay for it?

I guess with -those- heaters, you can save money and buy the 1AAC setpoint units for the least cost. And each probably shines bright enough to light your whole house. <g>
I see that you're a fellow gadget freak.
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