Digest for sci.electronics.repair@googlegroups.com - 10 updates in 3 topics

9:40 AM Penedão
puli3ib@gmail.com: May 28 06:35AM -0700

Hi Cristian. I´m looking for the same BIOS. Do you have it?
Look165 <look165@numericable.fr>: May 28 04:04PM +0200

Grains BIOS repair, they have a lot of BIOS.
 
Tim R <timothy42b@aol.com>: May 27 03:54PM -0700

On Saturday, May 25, 2019 at 4:42:30 PM UTC-4, Jeff Liebermann wrote:
> lights and read something on how they work.
> [Quiz] Why are plants green, but LED grow lights produce very little
> green light?
 
I'm not into indoor gardening and doubt I ever will be - not that many years left to experiment.
 
In the 70s I did an indoor garden for a season. It did very well with four foot fluourescents, the standard T12 that was in use back then. I think I used six tubes, four cool white and two warm white, for the balance.
 
I've read about LED grow lights and it all looked like advertising hype with no science behind it. Perhaps there have been some advances. I've been told the illegal growers mostly used metal halide fixtures, not something I'd want in my house.
Terry Schwartz <tschw10117@aol.com>: May 27 04:34PM -0700


> CFLs don't explode or start fires. One thing I've encountered are many people who describe events that are obviously not explosions as explosions.
 
> Green plants absorb & use red & blue light. Green light, when growing, is wasted.
 
> NT
 
I had a CFL start on fire. It was mounted base up in a can fixture. Luckily I was in the room at the time, or it might have taken down the entire house.
Jeff Liebermann <jeffl@cruzio.com>: May 27 05:14PM -0700

On Mon, 27 May 2019 15:54:21 -0700 (PDT), Tim R <timothy42b@aol.com>
wrote:
 
>> green light?
 
>I'm not into indoor gardening and doubt I ever will be - not that
>many years left to experiment.
 
Not a problem if you don't inhale.
 
>with four foot fluourescents, the standard T12 that was in use back
>then. I think I used six tubes, four cool white and two warm white,
>for the balance.
 
At the time, the authorities were monitoring household electric bills.
Any sudden and stable rise in consumption implied that the household
was using artificial lighting to grow something.
 
>I've read about LED grow lights and it all looked like advertising
>hype with no science behind it. Perhaps there have been some advances.
 
Is NASA a sufficiently credible source?
"Sole-Source Lighting for Controlled-Environment Agriculture"
<https://ntrs.nasa.gov/search.jsp?R=20150009399>
There's been quite a bit of research on agriculture in space and in
non-solar environments.
 
Try searching Google Scholar for research reports:
<https://scholar.google.com>
For example:
<https://scholar.google.com/scholar?hl=en&as_sdt=1%2C5&as_vis=1&q=LED+grow+light+agriculture&btnG=>
 
>I've been told the illegal growers mostly used metal halide fixtures,
>not something I'd want in my house.
 
It's now legal to grow marijuana in California. Much of the indoor
and underground farms have moved outdoors.
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Jeff Liebermann <jeffl@cruzio.com>: May 27 05:23PM -0700

>> green light?
>> <https://www.google.com/search?q=LED+grow+lights&tbm=isch>
 
>Green plants absorb & use red & blue light. Green light, when growing, is wasted.
 
Close enough but not quite complete. We see objects by the
wavelengths (colors) the object does NOT absorb, but does reflect.
Plants are generally green and therefore do NOT absorb green
wavelengths. Therefore, wasting power generating light in the green
part of the spectrum is largely wasted on plants.
 
Or so I thought.
"Sole-Source Lighting for Controlled-Environment Agriculture"
<https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150009399.pdf>
From a summary of the above article, it seems that plants do find a
little green light useful:
<https://advancedledlights.com/blog/technology/nasa-research-optimum-light-wavelengths-plant-growth/>
Green Light (500 - 600 nm) was once thought not to be necessary
for plants, but recent studies have discovered this wavelength
penetrates through thick top canopies to support the leaves in
the lower canopy.
 
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Tim R <timothy42b@aol.com>: May 27 05:53PM -0700

Thanks for the links, and the google scholar reference.
 
Interesting stuff.
 
I guess I probably can't buy high powered blue and red LED lamps at Home Depot. I guess I could test a high watt LED bulb over a plant some time, something legal of course.
 
I'm no longer worried about my super CFL exploding. I got my thermometer out to test it, and................it didn't work. The bulb I mean. The other lamps in the bag work okay, so I didn't get totally taken, but I was looking forward to seeing a miniature sun in my basement.
tabbypurr@gmail.com: May 27 11:10PM -0700

On Tuesday, 28 May 2019 01:14:10 UTC+1, Jeff Liebermann wrote:
 
> At the time, the authorities were monitoring household electric bills.
> Any sudden and stable rise in consumption implied that the household
> was using artificial lighting to grow something.
 
Now the technique is to fly over with IR imagine camera, and see hot lofts.
 
> <https://scholar.google.com/scholar?hl=en&as_sdt=1%2C5&as_vis=1&q=LED+grow+light+agriculture&btnG=>
 
> >I've been told the illegal growers mostly used metal halide fixtures,
> >not something I'd want in my house.
 
AIUI LP sodium are still more efficient, but not spectrally complete, so not suitable as the sole light source.
 
 
NT
tabbypurr@gmail.com: May 27 11:13PM -0700

On Tuesday, 28 May 2019 01:23:19 UTC+1, Jeff Liebermann wrote:
> for plants, but recent studies have discovered this wavelength
> penetrates through thick top canopies to support the leaves in
> the lower canopy.
 
If you're growing at home, the green is nearly all wasted as little gets absorbed. It therefore doesn't make sense to produce it - subject to an assortment of conditions, eg if you want white light for other reasons.
 
 
NT
Tim R <timothy42b@aol.com>: May 27 04:02PM -0700

I think the Curtis Mathes VCR I bought had a wired remote.
 
I paid extra for a lifetime membership on video rentals. Haven't got my money's worth yet.
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