Re: (ET) ET Headlights

[stevesgroups verizon net]

I bought a light bar from Amazon to put on my snowblower:

Auxbeam® 7.5" 36W 3D LED Work Light Bar 3600lm DC 9-40V CREE Spot Beam 30 
degree Waterproof for Off-road Truck Jeep Boat ATV Motorcycle Van

It seems like good quality and seems to put out good light, but I haven't 
really tried it out but for a few minutes:

https://farm2.staticflickr.com/1623/25239672462_38af3e36cf_m.jpg

I'm hoping the 40V rating is real and it will last - we will see, though 
maybe it will be next year before we get snow again.

I had converted my headlights to 36V, but I had to isolate everything from 
the frame. At some point I will go with LEDs for the headlights too. Might 
just use another light bar but it would be nice to have something to fit 
in where the current bulbs go. I have a bag of the 36V bulbs if anyone 
needs any.

-SteveS
 
 
On 02/27/16, Steve Welch<oneoldbird icloud com> wrote:
 
David & all,

Installed the new LEDs and cut new plastic clear lenses for the lamps. I'd 
say brightness is slightly improved over the standard incandescent, but 
not by a huge amount. Probably some of the improvement may be due to the 
colder light quality, but there may be some increase in absolute 
brightness. 

Since I don't really do much at night, I will probably run these until 
something dies, however if I was looking for a substantial improvement I 
would look elsewhere. Maybe to the ones Eric Adams recently posted 
about... 

I very nearly went with an off-road LED light bar that would have been 
similar in cost to the two of these bulbs and may well have been a better 
light. I would say that if the brightness of these new bulbs had been 
focused specifically on the turf, it might be adequate for dusk/dark 
mowing. But of course, it is just as limited by the stock reflectors as 
the stock bulbs are. Oh well - at this price point I don't mind a bit of 
trial-and-error. 

Best,

Steve


On Feb 20, 2016, at 1:44 AM, David Roden <etpost drmm net> wrote:

> On 19 Feb 2016 at 19:26, Steve Welch wrote:
> 
>> direct replacement LEDs: 
>> http://www.m4products.com/1142-17-5630-nw-natural-white-elite-series-wi
>> th-brighter-samsung-5630-leds-1142-1076-ba15d-base/ 
>> 
> 
> Watch out for those "calculated lumens." That usually means the spec 
> writers have simply summed the rated maximum output of the emitter chips 
> used. The catch is that the chips can't all run at maximum output 
> continuously because they'd overheat, so they never deliver their full 
> outputs in these retrofit bulbs.
> 
> I don't own a meter that measures lumens. That's lab stuff and 
> expensive. 
> To approximate the lumen output of various CF and LED retrofits, I use 2 
> cardboard boxes (they really should be spheres) of the same size, lined 
> with 
> white paper. I turn off the room lights and put the test light in one 
> box. 
> Then I try various incandescents in the other box until I find the 
> closest 
> match in apparent light output. (The human eye is actually pretty good 
> at 
> matching apparent illumination.) Since the incandesent bulbs have rated 
> lumen outputs, that gives me a rough estimate of the retrofit's lumen 
> output.
> 
> I've yet to try a 12v like this, but I've tried a few 120v multi-chip 
> ("ear 
> of corn" type) LED retrofits, all of them made in China. I find that 
> they 
> typically produce about one-third to one-half the claimed output. 
> 
> I looked on the website above. M4 products claim 640 "calculated lumens" 
> for this little guy.
> 
> They say it uses Samsung 5630 chips, but I can't quite tell from the 
> photos 
> how many (usually the specs say, but these don't). It looks like it has 
> 5 
> on the end and 5 or 6 pair around the sides, so maybe 15 or 17. 
> 
> The Samsung 5630 chip comes in various output ranges from S1 to S3. 
> Depending on range, it's rated for an absolute max of 28 to 32 lumens at 
> 4000K CT. Thus I don't see any way that this retrofit manufacturer (more 
> likely importer) could even calculate 640 lumens. Seventeen of these 
> chips 
> would have a "calculated" output of 476 to 544 lumens. And as I say, you 
> can't expect to get that output in the real world anyway.
> 
> http://www.samsung.com/global/business/business-
> images/led/file/product/lighting/201312/Data_Sheet_LM561B_Rev.006.pdf
> 
> Another odd thing. The retrofit bulb specs claim a CT of 4500K. Samsung 
> doesn't show a 4500K chip in the spec sheet. Tthey jump from 4000K to 
> 5000K. That could be an error in the bulb specs on the website, or the 
> chips they're using might be knockoffs. 
> 
> I'd say put a retrofit in one side, incandescent in the other, and try 
> the 
> lights. If the pattern is similar enough, you can usually tell which is 
> lighting up the garage wall better. And even if the retrofit has less 
> output than the GE factory incandescent, you may find that you see 
> better at 
> night with it because of its higher CT.
> 
> Please report back on how it goes. 
> 
> In the end, if you're satisfied with the performance and think you got 
> your 
> money's worth, then that's what counts. 
> 
> 
> David Roden - Akron, Ohio, USA
> 
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