Re: (ET) ET Headlights

[Steve Welch <oneoldbird icloud com>]

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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