Continued from my "good review" post about led tubes, here is a long post about bad bulbs.

I'm hoping someone would take the time to check data led sheet and math.

I have some 25W, 30W, 40W, and 50W versions of these cheap corn bulbs. They are for sale all over the web.

I'll stick with the 50W for now. All seem under powered.
It is listed as 165 X 5730smd, 50 watt, and 4800-lm.
Power: 5W,10W,12W,15W,25W,30W,40W,50W
Lumen: 450-4800lm

From my understanding, this makes sense. 5730 are .5 watt. Lumen also seem possible.

 

These were ordered for replacing 300 watt incandescent. About 4000lm.

They seem to be about half that.

A dispute with seller is at an impasse.
He claims light output is, as advertized, and downplays the input power. Stating, low cost and happy customers, is a defense.

My claim is that, 18 watts cannot produce 4800lm. Even if I don't have the ability to measure.

I don't want to negatively affect his business with bad feedback if there is any chance his specs can be justified.
Looking at light output thru a photo diode on the scope shows a strange wave form that I am unable to interpret.
Driver is capacitor circuit that should not be discussed here.

Could they mean "peak" readings?

 

Hello,

Looking at some websites, 150 lumen / watt is about the maximum possible with leds.

Bertus

 

I agree. 18W is more like 1600 lm and 30W ~2600 lm.

But my guess is the seller is genuinely misguided and not a scammer. It seems lots of people have 0 idea what a lumen is. Even on amazon there are torches claimed to deliver 400 lm. Their brightness is nowhere near the cheapo 400lm bulb in my bathroom.

 

Any chance your killiwatt meter is incorrect? Is a cross-check possible with another meter?

 

I checked with two killawatt meters and amprobe power analyzer.
When checking incandescent and CFL,they are right on the money.
Also checked 4ft and 8ft led tubes from several companies.

I expect exaggeration of lumen.
But watts is something easy to measure. Like grams or meters. You can only go so far with measurement error.

What is sad is that, these are capable of full output if driven hard enough. Could be they didn't last or couldn't dump the heat, so they dialed them back.
No aluminum. Just plastic.

I gave seller every chance to come clean, or even take me seriously.
Then turned down a silly offer of a few bucks off, and left honest feed back. Hoping to help the next guy.

 

I was just thinking. This would be a great start for a lighting project.

165 X .5 watt led pre-wired. The side strips all slide out and could be open up into a star pattern around the center.

All it needs is a driver and a flat heat sink to glue the strips to.

If a senior member in the USA wanted to take time to reverse engineer or Sim this for me, I'd send one. It's all out in the open.
I tried it a couple times, but just too frustrated with them.




E27-165LED 50W Size: 210*80mm (Length*width)

 

Hello,

You might want to have a look at these sites:
http://www.popularmechanics.com/tec...scent-vs-led-ultimate-light-bulb-test#slide-1
http://www.ledinside.com/news/2014/7/us_doe_to_amend_led_bulb_test_procedures

http://www.theledlight.com/led-definitions.html
http://www.theledlight.com/lumens.html
http://www.theledlight.com/about-led-light-bulbs.html

Bertus

 

Hello,

Looking at the graph on the following site, they expect a maximum of 200 lumens / watt in 2030:
http://www.eia.gov/todayinenergy/detail.cfm?id=15471

Bertus