100W COB LEDs on AliExpress or Amazon

W

Winfield Hill

Guest
Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.


--
Thanks,
- Win
 
On 9 Jan 2020 18:53:03 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.
Click to expand...

I did try pulsing some Cree white LEDs, to see how fast the phosphor
was. It was as fast as I could instrument, a few ns.

A 100 watt COB LED must be blinding.

At a smaller scale, the cheap "corn lamps" have some interesting stuff
inside.

https://www.dropbox.com/s/7oy70pxnc1c2d63/Corn_Lamp.JPG?raw=1

https://www.dropbox.com/s/4eb3fclkk7kq6qv/Corn_2.JPG?raw=1

High voltage PV coupler?


--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.

"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
jlarkin@highlandsniptechnology.com wrote...
On 9 Jan 2020, Winfield Hill wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.

I did try pulsing some Cree white LEDs, to see
how fast the phosphor was. It was as fast as
I could instrument, a few ns.

A 100 watt COB LED must be blinding.
Click to expand...

Yes, you can't look at them. I added some
measurements to the RIS-796 DropBox folder.


--
Thanks,
- Win
 
On Thursday, 9 January 2020 21:53:19 UTC-5, Winfield Hill wrote:
Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.


--
Thanks,
- Win
Click to expand...

Looking forward to giving this a try, Win.

I've got some lower voltage ones 10W coming that
should allow comparison. They were super cheap.

Some of the really cheap ones seem to have a few dim
LEDs so they're probably production fallouts. Shouldn't
affect the overall performance much unless there's a
systemic issue that affects the pulsed power capability
like bad wirebonds.

From what I can tell the yellow phosphor has effectively
zero persistence. The warm white ones have a bit of red
phosphor as well, might be similar.

I have a few grams of the raw NYAG yellow 6um (extra fine
grade) 545nm phosphor, by the way.

-
Best regards,
--Spehro Pefhany
 
speff wrote...
I have a few grams of the raw NYAG yellow 6um
(extra fine grade) 545nm phosphor, by the way.
Click to expand...

How do you apply a phosphor to an LED surface?


--
Thanks,
- Win
 
Winfield Hill <winfieldhill@yahoo.com> wrote in
news:qva3o70dhq@drn.newsguy.com:

speff wrote...

I have a few grams of the raw NYAG yellow 6um
(extra fine grade) 545nm phosphor, by the way.

How do you apply a phosphor to an LED surface?
Click to expand...

Very carefully.
 
On 10 Jan 2020 07:03:35 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

speff wrote...

I have a few grams of the raw NYAG yellow 6um
(extra fine grade) 545nm phosphor, by the way.

How do you apply a phosphor to an LED surface?
Click to expand...

It's usually mixed into epoxy and glob-topped on the chip.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.

"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
 
On Friday, 10 January 2020 17:15:19 UTC, jla...@highlandsniptechnology.com
How do you apply a phosphor to an LED surface?

It's usually mixed into epoxy and glob-topped on the chip.
Click to expand...

More likely silicone, as it is quite soft.

John
 
On Thu, 09 Jan 2020 18:53:03 -0800, Winfield Hill wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China). It drops about 33V at 3A,
for 100W power consumption. Anticipating Sphero's work, I'm playing
with pulsing to higher currents,
but this need to be done with the RIS-796, rather than switching a
power supply on/off.
I destroyed my LED, trying to get data at 15 amps. I anticipate >50V,
1.3kW at 20A. Sphero may go higher, >30A, towards 100V.
Click to expand...
YIKES! 100 W?!? I have built 4 units, now, of a strip of 20 1W Cree
LEDs on PC board material, to replace dual 48" fluorescent fixtures.
I got commercial LED power supplies, they draw 21 W from the mains, using
a real power meter. I'm really happy with them, they are in our kitchen,
and get a HUGE amount of daily use.

Jon
 
On Friday, 10 January 2020 10:03:56 UTC-5, Winfield Hill wrote:
speff wrote...

I have a few grams of the raw NYAG yellow 6um
(extra fine grade) 545nm phosphor, by the way.

How do you apply a phosphor to an LED surface?


--
Thanks,
- Win
Click to expand...

It's typically compounded and mixed with dimethyl
or phenyl silicone encapsulant. Epoxy is a better match for the
index of refraction but too rigid for the thermal
problems that come with high-power LEDs. The
phenyl silicone has less of a problem from
yellowing with age.

Best regards,
Spehro Pefhany
 
On Friday, 10 January 2020 15:33:24 UTC-5, speff wrote:
On Friday, 10 January 2020 10:03:56 UTC-5, Winfield Hill wrote:
speff wrote...

I have a few grams of the raw NYAG yellow 6um
(extra fine grade) 545nm phosphor, by the way.

How do you apply a phosphor to an LED surface?


--
Thanks,
- Win

It's typically compounded and mixed with dimethyl
or phenyl silicone encapsulant. Epoxy is a better match for the
index of refraction but too rigid for the thermal
problems that come with high-power LEDs. The
phenyl silicone has less of a problem from
yellowing with age.

Best regards,
Spehro Pefhany
Click to expand...

P.S. The R&D kits I've seen use a two-component silicone, but
apparently UV cured is also possible- but the phosphor tends to
absorb the UV and re-emit it at a useless longer wavelength so
it screws up the cure times.

Best regards,
Spehro Pefhany
 
On Thursday, January 9, 2020 at 9:53:19 PM UTC-5, Winfield Hill wrote:
Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.


--
Thanks,
- Win
Click to expand...

I recently bought some 50 watt flood lamps off Ali-Express. Vendors sell 110 volt and 220 Volt units. I ordered three 110 volt ones. And received 1 110 volt and 2 220 volt units. They are 5 leds by 10 leds and claim to be 4500 lumens. Larger and smaller ones are available. They do have some ics side so may not be good for pulsed light. They were just under
$4 each.

Dan
 
On Friday, January 10, 2020 at 2:54:48 PM UTC-5, Jon Elson wrote:
On Thu, 09 Jan 2020 18:53:03 -0800, Winfield Hill wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China). It drops about 33V at 3A,
for 100W power consumption. Anticipating Sphero's work, I'm playing
with pulsing to higher currents,
but this need to be done with the RIS-796, rather than switching a
power supply on/off.
I destroyed my LED, trying to get data at 15 amps. I anticipate >50V,
1.3kW at 20A. Sphero may go higher, >30A, towards 100V.
YIKES! 100 W?!? I have built 4 units, now, of a strip of 20 1W Cree
LEDs on PC board material, to replace dual 48" fluorescent fixtures.
I got commercial LED power supplies, they draw 21 W from the mains, using
a real power meter. I'm really happy with them, they are in our kitchen,
and get a HUGE amount of daily use.
Click to expand...

I bought some LED fixtures equivalent to the 48 inch shop lights that are not only as bright but include motion detectors so you don't need to switch them on and off. $25 at Costco. I haven't seen them in a while though. It might be worth bugging them about to see if they will get more in.

I also bought some LED strips with about 1 LED every inch or so. I hung it over my washer/dryer and each LED created a shadow. It was a bizarre effect and I got rid of them. There's a reason for a diffuser.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
 
How do you cool them?
On 9 Jan 2020 18:53:03 -0800, Winfield Hill <winfieldhill@yahoo.com>
wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China).
It drops about 33V at 3A, for 100W power
consumption. Anticipating Sphero's work,
I'm playing with pulsing to higher currents,
but this need to be done with the RIS-796,
rather than switching a power supply on/off.
I destroyed my LED, trying to get data at
15 amps. I anticipate >50V, 1.3kW at 20A.
Sphero may go higher, >30A, towards 100V.

Anybody played with these 100-element LEDs?
One bloke power 10 of them at 100W each and
outshined headlights, lit up a mountainside.
But pulsing could be useful for photography.
Click to expand...
 
LM wrote...
How do you cool them?
Click to expand...

They need to be mounted on a heatsink, at
least to add thermal mass. If the pulsing
duty cycle is very low the heatsink can be
modest, but if the pulse current increases
the power dissipation by say 10x, then a
10% duty cycle will be 100 watts, and even
a large heatsink will need a serious fan.


--
Thanks,
- Win
 
dcaster@krl.org wrote...
I recently bought some 50 watt flood lamps off Ali-Express.
Vendors sell 110 volt and 220 Volt units.
Click to expand...

The pulsed high-current approach requires bare LED
stacks, without any series AC-current control ICs.

I ordered three 110 volt ones. And received 1 110 volt
and 2 220 volt units.
Click to expand...

They are certainly convenient for AC offline use,
but the 220V ones don't work on 110V, right?


--
Thanks,
- Win
 
On Friday, January 10, 2020 at 2:54:48 PM UTC-5, Jon Elson wrote:
On Thu, 09 Jan 2020 18:53:03 -0800, Winfield Hill wrote:

Bought some 100W COB LEDs on Amazon for $10
(quite a bit more than I paid from China). It drops about 33V at 3A,
for 100W power consumption. Anticipating Sphero's work, I'm playing
with pulsing to higher currents,
but this need to be done with the RIS-796, rather than switching a
power supply on/off.
I destroyed my LED, trying to get data at 15 amps. I anticipate >50V,
1.3kW at 20A. Sphero may go higher, >30A, towards 100V.
YIKES! 100 W?!? I have built 4 units, now, of a strip of 20 1W Cree
LEDs on PC board material, to replace dual 48" fluorescent fixtures.
I got commercial LED power supplies, they draw 21 W from the mains, using
a real power meter. I'm really happy with them, they are in our kitchen,
and get a HUGE amount of daily use.

Jon
Click to expand...

They make these now as led replacements for 4' (four foot) florescent
lamp bulbs. Most likely other sizes too.

George H.
 
On Friday, January 10, 2020 at 8:30:17 PM UTC-5, Winfield Hill wrote:
dcaster@krl.org wrote...

I recently bought some 50 watt flood latmps off Ali-Express.
Vendors sell 110 volt and 220 Volt units.

The pulsed high-current approach requires bare LED
stacks, without any series AC-current control ICs.

I ordered three 110 volt ones. And received 1 110 volt
and 2 220 volt units.

They are certainly convenient for AC offline use,
but the 220V ones don't work on 110V, right?


The 220 volt one that I tested had a lot of the leds produce some light, but no where normal brightness. In other words it did not work on 110v.
Click to expand...


--
Thanks,
- Win
Click to expand...
 
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