LED test / review – Osram OSTAR Projection Compact LE UW Q8WP – Black Flat's big brother, very high luminance at higher flux!

56 posts / 0 new
Last post
Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

The_Driver wrote:
Because it’s more relevant for many lights where you can’t or don’t want to switch out the driver.
The real efficiency is of course much better compared to older LEDs.

I see your point. However this is not efficiency of the LED but rather the LED-driver combo.

Very low Vf makes linear drivers inefficient. But at the same time it enables use of very efficient buck drivers w/out falling out of regulation, leading to better overall flashlight efficiency than that of a high-Vf LED + linear.
Sadly, at higher cost. And even with 2 mm² LED currents get high enough to cause driver availability problems.

The_Driver
The_Driver's picture
Offline
Last seen: 19 hours 43 min ago
Joined: 10/20/2016 - 05:51
Posts: 1431
Location: Germany

Agro wrote:
The_Driver wrote:
Because it’s more relevant for many lights where you can’t or don’t want to switch out the driver.
The real efficiency is of course much better compared to older LEDs.

I see your point. However this is not efficiency of the LED but rather the LED-driver combo.

Very low Vf makes linear drivers inefficient. But at the same time it enables use of very efficient buck drivers w/out falling out of regulation, leading to better overall flashlight efficiency than that of a high-Vf LED + linear.
Sadly, at higher cost. And even with 2 mm² LED currents get high enough to cause driver availability problems.

Yes, we need compact high-current buck & buck-boost drivers for 3V LEDs. Although it doesn’t really make much of a difference at high currents. At medium currents they start to make a lot of sense. The LD4 linear driver is a very good, cheap option at high-currents. It’s also rather compact.

luminarium iaculator
luminarium iaculator's picture
Offline
Last seen: 2 days 3 hours ago
Joined: 07/07/2013 - 09:09
Posts: 2331
Location: X
led4power wrote:

Big disadvantage of XP-G2 is that it’s not factory undomed (tint issues after dedoming) and because of very high Vf (and often with large Vf variation between LEDs) light output starts to decrease almost immediately with single cells lights; this led can be driven with CC for a long time before output starts to fade.

Where someone sees disadvantages someone else sees advantage…

XP-G2 is still no 1 emitter in my single cell thrower builds (easy re flowing, easy de doming, easy centering, constant and very high lux performance, very reliable, imho the best and unbeatable led for single cell fet thrower lights).

Imho there is no big performance drop at all… Well it does happen because of DD or turbo mode of Fet driver with sagging 4.3-4,6A of current but that is nothing drastic comparing to XM or XP emitters in same configuration.

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

The_Driver wrote:
The LD4 linear driver is a very good, cheap option at high-currents. It’s also rather compact.

I absolutely love this driver. I mean the hardware features-size-price. But software doesn’t support e-switch. And is not open source, so I can’t customize it to my preferences.
Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

"koef3" wrote:
Because of the not symmetric shape the use of center rings made with lathe is not recommended

Would it be a problem to make a ring with too large, rectangular, centre opening and then adding a plug to make the opening acentric?
Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

According to https://www.production-partner.de/people/osram-ostar-stage/ the glass lens on top of Ostar Stage LEDs exists only to protect bond wires. There’s air between it and the actual LED.
I assume Q8WP is the same. If that’s so, removal of glass will make it brighter than the Blackie.

The_Driver
The_Driver's picture
Offline
Last seen: 19 hours 43 min ago
Joined: 10/20/2016 - 05:51
Posts: 1431
Location: Germany
Agro wrote:
According to https://www.production-partner.de/people/osram-ostar-stage/ the glass lens on top of Ostar Stage LEDs exists only to protect bond wires. There’s air between it and the actual LED. I assume Q8WP is the same. If that’s so, removal of glass will make it brighter than the Blackie.

It’s ar-coated on both sides though. So you might gain maybe 2%. Still, better than nothing. Thumbs Up

Enderman
Enderman's picture
Offline
Last seen: 2 days 4 hours ago
Joined: 11/03/2016 - 22:42
Posts: 4000
Location: Vancouver, Canada

It’s less than 1% output difference, not worth the risk since the glass is also bonded to the paths on the PCB and might rip them off.

koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

For Q8WP I can confirm, you can remove the glass cover without damaging the bonding wires.

It happened to me accidentally as I used a center ring which not fitted properly to the LED. However the gain in flux is absolutely negligable and also the tint hasn't changed.

 

@Agro: I would not recommend this since such center rings are used to 'hold' the reflector at the desired place at the LED and have to withstand high forces of it. I would doing so only if the reflector is screwed in but in this case there is no need either.

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

I spotted a minor weirdness in the datasheet.
The peak output is not at cool temps. It’s not at 25°C. It’s higher.
Furthermore, the loss from heating up to 85°C is just 3%.

I’m not sure if we should believe this…if yes, we can expect it to have real-life performance quite close to this test.

Enderman
Enderman's picture
Offline
Last seen: 2 days 4 hours ago
Joined: 11/03/2016 - 22:42
Posts: 4000
Location: Vancouver, Canada

Agro wrote:
I spotted a minor weirdness in the datasheet.
The peak output is not at cool temps. It’s not at 25°C. It’s higher.
Furthermore, the loss from heating up to 85°C is just 3%.

I’m not sure if we should believe this…if yes, we can expect it to have real-life performance quite close to this test.


Uh, what datasheet are you looking at…?
The highest output is at -40C, and that’s because that is where the graph ends.
Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

My bad. I looked at LE CG Q8WP datasheet instead. Facepalm

koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

Here the diagram of the LE UW Q8WP (same sample tested earlier) for forward voltage and light flux depending on temperature Tj (in °C).

 

 

I put a lot effort to make the thermal resistance from emitter to heatsink as low as possible to avoid errors.

 

For the next upcoming emitter tests I will publish also diagrams / measurements like this.

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

EasyB
Offline
Last seen: 10 hours 12 min ago
Joined: 03/09/2016 - 15:24
Posts: 1796
Location: Ohio

The temperature dependent output is really great and new data you are giving us!

I wonder, would you see the same shape curve if you did the experiment at, say, 5A instead of 0.7A? We are getting into very interesting device physics; potentially separating the effects of high current and high temperature on output.

koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

EasyB wrote:
I wonder, would you see the same shape curve if you did the experiment at, say, 5A instead of 0.7A?

Maybe, but at the moment I'm not able to measure the temperature dependence at more than 3 W LED power. Sad

I'm planning a lot more powerful Cool/heat setup for the future, but it's unclear when it would be ready. At this point I can only say - it's done when it's done...

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

koef3 wrote:



Here the diagram of the LE UW Q8WP (same sample tested earlier) for forward voltage and light flux depending on temperature Tj (in °C).


 



 


I put a lot effort to make the thermal resistance from emitter to heatsink as low as possible to avoid errors.


 


For the next upcoming emitter tests I will publish also diagrams / measurements like this.





koef3, could you overlay curves from manufacturer datasheet on that picture?
koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

The data of the manufacturer are valid for 1,400 mA only - but I measured with 700 mA due to design of test setup.

I am not sure if there is a significant difference between these measurements so I would rather not overlay curves on this picture...

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

Agro wrote:
koef3, could you overlay curves from manufacturer datasheet on that picture?

 

I did the test with 1,400 mA now, like the testing conditions in Osram's datasheet, including also overlay of curves from the datasheet.

 

In the datasheet the values are shown up to 120 °C Tj only, in my diagram up to 150 °C. The change in light flux shown in the datasheet matches very well, and the decrease of Vf is lower than stated in the datasheet. Very nice. Smile

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

Thanks Smile
It looks like the curves change with current, though just slightly.

koef3
koef3's picture
Offline
Last seen: 11 months 3 weeks ago
Joined: 08/28/2017 - 14:04
Posts: 138
Location: Cologne, Germany

Raw data

 

Osram OSTAR Projection Compact LE UW Q8WP

 

Amps    lm    Vf
0,20    84    2,70
0,40    154    2,75
0,60    221    2,79
0,80    282    2,82
1,00    340    2,84
1,20    395    2,87
1,40    451    2,89
1,60    503    2,92
1,80    553    2,94
2,00    602    2,96
2,20    650    2,98
2,40    693    2,99
2,60    740    3,01
2,80    784    3,03
3,00    823    3,05
3,20    864    3,06
3,40    909    3,08
3,60    942    3,10
3,80    980    3,11
4,00    1018    3,13
4,20    1054    3,14
4,40    1090    3,16
4,60    1121    3,17
4,80    1155    3,19
5,00    1187    3,20
5,20    1217    3,22
5,40    1246    3,23
5,60    1278    3,25
5,80    1306    3,26
6,00    1333    3,28
6,20    1359    3,29
6,40    1383    3,30
6,60    1406    3,32
6,80    1431    3,33
7,00    1450    3,35
7,20    1471    3,36
7,40    1491    3,37
7,60    1510    3,39
7,80    1526    3,40
8,00    1540    3,42
8,20    1555    3,43
8,40    1567    3,44
8,60    1578    3,46
8,80    1588    3,47
9,00    1596    3,49
9,20    1602    3,50
9,40    1605    3,52
9,60    1607    3,53
9,80    1606    3,55
10,00    1603    3,57

 

If you create diagrams / comparisons with this data, I would ask you to publish these charts in this topic and also to specify the source of the data used. Smile

Raw data of more emitter tests will follow in the next time. Stay tuned!

My LED tests: Cree SC5 based LEDs (WIP!)  ---  Nichia 319AT 83 CRI - Optisolis (3000/5000 K) - Lumileds Luxeon LXML-PWD9 - Luxeon MZ 5700 K (90 CRI, 3 V) - Luxeon V (CSP) 4000 K 70CRI - Luminus SST-40-W (+ dedomed) - Cree XP-L2 (+ High CRI variant) - XHP35 HI - XHP70.2 - CXA1304 COB - OSRAM OSLON Black Flat HWQP - SYNIOS DMLQ31.SGLE UW Q8WP - unknown 5050 LED ---- finished: JAXMAN M8 (Mini C8) HighCRI Triple

The_Driver
The_Driver's picture
Offline
Last seen: 19 hours 43 min ago
Joined: 10/20/2016 - 05:51
Posts: 1431
Location: Germany

Osram is a step ahead of Cree:

 

This graph shows the results of their research in the field of high luminance LEDs. At 4A (2A/mm^2) the efficiency of the Q8WP (same die and solder pad size as the XP-G2) is 32% higher than that of the XP-G2 S4 2B de-domed. As the current increases, the difference becomes even larger.

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

I think it would be more interesting to draw such chart with Watts instead of Amps.
The way you have it, low Vf LEDs have a natural advantage. If a high Vf and low Vf LEDs scored the same on your chart, the high Vf one would make more lumens and higher surface luminosity. So it would do a better job than the low Vf one.
And Q8WP happens to have much lower Vf than XP-G2.

If you’re that concerned about current (f.e. because you want to use linear drivers), compare lm/A over A.

The_Driver
The_Driver's picture
Offline
Last seen: 19 hours 43 min ago
Joined: 10/20/2016 - 05:51
Posts: 1431
Location: Germany

Agro wrote:
I think it would be more interesting to draw such chart with Watts instead of Amps.
The way you have it, low Vf LEDs have a natural advantage. If a high Vf and low Vf LEDs scored the same on your chart, the high Vf one would make more lumens and higher surface luminosity. So it would do a better job than the low Vf one.
And Q8WP happens to have much lower Vf than XP-G2.

If you’re that concerned about current (f.e. because you want to use linear drivers), compare lm/A over A.

I use current as the x-axis simply because LEDs are current driven devices. When you use a buck-regulator you will drive the LED with a specific current. Thats when you will see the benefit I’m trying to show here. As soon as a flashlight becomes larger with multiple cells this approach is better in my opinion.

EDIT: also making such a chart is actually more difficult because the LEDs have different wattages at different currents. I would have to use umeasured points on the curves between the measurements points and determine each one individually.

Agro
Agro's picture
Online
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 5384
Location: Ślōnsk

Frankly, I don’t see how a driving method justifies mixing units.
And drawing chart is just as easy with amps or watts – your software already interpolates points. It doesn’t even show where the measurement was. So yes, with watts the actual measurement points won’t be aligned on the X axis. But it won’t affect the curves.

The_Driver
The_Driver's picture
Offline
Last seen: 19 hours 43 min ago
Joined: 10/20/2016 - 05:51
Posts: 1431
Location: Germany

Ok, you’re right about that, but I don’t see a need for it right now.

Pages