I really donât get yâall, hung up on watts. Watts is an after the fact measurement of amperage and voltage. Watts is misleading, as you can get more lumens with less watts, look at Creeâs Product Configuration tool.
You donât feed watts to the emitter, you feed amperage (current) at the voltage it will accept. Wattage shows itâs efficiency. Like statistics on a football game, a team can blow away the other team in statistics but lose by a big points spread. Itâs the same way with the emitters making lumens. Voltage and current produce lumens, watts is a statistic of how efficiently itâs doing so.
Yes but we know how many lumens are produced by a certain wattage according to the data sheets. Efficiency is correlates to the flux bins given. So they all matter equally the same.
When the emitter is placed into a light and fed by a driver the numbers on the data sheet only show best case scenario. So if a light is using a certain number of watts measured at the tail we can assume only that the light is producing less light than data sheet. It cannot produce more.
So⌠this light is underperforming. Not a big deal, but there is no other way to spin the data. All that said, we need someone to measure the actual light output:)
Not true.
I can be if someone doesnât understand wat it means and how to use it (not saying you donât know it btw ).
10 Watts = 10 Watts.
10 volt x 1 amp = 10 watt, 1 volt x 10 amp = 10 watt.
If a emitter is doing 100L/W then youâll get 1000 lumens. (10x100)
It doesnât matter if the emitter is a xpl or xhp35. Lets assume they are both doing 100L/W.
Xpl: 3 volt x 3.33 amp = 10 watt x 100 lumens = 1000 lumens.
Xhp35: 12 volt x 0.83 amp = 10 watt x 100 lumens = 1000 lumens.
Point is, without knowing and using those other numbers watt doesnât say a lot. (for example the lumens/watt efficiency)
But with all those numbers it says everything.
In one thing you are completely right, current is what matters to us. It says a lot about how a led performs, but thatâs because we know our leds. (meaning we know what to expect and what it can handle)
I see people that read spec sheets and donât build lights.
For example, what do your sheets say about an XHP-35 at 4.5Amps?
What do the spec sheets say about an MT-G2 at 16Amps?
Or an XP-L W2 2B at 6.67Amps?
your wattage per lumen figure is going to vary according to the current youâre pushing, so you donât have a fixed number to work with. Just like the amperage is going to change as the cell dies, and the forward voltage will fall. All you really have is a voltage reading and current reading, everything else is playing the numbers. And the numbers are not nice. Whatâs the board temperature? The cell temperature? Whereâs the constant? Thereâs not one.
Yes, all these things you mention are not constants. They are variables. Variables make up equations that can be calculated. That is all we are trying to do. With the data reported thus far and as I calculated earlier, this light will not reach 1000 lumens. But we will wait to see. Hoping Iâm wrong.
Giorgio, could you please downsize the pictures in your review?
Those huge sizes are quite pointless, theyâre not even sharp enough for that many pixels.
Thanks.
O uhm⌠Nice light! Looks good. :+1:
But 1300 LM can be obtained with an XP-L too and then you donât need a boost driverâŚ
I have 4 XHP-35 E4 in my TM16. Each one is seeing 1.14A at some 13.1V making 1768 lumens. Collectively, the 4 are seeing 4.55A in parallel and making 7072 lumens.
Edit: The above said for the statisticians. Perhaps it will help figure the variables. It does seem like this light is not running very hard at all and should be doing more. (UT02, I mean)
Yes they are fine, but theyâre also a couple of MB and not worth the huge size.
Takes very long to load with the number of pictures on page 1.
1000 pixels width would be more than enough.
I have set the pictures based on the width of the page . Works best in most devices .
If i set them based on pixels they will not show properly on smartphones etc . Anyway , i will reduce the picturesâ relative width .
I am curious what different efficiency values different types of drivers have. I also read that modern boost drivers are much more efficient⌠If I look at the runtime graph of the U21, Iâm pretty pleased.
That doesnât matter.
You have used a lot of pictures of several megabytes each.
Setting the % page width doesnât matter, it takes unnecessarily long to load anyway, because the files are huge and many in number.
You should scale them down on your PC first before uploading.
Good point, because i forgot that a linear driver just turns the surplus Voltage to heat = waste.
But in this case the voltage has to be quadrupled (thatâs 4x) approximately, which is usually not that efficient.
A.f.a.i.k. boost and buck conversion works much more efficient when itâs within about 20% difference between input and output.