I see people that read spec sheets and don’t 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 you’re pushing, so you don’t 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. What’s the board temperature? The cell temperature? Where’s the constant? There’s 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 I’m wrong.
Giorgio, could you please downsize the pictures in your review?
Those huge sizes are quite pointless, they’re 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 don’t need a boost driver…
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 they’re 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 pictures’ 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, I’m pretty pleased.
That doesn’t matter.
You have used a lot of pictures of several megabytes each.
Setting the % page width doesn’t 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 (that’s 4x) approximately, which is usually not that efficient.
A.f.a.i.k. boost and buck conversion works much more efficient when it’s within about 20% difference between input and output.
Peak output being at 2.5A which occurs with 14.4V, or thereabouts, voltage is a bit more than tripled, not quadrupled, but still… the constant current style puts a heavy load on a dying cell by maintaining voltage at the cost of ever increasing amperage draw from the dying cell. Sounds problematic to me, considering that a hot cell can be a bomb. Factor in weak, cheap, and/or inferior components on the driver to save every fraction of a cent and it’s not a likely candidate for bumping power to for just anyone.
xhp35 has 2 versions 6v and 12v, if you are measuring from led 12v versions current will be half of 6v version. Measure voltage please if you’re measuring from led