Got a B35AM emitter on the way so now I started looking at how to drive it. Since it needs 6V, I have no spare driver lying around and started looking at Convoy’s 6V XHP70.2 driver (max output 5A). Voltage wise it should work fine, but the B35AM is rated for 1400mA, but the XHP is much higher (4800mA). So my worry is that the XHP driver will pump out too much current and fry the B35AM. As far as I know the emitter will just draw as much as it can and the driver will not limit it. So will this work or is this combo doomed to fail?
That’s too much, max is 4A on Eurekatronix boards and probably lower on Convoy boards, Convoy uses 3A for the B35AM.
Thanks for the quick answer. Will have to find a more suitable driver then. With the Chinese NY going on, it’s slow going anyway when it comes to getting parts. I’m not in a hurry, so enough possibilities to look up (either driver alone or with host). But if I understand you correctly, Convoy is using a dedicated driver for the B35AM (or maybe not specific for this emitter, but lower current output at least)?
They use the XHP50 driver IIRC, 3A.
Ah, that might be the case. The thought of an XHP50 driver hadn’t occurred to me since the ones I have are all the 3V version. Good to know, more options opened up.
Led is rated for max. 1.8A only. 2.4A for short burst. Convoy 3A driver is too powerful .
You could also mod your XHP70 driver for lower current by swapping the sense resistor with a higher value one, though you would need to source the proper value.
Since when did we limit ourselves to datasheet ratings 
Though 4A is really the absolute max, 3.5A is more reasonable.
Yeah, people do many stupid things for fun But probably it is quite easy to reduce output of that driver right ? By changing FB and OUT resistor combination or Rsence?
Probably easy once you’ve located it on the board. When it comes to replacing individual components, I’ve found that the problem is not the replacement itself. It’s actually getting the part (at a reasonable price and without order 100 pieces).
In the meantime, also found some buck drivers on AE that might work. Lowest current I’ve found so far is 2800mA.
Another thing coming to mind is using a Convoy 12-groups driver and set that to group 8 (max 50%).
As a kid I used to hook up regular 5mm LEDs to 220V, just to see them explode. Loved it, but unfortunately my parents did not agree
Yes, probably easiest way is to use group 8
Bollocks! The 3A driver is perfect for it. I’ve put it in an S21A with a B35A and it runs very well, warm but not hot. Convoy sells this set up ready made. Someone used a 4A driver with the B35A and said it got too hot, but 3A is fine.
A very quick unscientific test. Convoy S21B (3A driver) 35% vs 100. White balance set to daylight (no Kelvin given). I’ve heard the term angry blue a few times and on 100 the B35AM seems to start getting, let’s say, agitated.
Btw, for comparison, the DM11 uses a 3.6A driver.