Hi,
I have recently bought my first Convoy light: Convoy S2+ with Nichia 519A,5A 12groups . I am really satisfied with fabrication quality and LED choice.
I would appreciate longer run times, therefore I am looking how to reduce driver current output by half.
I suppose that the resistor with value R020 is sense resistor - am I right?
What should I do to reduce current to 2,5A? double the value to 40ohms? or reduce it to 10ohms? Is there any formula for relation of max current and resistor value for this particular driver?
I would like to use lantern mainly with diffuser to light up hunting cabin. So my main intention is to create 5% output providing sufficent light level with 10-12hours runtime.
I’m not positive but I believe the 17mm driver uses a 1206 size resistor; I know the 22mm convoy driver has a 2010 resistor as I just ordered a few resistors to swap on mine. I’d recommend at least 1/2 watt 1% minimum. You can find them on digikey, mouser, etc.
Here’s a link to digikey of 1/2 watt 1% in all the different resistances they have in stock.
Thanks for the info crbnfbr. Looks like this would be a good fit at 39 ohms and very reasonably priced (including shipping): RCS120639R0FKEA
BUT, I’ve had numerous issues with these Convoy SST drivers over the years and don’t want to mess anything up. I’ve had flickering issues, 0.1% and 1% essentially being the same, spontaneous programming mode, etc. Luckily the replacement drivers never had an issue.
And I see from my pics that some of the resistors are 10 ohms.
So after additional consideration, now that all 11 of my 50% drivers appear to be stable, I’m just going to be content with 4 levels.
Even though I was concern about modding these drivers, I decided to take a chance and mod one to get the extra mode. Why? With 4 modes, there’s a big jump from 3rd to 4th and an extra 1 in-between would be nice.
And if it went well, I’d swap out the resistors on my other quad Nichia E17A flashlights that I have set at 50%.
So I ordered some 1206 1/2 watt 1% SMD resistors on AE. When I replaced the resistor, the flashlight would only turn on in the highest mode and was very dim.
That’s when I realized I got the wrong resistors. I assumed the R020/R010 resistors meant 20 and 10 ohms, but instead they are 0.02 and 0.01 ohms. I ordered 39R0 resistors (39 ohms) and instead I should’ve gotten R039 (0.039 ohms).
Now I’ll have to wait until the right ones arrive to try again.
In case anyone is interested, the correct resistors eventually came and I promptly replaced the sense resistors in all 12 of my E17A flashlights. The first one I replaced I made sure the functions worked as should, which it did, and then onto the next one.
I was planning on doing a couple at a time over weeks, but I got into a groove and replaced them all in 2 days.
For the drivers that were using R010 resistors, I stacked 2 R039 (parallel) resistors to make 0.02 ohms.
The firmware was not impacted with any of them and thankfully it also didn’t change the brightness of the lighted switches.
I’m thrilled to have all 5 modes now!
Here’s a 20mm R010 driver that I replaced with parallel R039s: