D4SV2 Dual Channel 12A Driver


I created this account because I need some expertise for my first order at intl-outdoor.

I want to buy an Emisar D4SV2 with Osram W1 on channel 1 and Nichia 519A 5700K domed on the 2nd.

Now I have found a reddit thread that discusses ordering this flashlight with the 2x12A driver of the DM1.12, but I am not sure if there would be any disadvantages in doing so.

My concerns are the following:

1. I looked up some graphs and it seems that Osram W1 does not really profit from more than 4.5A per LED (however this varies between several measurements), while the 519A still gets bit brighter at 6A. If I find out that channel 1 does not profit, can I simply reduce the max PWM value in the firmware and have the same behaviour so to speak as the smaller driver or will this make the lowest modes brighter or "steppier" because 10bit PWM has a fixed resolution?

2. Will I loose other functionality (e.g. no more lighted switch or something else I did not think of)?

3. What could be the general advantages / disadvantages? Are there other things I need to know?

Please tell me what you think!


Welcome to BLF w0dash :beer:

I wouldn’t run either of them at 6A, the default driver is 9+9A I believe ? 4.5A is good for both of those LEDs.

6A is alright for 519A iirc from djozz test, but it’s into “diminishing returns”
But definitely only 9A (4.5A each) for the W1s. If it were me, I’d get the 9A/9A driver.

It's a pleasure to have you onboard, w0dash!


Would it be possible to ask for a 9A+12A driver? I think it is but I’m not sure.

That way you could run W1s on the 9A channel and 519A’s on the 12A channel.

12A+12A you could use W2’s and 519As. Won’t be as quite as much throw, but much more lumens and a wider spot. W2 can take closer to ~8A, but at ~6A it still performs well.

Personally, I don’t see a point in 12A. It’ll regulate itself after couple of seconds to much lower value because of heat. I’m wondering if difference between 9 and 12 is perceptible by human eye. With lower starting current there is a chance that it’ll be sustained for a bit longer.

Alright, I will go with the default driver then. :+1:

Next question is, which flashing adapter is the right one?

1) BLF driver programming key v3.2 launched on Oshpark

2) [Oshpark] HQ ProgKey - Universal Driver Programming Key

Or is the pin spacing the same?

Is there a reason you don’t just want to buy the one already assembled from Hank? One less thing to worry about.

Hank only sells it bundled with the USBASP for 15$, and I already have several of those programmers… If he had the pogo adapter individually for a reasonable price I would buy it from him.

You can email him and ask if he’ll sell just the adapter