I did struggle with working out what mA value to aim for and as a result what resistor to use. I couldn’t find any definitive information on how to work this out, until I stumbled upon a thread here in BLF: click.
I used that as the starting point for a rough first estimate. A D4V2 has 8 AUX LEDs per colour, so from that I could estimate the current per individual AUX LED for the D4V2.
The Tri-LED AUX board for the FW3A has 6 LEDs per colour, so I could estimate the equivalent current for an FW3A. Here’s the result:
Colour | D4V2 high (mA) | per AUX LED | FW3A high (mA, estimate) |
---|---|---|---|
Red | 3.00 | 0.38 | 2.25 |
Green | 1.26 | 0.16 | 0.95 |
Blue | 1.35 | 0.17 | 1.01 |
Note that the mixed colours have higher current due to the mixing of multiple RGB LEDs, so only the values for R, G, B can be used further calculations (hence the strike-throughs).
That doesn’t include orange, so I made a guess that, since orange is close to red on the visible light spectrum, I should choose a current value close to, but less than, red.
Hence, I chose 2.20mA as the estimate for my calculations for orange, which lead to a resistor estimate of ~180Ω (Vfwd for the LEDs I sourced is 2.1V). Since personally I think the D4V2 AUX brightness is a little too bright, I chose a 220Ω resistor as the starting point for my FW3A.
Since the above is not exactly precise, I was expecting that 220Ω would be the starting point and I’d be trying different values above and below that to find the best value. However, I was so pleased with the result with a 220Ω resistor, I stopped with that. So either the above method is genius (in which case, pat myself on the back), or it was a complete coincidence that 220Ω happened to be a good value (in which case, shhh, and don’t mention that 220Ω is the value for red AUX after shuffling the resistors for the Lume1 driver, so 220Ω working well for orange isn’t really a surprise, is it?).