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Meatsweats
11-24-2017, 01:25 PM
Can 30awg handle dual or tri strips? Anyone know for sure?

I’ve found a table online of max current/gauge but it’s not making much sense to me.

Thank you

jbkuma
11-24-2017, 07:20 PM
Definitely no. I recommend at least 24ga for 2 strip builds, I run 2ea 28ga for the +/- . I'm speaking from practical experience and testing these things for the past 2 years. Finer gauges don't show up on these tables, but 30ga is definitely insuficient. The resistance in the wire will vary by length and the result is heat. It can get glowing red hot. I actually had a bread more melt and catch fire.

Meatsweats
11-24-2017, 07:54 PM
Good info, thanks. Right now I’ve got a dual strip with 28g and I haven’t had a problem or noticed excessive heat. I have one wire coming off each strip’s +\-\data and they join at the adapter on the blade side, so 6 Wires down to 3 wires on the hilt side.

So would you recommend just bigger wires for the strips only? Does it matter for the speaker and switch wires?

I’m going to try and cram all this into a goth master chassis.

jbkuma
11-24-2017, 08:16 PM
For the speaker, switch, data lines etc it doesn't really matter at the lengths involved in sabers. 30ga is fine.

Meatsweats
11-24-2017, 09:30 PM
So just the strip +\- require bigger wires? What about the battery and recharge port?

Thanks again for your expertise.

jbkuma
11-24-2017, 10:16 PM
My builds have all been Arduino/DIYino based. The + is a homerun to the battery, the - to and from the board should be higher gauge. If you are using a power port with a kill key then both the - wires should be higher gauge since this is what feeds your board. I believe the PL and NEC boards work similarly, although I haven't reviewed the literature in a while. Basically if the leads are involved in feeding power to the pixel blade it should be a heavier gauge.

hapki
11-25-2017, 03:46 PM
Dang. I just used 30AWG on a build (PRIZM) including to to main LEDs (Coppernova). Based on this thread I should replace the 30 with something heavier. Dang. I was trying to save space, but I should have checked. I did use 28AWG for the battery and recharge port. I’m going to keep the 30AWG for the switches, accent lights, and speakers. So that’s not too much redoing.

jbkuma
11-25-2017, 06:41 PM
The current draw on a Coppernova is WAY less than a pixel blade. Pixel blades draw up to 60ma per pixel, per strip. A full white RGB would still only be 1 amp per LED, 3amps total, where as a full white, dual strip, 120 pixel blade would draw 14.4 amps from (potentially) a single supply line.

Meatsweats
11-25-2017, 10:32 PM
Jbkuma, so I’ve got a dual sk6812 rgb now with a 10a 18650. My understanding too is they are supposed to pull between 20-60ma per pixel. So if I have 250 led pulling 40ma dual rgb or 60ma for ‘white’ how is it not tripping the protection circuit?

jbkuma
11-25-2017, 10:42 PM
The actual functioning of electronic components is somewhat different than their listed ratings. LEDs only hit their peak draw at the peak voltage, as the battery discharges the current draw also drops. Since it doesn't start at 5v, it also doesn't start at max current.
My fellow developer Protonerd (known on FX as Obi_1) wrote this very detailed report on the characteristics of the pixels. https://github.com/Protonerd/DIYino/blob/master/Neopixels_Characterisation_report1.pdf

It would be interesting to compare the bench power test with Spacewindu's luminosity tests, but in the range of operation the perceived brightness of the blade won't change as much as you might expect.