I’m trying to nail down a power wiring issue I have a bunch of ws2812b strips each with between 3 and 12 leds. They were used in a different project and have 30gauge wire soldered on each end. Do I need to replace the 30 gauge wire if each strip is wired to the power bus ? The power bus is 14gauge silicon wire.
Silicon? Usually wires are made of copper, copper with tin plating, or sometimes aluminum (usually only for huge wires used in buildings, utility’s power grid, etc).
With copper, #30 is ok for a few LEDs but too small for a dozen. #14 is probably overkill for only 12 LEDs.
Sorry, I should have said silicon covered wire.
@Kevin_White @PaulStoffregen
Cable diameter and max. current: This is my rough approximation:
D [mm²] AWG max. Current [A]
continuous short term
0.25 23 2.5 4
0.50 20 5.5 7.5
0.75 18 8 11
continuous = hours, short term = few minutes.
Length = less than 3m.
If you are in doubt (or need longer wires), take the thicker cable.
Touch the cable - it should not get warm.
In your case AWG 30 = 0.05 mm²
continous = 0.5A, short term = 0.8A.
12 LEDs = 12 x 0.06A = 0.72A (if you really drive 'em at full brightness in white). AWG 30 should be fine.
Thank you Paul, for pointing out my mistake. Correct is:
AWG 14 = 2.5mm², then we are at 25A cont. and 40A short. This cable is good for 400 - 600 LEDs depending on your animation and certainly your power supply.
AWG 40 = 0.005mm² - this is good for just one RGB LED constant, and maybe two LEDs short term - and clearly too thin for me to even see it.
Maybe double check those numbers? For example, 40 AWG is 0.08 mm sq, not 2.5. https://www.rapidtables.com/calc/wire/wire-gauge-chart.html
I have blown curcuits couple times now. LOL