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I recently purchased an APA102 LED light stip (60leds/m) and read that it requires 18watt/meter, I am using approximately 4.5 meters so will roughly need to provide 81w. I did, however, struggle to find a dual power supply that could provide this, so I settled on an RD-125A power supply that can provide up to 15A at 5v, and am planning on reducing the brightness of the LEDs to 75%, to account for this.

I was then hoping to have a wire connecting the LED strip to a box containing the rest of the circuitry and the power supply. So I could detach the box, I wanted to have a connector that would allow me to plug the LED light strip into said box, and then from within the box, the connector would connect to the power supply and a raspberry pi.

My first thought was to use a 4 pole DIN connector and socket, but I wasn't sure if it's safe/advisable to use one when using ~15A, and thus I was hoping to find out if

  1. This is safe
  2. If not, is there any other connector that would work
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  • \$\begingroup\$ This design is kind of sketchy. I'm not convinced the LED strip itself is able to carry 15A. \$\endgroup\$ Apr 11, 2020 at 21:49

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TL;DR Distributing 5V is a bad idea. Use a higher voltage supply (e.g. 24V) with a local DC-DC convert for each strip.


I would highly suggest not trying to distribute 5V @ 15A at all. The voltage drop at 15A is going to be considerable unless you use very thick wire. You will struggle to find a connector with sufficient current rating that isn't excessively large and expensive.

If you think about it, if your wiring loom and connectors had a total resistance of only ~0.3 Ω, your entire voltage would be dropped across it. Even if it was only 0.1 Ω you are dropping a significant portion of your supply voltage.

Instead distribute a 24V supply. This would drop your supply current down to around 3.2A or so, which is much more reasonable. It will also be easier to find a supply capable of handling the current.

If your LED strips require 5V, then for each strip add a DC-DC convert to drop the supply down to 5V locally. By having a converter per strip, the output current for any DC-DC is lower than having just one, and the distance over which you are tranferring it is vastly reduced.

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I don't know this particular connector, but its data sheet could answer the maximum current question. If you don't have one, at least give a link or something (like where you got it).

I think your main problem will be the wiring. High current means high voltage drop, but you start only from 5V. So to avoid this, you'll need to bring separate (thick) wire along with your LED strip, and feed it several places.

If you can find the datasheet, and your isn't big enough, I'd look around in RC modeling forums, they use low (11.1V) voltages with high currents (10s of Amps). e.g. XT30, XT60 are reasonably cheap, have reverse polarity protection, and widely available.

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  • \$\begingroup\$ Hi, thanks for getting back to me! The DIN connector I had originally purchased was this one but it arrived today and I am not certain it is up to the job. \$\endgroup\$ Apr 11, 2020 at 12:11
  • \$\begingroup\$ I am also using this cabling where the specs are: 4 Core, 1.5mm^2 (which states up to 16A) and it's 2m long. \$\endgroup\$ Apr 11, 2020 at 12:14
  • \$\begingroup\$ Fortunately the same company has a bit more detailed website, where you can find the product. switchelectronics.co.uk/4-pin-din-panel-mount-socket-connector and switchelectronics.co.uk/4-pin-din-plug-connector both with 1A max current :( \$\endgroup\$
    – Nyos
    Apr 11, 2020 at 12:15
  • \$\begingroup\$ Thank you so much for finding that! So I should steer clear of this connector then! In the meantime do you know if the cable would suffice? I don't know a great deal about electronics so I hadn't thought too much about it \$\endgroup\$ Apr 11, 2020 at 12:16
  • \$\begingroup\$ en.wikipedia.org/wiki/American_wire_gauge your 1.5mm^2 wire is somewhere between AWG15 and 16, so around 12mOhm/m. Your wire's resistance is 24 mOhms one way, double that for back-and-forth (they're in series) and multiply by the max. current: 0.72V drop out of 5V. I'd say not great not terrible. Worth a try, won't explode or anything but keep in mind to replace (or add some more) if it's too dim. \$\endgroup\$
    – Nyos
    Apr 11, 2020 at 12:27
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"DIN connector" is a broad term. Please edit your post to include a part number or vendor link so we can evaluate the part you are considering.

Will you be plugging / unplugging things while power is on (hot plugging) or only when power is off? Hot plugging is much harder on the contacts, and you can't make up the current capacity you need by tying together multiple pins in parallel.

Anderson is well known for their high-power DC connectors.

http://www.andersonpower.com

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  • \$\begingroup\$ Hi, thanks for getting back to me! The DIN connector I had originally purchased was this one but it arrived today and I am not certain it is up to the job. With regards to hop plugging, I wont be doing - I will only be unplugging the device once the power is off. \$\endgroup\$ Apr 11, 2020 at 12:03
  • \$\begingroup\$ Why did you buy it then? It does not even contain a datasheet for the rating, but I assure you that connector cannot handle 15A. \$\endgroup\$
    – Justme
    Apr 11, 2020 at 13:35
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I'm not aware of any "DIN" connectors that age good for 15A, these connectors are signal connectors typically only good for about 1A. There's some similar looking connectors that are not DIN, which are rated for higer currents but not 15A

something intended for use with powerful batteries like like XT30 may be a bettter choice.

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