Getting my basic setup from my workbench to on display

[janastas]

Hi All,

So after my first attempt at tinkering and getting an LED strip working through my raspberry pi I'm now at the point that I'd like to setup my very basic lightshow running off my balcony with some music using xlights to load sequences onto Falcon Player

The gear I have is as follows:

• Rpi 3b+
• Rpi 28d+ hat
• 12v 2.5A power supply to power the pi and the hat
• around 7m of WS2812B that I plan to cut to smaller lengths.
• a usb sound card (USB audio sound card)
• UE Boom speaker

What I'd like to do is setup the led strip on my balcony as follows:

Screenshot 2020-12-17 123719.jpg

• janastas
• Dec 17, 2020

I have an outdoor powerpoint on my balcony so no issues getting power there.

Some additional things that I'll need are as follows:

• Power Supply (http://www.hansonelectronics.com.au/product/power-supply-s-400-5/)
• Water proof box (http://www.hansonelectronics.com.au/product/box-390x290x160/)
• Glands (http://www.hansonelectronics.com.au/product/4holegland/)
• Water proof 3 core pigtails (http://www.hansonelectronics.com.au/product/3-core-waterproof-pigtails-pk-25)

The plan is to connect the pi and 28d+ to the 12v 2.5A power supply
House the s-400-5 power supply and the pi / hat inside the water proof box (Will need to consider some sort of ventiliation)
Connect the led power ot the s-400-5 power
Data from the led strip goes to the data terminal on the channel of the hat

Some things I haven't bought but wanted some feedback on was:

• Should I just get individual inline fuse holders from the power supply to the pi and to the led strip or shoudld i get a fuse box that can take multiple inputs and outputs?
• 3 core cabling - any recommendatoins as to what I should use and something that is weatherproof and water resistant? (I think I'm only going to use 3m of WS2812B to statr off with at a brightness of 30%, there's 60 pixels per metre so worst case scenario current wise will be 0.06A per pixel @ 30% x 180 pixels =~ 3.25A
• Any tips for ensuring the cabling is connected to the pigtails correctly and in a waterproof and safe manner?

 

[AAH]

The rPi-28D+ has fusing for the outputs and if you're slightly creative you can use the WS2801 output's fuse as fusing for the rPi-28D+.
For cabling the 2 choices that I suggest are 3 core mains flex or 6 core 14/0.2 security cable with 3 cores used for 0V, 2 cores for +ve and 1 core for data.
Solder, heatshrink and potentially electrical tape for connecting the leads to the pigtails and to the pixels. Heatshrink solder sleeves are another possibility.

 

[janastas]

The rPi-28D+ has fusing for the outputs and if you're slightly creative you can use the WS2801 output's fuse as fusing for the rPi-28D+.
For cabling the 2 choices that I suggest are 3 core mains flex or 6 core 14/0.2 security cable with 3 cores used for 0V, 2 cores for +ve and 1 core for data.
Solder, heatshrink and potentially electrical tape for connecting the leads to the pigtails and to the pixels. Heatshrink solder sleeves are another possibility.

Thanks for that, I'll have a look into the 3 core and 6 core.

I like the idea of the heatshrink solder sleeves, a bit pricey but would be worth the money to ensure a good connection and that it stays waterproof.

I think I hopefully have a few days to decide before my order get's processed for the goody's I purchased from your site last night.

 

[janastas]

Also forgot to ask, pros and cons of solid vs stranded for the core?

I'm assuming the pigtails I'm getting a stranded and the led strips would be better for stranded but voltage loss over solid core would be less?

 

[Old Salt]

Also forgot to ask, pros and cons of solid vs stranded for the core?

I'm assuming the pigtails I'm getting a stranded and the led strips would be better for stranded but voltage loss over solid core would be less?

If you compare stranded and solid wire of a given gauge, you'll notice that the stranded is usually a little larger and much more flexible. The actual current carrying capacity is the same. The sum of the cross sectional area of the individual strands in stranded wire is the same or larger than that of solid core wire. Use stranded wire where ever there can be movement, and solid where no movement is possible. Solid core wire breaks rather easily where it's exposed to the elements, or needs to be wrapped up and put away after the season.

If you solder stranded wire to terminals, strips etc, tin the ends first. That will make your connections easier. If you connect to a strip, or anything with a pad, tin the ends first, apply flux to the pad, heat the tinned end until the solder melts, then bring the wire and soldering iron to the pad, making the connection. You'll apply less heat to the pad, reducing the possibility of damage. Tinning is the application of a thin coat of solder to the wire. No blobs of solder allowed, and you should be able to see the individual strands in a stranded wire through the solder.

 

[TerryK]

As Old Salt indicated, flexibility mostly. Stranded typically works better in terminals also because the strands will 'mush' out and give a larger surface contact. Stranded is also more immune to breaking. A crosswise nick is generally the cause of a wire break. The nick acts rather like a score mark weakening the wire at that point. And while nicks do creep in during manufacturing, most are in my opinion introduced during striping (I've done my share, strip, nick, cut and re-strip). While there are other differences, diameter, number of strands, strand diameters, and such, those are generally so insignificant that they will not effect any voltage drop calculations and can be ignored.

For most individuals a good wire chart of stranded sizes that includes resistance values in feet and/or kM will do fine for calculating voltage drops. Note that voltage drops exist in both the positive and negative wires to a string or strip.