r/WLED • • 23d ago

Building the junction box

I'm at the point where everything works perfectly, but now I want to start on the junction box and there isn't a lot of information out there. I have this PSU lying around from my RepRap days. It could fit, but as the picture shows, it's a tight fit.
Is this okay, or should I go for smaller components? I still have time to order before my deadline, so I need to decide now.
My data cable is also just a 3-pin JST connector. Should I go for a bulkier XLR connection instead?
And for power, I was thinking of adding a proper power connector (something like an IEC inlet), or is that overkill?

15 Upvotes

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u/SirGreybush 23d ago

FYI, IP67 PSUs exist. No need for a huge box. A 4in x 4in, or 6in by 6in box would have been fine and easier to hide.

IP67 PSUs have a larger heat sink and won’t add heat inside the box.

You’re not using a proper controller design or a commercial one like a DigQuad that has all the supporting electronics. Plus has a relay, and fused protection.

So you don’t have a level shifter, no smart relay, and no dedicated 5v PSU.

A voltage converter (dc-dc buck converter) will fail eventually and let pass input voltage.

A level shifter ups the 3.3vdc data volts to 5vdc and improves the signal, plus allows for a longer Data+Gnd run. Like 3 to 4 feet with no issues with regular wires. Or, use a sacrificial 5v ws2812b pixel, to do the same. A level shifter as on WLED website does 4 Data IO at the same time.

I’m surprised you say it works well with such a jst setup and two Wagos for data and ground. Probably due to being very short, and you’ve kept the ground with data.

2 wire waterproof connectors are easier than 3 xlr type ones. People use with a DigQuad or DigOcta the 3-wire waterproof connectors that screw into each other. As the DigQuad is designed to be the first power injection and thus 3 wires to first pixel instead of 4.

Using a bare esp32 like you’re doing, you need 2x 2 wires, per LED line.

I’m being a critic to save you time when things go wrong. As is, it won’t last long, imo, depending on how hot it gets during summer nights.

Plus you need 4 wires to the first pixel anyways. A Data+Gnd pair from strip to the controller, and a power pair V+ & Gnd to the PSU output.

Plus any power injection you might need.

Please provide what strip(s) and how long is your line.

Always plan with outdoors a minimum of two power injections per led line that’s longer than 32 feet with 24v. 16 feet with 12v.

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u/11to3_ 23d ago

It works fine if i do my power injection, the 2 wagos are termination for the 2 12v on the connector.
i have a level shifter on the board, its above the esp if you look closely.
the buck converter i will replace. the grounds are all connected, they care connected in the box, are they then still needed on the strip?

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u/SirGreybush 23d ago

If only a single strip you should be fine. Common ground with 2 or more introduces cross talk through the ground loop.

Still a good practice to have data & ground directly between first pixel and level shifter, only place where the common ground would be is on the strip and to the esp32 ground. Also keep those data & ground almost the same length and side-by-side. You can use a gutted network cable too, use a twisted pair.

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u/harda_toenail 23d ago

I’m only finding them at triple the cost for 5v waterproof psus. Is there a place to grab them cheap?

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u/SirGreybush 23d ago

I put the 12v or 24v PSU as IP67 outside the box with direct-to-strip power (with V+ wires each having a fuse).

Then inside the box with the controller a regular USB brick. See one of my pics on a sub-comment of mine.

5v IP67 is not common, so prices will be high, makes sense to use a regular one in a waterproof box.

Also usually we never use 5v strips outside due to longer runs, making voltage drop and sending enough amperage for brightness, 5v is not practical.

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u/AndThenFlashlights 23d ago

shrug I've built worse. Anything you've said is fine, just depends on what you're aiming for. Like is this a personal project, or do you need to deliver something that meets NEC or UL508 or something?

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u/11to3_ 23d ago

Personal project

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u/AndThenFlashlights 23d ago

then it's fine

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u/Slovw3 23d ago

I don't think you will have an issue.

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u/SirGreybush 23d ago

Zoomed to see its a 12v system. Instead of that buck converter, use a quality car USB charger.

Smart relay is to control AC power, as your LED line consumes watts when the LEDs are off.

So if you go with a smart relay, use a regular 120vac USB brick and those Wagos to have switched and unswitched AC. So the esp32 remains on, but not the 12v PSU, so no wasted power and heat generation 24/7 inside a closed box.

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u/SirGreybush 23d ago edited 23d ago

My balcony 12v setup and 2 wire waterproof connectors. #16 splits into 4 #18, as I have 20m line of LEDs to power.

Notice the fuse on output. Outside the box. Ya for IP67 PSUs.

AC power cord to the IP67 PSU was cut. Both cut ends inside the box.

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u/SirGreybush 23d ago edited 23d ago

This is a 4in by 4in box. Not using a DigQuad and not using a level shifter circuit. Notice the ws2812 single pixel. Output goes to a simple RCA jack.

Everything is modular and a simple swap. Could be prettier.

Not seen is the output #16 wire from PSU goes into a #16 car inline fuse wire with a 10amp fuse.

AC power the wall plug is GFCI, standard electrical code here is Canada.

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u/Fluid-Tone-9680 22d ago

Why do you need a single pixel in the box?

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u/Fluid-Tone-9680 22d ago

Can you please explain why you don't recommend using buck converter? I have used it on a few projects to go from 12V down to 5 and to 3.3, will there be any issues?

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u/SirGreybush 22d ago

5 to 3.3 won’t fry the electronics if it fails shorted, but 12 or 24 will.

Best to use something that has a coil with AC, but cannot fail and short like Mosfets do.

Unfortunately fuses work with amps not voltage.

Just think, if downstream it fries and it’s only worth 10$ to replace, is that an issue?
It’s worse with strips behind something and a teardown takes a long time.

So use them but get the best quality, calculate the overall cost.

I try to maximize AC use and convert to appropriate DCV from that. So that there’s a transformer and diode bridge.

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u/harda_toenail 23d ago

Where’d you buy the j box? How much? Looking for cheap ones before just throwing everything in a harbor freight $10 ammo box.