LED ceiling lighting

[pvdude]

I wanted to illuminate the shed where the solar electronics are installed.

The ceiling has 4' Fluorescent fixtures that I had converted to LED, but they are powered by the grid.
Did not want to re-wire these, so I bought some LED strips to stick on the ceiling.

16.4 ft. long (5m), 24VDC

5m White LED Strip Light - Highlight Series LED Tape Light - High-CRI Quad Row - 24V - IP20 - 1,317 lm/ft

This super-bright LED light strip is great for creating a high-power light fixture. It operates on 24 VDC and can be used in longer runs than 12V strips. The powerful LED tape light emits 1,317 lumens of cool, natural, or warm white illumination per foot. And with a high CRI (color-rendering...

www.superbrightleds.com

Found some used DIN rail power supplies on ebay, 480 watts, powered by 240vac from the Schneider WX-Pro inverters.

Very bright now in the room!
The only issue is RF noise, I turn the LED strips off when doing HAM radio.

 

[timselectric]

What voltage is your systems battery?
A DC to DC converter would provide less interference.

Edit: I see that it's 48v.
Just use a 48v to 24v converter.

 

[zanydroid]

Nice.

I would recommend some mounting clips though, the adhesive is more of a suggestion to stay up.

Some stapling of cables for strain relief would be good

Also if it’s super bright you could buy some diffuser channel to put this in to smooth and scatter it better and still have a decent amount of light. This will help protect and keep it up on the ceiling too. Or add a LED controller with dimmer between the power supply and LED.

 

[pvdude]

Just use a 48v to 24v converter.

Plan "B" is to just replace the 24vdc strips w/ 48vdc strips.
I could run them off the 48vdc batteries.
Not sure how much noise is coming directly off the LED, vs Lambda PS

Natural White - White Flexible LED Strip Lights | Super Bright LEDs

Our white LED strip lights come in a variety of color temperatures, brightnesses, lengths, and weatherproof ratings to match any application. Shop now!

www.superbrightleds.com

 

[timselectric]

Another advantage of running the lights directly from the batteries. Is that you can work on the system, without being in the dark.

 

[zanydroid]

They may have reduced lifespan/get pretty bright when running off pack voltage directly since it is going to be 10% above 48V

The LEDs should be all passive components (not true in all cases, addressable has processor in each LED but no SMPS).

 

[OzSolar]

Plan "B" is to just replace the 24vdc strips w/ 48vdc strips.
I could run them off the 48vdc batteries.
Not sure how much noise is coming directly off the LED, vs Lambda PS

Natural White - White Flexible LED Strip Lights | Super Bright LEDs

Our white LED strip lights come in a variety of color temperatures, brightnesses, lengths, and weatherproof ratings to match any application. Shop now!

www.superbrightleds.com

I would think all of the noise is coming off of the power supply.

I suspect the 48V strips may not like to see the ~62v during your batteries equalization cycle.

You might also look at the Victron Orion 48/24 DC-DC Charger. It can take a variable range of Vdc input and deliver a steady Vdc output.

 

[zanydroid]

Another thing I don’t like about 48V strips is that the touch safety of pulsed DC at that voltage (which happens after dimmer is added) is not super well understood IMO. 24V hedges against that and isn’t a big deal voltage drop wise anyway.

 

[Skypower]

I buy these little converters for all kinds of projects, Inexpensive, efficient, safe, compact, rugged, easy to mount, very clean output.
You literally need to get away from anything else if you want to attempt to find noise with a scope, it’s that low. Very little through loss which makes sense since they don’t get so hot. The one on the left is 48 to 24VDC and 720W. They are sold on Amazon under a bunch of different brands but I’m 95% sure they are all out of the same factory. Just fuse it correctly and you shouldn’t have any problems. PS if your fuse holder has brass contacts it may cause intermittent interruptions in time. Use NO-OX-ID “A SPECIAL” on the contacts or solder & heat shrink the fuse to bulletproof the project.

 

[pvdude]

I suspect the 48V strips may not like to see the ~62v during your batteries equalization cycle.

Yes, I had that realization when I connected the 48vdc battery box vent fan to the FLA batteries.
The Rotron fan did not sound happy @ 59vdc.
I'm going to do a test, and power the LED's w/ a Hewlett Packard linear/analog DC power supply.
No RFI from that PS.

 

[Skypower]

Yes, I had that realization when I connected the 48vdc battery box vent fan to the FLA batteries.
The Rotron fan did not sound happy @ 59vdc.
I'm going to do a test, and power the LED's w/ a Hewlett Packard linear/analog DC power supply.
No RFI from that PS.
View attachment 171202

At least that HP doesn’t need a subscription for it to work ?

 

[zanydroid]

One thing that could happen with a cheap buck converter is that something fails short and the output jumps to 48V

Also if you were worried about voltage safety it is useful to check which input pole the output is referenced against. These cheap things are probably non isolated. Sometimes they’re referenced against positive side

 

[Skypower]

One thing that could happen with a cheap buck converter is that something fails short and the output jumps to 48V

Also if you were worried about voltage safety it is useful to check which input pole the output is referenced against. These cheap things are probably non isolated. Sometimes they’re referenced against positive side

Pretty much every single timer, controller, sensor, buck or boot device I’ve gotten that came out of China is non isolated- the negative is common right through. This can get you into trouble if you don’t realize this if you have things like interconnected cables with shielded grounds to other devices that have different voltage potentials.

 

[zanydroid]

Pretty much every single timer, controller, sensor, buck or boot device I’ve gotten that came out of China is non isolated- the negative is common right through. This can get you into trouble if you don’t realize this if you have things like interconnected cables with shielded grounds to other devices that have different voltage potentials.

Yup. I don't know if my incessant spamming of the "check for non-isolation" is going to save anyone from the smokes...

That said, I don't think non-isolated matters for LED lighting other than the safety issue from pulsed DC. Non-isolated is usually OK if it is sort of at a peripheral that's isolated from everything else like a wireless access point or light. The tears start to flow when you get too ambitious and power say a raspberry pi connected to an increasing number of non-isolated or shielded signal cables.

 

[Skypower]

Yup. I don't know if my incessant spamming of the "check for non-isolation" is going to save anyone from the smokes...

That said, I don't think non-isolated matters for LED lighting other than the safety issue from pulsed DC. Non-isolated is usually OK if it is sort of at a peripheral that's isolated from everything else like a wireless access point or light. The tears start to flow when you get too ambitious and power say a raspberry pi connected to an increasing number of non-isolated or shielded signal cables.

I learned this lesson the by hot wire and good luck. Hey, what the? Why the? Ohhhhh.

 

[zanydroid]

I learned this lesson the by hot wire and good luck. Hey, what the? Why the? Ohhhhh.

How much was the damage?

Fortunately I learned this vicariously … I was rigging up a lot of expensive equipment (cameras) with a few DC DC converters between various components while also learning up on PoE. So I was reading the forums enough to see smoke stories before I blew anything up. Blowing up an HDMI port on $2000 equipment is not good.

 

[Skypower]

No damage. I was tucking wires away to close and things were working when I noticed that a wire was hot that shouldn’t be. I now fuse negative and positive on everything I build especially if it has non isolated devices and/or unlimited potential.

 

[pvdude]

Wanted to find out if the LAMBDA DIN rail PS were the source of all the noise or just some of the noise.
(Not sure if LED's can produce RFI)

So today, powered the LED's up on a 6434B HP DC linear, rated @ 40vdc @ 25A.

The LED's used 21A @ 24vdc, no RFI heard in the Collins HAM radio receiver!
But the 1967 vintage HP was really humming loud, and subsequently smoking.

Tried a larger, newer (1976) HP 6268B 40vdc @ 30A.
It was very RF quiet and no smoke.

So this experiment proved the LAMBDA switchers are 100% of the RFI here.

 

[stankaprogram]

LED strips can really brighten things up, and using those used DIN rail power supplies was a smart move. It's awesome that it's super bright in there now.
As for the RF noise, I get it. HAM radio can be finicky with interference. Turning off the LED strips during radio sessions is a good workaround.
By the way, I'm currently in the midst of renovating my house and garden, and I came across this cool entryway lighting collection. Lighting makes such a difference in a space, right? Any tips or experiences with entryway lighting?

 

[Skypower]

LED strips can really brighten things up, and using those used DIN rail power supplies was a smart move. It's awesome that it's super bright in there now.
As for the RF noise, I get it. HAM radio can be finicky with interference. Turning off the LED strips during radio sessions is a good workaround.
By the way, I'm currently in the midst of renovating my house and garden, and I came across this cool entryway lighting collection. Lighting makes such a difference in a space, right? Any tips or experiences with entryway lighting?

I’ve been doing a lot of LED light strips. https://a.co/d/0Gu8gSO
All are COB and “addressable”. Think like, continuous neon tube, infinite color variation. Because the LEDs are so close inside an opaque water resistant cover it’s very close to a continuous line of light. Also because there are so many LEDs the light output is massive if turned up. Why I like the addressable+controller is the ability to have any light temperature or effect that you can imagine. Things I have learned. The AC to 24 volt DC power supplies are noisy….all of them. The primary noise I’m referring to is the interference to the very sensitive device within the addressable type light strip and probably won’t be an issue for a single color strip. The noise would cause random flickering or artifacts along the strip. Things that helped; Having the power supply close to the start of the controller/light strip. A long run between the controller and light strip is also to be avoided. If you must hide the power supply and/or controller that necessitates a long run to the strip a low pass filter can help. Surprisingly, the low pass filter with six terminal that’s primarily designed for AC worked better than the DC type. The outputs of the power AC type power supplies are isolated. I found that bringing the house ground around to one side of the DC would also reduce noise but kinda like isolation. Having more than adequate capacity power supply is necessary. You can calculate the watts necessary by the foot of strip light. For instance the strip I used is 3.66 watts per foot. Example; if you have a 20’ length it’s 73 watts, so you’d NOT select a 75 watts supply, go with at least a 100 watt unit to not over work it and keep it cool. When the strip is at full white they draw the most current. If it’s got a green hue when set at white you have insufficient voltage because of a bad power supply or too long a run without power injection. It’s a good idea to inject additional power at about the 48’ point. The traces in the strip are too thin to convey power at distance and you have a voltage drop. The control signal line is directional (one end fed) and must be with arrows on strip. DC can be added anywhere along the strip as needed and will feed up and down the length. There are three power supplies I’ve used. The black PAUTIX 180 watt has a noisy fan. The 200 watt with two leads that literally has so much noise that touch screen on my oscilloscope wouldn’t function. And finally the thin low profile that powers my under kitchen cabinets lights. All using a low pass filters. There are three low pass filters I’ve used. The six terminal AC 25 amp, the four terminal DC 20 amp and the tiny DC 5 amp capacitor. I also the used the six terminal on an AC appliance 15 amps load and it immediately got hot so I don’t know what they were smoking when they rated it for 25. Everything seen purchased from Amazon.