I'm probably going to sound dumb, but I need some help with LEDs.
I need to run 4 lengths of RGB LEDs, 22' long each.
I need them to change colors together.
It is for a bus.
I believe 12V is limited to 16'. So do I have to go 24V?

I just need someone to tell me what to buy...lol.
The strips, the power supply and driver, etc.

Thanks in advance.
Rob

 

Do you have LEDs already? Are you planning on purchasing discrete LEDs or a pre-made strip.

BTW, there is no 16’ limit with 12V. The power supply and LED wiring together determine the length limit. You could run 100’ of LEDs with 12V with the proper power supply.

 

If each strip that you buy runs on 12V; then 4 strips in parallel can run on 12 V at a current capability 4 times larger. The power supply (bus battery) should be capable of over 4 times the consumption of a single LED string, which its specifications will tell. That should pose no problem. Which led string ? 4 of the 22' ones that have the color changing and control you want.

 

Do you have LEDs already? Are you planning on purchasing discrete LEDs or a pre-made strip.

BTW, there is no 16’ limit with 12V. The power supply and LED wiring together determine the length limit. You could run 100’ of LEDs with 12V with the proper power supply.

I was going to buy pre-made strip LEDs, probably off Amazon.
I just need them to change colors together. All 4 lengths.

 

If each strip that you buy runs on 12V; then 4 strips in parallel can run on 12 V at a current capability 4 times larger. The power supply (bus battery) should be capable of over 4 times the consumption of a single LED string, which its specifications will tell. That should pose no problem. Which led string ? 4 of the 22' ones that have the color changing and control you want.

I can't even find a 12V length longer than 16.4'
I was hoping to buy pre-made LED strips, off Amazon. RGB. And then a power supply and/or controller to have them change colors together.

 

----> https://wap.aliexpress.com/item/325...cdf-8bb1-ae5a3cae1d8c&gatewayAdapt=4itemAdapt

 

----> https://wap.aliexpress.com/item/3256804229479187.html?browser_id=e8c4b8f4cbad42ceb13fe19af72f31c9&aff_trace_key=&aff_platform=msite&m_page_id=001182a3f3300017d0dc62f16249cb6a31b0d821ea&gclid=&pdp_npi=2@dis!USD!!21.03!!!!!@2101d4a716606872706602418e21ef!12000029110763100!sea&algo_pvid=32e6db49-80c2-4cdf-8bb1-ae5a3cae1d8c&gatewayAdapt=4itemAdapt

thank you. but how to connect 4 of those together to run the same colors?

 

Look into Neopixels. You can run them from a few power supplies and control them with one Arduino.

 

Look into Neopixels. You can run them from a few power supplies and control them with one Arduino.

Thank you.

 

The hidden problem with long strips of LEDs is the tail end away from the power will be noticeably dimmer that the head end, simple due to the resistive losses down the strip. In my case I needed not quite 60 feet of beautiful waterproof RGB LEDs to go around my pool.

My solution was to use a dual output controller (similar to this one) powering two strips, each running half way around. While the far end where they meet again are truly dimmer, one does not notice this from across the pool.

I would probably do something different to run 4 strips like put bigger driver FETs into the controller in some sort of Hack-a-Day fashion. That allows you to add better connections (or just hard wire) to each strip.

 

The hidden problem with long strips of LEDs is the tail end away from the power will be noticeably dimmer that the head end, simple due to the resistive losses down the strip.

Or run power via extra wires to the opposite end (the tail end away from the power) of the strip. You can attach these extra wires by carefully soldering to the copper tabs which occur between every group of three LEDs.

 

The simple fix to get around the voltage drop in a long string is simple: Use larger wire external to the strings and feed each section from the larger wire. Certainly it is more wiring but not that complex. Remember that wire sizes must be selected to handle the load current.

 

...but how to connect 4 of those together to run the same colors?...

...then 4 strips in parallel...

From a single controller

 

From a single controller

And hope the controller has enough headroom in the output drivers to drive the total number of LEDs. You might be in luck because you might get two controllers with two reels.

 

I expect you could slave a power MOSFET driver off the first string (or the controller) to drive other strings.