I'm working on a project with 80 WS2811 LEDs. The power will be supplied by 12V 100W power supply. The distance between every LED will be 1m and total circuit distance will be around 80m (80 Leds * 1 m (1 LED per meter)). I am thinking to connect 80 LEDs in pair of 10 LEDs parallel or in series to overcome the Voltage drop problem and provide them power with an another external wire coming from the same power supply.

Will this work or there are some other cost effective ways?

LED Link: https://www.ebay.de/itm/100x-WS2811-RGB-Full-Color-Pixel-5050-LED-Module-Point-Light-16mm-20mm-26mm-30mm/202034762524

I am from a programming background so I do not have much knowledge about electronic stuff.

1) Parallel enter image description here


enter image description here

  • \$\begingroup\$ So you connect the supplies by group of 10 LEDs, but all the LEDs are still connected in parallel, right? Not in series? Because it seems those have an integrated IC and are certainly not meant to be connected in series (but, as always with ebay/aliexpress, there is no datasheet, so who knows?) \$\endgroup\$ – dim Feb 12 '18 at 21:13
  • \$\begingroup\$ @dim my main motive is that there should be minimum voltage drop as possible. I connected them parallel in photo but they are sharing a data line/signal line coming out from raspi . what dou think, is it better to connect themin series like shown in the second pic ? \$\endgroup\$ – Micheal Choudhary Feb 12 '18 at 21:35
  • \$\begingroup\$ both of the pictures show parallel connection \$\endgroup\$ – jsotola Feb 12 '18 at 23:47
  • \$\begingroup\$ So this thing will be almost as long as a football field (that's rugby pitch)? \$\endgroup\$ – Harper - Reinstate Monica Feb 13 '18 at 0:13
  • \$\begingroup\$ you could use multiple +12V supplies \$\endgroup\$ – jsotola Feb 13 '18 at 0:24

You cannot connect the supply in series for these devices. Your -12 V signal is actually Gnd for both supply and the data signal.

You can run multiple +12 V wires to groups of 10 along with multiple Gnd wires to groups of ten. This will reduce the voltage drop or allow thinner wires to be used. The data signal however needs to run serially through every device if you want to individually address each LED.

I think that is what you have tried to show in your diagram, and if so then it would work.

Look at the datsheet for the WS2811 IC.

enter image description here

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  • \$\begingroup\$ Thanks Jack, dont you think, it will be really costly to run multiple wires(dont know, how many) out of one power supply ? is it the best and the cost effective way ? \$\endgroup\$ – Micheal Choudhary Feb 12 '18 at 21:49
  • \$\begingroup\$ I'd suggest that the +12 V wire could be a single run, and the Gnd returns be perhaps 2-3 separate runs just to minimize the voltage drop that ends up in the signal path. For example run power to both ends of the string and an extra one to the middle of the string. \$\endgroup\$ – Jack Creasey Feb 12 '18 at 22:05
  • \$\begingroup\$ @Michaeljorg you have to run the voltage drop calcs. I've seen projects where a homerun to each segment in #8 wire beat running a mainbus with 1000MCM. This was a shorter distance than yours, but with 5V devices which are much more kitchy about voltage drop. \$\endgroup\$ – Harper - Reinstate Monica Feb 13 '18 at 0:17
  • \$\begingroup\$ @Harper This is not a 5 V system ...it's 12 V, and the only real voltage drop you need to be concerned with is the voltage drop in the return line since it subtracts from the data signal. \$\endgroup\$ – Jack Creasey Feb 13 '18 at 1:19
  • \$\begingroup\$ @JackCreasey I know it's 12V, read closely. Anyway I am agreeing with you, splitting up multiple homeruns is much more effective than you'd think. OK so 0.72w x 80 = 4.8A at 12V. Average distance 125' I see 2.0V roundtrip voltage drop using #12 wire. 0.8V using #8. That's very rough of course. Cut current in half (by splitting) you cut v.drop in half, and power loss by 3/4. \$\endgroup\$ – Harper - Reinstate Monica Feb 13 '18 at 3:04

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