Series or Parallel for LED strips

[Justin Bodley]

Hi!
I'm just sorting out bits for a media wall. I want to install RGBW strip lights with diffusers on 4 shelves plus behind the TV. Looking at the 24v x 10m strips. Do I just cut them and wire them in series or do I wire them in parallel to each area? If I wire them in parallel, will I need a bigger power supply as I'm guessing it will pull more current? Thanks in advance!

 

[mattylad]

If you cut them from the same strip then the power supply will be adequate.
Power them in series, power into one end, out of the other end to the next strip and so on.

 

[FrodoOne]

If you cut them from the same strip then the power supply will be adequate.
Power them in series, power into one end, out of the other end to the next strip and so on.

Such an arrangement is not in series.

The Positives and Negative leads in the LED Strip go from end to end
and
each of the LED "sections" are across these two (or five) conductors - in parallel.

 

[ebee]

Frodo,
Yes all the common LED strips these days are usually in parallel from an electrical point of view you are correct

(Just a point though, there used to be a make of units containing an LED each that were in fact wired in series - your supply needed a current regulated output that gave a constant current with 1 to N lamps, maybe 6 or 8 or some-such, I can not remember but I have not seen them for quite a few years now).

Anyway nowadays , usually you buy a strip or a roll and often power supply (12v or whatever) supplies the full strip up to a certain length and any volt drop, therefore brightness mismatch, is near imperceptible so no problem.

If you have very long runs or you make cuts or add sections with link-wires then volt drop might become more apparent according to the layout used and I suspect this might be what the OP was considering as "series" as in one after the other (although electrically all LEDs are still parallel ).

Example, on a long run it might make a comparison from one end to the other become more discernible especially if the topology brings the ends closely together - on simple way forward on such a plain long run it to connect the power more in the middle section area and any differences less noticable.
Another example, say a spokes of a wheel type of arrangement powered from one end and short interlinks of wire between each spoke in a series fashion, might yet again become a little less acceptable.
One solution to both examples might be to add extra conductors to the far end of the "chain" and reduce possible volt drop problems sufficiently.

Of course all of this depends upon the lengths and quality of the strips used so might be a pointless exercise on many configurations anyway but on longer runs might be worthwhile, suppliers data sometimes gives a clue on intended length of run for particular power supply units.
Some strips have their "busbar" csa more current carrying friendly than others anyway whilst other less pricey options those integral conductors may be not much better than a length of wet cotton thread in reallity.

 

[ericmark]

12 volts tend to be groups of 3 LEDs and a resistor in series, in parallel with the next group of 3 LEDs and a resistor in series, and a mark at the end of each group to show where they can be cut. 24 volts of course 6 LEDs, but you can also have a driver and a voltage range, with fixed current like 340 mA for example, and all LEDs are in series. The latter is not normally found with colour changing, but the lighting industry seems to have a problem with words, "Driver" was always a current regulated device, but now one finds voltage dependent devices called drivers.

It seems each new device is called after the device it replaced, so a bulb is often not bulbous, we have ballasts and electronic ballasts which are completely different, and transformers where the output matches the input, so have not transformed anything (isolation transformers) so one has to read what it says on the device, one can't assume.

I have four colour changing, colour temperature changing LED strips, two from Lidi, and two are TPC, and I just read the instructions which came with them.

 

[mattylad]

Frodo stop trying to be confusing to the OP.

Yes strictly speaking yes series is where you feed one then the other and so on however these must be added one after the other in a series chain.

The + from one goes to the + from the other, ditto the negative - they appear to be in a row (actually daisy chained) but then if someone who does not know what each actually is, then the description is correct.

If the strip is cut up, you absolutely must connect them with wires as if they were not cut up, it's that simple.

The strips do NOT want to be put in parallel. How the LED's are arranged on the strips is neither here or there.

 

[RandomGrinch]

If I wire them in parallel, will I need a bigger power supply as I'm guessing it will pull more current?

Frodo stop trying to be confusing to the OP.

I'm with frodo on this one. The OP is confusing the concept (series and parallel) at a component level, hence the reference to needing a more powerful supply.

If the strip is cut up, you absolutely must connect them with wires as if they were not cut up, it's that simple.

The LED strios can be connected in any form of branching network, just as long as the RGBW and Com channels are connected together correctly.

To aid understanding, its sometimes helpful to explain the technicalities.

 

[mattylad]

Yes, connecting them as if they were not cut up is exactly what the op needs to know.
Which is what I said.

 

[mattylad]

This is the strips in series:

This is the strips in parallel:

While the description may be technically incorrect, as far as the OP is concerned, series is the way they should be wired as that is what they described.

Justin, you can wire them either way, you will not need another power supply as it was designed to power all those LED's.

Connecting LED Strips in "Series" vs "Parallel" | Waveform Lighting

www.waveformlighting.com

We find it is important to clarify, because true electrical series connections will change the required input voltage. When people talk about wiring LED strips in "series," however, they almost always connecting LED strip sections end-to-end. When connected in this way, the LED strip input voltage remains unchanged. In other words, you can use a 12V power supply to power a 4-ft section of 12V LED strip lights with another 3-ft section of 12V LED strip lights daisy-chained.

 

[RandomGrinch]

Thanks, the link has a good explanation; but I'd still disagree with this...

as far as the OP is concerned, series is the way they should be wired as that is what they described.

With...

I want to install RGBW strip lights with diffusers on 4 shelves plus behind the TV.

four shelves and some strips behind the TV, any number of branch arrangements could be far better suited than connecting all the strips in 'series'.
Without knowing the layout, we can't say which way is better.

 

[Justin Bodley]

Thanks for all your replies. Because of the layout I want to run cables to each strip and preferably wire them in parallel from the controller. Here is a very rough drawing. I'm just not sure what size power supply to use. In total will be around 7m of RGBW strip. I'm guessing certain manufacturers have a different wattage per meter which also confuses things? I will probably purchase from Amazon. The LED controller will probably be one of these as I use Smart Life to control my home lighting and sockets. https://amzn.eu/d/5Pct0KN

 

[333rocky333]

Been to a few sites where joining strips end to end and creating over 5 meters has caused the first connection to fail
Most shop shelving utilises seperate tapes and each wired back to one unit as you propose.
24v is good choice and seems more reliable, look on uk commercial led sites they often sell more reliable stuff over the cheaper imported stuff and tend to state the wattage per meter, and recomended power source, 10 metres of any tape will always give the same total wattage as + and - will always be parralled regardless if you go end to end or any combo of branches

 

[FrodoOne]

I'm just not sure what size power supply to use. In total will be around 7m of RGBW strip. I'm guessing certain manufacturers have a different wattage per meter which also confuses things?

Current / Wattage depends on the
Type of LED Chip,
Number of Chips per Metre,
Total number of metres.

For SMD 5050 LED Chips, each Chip draws (up to) 0.2 W.
If you had a Strip with 84 Chips/Metre this would use (up to) 16.8 W/m.
At 12 V, this is 1.4 A/m

For 7 Metres, (at 12 V), this would require 9.8 A.

In that case, I suggest the use of a 15 A Power supply.
which is equal to the capacity of your proposed "controller".

 

[Justin Bodley]

Current / Wattage depends on the
Type of LED Chip,
Number of Chips per Metre,
Total number of metres.

For SMD 5050 LED Chips, each Chip draws (up to) 0.2 W.
If you had a Strip with 84 Chips/Metre this would use (up to) 16.8 W/m.
At 12 V, this is 1.4 A/m

For 7 Metres, (at 12 V), this would require 9.8 A.

In that case, I suggest the use of a 15 A Power supply.
which is equal to the capacity of your proposed "controller".

Thank you! I am looking to use 24v strip however

 

[trojanhawrs]

Current / Wattage depends on the
Type of LED Chip,
Number of Chips per Metre,
Total number of metres.

For SMD 5050 LED Chips, each Chip draws (up to) 0.2 W.
If you had a Strip with 84 Chips/Metre this would use (up to) 16.8 W/m.
At 12 V, this is 1.4 A/m

For 7 Metres, (at 12 V), this would require 9.8 A.

In that case, I suggest the use of a 15 A Power supply.
which is equal to the capacity of your proposed "controller".

I've never used these but my understanding is if it's 3 amps per channel and the positive is shared, you're limited to 3 amps per controller. At 24v 7m is right on the threshold @ 10W/m.