# LED Strip Light Installation

#### Paul Carr

Hi All, New to this so bear with me

ok, i am wanting to install led strip lights into my decking under the balustrades, i have a total of 40metres of SMD5050 300 leds per 5 metres, each 5 metres has a total output of 72watts.

I'm going to run them parallel, based one the below:

the transformer (A) will connect to the RGB Controller (B) then supply 3 strips of RGB LED lights, there will then be another 2 RGB amplifiers (C) which will each power 3 & 4 more strips each.

so my questions are:

(A) How much does the transformer power have to be
(B) What rating does the controller have to be
(C) what power do the amplifiers have to be

also i have RGB wire which is used to connect each LED in links, can this be used to run them parallel? & can the amplifiers be wired up to the one power source/transformer?

or if anyone has any better ideas then i'm all ears.

look forward to hearing form anyone who can help me.

Thanks

Paul

anyone?

(A) How much does the transformer power have to be
Well...
i have a total of 40metres of SMD5050 300 leds per 5 metres, each 5 metres has a total output of 72watts.
3 strips of RGB LED lights, there will then be another 2 RGB amplifiers (C) which will each power 3 & 4 more strips each
I'm not sure what I'm missing here, for I simply can't see why you can't work out that the strip is 72/5=14.4W/m.

Or why you don't know how long each strip will be. You have 3+3+4 = 10 strips. I have to make an assumption that each one is the same length, i.e. 40/10m. But you're the only one who knows how long each strip will actually be, and you're the only one who can work out the consumption of each strip at 14.4w/m, and therefore what the first 3 total, the second 3 etc.

So, as I said - I must be missing something, as from here it looks so obvious and easy, but clearly something you haven't told us means it isn't.

Also, my understanding is that you'll need 3 supplies, not one.

(B) What rating does the controller have to be
Enough to cope with the total length it is supplying directly.

(C) what power do the amplifiers have to be
Enough to cope with the total length each is supplying.

also i have RGB wire which is used to connect each LED in links, can this be used to run them parallel?
Yes.

& can the amplifiers be wired up to the one power source/transformer?
Check with the supplier, but I'm pretty sure the answer is no.

The SMD 5050 is a chip which uses 20 mA. This chip is often sold with a flexible printed circuit and some control but this varies all we know is the chip is 5mm² hence called 5050. The red will be 2.4 volt max the green 3.6 volt max and blue 3.6 volt max so around 20 mW per chip. Times 300 that's 6 watt but that does not include any power taken by the control device.

I would guess one would use three drivers one for each colour but that would depend how your going to use the chip. Most people will buy these chips already fixed to some device and I would think this is what you are doing but since SMD 5050 RGB is the name of chip we have no idea of other hardware in the package.

I have just re-read and how does 300 x 0.020 = 72? Maybe I have miss read data sheet and it's 0.020 mA per LED not per chip but that is still only 18W not 72W. Something wrong there!

20mA @ 12V = 240mW.

0.24 x 300 = 72.

ok maybe i've not really clarified with you on here, so let's start again!

I have 40 metres of LED lighting, each strip is 5 metres, total = 8 strips.

each strip is 72w, total 576 watts.

i have 2 x 360w transformers, one will power the rgb controller (has output of 3x4A), and the other will power the 2 amplifiers (20A total each unit)

the rgb controller will power 3 strips, and the amplifiers will power 3 strips and 2 strips respectively.

I will run them parrallel.

so i just need to know or clarify, if this is ok to do?

What are RGB amplifiers?

3 strips of RGB LED lights, there will then be another 2 RGB amplifiers (C) which will each power 3 & 4 more strips each
3+3+4=10.
I have 40 metres of LED lighting, each strip is 5 metres, total = 8 strips.

the rgb controller will power 3 strips
No it won't:
the rgb controller (has output of 3x4A)

so i just need to know or clarify, if this is ok to do?
How will you physically connect 1 PSU to 2 amps?

Also, as the led strips are outdoors, where are you going to put all the PSUs & amps?

20mA @ 12V = 240mW.

0.24 x 300 = 72.
No 20mA at 2.4 and 3.6 volt is what the chip data sheet says. As I have said if the chips are used with simple resistors then yes you could have 480Ω and 540Ω resistors with each chip but I would have thought it would use 3 chips and a resistor so they would be smaller or use a constant current power supply.

ok, i am wanting to install led strip lights into my decking under the balustrades, i have a total of 40metres of SMD5050 300 leds per 5 metres, each 5 metres has a total output of 72watts

Note output not input and the light output will be 20 mA @ 2.4 and 3.6 volt rest would be heat.

It is possible the chips are in a package as BAS shows, but that is a guess. I looked at This PDF I would think it's 20 mA per LED rather than chip it states Red = 40 mW and Green and Blue = 60 mW which would mean 8 volt for whole chip giving 160 mW per chip. With 3 LED's per chip that's 100 x 160 = 16 Watt per 5 meter length. If they count each chip as one LED rather than 3 then 48 Watt per 5 meter length, but that's no where near 72 Watt. They could use a resistor for each chip which could mean it would use 72 Watt when including heat from resistor, but even that does not add up to 72 Watt and that would be input not output.

If I was designing a unit to use those chips with a 12 volt power supply I would use groups of 3 chips per resistor. Or use 48 volt maximum current regulators with 13 chips in series.

But point is it is all guess work. All we know is the chip type we have no idea how wired into a strip. There is nothing in Paul Carr's description anywhere which says 12 volt. It may be 12 volt, but how do we know that? The chip is likely 2 and 3 volt why should we think package designed for 12 volt?

ban all sheds, thanks for your help the diagram is a good start.

the lights will run on 12v.

so we have clarified the rgb controller will only power 2 strips, this is the rgb controller bought http://www.amazon.co.uk/gp/product/B00B22XN22?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

The rgb amplifier however are 20A, these are the ones bought http://www.amazon.co.uk/gp/product/B009ZPH6W6?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00 ,will this be suffice to power 3 strips, i'm presuming so as it's in your diagram?

I will run 2 strips from the rgb controller and 3 strips from each rgb amplifier.

also as per your power supply advice, i need 3 transformers, i bought these http://www.amazon.co.uk/gp/product/B012MZ3156?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00

so after the advice given, i think i'm good to go?

just thinking aswell, these 3 power supplies will need to go into one extension lead, what would be the best one to use which can handle the load?

Thank you BAS seems I was not the only one to realise something wrong with the spec. As to power supplies the ones linked to are clearly designed to be used inside some other enclosure and likely will need cooling. Signal amplifier is really a relay which allows you to add extra strips all controlled together, but these units all need some protection I would say a computer case should do the job since it can take fans and has cooling ducts.

For 12 volt extra low voltage not really a problem, but for 230 volt low voltage the enclosure needs to have the appropriate IP rating top and rest. At 360W you could have 3 units on a 6A supply so bringing this into layman's language the whole power normally supplied to light a whole house will be needed to supply your 3 power supplies.

576W of lighting using 70W metal halide lamps i.e. 8 flood lamps would light a supermarket car park to give you an idea of amount of light.

When trying to light a long run as for example a runway instead of voltage we use current. Since LED's are current dependent devices these are ideal for long runs as first and last LED on a 320 mA driver will be same output. A driver controls current not voltage. However what you have selected uses constant voltage and likely as per BAS link you will see the output drop along the length. Since they use resistors to limit current they are very uneconomic to use half the power goes in heat.

It does seem rather pointless to use expensive LED's and then have a whole device which only matches a simple tungsten bulb.

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