50/50 led tape and usb supply

[big-all]

over the years i have bought many 5m x 12v led tapes and they all seem to need a 12v 6amp supply so 72w supply but these usb suggest 9w at 5metres so a 2amp at 5v supply or more am i misunderstanding how they work or do i need a greater than 2mp supply ???
https://www.ebay.co.uk/itm/284278993188

 

[SUNRAY]

over the years i have bought many 5m x 12v led tapes and they all seem to need a 12v 6amp supply so 72w supply but these usb suggest 9w at 5metres so a 2amp at 5v supply or more am i misunderstanding how they work or do i need a greater than 2mp supply ???
https://www.ebay.co.uk/itm/284278993188

From that listing:

• Input Voltage: DC5V

• Electric Current<2.88A/M

So 14A for 5m

 

[RandomGrinch]

Hi,

I'm afraid there is some 'smoke and mirrors' going on here!

'This USB strip light is not just for TV's - it can also be used on computer monitors, in the car or anywhere where have a spare USB port'

The standard specs for a USB 2.0 port support a device current of 500mA. The limit for a USB 2.0 charger is 2.1A, I believe the limit is set to avoid heat damage to the cables and connectors (USB 3.0/C chargers can reach higher currents).

If you look at similar products from Amazon, the reviews can be quite scathing!
If as the information suggests, the strips take <2.88A/M, that suggests that they could take up to 2.88A/M; 14.4A @5V = 72W.

Quite a coincidence that it matches your 72W 12V supply!

Basically, the the discription lists the figures for the absolute best case scenario, even if this isn't physically achievable!

At best you will get a fairly dim led strip (powered at 5V 2.1A). At worst, the strip won't light at all, or you will get a very dim red glow (powered by a standard 500mA USB2.0 port).

Of course, this will also depend on how long you cut the strips.

I hope that makes sense!

 

[big-all]

i tried to find a "normal " setup as i know it with power brick and socked but couldnt find any easily so assumed things have moved on ------- wrongly it seems ??

 

[RandomGrinch]

SMD 5050 LED (BTW, the number refers to the chip size of the LED; 5.0 X 5.0mm) strips with 60 LED/M & 14.4W/M have been around for a while.
The efficiency of these LEDs hasn't improved greatly over the years!

Even when a 12v PSU is included in a kit from Amazon etc, the supplies can be of the cheapest quality imaginable.
Although, often the led strips themselves are perfectly usable, even if the PSU's aren't.

Another consideration for power use is the colour you choose - if you choose white, that will run all 3 RGB LED's at high brightness to get the white light. If you wanted a white light, it would be far more efficient to choose a specific white LED strip.
Alternatively, if you were to run the strip in plain red, green, or blue, a 2.1A supply could be more than adequate.

If you would like to let us know how you want to use the strips, maybe we can help source something?

 

[big-all]

mainly white under cabinet light with a bit off gimmickry so the wrong sort really
would work with 2m but prefer longer as more interesting ??

 

[big-all]

ok another avenue off thought assuming it is a 12w per metre requirement is there a source on e bay or perhaps slave zone prime that have greater than 24w up to 72w available as i cannot find any ??
or even starting again can you suggest a setup with mainly white but jazzy colour choice via remote and power brick for at least 2m but preferably 5m ??
thanks

 

[RandomGrinch]

If you want something jazzy and app controlled, you could look at:

https://www.screwfix.com/p/tcp-5m-l...lm/576pk#product_additional_details_container

This is where things can get confusing - this set is rated at 17W, but that is ok. They are not using SMD5050's and the led density is less @30 LED/M.

It is also an RGBW strip; rather than the RGB LEDs all lighting to give white, there is an integrated white LED.
This saves a lot of power.

And given that it's supplied by Screwfix, returns shouldn't be an issue, if it does fail.

The only slight issue, is that it doesn't come with a separate remote control.

 

[big-all]

ok thanks screwfix didnt even come to mind and its only half a mile away beside tool station lol
my mobile is 8 years old and playing up 'i dont do gadgets unless they throw wood everywhere
the only thing connected to the internet is this laptop and the mobile phone
no boxes for tv services just an aerial
so perhaps a good old fashioned remote control is essential even iff its only to dim the lights

 

[big-all]

ok update
lights arrived today used an official 2.1ah usb adapter for a ryobi li-ion battery as a cheaper option to damaging any mains device

as expect 5m works all functions [except dimmer]but a very low light level with a bluish tinge far more so than a day white bulb
i then cut the strip to 2.6m as the under cabinet length but visually seemed no brighter the dimming function doesn't work with any combination
the actual output would be similar to perhaps an 60-80w/800-1100lumin bulb where as the correct input would be about 3 times that level