Power for ws2812b and arduino

[Lee Todd]

Hi all.
I've only just found this site and not sure if this is the right one to post this in.
Im building a set of lights using the the ws2812b led strips. Its going to have 2x 4 meter 30led/meter and if I run it at full brightness and white it will require approx 14amps.
My long term plan is to run it from a 12volt battery and have that charge during the day by solar but for now might have to be a mains to 12 volt. I would do the mains to 12 so it will be easy to switch.
Where im stuck is on the psu for it and when using a battery what is required to cut the output when the voltage is low as not to kill the battery.
Ive looked at is a 12v to 5v STEP-DOWN BUCK CONVERTER
http://www.ebay.co.uk/itm/171530222...l?_from=R40&_sacat=0&_nkw=171530222865&_rdc=1
and a UBEC from the model world
http://www.hobbyking.com/hobbyking/...V_2_12S_SBEC_w_Selectable_Voltage_Output.html
Im not sure which would be better of if you guy and point me to something else. Im not planning of running it at full power so to be able to burst to 14amps or so and have 8-10amps normal may be ok.
Not seen anything for cutting the power yet though but know lead acids dont like to be over drained.

Thanks in advance

Lee

 

[ver chan]

14 amps! REALLY, are you sure! please post your schematic diagram so we can send you some good advice.

 

[JWHassler]

2 x 4M x 30-LED/M * .06A/LED is indeed 14.4 Amps.
It's kinda hard to find a high-amp buck-regulator with an enable function: here's one the enable is described almost as an afterthought.
You could use multiple regulators if on/off is easier to find in lower-wattage units.
If you run into voltage-drop issues because of the strips' length, you may have to de-centralize the power-distribution, anyway

 

[Lee Todd]

thanks JWHassler
this me be stupid but what do you mean by enable function. so im not the only one to have this issue then. the one you link to is going to be too small. i must admite 14amps is the max and chances are i will not run it at fill white and brightnes but nice to have the option. what do you think to the 2 items i linked to. ive also got to get a low voltage cut off somehow so i dont kill the batterys
thanks

 

[JWHassler]

By 'enable' I meant a control-line into the regulator that would disable it without the need for physical disconnection.
This would be a function of the low-battery cutoff.. which you don't have.
I don't know what you know, and so can't tell you to make your own, but here's a ready-made unit that does not need an enable.
Also, you really could use multiple, smaller regulators as long as they all share a common ground

 

[ver chan]

if your load current demand is just 1 ampere, i think it is more practical to provide just only 2 ampere supply instead of 14 amps.

 

[Lee Todd]

ver chan,
if you look at my last post you will see 14amp is the max and 7-10 will probably do, not 1amp.

JWHassler
That link looks like what im needing. Will look to find one in the UK. Think I might go with the UBEC idea for the PSU. I know its rated at 20amps but least I will not kill it

 

[ver chan]

ver chan,
if you look at my last post you will see 14amp is the max and 7-10 will probably do, not 1amp.

lee todd---its just a suggestion only, not a direct answer to your inquiry, you have a choice to change your load for a smaller demand for power and current but giving the same output and performance, for example-, incandescent bulb requires a larger amount of power but LED lights has less consumption than incandescent, however its up to you, im giving you just a suggestion,,, more power to you, im hoping for your success.

 

[Lee Todd]

Hi Ver Chan
Sorry if I sounded a bit off, was a bad day. I also thought I had posted this but just noticed I had not. I appreciate your input but for the project im doing it will be 240 led's. the only way I can lower the amps is to keep the brightness low but that kind of defeats the point of what im doing. I agree that 14amps or even half at 7 is a lot which is why it is causing me issues and hence finding this site. I have seen lots of supplies that do 4 amps and that would make life simple but they are just not enough power. As said in my last post I think im going to try a UBEC from the model world and see how well it works.