Hello,
i hope someone could point me into the right direction on how to properly setup a power injection.
My current setup is using a powerbank connect to a pixelblaze and from there to the Leds.
Can i connect additional wires with the screw in connector mounted on the pixelblaze for the power injection at the halfway point and or the end?
Thank you!
Only so much power can go through the pixelblaze, so that powerbank should be connected to the screw terminals and not to the USB port.
Then you can indeed run power directly to the middle or end of the strip!
You can absolutely connect cables to your screw terminal to go to your injection point, but only if you power also the pixelblaze through this screw terminal as well. Like this, power will go from the powerbank to the screw terminal, then from the screw terminal to your LED, without passing through the PB components.
Be careful though, if you power your PB through the USB (as explained by sorceror above), do not put the LED on the screw terminal because in this case the current will go from the powerbank to the LED by passing through the PB PCB and components, destroying it if the current is too high.
Thank you for your reply. Would something like this work?
If i go from the powerbank directly to the screw terminal i assume i can just cut a usb cable in half and connect it to the screw terminal or is there are more elegant solution?
Yes, this will work. I usually screw a cut USB cable to the terminal of the pixelblaze, then i connect all the injection points to this terminal as well.
But keep in mind it means the sum of intensities of each injection point will be in the cable between the powerbank and the screw terminal, exposing you to voltage drop and heat if the cable is too thin or/and too long. I recommend to use a “strong” USB power cable (only has 5V/GND inside), not a data cable (has much smaller power cables to fit data). Else you can make your own cable with thick wire and a USB connector.
Considering you’re using a powerbank, I guess your Amps will be limited (2-3A max in general ?), so get a cable rated for at least that, and the shortest cable possible of course. Also I doubt you will be able to light up your LED at max power ( a powerbank is too weak), or else you won’t need injection points.
If you can give a bit more details (how many LED, type & density of LED, distance between powerbank and LED, max Amps of your powerbank), i’ll help you.
The project i’m working is a jacket with close to 600 2812 leds. Powerbank and pixelplaze will be inside the jacket in a pocket.
I will run two additional 16awg cables to halfway and end with rough ~15in/40cm and 30in/80cm
Not sure if two powerbanks would be a better option and wiring up like this:
For sure you won’t be able to run these LED at full power “white” with one (or even 2) powerbanks, or else it’s going to overload (and then cut off) the powerbank (it has a max Amp protection). I barely run 200 LED with a 2.4A powerbank. Might be a bit weak if you want to push luminosity or avoid cutoffs.
However in practice you don’t need full white 100% luminosity, especially for a wearable (I assume it’s for Burning Man ? :)).
Therefore it’s not even sure you will need to do this many injection points.
I’d recommend to do tests to see if you actually need these injection points, i think beginning and end (not even sure it’s needed honestly) are more than enough, especially if you cable from the power with AWG16.
To give you an idea, I run 2x 200 LED behind 40cm of AWG18, and i have no noticeable voltage drop at 100% power = 25W per strip = 5A !!! Considering your powerbank is 3A max = lower voltage drop. You can start your tests with feeding power only at the beginning of the strip (with data).
You can indeed use 2 powerbanks to increase the power (less LED per powerbank) or battery life, however make sure these 2 powerbanks have their +5V separated:
Hope it helps !
You can run 300 LEDs on a power bank, but only with the brightness down a fair bit. You will not likely need power injection since the current would be relatively low.
Thank you for your replies.
Will report back on how it all went
