HP Power Supply - Breakout Board

bpratt said:
Just looking at them now.
Would I be right in assuming any of these HP power supplies prefixed with DPS takes the same breakout boards ?
These power supplies look like a winner, even used if I got a spare it should still be pretty good value.

Looking like my mega tree will be 12v one now.
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I am also converting my tree from 5v strip to to 12v strings that was my motivation for the original purchase. My 5v 400w meanwell was over $400 NZ and a 12v 1200w HP (2nd hand) was well under $100. I checked out the PS model number and breakout board for compatibility, I'm not a guru on the electronics so I rely on the sellers recommendations some do seem to be able to be used across a wide range though.
 
kevr said:
I am also converting my tree from 5v strip to to 12v strings that was my motivation for the original purchase. My 5v 400w meanwell was over $400 NZ and a 12v 1200w HP (2nd hand) was well under $100. I checked out the PS model number and breakout board for compatibility, I'm not a guru on the electronics so I rely on the sellers recommendations some do seem to be able to be used across a wide range though.
Click to expand...

Sadly a 400W 5V and 1000W 12V will power just about the same number of pixels. 1450 5V vs 1515 12V. There is a big difference in price though.
 
depends what type of 12v pixels you are talking about really
 
AAH said:
Sadly a 400W 5V and 1000W 12V will power just about the same number of pixels. 1450 5V vs 1515 12V. There is a big difference in price though.
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Why is that then?

I'm getting more and more confused, thinking that with 12v the cabling can run a little bit further with less issues of voltage drop at the end of a run versus 5v..

I'll still go 5v for other parts of my display, where the power supply is closer, but thinking these 12v HP power supplies is a good option for my megatree and some other lights such as arches close by to it.
 
bpratt said:
Why is that then?

I'm getting more and more confused, thinking that with 12v the cabling can run a little bit further with less issues of voltage drop at the end of a run versus 5v..

I'll still go 5v for other parts of my display, where the power supply is closer, but thinking these 12v HP power supplies is a good option for my megatree and some other lights such as arches close by to it.
Click to expand...

In general all pixels will run at the same current regardless of whether they are 5V or 12V. In the case of WS2811, WS2812 and the multitude of compatible ones this is 18.5mA per colour or about 55mA when on white. Individual leds have a voltage drop of between about 2.6-3V depending on the colour. All the rest of the 5V or 12V gets dropped as heat in either the pixel chip or a resistor on the pixel pcb. The advantage of 12V is that there is a much greater voltage drop before you start getting into colour changes and latchups due to voltage drop. A 5V pixel can probably tolerate about a 1V voltage drop and still maintain uniform colour whereas a 12V pixel (node not strip) can comfortably handle a 3-4V drop before pixels start losing consistent colour representation. This means that even though both lots of pixels are drawing the same amount of current the 12V ones don't need as heavy wiring as the 5V ones do.
There are some variations to this rule. 12V strip uses 3 leds in series so produces 3 times the light for a given pixel but as there are 3 leds in series the voltage across the leds jumps to 7.8-9V so they can only afford about a 1-2V voltage drop. Another variation is the INK1003 strip and matching styles which are powered by 12V but have a stepdown 5V regulator to power the pixel IC and leds. The regulator is relatively efficient so you get most of the best of both worlds. You get the lower voltage drop of a 12V distribution system and the more efficient power usage of 5V leds/pixels.
The final variation is a new breed of pixels that are 12V but use some cunningness to run off 12V but effectively power the leds at 5V. I can't think of what part numbers these are offhand but they certainly aren't the common WS2811, WS2812 and UCS1903 types which are the most common.

The final calculator on https://www.da-share.com/calculators/led-strip-string-current/ allows you to see the currents and wattages that you can expect with 5V and 12V 2811 pixels. From this you can calculate that 1500 5V pixels will use 416W on white and 1500 12V pixels will use 999W on white. That extra 600W is just extra power supplies, heat and power costs that you get to pay for for the same amount of light.
 
I use HP server power supplies in my display and have a few breakout boards for sale if anyone needs any....the model of HP power supply I am using is shown in the ad...this power supply powers my 2000 pixel mega tree no problems...I did successfully adjust the voltage on these internally to around 11.6-11.8 volts but can't remember where the tutorial was...but you can adjust the voltage on these as they tend to run above the 12 volt mark.
https://auschristmaslighting.com/threads/hp-sever-power-supply-breakout-boards.11490/
 
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