how many amps will a 12v fifty node smart pixels rgb string draw

[sysco]

can anyone tell how to test a 12v 2811 -50 count  smart pixel  node string to see how many amps it will draw. Seen a video on youtube but it was for dumb nodes not sure if it would apply to smart pixels thank you

[LOR Staff]

It's going to be different for each mfgs string -- it's not a constant.  A mfg could have used super high power LEDs on a string or they could have used very low power LEDs.  For the correct number, you need to contact the mfg.

A rule of thumb (that you should not rely on when sourcing power supplies, controllers, wires, etc) is slightly less than 4A for 100 pixels at 12V,  slightly less than 4A for 50 pixels at 5V.

[TheDucks]

As Mike said: Contact the Mfg.

My 50 ct pixel strings are 3A (white).

Rule of thumb: Size your PSU at 125% of expected load. You never want to be up against the wall, odd things happen and the life of the PSU can suffer.

[sysco]

Ok guys thank you for your reply

[k6ccc]

Measure one string and you will know...

 

[sysco]

This is the reply from the company from whom I bought my 50 count 12v rgb smart pixels from. I have the lor 16 channel pixel controller  v4 and I also have pix  con 16 pixel controller and I also have 4 channel  pixel controller. I don't think these boards have  the ability to change the amps  built in to them.I believe it has to be done in the hard ware utility  is this right  new to rgb ??? thank you

  don't have a video on this, but our 12v 12mm pixels are 0.06amps per bulb, if you are running the full white. The amps change based on the color the bulb is projecting. So if you plan on 3amps for a 50 count strand you’ll be safe. (50 x 0.06amps = 3amps)

 

The calculate watts: amps x voltage = watts

In the case of the 50 count strand: 3amps x 12v = 36 watts. Again, this assumes you are running full white on the lights which would be your worse case scenario. 

 

Not to complicate this, but most rgb controllers have the ability to reduce the output of the strands. So you could set the controller to 50% output, which would reduce you to 1.5amps, yet, the brightness of the lights will still be good enough for your display. This would let you reduce the amount of power supplies you need to run your lights. 

 

[k6ccc]

The amp rating of the controller board is just that - a max rating.  Has nothing to do with how much current is passing through it at any given time.  As a general rule of thumb, most controller boards are rated for either four or five amps per output.  There is also generally a max limit for either the entire board or each half.  Your three amps per output should be fine for any controller that I know of.

As for your last paragraph, the Pixie controllers have no ability to reduce the outputs by a percentage, the PixCon16 does.

 

[sysco]

26 minutes ago, k6ccc said:

The amp rating of the controller board is just that - a max rating.  Has nothing to do with how much current is passing through it at any given time.  As a general rule of thumb, most controller boards are rated for either four or five amps per output.  There is also generally a max limit for either the entire board or each half.  Your three amps per output should be fine for any controller that I know of.

As for your last paragraph, the Pixie controllers have no ability to reduce the outputs by a percentage, the PixCon16 does.

 

Can you tell me how the pix Con 16 does it thank you

[Mr. P]

14 minutes ago, sysco said:

Can you tell me how the pix Con 16 does it thank you

In the Advanced Port Setting you can set the Max Intensity. You can also adjust the intensity in the Sequencing Suite Software as well.

[uncledan]

Don't go off of what the manufacturer tells you.  Test the strings.  You can buy a $10 meter from Harbor Freight.  I've never had 12v nodes that were 60ma white.  I run my whole display at 30% intensity or less.  Average is around 20ma white at 30% intensity

[sysco]

1 hour ago, Mr. P said:

In the Advanced Port Setting you can set the Max Intensity. You can also adjust the intensity in the Sequencing Suite Software as well.

 

1 hour ago, Mr. P said:

In the Advanced Port Setting you can set the Max Intensity. You can also adjust the intensity in the Sequencing Suite Software as well.

Mr.P  thank you for your reply

[sysco]

16 minutes ago, uncledan said:

Don't go off of what the manufacturer tells you.  Test the strings.  You can buy a $10 meter from Harbor Freight.  I've never had 12v nodes that were 60ma white.  I run my whole display at 30% intensity or less.  Average is around 20ma white at 30% intensity

Can you tell me how to test them  thank you

[TheDucks]

This is where having a Hall Effect clamp-on Amp meter would be handy. Not cheap, but, they work sweet. Just like you would with the AC version

Come to think. Use a Kill-a-Watt.  Very cost effective.

Measure the idle watts, then set 1 string to white.  The diff, should be close enough for planning (you couls then do multiples, to see if it tracks

[uncledan]

2 hours ago, sysco said:

Can you tell me how to test them  thank you

The easiest is to get a DC clamp ammeter.  Not cheap but I find it very useful in this hobby.  You can purchase a Digital Multimeter such as this for as little as $5.00.   https://www.amazon.com/Function-Digital-Multimeter-Harbor-Freight/dp/B07BV833YN   Its only rated for for 5a so need to be careful.  Most of them are fused internally.  You're running the power through the meter (in series).    You could also use something like this which is typically used in the RC hobby.  https://www.amazon.com/Precision-Detector-Analyzer-Current-Voltage/dp/B07PKHPC1T/ref=pd_day0_hl_60_7?_encoding=UTF8&pd_rd_i=B07PKHPC1T&pd_rd_r=002a392b-664e-11e9-a637-6b060766031a&pd_rd_w=VRPv3&pd_rd_wg=f8JlA&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=T9D8F80Q013Q746QM7C6&psc=1&refRID=T9D8F80Q013Q746QM7C6   

[Mr. P]

7 hours ago, TheDucks said:

Come to think. Use a Kill-a-Watt.  Very cost effective.

Totally agree, this should be a tool in every lighters bag. You can measure a single string or an entire circuit.

https://www.homedepot.com/s/kill%20a%20watt?NCNI-5

[TheDucks]

27 minutes ago, Mr. P said:

Totally agree, this should be a tool in every lighters bag. You can measure a single string or an entire circuit.

https://www.homedepot.com/s/kill%20a%20watt?NCNI-5

I was thinking of doing DC strings indirectly with it. Breaking a + line to insert the typical Amp meter is a real PITA, so measure the PSU AC load delta

but I just did a search and things have changed (still pricier than a cheapo DVM) https://www.amazon.com/Extech-MA120-Clamp-Current-Detector/dp/B000BEZV5O 

there are ones under $100, that you just clamp around the lead like you did with the old AC ones (that I have a couple of)

[PhilMassey]

The other alternative to breaking wires is to remove the channel fuse from the controller and measure the current across the fuse terminals. Again the DVM needs to have enough current handling to support this.

[jerry72]

I have always used a simple equation that was taught to me when i got into Pixels. Each pixel at .06 amps. Easiest is 60 X x amount of pixels / by 1000. IE 60 x 50 / 1000 = 3

[uncledan]

38 minutes ago, jerry72 said:

I have always used a simple equation that was taught to me when i got into Pixels. Each pixel at .06 amps. Easiest is 60 X x amount of pixels / by 1000. IE 60 x 50 / 1000 = 3

I've tested actual current draw on over 30,000 12v nodes.  NONE of them were 60ma(.06 amps).  That's a very safe number if someone doesn't have the capabilities to actually test them.  I find it nice to actually test items in my display and not just go off of what a vendor tells me.  

[LOR Staff]

On 4/27/2019 at 11:47 PM, jerry72 said:

I have always used a simple equation that was taught to me when i got into Pixels. Each pixel at .06 amps. Easiest is 60 X x amount of pixels / by 1000. IE 60 x 50 / 1000 = 3

That's the rule of thumb for 5V pixels ONLY, not 12V.  

 

On 4/28/2019 at 12:36 AM, uncledan said:

I've tested actual current draw on over 30,000 12v nodes.  NONE of them were 60ma(.06 amps). 

At 12 V they probably shouldn't be (but again, this depends on MFG).  At 12V the rule of thumb says they should be drawing somewhere around .034 each (100 * .034 = 3.4A +/-)

 

AGAIN - you can NOT consider voltage and/or amperage separately.  They go HAND IN HAND.  This is electricity and it is UNFORGIVING.  Please take the time to properly learn the math.  It really isn't hard.

 

Let's take the time and show a real world example.  Take a look at this strip:

https://www.alibaba.com/product-detail/High-Quality-Price-Red-Smd-5050_60798926705.html?spm=a2700.7724857.normalList.90.321d5951DMrwYV

So we have to do a little reading between the lines since this is China.  From what I can make out, this particular strip can be mfg as 12V, 24V or 48V, and is 12 pixels/m (60 pixels total) and draws 72w.

Q1:  Can a PixCon16 safely run this entire strip at 12V without injection?

Q2:  How about 24V?

Q3:  48V?

So the first thing you better notice is that this is 60 pixels, NOT 50 or 100.  Right there the rules-of-thumb need to be thrown out.  But you say 'Hey, 60 is less than 100 so at 12V I'm good."  Nope.  Read the answers below....

A1 - 12V? No way Jose!  The specs say 72w.  At 12V that is 6A (72/12 = 6).    6 > 4.  Board go BOOM.

A2 - 24V? Sure will.  At 24V this strip draws 3A (72/24 = 3).  Board is happy.

A3 - 48V? No way Jose!  WHAT?! I hear you..  You are saying 72/48 = 1.5A!  That's fine!  Now go read the PixCon16 specifications.  It is ONLY rated to 30V.  While the Amperage is good, the voltage will make board go BOOM! (page 30).

So what did we learn here? 

• Just because we have less than 100 pixels does NOT mean we can run this strip on a pixel controller at 12V!  This strip of 60 pixels consumes 6A 50% more than the board rating.  The 'rule of thumb' is completely shattered.  You MUST consult with the mfg before real world applications.
• You need to consider BOTH amperage AND voltage together.  At 24V this strip and the controller work just fine together.  At 12 things go boom.  At 48 we are below the amperage rating....
• BUT!  You can't just forget about Voltage!  At 48V this strip comes in at 1.5A which is well below the rating of 4A.  HOWEVER the voltage of 48 is well ABOVE what the board is designed to handle.

 

Is the rule of thumb worthless then?  Nope.  It is a VERY valuable tool.  It WILL handle 95% of situations.  But be sure you use that tool correctly.  It will work great for back of the envelope ESTIMATES - most pixel controllers are good for 4A per port, most will run 5v or 12v and most pixel strings you find fall into the 18w/50@5V or 35w/100@12V. 

But that does not mean:

• Your pixels don't draw MORE amps than the rule
• Your pixels don't run at something other than 5V or 12V
• Your pixel controller supports the amperage OR voltage or POWER consumed.

TL;DR:  Before applying power and destroying your pixels, your controller, or possibly the house they are attached to you need to do the REAL math.  The real math comes from the values in the specifications from the mfg of both the pixels AND the pixel controller.  Or purchase everything from us, do it the way we tell you, and don't worry about it