Falcon F16 power question

[dannyp]

Ok so now I have officially confused myself again.

I have a Falcon F16v4 controller and a SRX1 Smart Receiver. These are powered from a Meanwell 600 watt 12 volt power supply.

When I set these up in the Xlights Visualiser and add the props to the outputs, its shows that they use 6.5amp for approx 500-600 leds at 30% (for example). When I hook the lights up to the outputs and test them (either through Xlights or simply using the test button on the smart receiver) they go through the test sequence, no problem. Where my confusion lies is that the specs for the F16 say that the max per output is 5A and 30A for the whole bank.

So why don't the fuses blow? I cant see any way that you can run 1024 leds and stay under the 5A limit. I'm obviously misunderstanding something and having read the 101 manual, I don't think I am looking at this correctly.

Any clarification would be of great help.

 

[Johnnyboy]

If you connected up all 1024 leds to a single outlet, ran them at 100% white, you would find that after about 200 or so pixels they would start flickering, then not light up at all.
To get around this voltage drop, there are a number of different options people do.
1. Keep all outputs to around the 200pixel amount. This works fine but leaves a lot of unused capacity from your controller. You will find that you need a number of controllers depending on your display.
2. Power Balancing. This is when you connect from the same power supply that is powering your pixels (Note: for balancing, it must be the same power supply you are using for each set of pixels). and connect up the positive and negative wires to boost/inject/balance the power at that point. Below sketch shows this. I've shown 900 pixels only, but you get the idea.


3. Power Injecting, Lets you use a different power supply if you want. In this situation you must disconnect the positive wires when the new power supply takes over. Its important that the negative wires are connected however.

Either option 2 or 3 lets you get to the maximum pixel count. It is best practice to put fuses between power supply and balancing/injection points as i've shown in the pics above.

There are a range of different pre-made connection Tee's that you can use depending if you want Injection or Balancing. Read this post to see the different types depending on your needs

Tees now available - 13.5mm Ray Wu and xConnect

The first of the 2 (types) of new products is finally on the site. These are 4 different tees made with flat wire pigtails so that they are nice and light and they can virtually do a butt join. The 2 power injection wires are bare wires to allow for the user to decide what sort of connector they...

auschristmaslighting.com

Hope that helps

 

[Skymaster]

So why don't the fuses blow? I cant see any way that you can run 1024 leds and stay under the 5A limit.

Fuses have trip curves, they aren't instant-blow at 101% load. This is the trip curve for a typical blade fuse, for example.



As you can see, in order to trip in 0.1 seconds, you need to be pulling 320% of the rated current, so 16A before it trips. The graph above shows that even at 125% (6.25A) it wont trip in 500 seconds!

The other thing to consider is that pixels don't use their full rated current, even at full white. This is caused by the resistance of the wire limiting the maximum current possible. This is also what causes power drop, and the issues that @Johnnyboy is referring to above.
For every pixel you add, the total current goes up by slightly less than the previous pixel you added. - If you were to plot number of pixels across the bottom, vs current across the vertical axis, you'd get a logarithmic looking graph, rather than a diagonal perfectly straight line if it was completely linear.

 

[DarkwinX]

@dannyp I've asked a similar question with this group around how many lights can you truly fun before you reach a limit or a fuse blows. Someone showed me this great video on fuses which both indicates not to buy cheap ones but also the way they are designed to work.
View: https://youtu.be/apQU_VuJlFU?si=uhlyGSD8EZdKGEVy


It's also more likely you'll end up making the lights flicker or misbehave before you start blowing the fuses as JohnnyBoy has mentioned.