Author Topic: Smart String FAQ's  (Read 6671 times)

Offline RJ

  • Administrator
  • Sr. Member
  • *****
  • Posts: 8507
Smart String FAQ's
« on: May 07, 2011, »
Smart Strings FAQ's

I have been asked so much about the Smart Strings and have seen and been pointed to so much information right and wrong saying Good and Bad about Smart Strings I decided it was time I posted a FAQ that would both answer the comments and explain the reason that Smart Strings is not configured like other RGB setups.

First, Everything is a trade off and this is not a post to say that Smart Strings are correct and everything else is wrong. The right setup is one that does what you want and makes you happy. If that is Smart Strings, great! If it is something else this is also great.

1 -  Using 12 volts uses 300% more power (or what ever figure).
   
Using 12 volts instead of 5 volts does use some more power but nothing like that. It uses 17% more power in measurement. But remember this is 17% more than a 5v led and so unlike using 17% more power than a incandescent light it is 17% more of the small amount of power an LED uses. in the end it is trivial in my opinion.   

2 - They are dimmer than other pixel strings.
   
Measured with a light meter they do output a slight less light. But this is not really noticeable by the eye when you compare them side by side.

3 - The last led's on the string are dimmer than the rest.
   
Again with a meter you can measure this but not really noticeable with the eye. Not one person has ever been able to see it in my lights even at 128 nodes. You likely did not see it on my demos did you. If #2 and #3 were really a issue would    the people that brought it up that supported 5v lights now be supporting these lights? These RGB devices are so bright compared to your Christmas lights you will not be worried about this.

4 -  Because it uses more I have to use lots more power supplies costing more.
   
Not true. The fact is because the cheapest power supply you will find for high current is a computer power supply like we use on Smart Strings, and because they put far more 12v power out than 5 volt it is cheaper to run 12v in the final.

5 -  The extra heat from running at 12volts will kill the lights.
   
I live in central Florida and have not had any issue with then dying. They do not run very hot. The parts are designed to operate much hotter than they run.

6 - Having one controller on each string makes it cost more per string than the controllers that handle multiple strings.
   
I have seen the math done also. They always add the cost of a hub for smart strings based on you need a hub to run the string.  They leave out that if you run more than one controller you need a switch for their solutions. So add its cost and it washes out. I think when we get our shows done Smart Strings will be less expensive in the long run and will have some other benefits as you will see. 

7 - Cat5 can not handle the power you are running to the smart strings.

Not true, I have seen the figure .577 amps for 24 ga wire used as the proof of this. This comes for a wiring chart you can see everywhere . The chart is for wire used in house. If you read the charts legend it tells you the current limit is not based    on heat or safety but on insuring there is no more than 3% voltage drop. Since we are running 12 volts we are not limited to 3% voltage drops we can handle much more.  As far as safety and current limits I go by the MIL-STD-975 spec and aviation codes which say how much you can safely run on a 24ga wire in an    aircraft because they are very safe codes to go by and they are based on DC power loads on 12v and 24 volt systems when people lives count on it.
You are not allowed to view links. Register or Login
   
Now using this understand we send our power over 3 24ga wires in the cat5. Not just one 24 ga wire. This equates out to a larger conductor than the 20 ga that the lights are wired with themselves.

8 - Why did you go with a controller at each string instead of the way most systems are going with a controller running many strings?

One easy word - "Flexibility" I thought about going that route and it would have been great for the mega tree I was building at the moment. But when I looked forward and thought about things like my Mini trees and eves and other areas I would be adding RGB to soon, I saw that having a more expensive controller with multiple strings attached would be a liability to me.
 
See the nodes are limited on how far you can run from the controller to the nodes. As well as how far between nodes you can run. So for example my mini trees are 16 ft apart. If my controllers were 4 string units how would I put one to handle four trees? You can not go that far from a controller so if I put one in the middle of two of them I could only run two trees. I just wasted a 4 string controller on 2 mini trees. That is going to drive my cost way up. this is going to happen often    with eves, bushes, window edges. If you look around you see it already with the talk of relay units and using extra nodes as blanks to retransmit. Adding these    will add cost and more stuff to deal with adding complexity.
    
With Smart Strings you simple put one cheap controller at each mini tree and since the data and power can run like 100 ft over the cat5 since it is 12 volts so power drops is not as big a deal and the data is rs485 like DMX. You only have a single cat5 run to each one and you can do it cheaper.  I know that like I, my users never know what they will want to do next so flexibility becomes very important. 
 
9 - I heard that you had to hang an ugly piece of pvc on the end of each sting.

Well you can enclose them any way you want but this is easy and cheap for me. No matter which controller you use it must be attached close to the end of the string and enclosed somehow? In fact a multi string controller is larger so it would    be a larger something. The images of mine showed them right at the end of the    string because the first lights did not come with leaders on them as the later strings do. You can put the controller up to about 6 ft away from the first light and hide it the same as other controllers. I painted them flat black and you can not see    them.

10 - Why use a Computer power supply instead of a 12v only single output unit?

Well you can do either if you want. The reason is cost. You simple can not get more power cheaper than we can using 12v out of computer power supplies. We    all want to save money and have it easy. I made the Hub to allow you to plug the ATX supply to the board with out cutting or modifying it so if it fails you can remove it and get it replaced on warranty. It also can be used still for other things like a computer.

11 - Why didn't you just stay with DMX for the Smart Strings? 

DMX is a great protocol for standard lighting and Smart String hub even convert your PixelNet feed to give you DMX from it to run your DMX equipment. But when you are handling the kind of channel counts RGB brings on even small shows the 512 channels per universe is a major limitation.

12 - Why did you not just use Ethernet all the way to the controller like others have.

Well again for a number of reasons. First Ethernet modules cost too much on your controller unless you are going to do many string outputs on one controller. As explained that was not my intention. Also you can daisy chain the RS485 PixelNet uses but the Ethernet takes switches (or hub). It would expensive to add    a switch on your controller to do this. So to have low cost, simplistic and flexible I went with a protocol in between the Ethernet feed and the limited distance data for the strings themselves.  This lets me have everything I want easily and cheaply. I also would not be able to use 3 pair to provide power and then use    standard Ethernet equipment. so power would need to be feed on other wires which makes setup and teardown more work and more to store. Also then you have more to change when you make changes in the yard since you power and your data cables would need to change.

13 - Why do you only support one type of lights when other support many?

This is also a simple answer. I had them create the nodes for me so I could use all 12 volt lights. all the other devices are 5 volt so where not compatible. Also they tend to be 4 wire instead of three wire. Since I could get everything made with    this setup and chipset I say no reason to add complexity to it. There is only one firmware for the Smart Strings. One of DLA main goals is to make things simple so anyone can succeed with do it yourself lighting.

In the end everyone thinks theirs is the best idea so you need to look at it all and make your own choices based on what will be best for you. Do not let others including myself talk you into anything. I hope this helps answer some of the question I have seen about Smart Strings

RJ
Innovation beats imitation - and it's more satisfying

Offline TheBanker

  • Sr. Member
  • ****
  • Posts: 308
Re: Smart String FAQ's
« Reply #1 on: May 07, 2011, »
awesome......
Will

Offline caretaker

  • Sr. Member
  • ****
  • Posts: 1750
Re: Smart String FAQ's
« Reply #2 on: May 08, 2011, »
Thanks RJ!   Hopefully this clears the air and everyone can play in the sandbox together.
Jeff Squires
You are not allowed to view links. Register or Login

Offline therealbigjim

  • Sr. Member
  • ****
  • Posts: 489
Re: Smart String FAQ's
« Reply #3 on: May 08, 2011, »
Thank you for the through explanation.
"If you want more lights sell that old mustang"
        You are not allowed to view links. Register or Login

Offline Trepidati0n

  • Sr. Member
  • ****
  • Posts: 126
Re: Smart String FAQ's
« Reply #4 on: May 12, 2011, »
Q14 - No matter what you do, I won't like it....how do you explain that?  <fp.
No electrons were harmed during the creation of this thread. All threads are made with 100% recycled electrons. No electrons were discriminated against based upon race, age, religion, or direction of spin. The views in this post may or may not reflect the views of DLA or the views outside my window.

Offline drlucas

  • Sr. Member
  • ****
  • Posts: 947
Re: Smart String FAQ's
« Reply #5 on: June 25, 2013, »
Can we update the FAQ for #10? I see in the wiki there is a picture of the hub ,but it just says PC ATX Power Supply and shows a single line going to the board. The question that I have is do I use both the 24pin and 3x4pin connectors, or just the single 24pin connector? I believe the answer is both because the 24pin connector will power the chips on the board that require 3.3 and 5v and the 4pin connectors will help spread the load across other wires.....and also one should only use a single power supply for each hub. I think I've generally seen a few posts that suggest that as the best way to go.

I do however not know the correct answer to this question and figured it might a common question. Can anyone help clarify  ??


10 - Why use a Computer power supply instead of a 12v only single output unit?

Well you can do either if you want. The reason is cost. You simple can not get more power cheaper than we can using 12v out of computer power supplies. We    all want to save money and have it easy. I made the Hub to allow you to plug the ATX supply to the board with out cutting or modifying it so if it fails you can remove it and get it replaced on warranty. It also can be used still for other things like a computer.
-Ryan Lucas-
- Pickering, Ontario, Canada, Eh?! -

Offline rrowan

  • Administrator
  • Sr. Member
  • *****
  • Posts: 5894
  • 08096
Re: Smart String FAQ's
« Reply #6 on: June 25, 2013, »
You are not allowed to view links. Register or Login
Can we update the FAQ for #10? I see in the wiki there is a picture of the hub ,but it just says PC ATX Power Supply and shows a single line going to the board. The question that I have is do I use both the 24pin and 3x4pin connectors, or just the single 24pin connector? I believe the answer is both because the 24pin connector will power the chips on the board that require 3.3 and 5v and the 4pin connectors will help spread the load across other wires.....and also one should only use a single power supply for each hub. I think I've generally seen a few posts that suggest that as the best way to go.

I do however not know the correct answer to this question and figured it might a common question. Can anyone help clarify  ??


10 - Why use a Computer power supply instead of a 12v only single output unit?

Well you can do either if you want. The reason is cost. You simple can not get more power cheaper than we can using 12v out of computer power supplies. We    all want to save money and have it easy. I made the Hub to allow you to plug the ATX supply to the board with out cutting or modifying it so if it fails you can remove it and get it replaced on warranty. It also can be used still for other things like a computer.

In the wiki equipment page under the hubs is this post and warning:
NOTE: POWER CONNECTORS: ALWAYS use the (3) 4 pin power connectors with the 24 pin connector
Failure to add the extra power connectors can/will damaged the PS 24 pin Connector and Hub from excess current


I hope that helps :)

Rick R.
Light Animation Hobby - Having fun and Learning at the same time. (21st member of DLA)
You are not allowed to view links. Register or Login
Warning SOME assembly required

Offline rm357

  • Sr. Member
  • ****
  • Posts: 1282
  • 31088
Smart String FAQ's
« Reply #7 on: June 25, 2013, »
It should be stated in several places that you need to use all of the hub power connections.

The reason is that each connection pin can only handle so much power.

The 12 volt pins in the big connector (2?) are rated at something like 6 amps each, the smaller connectors at something like 10 amps each. All 4 connectors added together gives you about 42 amps to drive the smart strings...
Robert
Warner Robins, Georgia, USA

Offline drlucas

  • Sr. Member
  • ****
  • Posts: 947
Re: Smart String FAQ's
« Reply #8 on: June 25, 2013, »
Well...i think the red bold font on my computer gets masked to all white and was invisible for me....

That's the story and Im sticking to it.

I guess I'm more a visual person and like pictures. Maybe if the text talked slower I'd of seen this.

.....add that to dumb question of the day for me.
-Ryan Lucas-
- Pickering, Ontario, Canada, Eh?! -