DiyLightAnimation

Hardware => Lynx Smart String => Topic started by: sittinguphigh on March 16, 2011,

Title: Questions about smart strings.
Post by: sittinguphigh on March 16, 2011,
How many amps does a 128 smart string with a controller use?

Can you use a 12 volt battery to run a light string?

Can you run smart strings in a line one after the other if you seperate them with a smart string controller? Not using a hub.

Can you seperate a 128 smart string by extending the wire in the middle of the string? Lets say by a foot or two. That would make two sets of light strings with a two foot wire seperating them using one smart string controller.

Thanks

Mort



Title: Re: Questions about smart strings.
Post by: RJ on March 16, 2011,
You are not allowed to view links. Register or Login
How many amps does a 128 smart string with a controller use?

Check the power requirements document in the wiki :
http://diylightanimation.com/wiki/index.php?title=Equipment#PixelNet

You are not allowed to view links. Register or Login
Can you use a 12 volt battery to run a light string?

No 12v batteries are not really 12 volts these need 12v DC regulated power

You are not allowed to view links. Register or Login
Can you run smart strings in a line one after the other if you seperate them with a smart string controller? Not using a hub.

No the power comes from the cable to the controller they can not be daisy chained in that way. The power is put in the cable with at the hub you must use a hub.

You are not allowed to view links. Register or Login
Can you seperate a 128 smart string by extending the wire in the middle of the string? Lets say by a foot or two. That would make two sets of light strings with a two foot wire seperating them using one smart string controller.

Yes but not real far. A few feet would be fine. you also can not do this over and over on a 128 node string as the lenght of cable over all matters. You can do it more on a shorter string.

RJ
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
Thanks RJ for the information. Your always got something bigger and better to up grade to. That's great.

Let me see if I got you right.

You need to use a AC  power source and convert it to DC. Because a lead battery is not really 12 volts.  So there is no way to make it work with strait battery power. So I would use a invertor to make it work with a battery. What would I need to convert AC to DC?  Can I get something small in size? I'm limited on space.

And I take it that the strings can't be used without the controllor.

It would be great to have RGB for the Christmas Parade.









Title: Re: Questions about smart strings.
Post by: RJ on March 17, 2011,
Instead of going from 13 - 14 volts DC to 120v ac then back to 12v dc why not find a 12v DC/DC power supply that will take in 13-14 v DC and give you regulated clean 12v.

I can not help beyond saying they exist but do not know what one would cost. It all depends on the amount of amps you need(lts of nodes or just a few.)


RJ
Title: Re: Questions about smart strings.
Post by: CaptKirk on March 17, 2011,
RJ, whenever I measure a car battery, I get 12V, now when the car is running, the alternator will kick up the voltage as high as 14+ volts, but a car battery alone (no charger, or what not) should be 12V or am I really wrong (again)?  12.1, or 12.2 should not matter as well as a little lower, or are these nodes really voltage spike sensative?
Title: Re: Questions about smart strings.
Post by: chrisatpsu on March 17, 2011,
Car Batteries are not 12 volts

http://www.landiss.com/battery.htm (http://www.landiss.com/battery.htm)
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
OK that would work. I take it I would need kit 3?

I'm I limited to the lenght of the wire before the smart string controller?

Thanks

Mort
Title: Re: Questions about smart strings.
Post by: TAdamsOK on March 17, 2011,
The main deterant (for me) would be that the battery would have no regulation in the event of a short.  Ok technically it would due to the back emf produced by the batteries internal resistance, but that is not going to be issue enough to stop your wires, controllers, etc from getting toasted.  

Using a sine or square wave inverter and subsequently re converting to DC would likely consume 10-20% (or more) of the power of the system due to loses in the inverter/rectifier. May not be an issue really since your thinking of a mobile show, but that would depend on the output current needed and the size of the alternator on the vehicle and any other demands on the alternator.  I would say RJ is correct.  A DC/DC converter would be the best choice.  
Since we are only talking ideas, you could use a good compact AC generator.  I would suggest a field load though on the generator since their regulators typically do a better job regulating 2500 to 2900 watts than they do 0 - 400 watts.

On a side note, if you're dead set on using batteries, you could make some Edison cells (DIY style!) and string 10 of them together for 12v.  Charge density is a bit of an issue along with charge efficiency, but they practically never wear out!  (sorta expensive to make right now though and probably not very compact.)  Also if you did end up with a 13.2v battery, since that is only a 10 percent variance (12.6v is only 5%) that would most likely be within the tolerance of the 12v components, but someone with the tech sheets for all the components would have to make that call.  Ironically that article says car batteries are not 12v, but spends most of its time talking about the charging requirements of different composition batteries instead of the actual battery voltages.  Good read though!
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
I would be using a wheel chair only battery and no charging system. I only need it for 3 hours.

Title: Re: Questions about smart strings.
Post by: TAdamsOK on March 17, 2011,
How many amp hours is the battery rated for, and what all are you planning on running off of it?  I'm concerned that if it is running a good sized show/computer, it may run out of capacity before the 3 hours.
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
I have 36 amp battery and a 26 amp battery if I need it.  6 to 8 sections at  25 to 50 lights nods. 
Title: Re: Questions about smart strings.
Post by: travailen on March 17, 2011,
Maybe you could use two batteries and get a 24VDC to 12VDC converter. That would give you good regulation, short circuit protection and you could run the batteries down to about 9 volts and still get your 12VDC for the lights.

Rick S
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
Didn't know you could do that.
Title: Re: Questions about smart strings.
Post by: TAdamsOK on March 17, 2011,
So worst case scenario would be 400 nodes running pure white which is roughly .03A per node at 12v that is 12A max draw (neglecting controller loads).  With no loses a brand new 36 Ah battery would do it (barely), but since it's a christmas parade and temps are probably not going to be around 80 degrees so it probably isn't enough battery.  Now if your actual draw was 3 amps average it would run you for 10ish hours.  Make sure its a 36 Ah battery though and the 36 amps is not a HCA or CCA rating as those are about worthless for figuring capacity. 

Using both in series and going 24 to 12v is a very good idea! it would also drop the max draw to 6 amps and give you ample capacity to run that for more than the required time.
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
Just looked around at DC to DC and AC/DC power supplies.

I couldn't find any thing that would work yet.
Title: Re: Questions about smart strings.
Post by: D56VillageNut on March 17, 2011,
For what it's worth on DC/DC connverters check out TRC.
http://www.trcelectronics.com/dc-dc-converters-pcb-enclosed.shtml

Not sure about a distributor in your area but I'd find model number that would meet your needs and then shop around and even hit eBay.  Just a point to start getting some info.

Alan T
Title: Re: Questions about smart strings.
Post by: chrisatpsu on March 17, 2011,
are you gonna have room to fit all this stuff?    ;)
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 17, 2011,
I think I can.
But there is a problem I keep seeing in the power supplies.

To get the correct amount of amps lets say at the most 12 amps but could go as low as 7 amps.
I would need to many volts. You lose power.
Title: Re: Questions about smart strings.
Post by: rm357 on March 18, 2011,
Two batteries in series does not reduce the current required per battery unless you are using a dc-dc converter - wich will not be 100% efficient.

If you could tie into a vehicle with a charging system, you could build a relatively simple high current 12v regulator.

RM
Title: Re: Questions about smart strings.
Post by: smartcontrols on March 18, 2011,
Hi Mort,

In my PM where I first suggested you might need a DC/DC regulator for your project this is along the lines of what I had in mind.

http://www.powerstream.com/dc12-12-8A-isolated.htm (http://www.powerstream.com/dc12-12-8A-isolated.htm)

I am not suggesting this exact one as I have not gone over your exact requirements. If you search around I am sure you can find a better price and fit for you, but just to get you on the same track I was.

There are also direct ATX power supplies that use a 12vdc input but they seem to be a little pricey and I am not sure you need that much power or have room for them.

-Jeff
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 19, 2011,
Thanks Jeff.

That would work the best if I can find one that gives me 12 amps continuous current output.
I know it will be less then 12 amps but I would hate to come short.

Title: Re: Questions about smart strings.
Post by: travailen on March 19, 2011,
Many large trucks have a 24V system but, most vehicle electronics are made for 12v. So, there are lots of inexpensive 24v to 12v converters around.

I found this one on Ebay.  It is rated at 360W continuous, 720w peak. Not necessarily a recommendation, just a thought.

http://cgi.ebay.com/NEW-24V-DC-12V-DC-Power-Step-Down-720Wtt-Converter-/290541213697?pt=LH_DefaultDomain_0&hash=item43a59b1801 (http://cgi.ebay.com/NEW-24V-DC-12V-DC-Power-Step-Down-720Wtt-Converter-/290541213697?pt=LH_DefaultDomain_0&hash=item43a59b1801)

Rick S
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 20, 2011,
That looks good. I would get 30 amps. But it doesn't tell you how many amp battery you need to use. I'm limited to about 6 inch square battery. It looks like you loose amps in convertion.

There must be equation to follow or a on line convertor. I will look around?
Title: Re: Questions about smart strings.
Post by: rm357 on March 20, 2011,
What are you plnning to do with this. It almost sounds like you want to walk a parade...
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 20, 2011,
I'm putting it on my horse. The picture is not my horse but it gives you a idea what I'm trying to do. I will have a second cinch on the rear of the saddle. I will have saddle bags and a cantle bag on the rear of the saddle. I did it last year with a indoor mr christmas controller. I have it set up for this year with 8 channels using a express. But I wanted to be able to change the color at least once and maybe have a wave or chase.
So people were saying use the smart string. I'm still working on trying to come up with a recorder/player. It will really be hard to use a lab top even a 10.1 lap top. I need something I can turn off and on with out little effort.
Title: Re: Questions about smart strings.
Post by: smartcontrols on March 21, 2011,
Hi Mort,

You may want to take a look at this one. Looks like it will do about 12 amps continuous and is still small. It also has the ATX outputs for you to connect to the hub.

http://www.mini-box.com/M4-ATX?sc=8&category=981 (http://www.mini-box.com/M4-ATX?sc=8&category=981)


-Jeff
Title: Re: Questions about smart strings.
Post by: sittinguphigh on March 21, 2011,
I called the company and yes they said it would work. Using 300 nods the amps if all the light were on all the time would be 9.0 amps. I may go as low as 5 amps.