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DevMike

Use a ferrule, save a board (Low Voltage RGB/Pixels)

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Dealing with low voltage wiring brings with it a new set of challenges.  We tend to be more lax when it comes to things like wire strip length, how tight we make the connection, and a host of other things.  Since we are dealing with low voltage connections,  the terminals are usually much closer to each other.  

All of these things conspire together and lead to controllers that won't work, or boards that are blown, and a lot of hair pulling.

I have previously talked about being able to burn down your house as quickly at 12V as you can at 120V, so we are going to skip talking about that.  Instead I want to focus on channels/ports that don't work, work improperly, or worse:  you blow them up because of a short.

It is very easy to short a port on a CMB24, Pixie, or Pixcon:  The screw terminals are located close together, and you may have over-stripped the wire by only a few millimeters.  You lightly pull on the cord, the wire slides out a little from the terminal, touches another and BZZZT....Or, you don't twist all the strands of a wire tight enough.  One strand gets loose ends up near the next terminal, BZZT.

Now you've blown a Mosfet, a fuse, or worse - damaged the board itself.

What happens the most with me is I try connecting things with the proper strip length, and the wire from a different terminal will 'pop' out.  I put that wire back and really honk down on the screw.  There is just not a lot of wire for that connector to grab on to.  Blam.  I just busted the connector.  

Most of the wire leads LOR supplies are stripped to the proper (short) length and 'tinned' - dipped in solder to prevent the stray strands from escaping. That is usually enough.  But what about wires you strip yourself?  I am guessing that many of you don't have a solder pot around.  Or what about if you want a little MORE security than just tinning a wire?  There is another way:  insulated ferrules.

What the HECK is a ferrule?  It is a small metal tube that you crimp onto the end of the wire that holds all the strands together.  Because it is a sold piece now it is much easier to insert into a connector.  It is large enough that you can make a good connection without over-tightening the screws.  The insulated end protects you from shorts.

Here is a good video on how to use them:

Ferrules are CHEAP.  I recommend an assortment of sizes from 10-22/24 AWG as your first purchase (or these) - that should cover both power leads as well as leads from pixels/etc.  When you run out of the smaller ones, just purchase that size in bulk.

The person in the video is using a different kind of crimp than I would suggest for smaller gauge wire - like what we deal with on pixels and dumb RGB strips.  Instead, I would recommend a 'self adjusting square' crimp.  Do not use any manual crimp (the strip tool in the video) or ones like this.  You don't need to break the bank, but do purchase a 'better' (more expensive) crimp.

Yes, you can add ferrules to wires that are already tinned, if you like.

There is one thing I would like to add/correct/comment on from the video.  If I remember it correctly in there he says to only strip the wire to the length of the ferrule.  I personally don't like that suggestion. 

Instead, I like to strip mine a little longer than the barrel part, and then trim the excess.  

When you insert the wire, do so until it 'bottoms out'.  If you are using a ferrule of the right size, that will be the insulation hitting the inside top of the barrel, and you should see the wire come out the bottom of the barrel.  Now crimp and then use a sharp pair of side cutters and remove the excess wire flush to the ferrule.  

Just don't forget to do the cut.

My reasons:

  • If you strip a little too short, you don't get a full connection on the entire barrel length when you crimp.  You won't be able to tell.
  • If you use a ferrule that is too small, you may only catch a few strands, which you'll see instead of the actual full wire come out the bottom.
  • If you use a ferrule that is too big, the insulation won't 'bottom out', and instead you will see it exit the bottom of the connector.
  • If the ferrule slips during crimping, you'll be able to tell.  If you don't see wire out the bottom after the crimp, cut it off and re-crimp a new ferrule.

Oh, and make sure you CLOSE that container!  Don't do what I just did about 10 minutes ago.  I was putting some ferrules on some CCR II ribbons for testing, and knocked the box on the floor.  

1000 small ferrules on the ground, and they need to be sorted by  color.  Some one kill me now! :) 

Do a professional job:  Ferrule your wires!

(4/5/2017 edit note:  I combined several of my messages into this one, and removed some others to keep things clear)

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It won't let me "Like" this, so I'll post it instead.

 

LIKE!

 

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Yes, excellent tip - and another gob of money sent Amazon's way... :)

Fortunately, having not seen this beforehand, I did not blow anything up or otherwise ruin it. :)

This appears to be the exact same crimper as Mike mentioned, but as of this moment is $5 cheaper and has Prime shipping, which the other does not offer. 

 

Edited by jtomason

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Yep, I did that as well today. Jtomason, Thanks for the link on the crimper with Prime. Gotta make use of my Amazon Prime membership regularly [emoji3].


Sent from my Droid Turbo via Tapatalk, so blame any typos or spelling errors on Android

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