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Topic: Can I use Cat5 cable to wire my lights? (Read 3920 times) previous topic - next topic

I'm building and LED wall and using shift registers to control my LEDs.

Seeing as how each shift register controls 8 LEDs, would Cat5 cable be okay to use as my wiring? I was thinking since Cat5 has 8 wires in it, it would be great to use but I am concerned that the gauge might be insufficient. Thoughts?

Also, I bought some shift registers (74ACT299PC) and they didn't come with the piece that you would normally set into your board and then set the shift register into that. I have no idea what those are called. Can anyone point me in the right direction so I can order some?

Thanks

#1
Mar 31, 2011, 06:46 am Last Edit: Mar 31, 2011, 06:52 am by carbine000 Reason: 1

Quote
I was thinking since Cat5 has 8 wires in it, it would be great to use but I am concerned that the gauge might be insufficient.


It depends on how much current you are running through the cable and how long the cables are. Note that putting the shift registers and the LED drivers in the place where the LEDs are makes it easier to control and power them.

I have common anode LEDs and I was figuring it was going to be about 23 mA per LED.

Each wire on the cat5 will be 1 pin on a LED. I'm already wiring my lights in groups of 8 and the cat5 has 8 wires in it. Im using 96 common anode LEDs and 36 shift registers. I want to create a separate "box" that will house all the controller boards and I figured that I could use the cat5 since it has 8 wires in it. I'm wiring the LEDs in groups by color so that all the reds are together and all the greens and blues are together. So the first shift register will be Red 1-8, the second will be Red 9-16....and so on. I think its best that the circuitry be in a separate housing from where the lights are so I will need some sturdy wires to connect all the lights to the circuitry. And since the cat5 has 8 wires in it and there is already plenty of great suff for it, that it would be great.  I figure I could use server racks and stuff like that. I'm going to need 36 cat5 wires to connect to my controller housing.

I have 96 common anode LEDs = 288 pins = 96 red, 96 blue, = 96 green.
96 pins / 8 i/o pins per shift register = 12 shift registers per color = 12 x 3 = 36 shift registers
36 shift registers = 36 cat5 cables with 8 wires per cable.




Quote
they didn't come with the piece that you would normally set into your board and then set the shift register into that. I have no idea what those are called. Can anyone point me in the right direction so I can order some?


If you are saying that you have surface-mount chips, then you need a break-out or adapter board like this...

http://www.futurlec.com/SMD_Adapters.shtml

If you are saying that you need sockets, then something like this...

http://www.futurlec.com/SockIC.shtml


YES! Sockets. That is what I need.

CrossRoads

74AC299PC- the PC indicates plastic DIP.

Cat5 has 4 pairs of 24 guage wire, yes? You are controlling 8 LEDs?  Where does the wire that will be the other side of the LEDs come from?
That size wire is more than sufficient for 20mA of current, which is about the continuous limit of most 5mm type LEDs.

Depending on how you are building your board, wirewrap sockets might be easier to work with as well.
I use these pins to build up a lot of boards
http://www.marcospecialties.com/product.asp?ic=SIP20L
and then wirewrap everything together with 30 guage wirewrap wire.  Way quicker than soldering, way easier to make a change or to fix a mistake also.
You can get also get a 24 guage wirewrapper and wrap the cat5 to the pins.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

#3
Mar 31, 2011, 07:04 am Last Edit: Mar 31, 2011, 07:09 am by carbine000 Reason: 1

74AC299PC- the PC indicates plastic DIP.

Cat5 has 4 pairs of 24 guage wire, yes? You are controlling 8 LEDs?  Where does the wire that will be the other side of the LEDs come from?
That size wire is more than sufficient for 20mA of current, which is about the continuous limit of most 5mm type LEDs.



It goes:   LED cathode -> cat5 wire -> resistor -> 74ACT299PC i/o pin

Here is a picture....





Depending on how you are building your board, wirewrap sockets might be easier to work with as well.
I use these pins to build up a lot of boards
http://www.marcospecialties.com/product.asp?ic=SIP20L
and then wirewrap everything together with 30 guage wirewrap wire.  Way quicker than soldering, way easier to make a change or to fix a mistake also.
You can get also get a 24 guage wirewrapper and wrap the cat5 to the pins.



^nice

With the other kind of sockets, once you snap it in, it can't come out, right?

I have routinely used cat5/5e cable for low-voltage switching applications, and have a word of advice.  If you can get your hands on "patch" quality cable, as opposed to plenum cable, do it. 

The patch cable tends to be stranded, the plenum is solid conductor.   Couple of small radius bends in a plenum cable can cause loss of conductivity / increased resistance, and those are a BEAR to isolate / work out, the stranded-patch cable tends to be more forgiving.

The patch cable tends to have thinner / more flexible insulation.

The patch cable is usually cheaper. 

Unless you're worried about any accidental smoke from your project being inhaled in large quantities, go with patch/stranded if you can get it.  Plenum cable has to meet all kinds of building codes concerning fire specification / "air handling" qualities, and frankly isn't worth the bother in this regard.
yes, have some.


I have routinely used cat5/5e cable for low-voltage switching applications, and have a word of advice.  If you can get your hands on "patch" quality cable, as opposed to plenum cable, do it. 

The patch cable tends to be stranded, the plenum is solid conductor.   Couple of small radius bends in a plenum cable can cause loss of conductivity / increased resistance, and those are a BEAR to isolate / work out, the stranded-patch cable tends to be more forgiving.

The patch cable tends to have thinner / more flexible insulation.

The patch cable is usually cheaper. 

Unless you're worried about any accidental smoke from your project being inhaled in large quantities, go with patch/stranded if you can get it.  Plenum cable has to meet all kinds of building codes concerning fire specification / "air handling" qualities, and frankly isn't worth the bother in this regard.


I don't think that will be a problem. Thank you for the advice, I'll get "patch" cable.

CrossRoads

Both sockets will hold the parts securely, both will let you remove the part if needed.
Here is a board I wirewrapped with the marco specialty website sockets.
A Duemilanove or Uno will have the other kind of socket.
The pins can be snipped off in lengths of 2, 3, 8, 10, etc and used for multiple things
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.


Both sockets will hold the parts securely, both will let you remove the part if needed.
Here is a board I wirewrapped with the marco specialty website sockets.
A Duemilanove or Uno will have the other kind of socket.
The pins can be snipped off in lengths of 2, 3, 8, 10, etc and used for multiple things



I like it. My thanks to you, again. :)


I have routinely used cat5/5e cable for low-voltage switching applications, and have a word of advice.  If you can get your hands on "patch" quality cable, as opposed to plenum cable, do it. 

The patch cable tends to be stranded, the plenum is solid conductor.   Couple of small radius bends in a plenum cable can cause loss of conductivity / increased resistance, and those are a BEAR to isolate / work out, the stranded-patch cable tends to be more forgiving.

The patch cable tends to have thinner / more flexible insulation.

The patch cable is usually cheaper. 

Unless you're worried about any accidental smoke from your project being inhaled in large quantities, go with patch/stranded if you can get it.  Plenum cable has to meet all kinds of building codes concerning fire specification / "air handling" qualities, and frankly isn't worth the bother in this regard.


Will 4 ft lengths be okay?

CrossRoads

Sure - its not like you have sensitive signals there, any noise will not show up on the LEDs.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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