XLR Pinout Question

[arfinator]

Does Pin 1 in an XLR Cable, which I've found is listed as the ground pin, need to be a ground?

What I am asking is could Pin 1 send power like Pins 2 and 3 do? I was hoping to use all three of these pins to send power to a custom cue light system, but I haven't been able to find a straight answer to this.

Any ideas / thoughts?

Thank you, guys!

Hess

 

[soundman]

at the end of the day it is another connector. The issue I see with using it to send power is that in some connectors it may be wired to the connector shell. If you energize it you will energize the connector shell. Not good.

If you make your own cables and are under the rated capacity of the connector go for it. I have made E-Stop switchs that are based on 3 pin connectors but I only needed two pins and made sure that they were wired with the female end on the switch so the chance of hooking it up to the board was reduced.

 

[arfinator]

Thank you, so much!

 

[TimmyP1955]

Consider using something other than a 3 pin, so that something else cannot be connected by mistake.

 

[GageStryker]

I'm with Timmy on this one. There's a LOT of things that can go wrong with 3 pin.

I'd suggest wiring it for 4 pin XLR. People generally expect power (+24v) on a 4 pin cable, and even if you run at a lower voltage, you won't run into trouble. And that way you can run power x3 AND a ground if you need it.

 

[Dionysus]

First, a good memory aide is "XLR eXternal Line Return" or Shield instead of 'external'. Just makes it easier to remember. And yes there is a bit of a difference between a shield and 'ground' which can mean many different things.

If you are wiring CABLES always wire 3-pin XLRs the same way so there are no mixups. If you make an adapting cable make sure it is clearly and permanently labeled!!!

As for using 3-pin XLRs for something other than audio BE CAREFUL. If there is any audio around, somewhere, some time, someone WILL make a mistake and hook it to an audio device and cause some serious problems.

I agree that 4-pins are a better solution as they are used much less often and often carry power. Facing them the other way so that they can't be accidentally hooked up without a turnaround.

Depending on what you are doing, there ARE other connectors that can be used... Did not notice you saying what you really ARE doing with them.

 

[arfinator]

A 4 pin XLR is definitely an option, here. I hadn't really considered it.

My university uses endless amounts of zipcord for our Qlights, and it makes me want to cry. So, I am making a Qlight system that used XLR and LED lights to make it a decent system that didn't involve wire nuts and pain.

I am embedding in a daisy chain option for fewer runs of cable, so I have two positives and a common neutral.

I was planning on labeling it permanently with a differently colored connector, so there isn't really the option of plugging it into something, wrong.

 

[Grog12]

I was planning on labeling it permanently with a differently colored connector, so there isn't really the option of plugging it into something, wrong.

Having worked in more Unversity systems than I care to count....There is always an option of plugging in something wrong

Make sure there are copious amounts of paperwork documenting your new system. If you're a student you want it to be clear how it works because someday (hopefully) you'll graduate.

If you're an educator, well those 10pm phone calls get real old real quick >:>

 

[JD]

Big reason Pin #1 is "ground" on XLRs. Pin 1 IS different. The connectors are designed so that pin 1 engages BEFORE pin 2 & 3. Look at it closely, you will see that on the female, the contact is closer to the surface.

 

[arfinator]

I hadn't noticed that before. Thank you, guys! I really appreciate your help!

 

[Morpheus]

Having worked in more Unversity systems than I care to count....There is always an option of plugging in something wrong

Make sure there are copious amounts of paperwork documenting your new system. If you're a student you want it to be clear how it works because someday (hopefully) you'll graduate.

If you're an educator, well those 10pm phone calls get real old real quick >:>

heh, the TD at my school always says "the problem with making it 'idiot proof' is that idiots are too ingenious.."

 

[ship]

A 4 pin XLR is definitely an option, here. I hadn't really considered it.

My university uses endless amounts of zipcord for our Qlights, and it makes me want to cry. So, I am making a Qlight system that used XLR and LED lights to make it a decent system that didn't involve wire nuts and pain.

I am embedding in a daisy chain option for fewer runs of cable, so I have two positives and a common neutral.

I was planning on labeling it permanently with a differently colored connector, so there isn't really the option of plugging it into something, wrong.

You are doing what? Explain further please.

 

[ship]

Having problems in general with these concepts of XLR - 3pin microphone cable in use for power cable. Yea... it's done - normally by those that don't know any better but a school should know better and avoid such as presented above, situation where something that improperly trains people in blowing stuff up when wrongly connected as it will at some point.

Especially in school is the concept where we might idiot proof a system and or train them in what's at least better in concepts for idiot proofing once they get into the real world. Such stuff should be done... lots of plug types on the market in even assuming XLR plugs are rated for voltage.

The shell of a XLR for say 4-pin ground as opposed to pin 1 shield. Different things ground verses shield.

 

[arfinator]

@ship:

I am trying to create a Qlight system that uses a cable other than zipcord (which is what we use, now).

My idea was to use XLR cable, since we have so much of it. The SM would have the QLight console with toggle switches, and the power would run through the XLR to the stage, where it would power three small LEDs for each Qlight.

Simply to reduce the amount of cable that we have to run, I was going to use a common neutral and two positives to power two independently controlled Qlights with one run of cable.

I discovered, through this thread, that I could use a 4pin XLR cable to accomplish this:

Pin 1 - Ground
Pin 2 - Common Neutral
Pin 3 - Positive #1
Pin 4 - Positive #2

With this system, everything is combined into a neat system, as opposed to our current (dreadful) system of zipcord, wirenuts, etape, and colored 60w light bulbs.

Does that make more sense?

 

[derekleffew]

Perhaps something useful may be gleaned from the thread LED Cue-light. FWIW, I see nothing wrong with using 3-pin XLR in a low voltage situation; after all, it works fine for DMX.

From TMB Press Release (although the product doesn't appear on TMB's site any longer):

Last but not least, TMB (1195) – Introducing the new ProCue theatrical cue light system with constant monitoring and interaction between Master Station and Outstations. The programmable Master Station is available in 4-, 8-, and 12-way desktop models, plus 12-way rack-mount. All Master Stations have bright STANDBY and GO push-button LED indicators with flashing and steady modes for two-way signaling. The unique Outstation provides 2-way communication via illuminated push-buttons with 180° viewing angle. Performers or technicians can silently acknowledge they are in position and ready. All interconnections use standard 3-Pin XLR cable.

See also http://leonaudio.com.au/cuelight.htm.

 

[JD]

Three potential cue states?

You could actually do that over two conductors. Use a 5vac wall-wart at your control end. Put your current limiting resistor (probably about 1k ohm) at the control box. Use a couple of diodes in the control box to split the output to three switches. One diode in one direction, the second diode in the other direction, and the third switch gets fed without a diode. At the other end, use one tri-color LED (Radio Shack.) Switch one = red, Switch two = green, Switch three = amber. Best of all, the circuit will only conduct 5ma at 5 volts with that resistor, so it's unlikely you will harm anything that accidentally gets patched in. (Short of plugging it into a microphone jack on the sound system with the volume cranked!)

Whole project should set you back about $10

 

[ship]

@ship:

I am trying to create a Qlight system that uses a cable other than zipcord (which is what we use, now).

My idea was to use XLR cable, since we have so much of it. The SM would have the QLight console with toggle switches, and the power would run through the XLR to the stage, where it would power three small LEDs for each Qlight.

Simply to reduce the amount of cable that we have to run, I was going to use a common neutral and two positives to power two independently controlled Qlights with one run of cable.

I discovered, through this thread, that I could use a 4pin XLR cable to accomplish this:

Pin 1 - Ground
Pin 2 - Common Neutral
Pin 3 - Positive #1
Pin 4 - Positive #2

With this system, everything is combined into a neat system, as opposed to our current (dreadful) system of zipcord, wirenuts, etape, and colored 60w light bulbs.

Does that make more sense?

Ah' I get it now and nope cannot do it. "Ground" which is really a drain or shield for the data, and common neutral in my opinion are different things in needing to be at very least souce of connection different. I could be wrong but this data reference point (pin 1) if there should be some sort of high voltage short than would now be a problem by way of data indexing to zero say.

That's me of course and also seeing a different pinology than say Chroma Q cable that has shield/outer shell as drain, pins one and four as power and 2 & 3 as data.

XLR plug for data and power... often bad Karma in having to mark what cable is for what purpose. Got four types of 4-pin XLR where I work and it is probleatic.