Power inject using unused outputs?

[brichi]

I have a pixie 4 just for my 2 windows upstairs so outputs 3 and 4 are open, I need to power inject into the window frames being the whites fade after about 50 pixels, 

My question is, Can I use output 3 and 4's + & - to inject power to the frames on 1 and 2 being they are not being used for anything or is it better to run the power right from the p/s to inject? I like the idea of using the pixie outs to inject being I can leave the connector on it and just plug in for the holiday vs getting a fuse block to split off from the /s and having to use screw terminals each time

 

thanks for any info guys! 

Edited July 6, 2017 by brichi

[k6ccc]

Sure.  I'm doing exactly that with a SanDevices E6804.  Same situation as you - I'm only using two outputs, and then using outputs three and four for power injection.  In my case it also worked out very well mechanically.  The E6804 is inside of a 6x6x4 electrical box so there is not a lot of extra space.  In my case, the two strips are between 20 and 23 feet long, and I just barely noticed a color shift at the ends.  I'm feeding the power injection about 6.5 feet from the far ends (because it was mechanically convenient).

 

[nasa1952]

I'm set up for feeding power injection to the end of the 168 node string for my Matrix. But after viewing the matrix live I set the intensity down to 70% and have good color and didn't need to inject Power. I'm using 6 outputs 1,2,3 for power and data 6,7,8 for power only. 9,10,11 power and data 14,15,16 for power only. After I have the matrix mounted on the house I will be able to make the call on if I need to inject Power because I have to change the intenity up to 80 Or 100%. AlfaPix 16 with 2-350 Wat power supplies.

Sent from my XT1650 using Tapatalk

[brichi]

awesome, thank you guys, i will wire it up powering from 3 and 4

[B.Y.R.G.]

8 hours ago, nasa1952 said:

I'm set up for feeding power injection to the end of the 168 node string for my Matrix. But after viewing the matrix live I set the intensity down to 70% and have good color and didn't need to inject Power. I'm using 6 outputs 1,2,3 for power and data 6,7,8 for power only. 9,10,11 power and data 14,15,16 for power only. After I have the matrix mounted on the house I will be able to make the call on if I need to inject Power because I have to change the intenity up to 80 Or 100%. AlfaPix 16 with 2-350 Wat power supplies.

Sent from my XT1650 using Tapatalk
 

I run all of my pixel strips and bullet nodes intensities at 50% or below which allows for longer runs without injection.  They are way too bright at 100% for me and with all the flashing and blinking it's hard on the eyes.

[prevue12]

As a electrician in a former life, why do I hate the term "power injection" so much?  It is fundamentally wrong, I will get over it, but it will always nag at me.  

[k6ccc]

Got something better?

 

[prevue12]

 

22 hours ago, k6ccc said:

Got something better?

 

It's to late now, too many people use the term without knowing that you can't "inject" power, (Even if it is so wrong  ) .

[B.Y.R.G.]

Sheesh I was hoping for a new description and not the "it's too late now" card.

[prevue12]

50 minutes ago, B.Y.R.G. said:

Sheesh I was hoping for a new description and not the "it's too late now" card.

Let me work on it for a day, I'm sure I can come up with something better that will be more technically correct, but 100% ignored.  I was in the Navy, and now work in a job that I still need to deal with military acronyms on a daily basis, I should be able to makeup some wonderful ideas!  

 

Off top of head, and procrastinating from cutting the grass in hot and very humid VA weather):

PVU  (or PEU depending on what you like for use for voltage abbreviation, PE-U is more fun to say) Parallel Voltage Usage 

MPS  (MiPS)  Mulitple Power  Sites.

VDCS  Voltage Drop Compensating Site

CTSNMIS  Conductor To Small Need More Current Site

 and yes, I hope people realize I'm just having fun with this now.  

[TheDucks]

Actually, Power inject is not really wrong as used. You are ADDING something (more Volts )

The definitive case is Data and ground are passed on.at the inject point

POE injectors have a Net (RJ45) input, they inject power onto the Output RJ45  Network connectors, additional pins.

[prevue12]

2 hours ago, TheDucks said:

Actually, Power inject is not really wrong as used. You are ADDING something (more Volts )

The definitive case is Data and ground are passed on.at the inject point

POE injectors have a Net (RJ45) input, they inject power onto the Output RJ45  Network connectors, additional pins.

Power is a function of how much Current is drawn at a certain voltage, you can not inject power.  If a system operates at 5V and draws 10 amps,  that 50 watts of Power,  You can not Inject 60 watts and have 10 spare floating around.

In this case:

Power = E*I , I²R, or E²/R   all relate back to how much Current is drawn at a certain voltage,  yes even  E²/R  ( P=I*E,  I =E/R sub in, and E*(E/R), current is just hidden).

You can not INJECT anything, current is drawn on what resistance is at certain voltage.  I= E/R.   Never once, in any class  or working as commercial electrician, was the term/phrase, Power Injection used, or taught.  Its just plain fundamentally wrong, but we can call it that, it just bugs me, Mr. Ohm would agree with me if he was still around, I bet. 

But as I read your profile I see you were a Electronic Tech in the Navy you should know that...... Where you a Nuke, or conventional?

[TheDucks]

26 minutes ago, prevue12 said:

Power is a function of how much Current is drawn at a certain voltage, you can not inject power.  If a system operates at 5V and draws 10 amps,  that 50 watts of Power,  You can not Inject 60 watts and have 10 spare floating around.

In this case:

Power = E*I , I²R, or E²/R   all relate back to how much Current is drawn at a certain voltage,  yes even  E²/R  ( P=I*E,  I =E/R sub in, and E*(E/R), current is just hidden).

You can not INJECT anything, current is drawn on what resistance is at certain voltage.  I= E/R.   Never once, in any class  or working as commercial electrician, was the term/phrase, Power Injection used, or taught.  Its just plain fundamentally wrong, but we can call it that, it just bugs me, Mr. Ohm would agree with me if he was still around, I bet. 

But as I read your profile I see you were a Electronic Tech in the Navy you should know that...... Where you a Nuke, or conventional?

there is no point injecting Voltage if there is no current flow (AKA Load)  P=I*E

[k6ccc]

Actually there is an example in electrical distribution systems that is very close to what we do. It used to be very common, but less so these days. For those with underground distribution, this may be harder to visualize, but for overhead distribution area, it should be pretty easy. Generally today there will be a pole top transformer that takes a sub-transmission voltage (usually between 2.4 and 16 KV), and steps that down to 120/240 volts to feed your house and a few neighbors. What used to be very common was that 120/240 volts wires would connect to dozens or even hundreds of houses. Every block there would be a transformer from the sub-transmission and add power to the 120/240 wires. As load increased due to houses using more power, the utility would simply add another transformer somewhere on the line between two existing transformers. Over years, this would continue until there were transformers every few houses. Many of those systems have been converted to a few houses being fed by one transformer. Like most things in life, there are advantages and disadvantages to this type of distribution.


Sent from my phone using Tapatalk, so blame any typos on Android!

[prevue12]

Still not power injection, but it paralleling the power source.............like to see them mess up and connect the wrong phases.  

I've seen an SSTG on a Aircraft Carrier shake a little when paralleled out of phase a little too much when bringing it on line. 

Edited July 9, 2017 by prevue12

[TheDucks]

17 minutes ago, prevue12 said:

Still not power injection, but it paralleling the power source.............like to see them mess up and connect the wrong phases.  

I've seen an SSTG on a Aircraft Carrier shake a little when paralleled out of phase a little too much when bringing it on line. 

You should NOT leave the lead from the previous pixel power (red?)  connected, only ground as that is also part of the data/clock circuit.

Yem, when the EM's mess up, things get dark. It is worse when the Diesel also fails to start  (ETR-2 on USS Forrestal CVA-59)

[k6ccc]

2 hours ago, TheDucks said:

You should NOT leave the lead from the previous pixel power (red?)  connected, only ground as that is also part of the data/clock circuit.

That depends on the power source.  If the power injection is coming from the same power supply, there is no problem with leaving it all connected.  However if the PI is coming from a different power supply, TheDucks is correct in that the positive power from the two different power supplies should not be connected.  See drawings starting about half way down this page:  https://www.doityourselfchristmas.com/wiki/index.php?title=Power_Injection