Can a POE switch be used to power IR illuminators?

[Sybertiger]

Specifically, I'm asking if a POE+ switch will power an IR illuminator in the following configuration:

POE+ switch ---> CAT6 ---> Passive Splitter (power only used) ---> IR Illuminator

Will the POE switch autosense detect no connected device and therefore not supply power with only an IR illuminator connected?

I don't want to do the funky thing where you use the POE switch port to power up the IP Cam plus an nearby IR illuminator by using splitters. If what I'm asking doesn't work because of autosense what POE power supply do you suggest for simply powering IR illuminators?

I suppose I can set up a power strip and plug in 4 or 5 of the DC power supplies that comes with the IR illuminator but was hoping for something more elegant.

 

[tigerwillow1]

Before responding I need to clarify the definition of passive splitter. Passive to me means no transistors, SCRs, etc., either discrete or in an integrated circuit. I use the splitters that draw standard ~48 volt POE power from the switch, and have a 12 volt DC output + non-poe network output. With my splitters, they begin drawing power from the switch with neither output connected, so I can use them to power a 12 volt illuminator with no camera plugged in. However, that doesn't necessarily mean it will work the same with every splitter-switch combination. The splitters are cheap enough that my opinion is to just buy one and see if it does what you need it to.

 

[Sybertiger]

Yes, I know about the active splitters that are sold that convert 48VDC to 12VDC. I was wanting to avoid buying 4 or 5 of them and was thinking that a passive splitter could do the same thing but on second thought a passive splitter would not transform from 48VDC to 12VDC. Sounds like I either need to purchase active splitters or go the route of a power strip and plug in all the 12VDC adapters that come with the IR illuminators.

 

[Sybertiger]

With my splitters, they begin drawing power from the switch with neither output connected, so I can use them to power a 12 volt illuminator with no camera plugged in.

Wonder how much power your active splitter draws during the daytime went the IR illuminator is not active....very little I assume?

 

[forzabiondo816]

I have a POE motion light running in line with a POE IP cam. the light is rated at 8w. Should be possible as long as you verify all of the power requirements.

 

[tigerwillow1]

Sorry to be nitpicky about the terminology, it's just so darn easy to mis-communicate. What I think of as a passive injector/splitter is one where you used the unused blue and brown pairs to carry power. I don't have any experience with them, but I think the big issue would be carrying 12 volts instead of 48 volts. The current with 12 volts would be more than 4x as when using 48 volts, leading to a lot more power loss in the wires. You'd have to run the numbers to know how significant this would be. My guess is that it would be very significant on a long cable run, overshadowing the power lost when using a splitter that converts 48 to 12 volts.

 

[Sybertiger]

Yeah, I think running 12VDC over 100ft Cat6 is not the way to go. If it were AC it'd be another story.

POE+ switch (48VDC+) ---> CAT6 (100ft) ---> Active Splitter (12VDC) ---> IR Illuminator (15.4w max)

I bought some active splitters on eBay for 4/$14 so at $3.50 each it's not as big a deal as I first thought.