one of my favorite tricks is to wire up the RJ45 with the blue and brown pairs...I leave them hanging out...Then, I grab the power supply for whatever device I'm powering, chop it in the middle, strip the wires, and splice them onto the blue (for positive) and brown (for negative) to send passive POE down the cable... Works pretty good...only had one problem with a lack of volts/amps at the powered device....It's a nice alternative to true POE and cuts down on extension cords, and ugly wires hanging around the cameras......... IF anyone wants to know more about this trick, a simple google search will work to provide sufficient information... OR, just find out the size of your power jack and buy a passive POE splitter for (usually) less than $5.
An alternative to this is to modify an existing cable and add passive POE is to grab a razor blade and slice open the protective cover on the cable VERY carefully and expose the pairs about an inch back from the connector... With everything unhooked, cut the blue and brown pairs and cut the cable shield a few inches back to give you a few inches of blue and brown wires to work with... The blue is typically used for the positive connection and brown for the negative (in standard POE).. Then take your power supply and cut it at least 6 inches from the jack and strip the wires back to expose the positive and negative. Now, grab our favorite roll of electrical tape, or soldering gun, and connect the power supply at one end, and the power jack at the other end... Depending on the rating of your power supply, and the rating of your camera, switch, router, IR light, sensor, or what ever it is you are powering, it should work...
*** caution. TOO long of runs and not enough voltage/amperage = not enough watts to power your device...so, may take some trial and error to figure out if your (for example) 5 volt 1000 milliamp power adapter will provide enough juice to power your foscam at 50 or 100 feet...
volts/ohms = amps
volts * amps = watts (1000 milliamps = 1 amp)
voltage drop over long distances of wires is normal... an alternative to buying an expensive POE injector is to hop on ebay, or go to your local junk computer store and find a laptop, printer, phone, or any other power adapter with the same voltage, or slightly more, and put it to use...
One example is: for standard POE, find a 48v power supply that is rated at 500 milliamps...this will provide 24 watts... and chances are your POE camera doesn't use 24 watts... Then use the "splice" procedure above to add the 48v on the blue/brown pairs and you have considerably cheaper POE...
Another example is: something similar to my junk foscam that has a 5v 2000 milliamp adapter... can check ebay, or junk computer store, and find a 9 volt power supply with a comparable amp ratting, or more amps.... (even a 12 volt power supply will work but be careful, some cams might fry with too much voltage so do some research before you fry a cam trying to save $20)...... The 9 volt power supply spliced in the cable in the passive POE manner will work just fine on a long run... the reason is that the voltage drop over the distance cuts the 9 volts down and as long as you have enough amps to keep your wattage rating within specs, it will work perfectly.
So, to make use of all of this garbled theory/knowledge, i'll share my personal POE setup with you.. I was able to find a 48V power adapter that came from an unknown piece of equipment at my local junk computer store, gave them $10 bucks for it, even though they should have given it to me for about $2, considering they had $10-$15 each marked on about 1000 different mix/matched power supplies and they would never sell them...But hey, everyone has to make a buck... and I didn't have to wait for shipping.... I digress.... anyway, 48v 1amp is the rating...that = 48 potential watts of power... SO, I'm going to use it to power at least 2, maybe 3 of my 3mp bullet cams that will be running on between 25 and 100 feet of cat6 cable. I'm going to get a $1 power strip/bus common at radio shack or just about any electronics store, and put the 48v form the power supply to it, then grab the juice and run it into the blue/brown pairs on the cat6 cable, and have POE on those cameras for about $12.
BTW, there are several youtube videos that you can find relatively easy regarding DIY POE....
And to clarify, some of my success/failure... running a nice 2mp cam with IR's on the front of my house...powered in the attic with an outlet...RJ45 spliced for passive POE with standard provided power adapter over a 40 foot run of cat5..works perfectly... AND, I have the Ethernet cable plugged into an actiontek powerline 500mbps adapter.... I would have used standard POE with this cam, but I didn't realize it wasn't a true POE cam when I bought it...oh well..live and learn... Passive poe is working just fine... and there is a lot less mess in regards to wires going all around my house..... (would have just went wireless with this cam like it used to be for the previous 2 years, but got addicted to the better frame rate of wired connections).....
not sure how this post ended up being so long, but hopefully someone out there benefits from my ramblings.
An alternative to this is to modify an existing cable and add passive POE is to grab a razor blade and slice open the protective cover on the cable VERY carefully and expose the pairs about an inch back from the connector... With everything unhooked, cut the blue and brown pairs and cut the cable shield a few inches back to give you a few inches of blue and brown wires to work with... The blue is typically used for the positive connection and brown for the negative (in standard POE).. Then take your power supply and cut it at least 6 inches from the jack and strip the wires back to expose the positive and negative. Now, grab our favorite roll of electrical tape, or soldering gun, and connect the power supply at one end, and the power jack at the other end... Depending on the rating of your power supply, and the rating of your camera, switch, router, IR light, sensor, or what ever it is you are powering, it should work...
*** caution. TOO long of runs and not enough voltage/amperage = not enough watts to power your device...so, may take some trial and error to figure out if your (for example) 5 volt 1000 milliamp power adapter will provide enough juice to power your foscam at 50 or 100 feet...
volts/ohms = amps
volts * amps = watts (1000 milliamps = 1 amp)
voltage drop over long distances of wires is normal... an alternative to buying an expensive POE injector is to hop on ebay, or go to your local junk computer store and find a laptop, printer, phone, or any other power adapter with the same voltage, or slightly more, and put it to use...
One example is: for standard POE, find a 48v power supply that is rated at 500 milliamps...this will provide 24 watts... and chances are your POE camera doesn't use 24 watts... Then use the "splice" procedure above to add the 48v on the blue/brown pairs and you have considerably cheaper POE...
Another example is: something similar to my junk foscam that has a 5v 2000 milliamp adapter... can check ebay, or junk computer store, and find a 9 volt power supply with a comparable amp ratting, or more amps.... (even a 12 volt power supply will work but be careful, some cams might fry with too much voltage so do some research before you fry a cam trying to save $20)...... The 9 volt power supply spliced in the cable in the passive POE manner will work just fine on a long run... the reason is that the voltage drop over the distance cuts the 9 volts down and as long as you have enough amps to keep your wattage rating within specs, it will work perfectly.
So, to make use of all of this garbled theory/knowledge, i'll share my personal POE setup with you.. I was able to find a 48V power adapter that came from an unknown piece of equipment at my local junk computer store, gave them $10 bucks for it, even though they should have given it to me for about $2, considering they had $10-$15 each marked on about 1000 different mix/matched power supplies and they would never sell them...But hey, everyone has to make a buck... and I didn't have to wait for shipping.... I digress.... anyway, 48v 1amp is the rating...that = 48 potential watts of power... SO, I'm going to use it to power at least 2, maybe 3 of my 3mp bullet cams that will be running on between 25 and 100 feet of cat6 cable. I'm going to get a $1 power strip/bus common at radio shack or just about any electronics store, and put the 48v form the power supply to it, then grab the juice and run it into the blue/brown pairs on the cat6 cable, and have POE on those cameras for about $12.
BTW, there are several youtube videos that you can find relatively easy regarding DIY POE....
And to clarify, some of my success/failure... running a nice 2mp cam with IR's on the front of my house...powered in the attic with an outlet...RJ45 spliced for passive POE with standard provided power adapter over a 40 foot run of cat5..works perfectly... AND, I have the Ethernet cable plugged into an actiontek powerline 500mbps adapter.... I would have used standard POE with this cam, but I didn't realize it wasn't a true POE cam when I bought it...oh well..live and learn... Passive poe is working just fine... and there is a lot less mess in regards to wires going all around my house..... (would have just went wireless with this cam like it used to be for the previous 2 years, but got addicted to the better frame rate of wired connections).....
not sure how this post ended up being so long, but hopefully someone out there benefits from my ramblings.
