2.1mm plug adapters and question on baluns

[inforlonghaul]

I have two questions I'm hoping somebody could answer me on. This is in reference to a 24 VAC system that I'm stuck with having to maintain and I've only worked with IP and basic 12 DC systems. Electricity is totally not my thing.

Question 1:
The 2.1mm power adapters like the ones below. I know they're more commonly used with 12 DC applications, but can they also be used for 24 VAC? I'm not a fan having to hard wire the siamese and camera wires together. Can these be used or is it a bad idea?


Question 2:
The caveat to this system is not only is it a 24 VAC system, they also use power/video baluns. The baluns they bought me are EV-BL910PA but specs are sketchy. One site I found did say its suitable for 12DC. No mention of 24VAC. Would this work on 24VAC power supplies or would it burn up?

Its specs are:
Maximum Output: 1.1Vp-p
Loss Ratio: >2dB
Rejection Ratio: <15dB
Interference: >40dB
Transmission Distance: 2200 Ft
BNC Resistance: 75oh

I would greatly appreciate your support. I'm hoping to get the school to eventually get rid of their 6 DVRs in this building and convert over to IP since the wiring is already in place, but until then...

 

[nayr]

Q1: It should work
Q2: It'll likely burn up, but 24vac can be converted to 12vdc very simply with some diodes.. if you stop it from alternating, it becomes direct current at half the voltage.

Try this: https://www.amazon.com/R-Tech-Current-Adapter-Surveillance-Security/dp/B00A6HABYM

 

[tigerwillow1]

Q1: It should work
Q2: It'll likely burn up, but 24vac can be converted to 12vdc very simply with some diodes.. if you stop it from alternating, it becomes direct current at half the voltage.

Try this: https://www.amazon.com/R-Tech-Current-Adapter-Surveillance-Security/dp/B00A6HABYM

Not that simple with the diodes. If unfiltered, the diode rectifier output will be pulsating DC with peaks of 34 volts (with a 24 volt AC input). If the output is filtered, the DC output will depend on the load, possibly as high as 34 volts. 24 volts AC is 68 volts peak-to-peak, 34 volts peak positive, and 34 volts peak negative. If you make a DIY converter, the output needs to be filtered and regulated.

 

[nayr]

should have phrased that better, I was trying to describe it in simple terms.. not that you only need to wire up some diodes and get 12vdc, just its electronically very easy to convert it.

now that I revisit that statement i see your concern, if you do DIY a converter you will require more than I implied.. clearly.. though in my defence I never assumed he would DIY one.. but thats what I get for assuming.

 

[NoloC]

Looks like the balun is made by Evertech USA. http://www.evertechusa.com/ev-bl910-pa-2-passive-video-and-audio-balun-transceivers-with-mini-coax-cable-and-power-connector.html You could contact them and ask.

They didn't provide a schematic of the balun but if it uses separate pairs within the cat5/6 cable, it should work OK for AC. SO I am just guessing here but of the 4 twisted pairs available in th cat5/6, I assume they use one for video, one for audio and maybe two for power. You could learn a lot with a VOM as to pin out. 2200 feet is a wet dream and makes the company seem pretty flaky to spec that. 12VDC won't go very far on cat5/6 so the 24vac is actually more likely to work. You might have to locally power the cams depending on distance. I am assuming you need 24vac to power the cams.

The power connectors are "agnostic" as to ac or dc and will be fine.

Cut yourself a cat5 cable and strip the ends so you can put your VOM in continuity mode and verify pin outs to be sure. But I think you will be OK.

Good luck!