Confused About Power Consumption on Multi-Camera System

[moe 0]

Hi,

I recently purchased a Q-See 4-camera system. The cameras say Power:DC 12V and the power adapter says Output:12V. Also included was a power splitter to hook up all 4 cameras to the single DC switching power supply.

 

I was wondering if someone could explain why the manual says, "Warning! If you have a multi-camera package, the included power adapter is designed to provide enough voltage to operate multiple cameras. Connecting a single camera to the adapter can cause the optical chipset of that camera to burn out and become useless."

 

If the adapter outputs 12V and the cameras are rated for 12V, how could the camera burn out? Am I missing something here? Does a switching power supply work differently?

 

Thank you.

[Dirk_D 0]

....that doesn't make sense....

[gb5102 0]

Makes sense if it is an unregulated power supply. With unregulated, the voltage is dependent on how much load is on the power supply, little or no load=higher voltage output.

 

But as far as I know all 'switching' type power supplies are regulated, I've only seen heavier transformer type power supplies being unregulated. If unsure, measure the voltage on the power supply, if it is 12v with no load(cams) on it then it is regulated

[Numb-nuts 1]

Gb got it SPOT ON... as the load increases the voltage drops but if it doesn't the voltage is potentially too high for the camera.

 

In other word the PSU is rated in watts ( a good indication that its unregulated) and the voltage will reduce to 12v ONLY when the load is equal to 4 cameras. Put just one on and the voltage will be too high. a regulated PSU can support one or 4 cameras without risk, therefore the removeal of a camera for say cleaning or servicing doesn't put the others at risk.

 

Thats what happens when you go hunting for bargains. I'm willing to bet if you'd known that BEFORE buying you would not have bought it? Cut your losses and buy a 12V/5 amp regulated power supply from either a local electronics store or from ebay.

 

The good news is these are not so expensive so you will only have lost a small amount on the unregulated switching power supply unit you bought.

 

Thank goodness you came on here to ask. It could have potentially cost you a camera also

[moe 0]

So I tested the voltage at the 4 way DC power splitter with a multimeter.

Cameras connected:

0 cam: 12V

1 cam: 11.95V

2 cam: 11.90V

3 cam: 11.85V

 

So it sounds like it's safe to use with less than 4 cameras plugged in, right?

 

Thanks!

[Numb-nuts 1]

When something is non-standard you cannot take anything for granted......

 

For a very small amount you can save yourself a real headache, get a 12v5A regulated PSU with four way output

it will be better for you in the long run.

[KENSTV 0]

Numnuts is right--get a better power supply, yours is regulated but from your voltage readings not very well ! also you are not seeing the full load unless the IR is on in the cams, the camera electronics pull less than the IR load and I'll bet you will see even worse regulation with them on--power supplies are cheep compared to camera costs !