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Power the camera with an external supply

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Re: Power the camera with an external supply
« Reply #10 on: 01 / February / 2014, 14:58:03 »
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Hmmm. That's a good point. Assuming that a flash is the highest peak at a camera one might come to the conclusion that when using the camera without flash there is so much overhead that two cameras driven by one power supply is safe?
No way to know but its safe to assume Canon did not plan on powering two cameras from their external supplies and that they did not "over design" their power supplies to support two.  So the power needed is likely what those supplies will provide.

You could test and see.  But failures will likely be somewhat random if it works so lots of testing would be a good idea.  You probably also want to monitor the temperature of the supplies.
Ported :   A1200    SD940   G10    Powershot N    G16

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Offline ahull

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Re: Power the camera with an external supply
« Reply #11 on: 01 / February / 2014, 15:39:06 »
There may be other issues too, the more current you drain, the more stressed the power supply will become. If you over stress it far enough, it will blow up or shut down, but before it reaches that state, typically things like noise and ripple  will increase, regulation will suffer, and there is a real chance you may damage the cameras.

I would assume the maximum current one of these cameras is likely to draw, will exceed 1 Amp, so worst case scenario is that two will exceed 2A, at which point we may start to see some irreplaceable magic smoke emerge from either the power supply, the cameras or possibly both.

I wouldn't be too keen on conducting the experiment. 

If you do decide to try, then you might need to think about some smart power management, for example, don't allow  both cameras to zoom at the same time, avoid the use of flash if possible and so forth.

This sort of trick allows large servers to run lots of hard disk, with theoretically under rated power supplies by ensuring only one of them starts up at any given time, since startup current is largest power demand of a hard disk. Once all of the drives are spinning, their current demands are more modest. The same *may* be true of canon cameras...
« Last Edit: 01 / February / 2014, 15:44:17 by ahull »

Re: Power the camera with an external supply
« Reply #12 on: 01 / February / 2014, 15:49:30 »
Well Flash is at no time used. Actually the flashes are prevented to pop out with some tape. And it is no problem to have a delay on the multicam.lua when zooming. Am I right when saying that the only real peaks are flash and zoom?

I won't go a risky way but maybe one could somehow come to a point to say "If you don't do this and that then you are on the safe side".

Re: Power the camera with an external supply
« Reply #13 on: 01 / February / 2014, 15:57:48 »
Well Flash is at no time used. Actually the flashes are prevented to pop out with some tape. And it is no problem to have a delay on the multicam.lua when zooming. Am I right when saying that the only real peaks are flash and zoom? I won't go a risky way but maybe one could somehow come to a point to say "If you don't do this and that then you are on the safe side".
I think you will also find that high points of processor activity will bump the current way up - specifically when shooting (focus motor and mechnical shutter),  processing the image (DSP working hard), and writing to the SD card.

So if you want to simplify the rig,  I would suggest buying bigger power supplies.  Putting multiple cameras on a cheap chinese supply that really only maybe was robust enough for one camera just does not seem like a good idea.
Ported :   A1200    SD940   G10    Powershot N    G16


Re: Power the camera with an external supply
« Reply #14 on: 01 / February / 2014, 16:00:59 »
Okay. Thanks a lot for all your cents. I'll keep the 50 supplies. Security outs convenience.

Thank you very much!

Re: Power the camera with an external supply
« Reply #15 on: 01 / April / 2014, 00:35:58 »
Did anyone try running the camera 24/7 plugged in with a motion detection script? I'm a bit worried it might overheat (sx130).

Re: Power the camera with an external supply
« Reply #16 on: 01 / April / 2014, 11:18:49 »
Did anyone try running the camera 24/7 plugged in with a motion detection script? I'm a bit worried it might overheat (sx130).
There are many CHDK scripts that are run 24/7.  There is nothing special about motion detection that would increase the camera temperature over an intervalometer script.  But if you are worried about it,  it would be easy to add a couple of lines of code to your script to monitor the sensor temperature and shutdown the camera if it exceeds a preset limit.
Ported :   A1200    SD940   G10    Powershot N    G16

 

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