Power Adapter for Canon Rebel XS
Posted 23 October 2011 - 02:59 PM
Does anyone know what the voltage is for that power going to the camera? Is it 12V and could I just wire it up to a plug so I can use a 12V battery to power it? If not, are there any adapters made that plug into 12V and power the Canon XS?
Posted 23 October 2011 - 04:55 PM
The dummy battery is just a shell to patch in the battery voltage. It should be 7.4V and no greater than 8.4V.
Use an external power regulator to drop 12V to 7.4V outside the camera body.
Posted 23 October 2011 - 05:48 PM
Posted 23 October 2011 - 06:08 PM
Posted 23 October 2011 - 06:20 PM
The Canon XS doesn't have an external power jack (nothing I have found anyway). It uses a "dummy" battery to connect to the terminals in the battery compartment and you plug into that. The only jacks I can find is video out, USB, and the external shutter control (very simple to make an external shutter release).
73 de VE3SNW
Posted 23 October 2011 - 06:35 PM
Posted 23 October 2011 - 07:14 PM
Posted 23 October 2011 - 10:09 PM
css_hello: thanks for the voltages! I'll see if I can come up with a 7.5v regulator.
Eddie: that $15 AC adapter on Amazon was the cheapest one I found too. I'll probably get that just to use the dummy battery part.
It would be nice if I can open up the block with the transformer in it, gut that section, and put a 12V to 7.5 volt regulator inside. Then I could use the AC cord for the 12V power lead and just replace the 120V plug with an appropriate 12V one. Of course, those things tend to be pretty well sealed up so I may not be able to do that.
In any case, it doesn't look like there's an off-the-shelf 12V solution so this will be a job for a winter weekend.
Posted 23 October 2011 - 11:01 PM
You have two choices for a regulator. Linear regulators are cheap, very simple to set up and use, but aren't the most efficient when looking at power consumption. Powering your 8v regulator from a battery (13v to 11v) will result in 60 to 72% efficiency. The remainder of the power taken from the battery will be dissipated as heat. DC-DC switching supplies are much more complicated to build, more expensive to buy, and usually run in the 85-90% efficiency range.
If you have AC power available; then it doesn't make any difference. If you're powering your scope from batteries; you'll need to decide if the cost of the power savings of the DC-DC converters are worth the lower load on the battery.
Posted 24 October 2011 - 07:48 AM
I think the second item is the way to go. Put it in an aluminum diecast box, bore a hole in each end for the two cables, set the voltage, and power it from your scope supply. I'm going to order two since I have a 3.7VDC camera and a 7.4VDC camera to use for astro work.
Posted 24 October 2011 - 10:19 AM
Just bought a couple myself. At this price, it's chump change, but I am a little concerned about electrical noise from a switching supply. That can sometime end up showing up as noise in images. I'll have to see how that goes. May want to put a filter capacitor on the input and output, plus putting it in a metal enclosure would help.
Posted 24 October 2011 - 12:35 PM