cheap and easy PSU for Canon EOS

I think lot of guys here on Instructables know how much satisfaction is obtained building a gadget entirely by ourselves, but... sometimes it could be a clever solution opting for some nice and ready accessory. I think this is one of these cases.
I recently had the need to have a power supply for my Canon DSLR, an EOS 40D, to make some timelapse. For this pourpose I've bought an LM2596S step-down adjustable power supply module from eBay, it's very cheap, efficient, compact, and (I hope) safe... and it fits exactly inside my exhausted lithium battery case. And this instructable could be handy adapted for almost any digital camera battery, the only requirement is that the case contains the power supply module.

Step 1: Intro

The new psu is intended to work with a wall-plug transformer the same as with any DC power source between 9 and 35V, as a car battery or almost any wall-plug psu. This could be very handy in case of timelapses, gigapan shots, or long movies.

Comments

[tvm777]

Its a good solution, i have a 550D, same solution for it??
wich module did you use? i find this one cheap:
http://www.ebay.com/itm/LM2596S-DC-DC-Step-Down-Adjustable-Power-Supply-Module-zl-20120129-002-/170855921526?pt=LH_DefaultDomain_100&hash=item27c7ce7776&vxp=mtr

[andrea biffi]

that seems right, you can found other ones clicking on the link in the first step

[8steve88]

Hi there.
Great Instructable. I have an EOS40D and reckon your solution it would solve another problem as well. - Do you know if your battery has enough charge left to power a sensor cleaning session? With this solution it doesn't matter - just plug in and go.
Even with my battery grip -two batteries- I have to recharge just to be sure that the large drain of holding the shutter open won't flatten the batteries. Problem solved. Thank you.

[andrea biffi]

that seems right, you can found other ones clicking on the link in the first step

[andrea biffi]

yes, also Canon recommends using the PSU to clean sensor.

[jamesobrady]

Great instructable !!
On the protection diode, have you wired it in parallel with the supply?

[andrea biffi]

Yes, with reversed polarity.

[andrea biffi]

then I decided to not add any protection diode, in parallel is too dangerous due to diode blowing, and in series it takes 0.7V (or 0.35V for a Schottky diode), so I decided to trust in circuit own protection.

[lionel1024]

Excellent!

[andrea biffi]

Thanks! Your comment really helps me. I actually had some doubt about the way to add the diode. I didn't want to lose power (especially with an external battery supply), but you're right about diode blowing... I'd have to think about that.
Yes, maybe 0.7V are not too much, and a better protection should be good, I don't know what could happen to the circuit with a reversed voltage from a car battery with 50A... I'll update the circuit and the Instructable...

[RichardBronosky]

I'd like to see how this fits into the camera.

[sdtacoma]

That's what I came to say. I like the idea, but no way would the batter fit back into the camera.

Andrea, can you show us how that works?

[andrea biffi]

Of course!

[sdtacoma]

Very cool. I don't think my camera has that little "door" so I wasn't sure how that was going to work. Thanks for the update. Great photos BTW.

[RichardBronosky]

Yes, I have the Canon XTI and the battery tether port is different. May still be doable though. photo from: http://www.dcresource.com/reviews/canon/digital_rebel_xti-review/

[g elliot s]

why not just buy one that's made for the camera?

[Treknology]

Even when new, I've yet to see a video camera with a battery that can outlast a single cassette. My solution has been to build a bracket that holds that camera and supports an SLA battery on the shoulder (also a major improvement in stability). I never thought of publishing it because most people complain about the weight of the battery!

[Helperlein]

The batteries give a voltage range between 8,4V and 6V.
Why didn't you just take a 7,5V external PSU instead of a PSU plus a Step-Down to 7,4V? At least if somebody does not have PSU yet, I would recommend just to buy a PSU with the right voltage and they are almost done. No voltage error, plus wiring is one step easier

[andrea biffi]

And with Canon unfortunately an external PSU isn't enough because Canon EOS have no DC-IN female plug.

[andrea biffi]

Hi, one reason is that I've tons of 12V DC and 9V DC PSU, because almost all devices uses that voltage (some uses 5V too) and when device breaks it left the PSU well functioning. As I've lot of them I assume many people have at least one of them. Then there is the main reason: with that you can use any battery from 9 to 35V, included a car-battery of 12V. There is more: if any device in your equipment is powered with a similar PSU you can use the SAME battery to power them all.

[andrea biffi]

Here is the image of the battery in position, note the rubber door, I think every Canon EOS has it..

[KT Gadget]

What you could do for the LED indicator is remove the SMD LED and replace it with a extended wired LED to point out of the pack, or get one of those bent acrylic pieces that are used to show the indication bars when the lights can't be flush with the case (not sure what they are exactly called).

Nice ible though, this might be one I will use in my Olympus when I get to more extended pic/video projects. Have you tried it through a 12V car plug to see how it performs?

[andrea biffi]

the battery should fit inside the camera, anyway it could be useful to see if power reach the battery.
I think Olympus has a DC-IN power plug, you don't need this (if you have the right voltage power supply).
I didn't try 12V car plug, but I've tried 35V and it works good.

[Helperlein]

Adding to the comment below, I think it is more important that the power supply, internal or external, can give enough amperage. It would be useful to know this for anyone who would like to use this (100mA, 500mA, 1A, 2A,..?)

[andrea biffi]

Almost all wall-plug 12V transformers have 1A amperage. These work good, maybe you could try 0.5A too, but I doubt it's enough. Any battery more than 1A is good. I think 9V 200mA are too weak.

[meanpc]

Nice job! Would be nice if Canon included a DC input from the factory, wouldn't it? Especially since we are using them for video a lot now, which burns a ton of battery.
Can you show the camera with your battery installed? I would like to see how you have the wire routed.

[andrea biffi]

Yes I'll take the picture soon. Canon always wants to sell more accessories, see also timelapse features or flash transmitter... :-(