Cheap DC power for Canon 60D

I have a small super 8mm setup with my 60D. I got sick of the battery auto power off so I bougth a small "DR-E6" (non Canon) power adapter with AC power brick for my 60D at ebay.
It was dirt cheap and i got a bit suspicious when it said 8.1V on the power brick, and i can accedently connect this thing to one of my 12V DC supplies or even a 11.1V lipo.

So i decided to open the the fake battery adapter to see if it was safe to power from other sources. Inside i found this:

Only a smothing cap 2200uF 16V. Not very safe if i connect something else than the supplied power brick.

I found this in my drawer:  LM2596 based Adjustable DC Step-Down Converter from ebay.

 

Connected it to the power and adjusted the voltage using the smal blue potmeter until it gave me 7,56V:

Loaded it with 10 Ohm power resistor (756mA) and noted that the voltage did not drop much. I also tested with a 12V DC supply and it gave the same result.

Fitted PCB in the battery shell with double sided tape and soldered on the output wires:(the polarity in the pucture turned out to be wrong! Check the polarity on a normal canon battery, i didnt :-/ )

 Put on some hot glue for isolation and cable fixing

O

 Glued togeather with super glue:

I tried it and it did not work. I measeured output voltage on the to slits in the adater and realized i had negative voltage. But the camera survied, i had to open up again and switch the powercable on the pcb. Now it works. :-)
During startup of the camera i get this choice, i have to select 'ok', after that the camera works fine.

 Here you see the cable entry of the 60D body.

 Thats it, i can now power my 60D from anything like car batteries and magicshine battery packs. :-)