Full set of pictures...
http://fecundswamp.peanutonastring.com/usb_batt/index.htmlI made my own last night. All I can say so far is that it powers my MT. It outputs +5V on pin 1 and Ground is on pin 4 of the Female USB jack. From all I could read, that is all any of the new USB powered devices need. I hope it doesn't hurt the unit in anyway.
I used a Female USB "A" to PS/2 adapter I got with a mouse or keyboard. It had some rubber around it, after removing that is was easy to find nice wires. I got a 7805 +5VDC Voltage Regulator (1 amp) from Radio Shack for $1.59, part# 276-1770. I had a Sucrets container that seemed to fit the bill.
I also bought some 10mm Insulated Standoffs (Part# 276-1381), $2.79. I used one standoff to attach the 7805 to the case. The USB I hotglued to the case. This was suppose to be a quick and dirty test to see if it works. It does.
I followed the pinouts frm here
http://pinouts.ru/data/USB_pinout.shtml and connected the positive lead form the batteries to the Input of the 7805. I connected the negative lead to the Ground of the 7805. The Output of the 7805 goes to Pin 1 of your USB Female Type A jack. Pin 4 of that jack then goes to the Ground of the 7805.
I used Two 9 Volts, the 7805 can handle a total of 35VDC, so that isn't a problem, I just don't know if you really need two... but WTH, more is better!!!!!
I am no rocket scientist folks, correct me if you are trained... all I possess is the power to read and some soldering skills. Here is another reference I used...
http://www.hackaday.com/entry/1234000270029372/I will be testing the record time soon, using MP3 @ 128 my 2GB CF card says it will record for 35 hours... I thought I would leave it run till it shutdown, but do I really care if it will record for 35 hours? I mean, if it will stay on for a night of recording and listening in the car ride home, that would be enough.
I imagine the real advantage would be if you were not going to be ear a AC outlet for a weekend or if you are recording festivals.
Digi-key has some 7805's that look much than the RS one, and you can get PCB mounted USB jacks too...
1 10 497-2947-5-ND IC PREC REG 1A 5V TO-220 0 0.97500 $9.75
2 10 ED90001-ND CONN USB RECEPT TYPE A PCB 0 1.04000 $10.40
And I think the next version might have a nicer case, a Serpac M-6
http://www.serpac.com/products_m-6.htmI hope to hear any suggestions or warnings you all might have.
be well