I wanted a USB charging/power jack in my motorhome. All of the ones I found were too expensive and ugly. I built this one for about $2.00.
Step 1: Parts and Tools
I usually buy too many of some parts, just because I might ruin one, or might need it for something else. It helps keep the shipping costs down. If you run down to Radio Shack for the parts, this will cost a lot more
- 1 LM7805 voltage regulator $ .31
- 2 PCB mount usb jacks 1.20
- 1 heat sink .24
- 1 PCB mount screw terminal .25
- 1 capacitor 0.1uF .10
- 1 capacitor .33uF .10
- JB weld epoxy
The PCB board and aluminum were out of the scrap box.
- Hand nibblers to make a nice square hole
- Soldering iron
Step 2: Assemble Board
Assemble the board using the schematic for wiring connections. I soldered all of the connections on the USB jacks just to make a more solid mount. I also bent over the mounting tabs and soldered them.
Step 3: Cut the Panel and Mount the Board
I use a table saw to cut aluminum, you can use an old blade that you don't want to use for making nice cuts in wood.Be sure to wear your safety glasses. I really like those nibblers for making nice square holes. To make everything nice and solid I added the extra braces made out of scrap PCB board..
A LM7805 will handle two usb devices, it is rated at 1 amp, and USB device specification calls for a 0.5 amp draw. You can use input voltages from 8 to 35 volts. My heat sink is probably a little big, but I had it and better safe than sorry. The next ones I will make up PCB boards for so I don't have to solder all of the wiring together.
Step 4: Update
I don't like the way my boards look when I just solder them up so I made a printed board for the next one. While I was at it I made a sled to cut PCB board with my table saw. Here is the instructable Easliy cut PCB with your table saw.