July 14, 2009
USB Power from the HIROSE 4pin connector
The purpose of the box is to be able to charge/power small cameras and
cell phones, using NP-type batteries and all HIROSE 4-pin compatible
connectors. It was inspired by an idea from Nick Masiuk. All parts are readily available from the Internet and can be
ordered as a kit or assembled from Gotham Sound and Communications:
This article is also available as an Instructable.
DISCLAIMER: This article is presented for educational
purposes only. Use at your own risk! Observe polarity!
This is a pigtail USB A jack, equivalent of the panel or PCB
mount computer jack. We used this one because of easy hook-up/installation,
but you can use any compatible product.
On the picture you can see the wires:
Ground wire (in black shrink tubing)
Red/ black wires. Red is positive (+),black is negative (-)
Green/white wires. Data wires. For some devices they will need to be soldered together,
in order to switch the device in charging mode.
Read more about USB standards
on the web. All parts are listed on Schematic
The next thing was a enclosure choice; it's totally up to
you. We decided to squeeze everything into the smallest box (on the left).
It's easier to work with the bigger one though...
Here is the complete parts collection. CW from the top: box,
DC/DC converter, pigtail USB jack, HIROSE 4-pin panel mount connector, screws.
You'll need a couple more hook-up wires- red and black color (for polarity
matching) and 20-22 gauge.
Close-up of the DC/DC converter. This one is from Mouser
and takes 9-18V input. Part number is on schematics
page. Two ceramic capacitors, wired across the input and output,
serve the purpose of extra filtering/reducing interference.
This is how I did the cutout for USB mount. A mechanical part
of the project is a little messy and needs some drilling, filing, measuring.
The good part is - you are the one to arrange everything according to your
And two holes for mounting screws.
Cutout for HIROSE connector. The little notch on top was filed
with a square mini-file.
All wired up, just before the final assembly. A 30 watt soldering
iron will do the job. If you've never done that- go online and search.
That's it, install the cover, and you're ready to charge your gadgets!
The pin-out is standard for Hirose - pin 1-Ground(negative-), pin 4-positive(+) After putting it together, we decided to add optional reverse polarity protection (stuff happens...) and visual LED indicator for USB output.
Details are on the schematic.
Good luck with the project!
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