Lightweight cordless mod

liquidweaver
Posts: 4
Joined: Tue Nov 08, 2011 11:15 pm

Lightweight cordless mod

Post by liquidweaver » Tue Nov 08, 2011 11:20 pm

Using the circuit here: http://en.wikipedia.org/wiki/Joule_thief

I screwed a AA holder to my TrackClip pro, and it runs well on one 1.2v AA NiMH rechargeable cell. I was able to fit all the electronics inside the clip itself, so the only thing that sticks out is the battery. I measured the current draw, it's about 60mAh, so it ought to run about 2500/60 (about 40) hours per charge if the spec is right on the cell.
[img:right]https://fbcdn-sphotos-a.akamaihd.net/hp ... 7664_n.jpg[/img]

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

Re: Lightweight cordless mod

Post by NaturalPoint - Mike » Wed Nov 09, 2011 12:45 pm

Very nice! I like the 1 battery modification alot.

MaddHatter
Posts: 12
Joined: Mon May 16, 2011 3:28 pm
Location: NY

Re: Lightweight cordless mod

Post by MaddHatter » Fri Nov 11, 2011 6:30 pm

very cool man. good job

dradecki
Posts: 23
Joined: Sun Aug 10, 2003 5:00 am

Re: Lightweight cordless mod

Post by dradecki » Wed Feb 22, 2012 9:26 am

Very cool. Any chance you could post a how-to on doing this?

Thanks

liquidweaver
Posts: 4
Joined: Tue Nov 08, 2011 11:15 pm

Re: Lightweight cordless mod

Post by liquidweaver » Wed Apr 04, 2012 10:30 pm

I tore a ferrite toroid off an old motherboard and used some enamel magnet wire (30 AWG), 20 turns on each side.
Make sure you reverse the turns for the sides!
For the transistor I just picked the super common BC547B transistor. You should be able to use just about any small signal NPN transistor though - this is a pretty inexact circuit. I used a 1K resistor on the primary coil, specifically a common 1/4 watt 5% carbon film( see http://goo.gl/ZLXk0 )

If you pick a smallish toroid, you can solder everything up and pack it on the gap in the clip without too much issue.
I was able to use an energizer 1.2v NiMH cell for about a month before it had to recharge... which was good, DCS A10 was hard enough without having to worry about the sensor :)

If you guys need more help, let me know and I might go ahead and post a more thorough guide.

NaturalPoint - Mike
Posts: 1896
Joined: Tue Feb 01, 2011 8:41 am
Location: Corvallis, OR

Re: Lightweight cordless mod

Post by NaturalPoint - Mike » Thu Apr 05, 2012 12:09 pm

Oh, nice. You packed the joule thief into the existing TrackClip Pro housing?

liquidweaver
Posts: 4
Joined: Tue Nov 08, 2011 11:15 pm

Re: Lightweight cordless mod

Post by liquidweaver » Thu Apr 05, 2012 1:03 pm

Yes. Actually, if there was a lot of interest, this wouldn't be too hard to make en masse as a more legit pcb design.

liquidweaver
Posts: 4
Joined: Tue Nov 08, 2011 11:15 pm

Re: Lightweight cordless mod

Post by liquidweaver » Thu Apr 05, 2012 1:04 pm

Thanks.

Idlemind
Posts: 5
Joined: Mon Apr 09, 2012 7:38 pm

Re: Lightweight cordless mod

Post by Idlemind » Mon Apr 09, 2012 7:49 pm

This is so cool - I literally cringed when I saw the Trackclip pro was USB. (Mostly because my Belkin USB HUB just died the notorious overheating death) but at least they thought ahead enough to let you piggy back another usb device onto it.

For something that clips onto your head a battery powered version is a no brainer?! I already look geeky enough without even more wires coming off of me lol.

Ezrem
Posts: 1
Joined: Thu May 10, 2012 12:23 pm

Re: Lightweight cordless mod

Post by Ezrem » Thu May 10, 2012 12:27 pm

Did you make any other changes to the wiring of the TrackClip Pro (different/removed resistor), or did you just connect the positive and negative of the Joule Thief in place of the positive and negative from the USB port?

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