a light for ALL cell types

[James S]

Hi Folks,

I've posted a few picts of todays project

It's too late to fill in much in the way of details, but it's a single white LED fed through a single transistor step up circuit and built into a small clamp so that literally any 1.5v cell can be placed into it. I've run it from a button cell, N, AAA, AA, C and D.

The step up circuit is not as efficient as some of the newer ones, but it will run down to a very low voltage and still maintain a "usable" light. It's not comfortable to look into it, but it doesn't reach the blinding level.

I have many different flashlights that use so many different sized cells now that I needed something to get the last bits of power out of them.

These pictures were taken before I potted the electronics and the LED in some epoxy, so the finished product is a little better looking that what you're seeing.

Comments? Suggestions?

http://www.sentman.com/led/clamplight/

Thanks!
James

 

[Rothrandir]

wow, that is halarious. how did you ever think of that?

that is a great idea.

 

[MR Bulk]

James, that is quite brilliant, actually. And if you could incorporate a springclamp-type clip it could load and use even faster.

 

[Deviant]

hey that's an idea!

this method can be used to charge the odd size NiMH

Whistler do u hear me? u can use this method to charge your 1/5A batts

 

[EMPOWERTORCH]

At last, a torch that's not fussy about what you feed it on!
I don't know why the big torch manufacturers havent cottoned on to the idea of a "universal" torch. It's always the case that you might be travelling by car or motorbike, and, say, your bike breaks down. Its the dead of night, mnd you hunt in your tankbag for your trusty torch, only to find that the batteries are dead, With something like this you could find the odd cell to fit it, say out of your keyfob alarm remote or even a quartz watch. Hey presto... light!

 

[James S]

I've been staring at the movable contacts in my charger for a long time wondering how I could do something like that without a plastic molding system

The clamps work pretty good. It's not too difficult to get a connection to the bar, though I think that is a weak point. I measured the resistance of the connections at 5 ohms, which isn't too bad.

I also looked at the squeeze clamp type, but I didn't see one that would open out to a D cell length and still be parallel and they would be bigger than this too, although my local home depot may not be all that well stocked with various clamp models. I'll keep exploring.

It's fun that the coil, resister and transistor all fit into the holes in the plastic casting of the front piece! So the only thing to hang on the outside is the LED. In future I will use some kind of an angle iron to mount it in instead of just gluing it up there.

The other thing that needs work are the connector pads for the cell. Right now all I'm using is some wire wrapped around it. I think I may put some copper plates under it to make them stick out a bit further as it feels to me like I have to over tighten the clamp a bit to get it to make reliable contact on some D cells negative side.

I could also cut down the clamp bar a bit as you only really need it to go as far out as a D cell, which would make it easier to stow away.

I'm having entirely too much fun

James

 

[reviewum]

I know this is an old thread, but DANG this is cool!!!

I just have to learn an easy way to build a step up circuit out of all my parts I pulled from a radio and laptop. I've got transistors, coils, etc. but just don't know enough about electronics YET to put them together to make something useful!

Great work James, and I really love your site!

 

[John Frederick]

That is a great idea! For those like me who are electrically-challenged here's an idea; just mount an ARC AAA head to the clamp.

Any updates on this mod James?