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Update and request for advice


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Timothy Forde
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Joined: 16 Jun 2004
Posts: 247
Location: Vic ,Belgrave South


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Update and request for advice

Hello all
I’ve been rather quiet lately and just giving an update.
I have been working at a laser skirmish site http://www.laserstrike.com.au/ as a ref and have been taken on as a trial technician for there weapons (got to love it) and more relevant to this forum I’m also building my own weapon with parts from this site http://www.fragtag.com.au/. If it can make it up to standard I may also end up making these for the field.

Now that you are all up to speed a few questions.

I am trying to locate cheap chargers that don’t need to be very fast for NiMh. The main thing is cost, as we need a lot of them. For one idea do the drill chargers we use have a cut-off when there fully charged?

Another item I am trying to get is an Infer Red camera for focusing and testing the IR LED’s. Any suggestions?

Thanks all

Just a note I plan to get back into my robot ASAP but as this is going to get me money it has to take priority for the moment
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Post Mon Nov 13, 2006 12:13 pm 
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prong
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Joined: 19 Jun 2004
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If you are charging slowly then you can just use a low current charger, the batteries will just disspait the power as heat when fully charged, while this is not the greatest way to do it if the current is low enough the batteries will be fine.

This is how the drill chargers do it I believe


As for IR receptive camera, just about any digital camera or ccd or cmos unit is sensetive to IR, pretty much anyhting will do the trick.

Post Mon Nov 13, 2006 12:30 pm 
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Timothy Forde
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Joined: 16 Jun 2004
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Location: Vic ,Belgrave South


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My only worry with those cheap chargers is over time will it damage the battery? These things get used and charged a few times a week
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Post Mon Nov 13, 2006 12:34 pm 
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prong
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Well, from my understanding if the charge current is low enough then it will not harm the batteries. Of course that low a charge current might take 12 hours just to charge the batteries.

I would suggest some research into making you own smart charger circuit.
That way you will know you batteries are getting the correct charge. Of course then things get more expensive.

The other options might be running these things of removable AA batteries and using a seperate commercially available charger or chargers. Once again, more expense.

Post Mon Nov 13, 2006 12:56 pm 
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Spockie-Tech
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Joined: 31 May 2004
Posts: 3160
Location: Melbourne, Australia


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Good Info on NiMh Batteries here
http://en.wikipedia.org/wiki/Nickel_metal_hydride_battery

Factors to be considered when seeking a suitable charger.

How Many Volts (cells)
How User Friendly (LCD menu's, or push-and-go idiot proof)
Needs to run from 12vDC or 240v AC ?
and how many of them do you need ?

The Swallow Advance is a nice unit that runs directely from 240v for about $130
http://www.hobbymodelwarehouse.com.au/index.html?lang=en-us&target=front.html

You can get a 12v powered version for around $80-$90 if you hunt around.

They will charge your NiMh packs properly as well as doing lots of other batteries as well as allowing you to capacity test them.
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Post Mon Nov 13, 2006 1:59 pm 
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original_carnage
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Joined: 12 Jul 2004
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Location: Toowoomba(ish), travel to Brisbane


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Hi Tim - welcome to the wonderful world of recreational jungle combat Laughing

as Brett said - the Swallow advance is great.
Besides 4 OMNI chargers (running through converters) to pump up my guns batteries, we now also have 4 of the new Swallow advance chargers going straight from the mains.... great stuff.

We do all our guns at just 2 amps. The batteries get cycled once per month to keep them in good condition.

Don't get concerned over the price of the chargers... the tax man lets you have all kinds of spent money back when there is one of those magic ABN numbers involved...

IR cameras - try a security equipment shop (the kind that sells cameras and stuff). They are cheap as.
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Post Wed Nov 15, 2006 11:10 am 
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prong
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Joined: 19 Jun 2004
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Just note that any camea will pick up IR, the ones labbeled IR just have IR leds for invisible night time illumination!

Post Wed Nov 15, 2006 11:16 am 
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Timothy Forde
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Joined: 16 Jun 2004
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Location: Vic ,Belgrave South


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Thanks! didn't know that!
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Post Wed Nov 15, 2006 9:14 pm 
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Valen
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Joined: 07 Jul 2004
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your actually probably better off with cheap cameras.
The better ones have IR filters (and better IR filters) on them.

Why don't you just use an IR laser? they are worth ~$10 or so?
put a red laser on it too just for the look of the thing. ;->
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Post Wed Nov 15, 2006 10:19 pm 
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prong
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IR laser would be very hard to hit anything with. Back in hgihschool some friends and I made a prototype laser gun game, we used a red laser pointer to trigger some phototransitors. Even with a bunch of them it was rediculously hard to aim the laser accuratley over a room, even while still.

You need to diffuse the IR laser, or use IR leds and a lens to get a decent sized dot.

I have yet to see a camera, expensive or otherwise, that cannot pick up IR!

In fact many video cameras have IR leds for that exact purpose, they use them for nighttime illumination.

Post Wed Nov 15, 2006 10:35 pm 
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Grotto



Joined: 30 Aug 2005
Posts: 38
Location: Morisset NSW


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Best cameras I can think of for the focussing would have be
any old and dirty CCTV camera but preferably one that is
Black & White ONLY. They almost never have IR filters on them.
Try to connect it to a B&W tv/monitor if you can as its easier on the eyes.

Shine you IR leds onto a sheet of matt black cardboard for the
best visable result.

Oh, and kill all fluro lights in the vicinity, they can sometimes generate
IR as well...

G'luck
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Post Tue Nov 21, 2006 2:47 am 
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