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FrozenGate by Avery

PLUG & PLAY CO2 BURNING LASERS only $150 DELIVERED

Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

NS -- - You da man :D I can't believe 18650 are up to the task but carry on ;D

I've smoked two sensors here so I need to move the thermal head away from the OC of the laser. Are you getting 10 amps from those cells? Must be to get a beam like that.

Mike
 





Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

hi all,

here are some pics of my C02 laser and the box i built for it.


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tell me what you think :D
 

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Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Looks like a winner --- Is that blue box up front a targeting laser?

BIG wires speak of power ;D Is that the PWM behind the PS?

Mike
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

hi Mike thats not a targeting laser, but that would be a great spot for one. that is just a blue plastic cube I dtilled in the top and the side to hold the front of the laser steady,,,, and yes that is the pwm directly behind the amp with a 1/2 inch space between them, the 30 volt power supply can be removed with four screws and the top plexiglass slides open for ventilation or to tinker...the switches for power and pwm are next to the powercord disconect with a nifty little level hot glued on the side of the case I just need a handle and a target laser,, its really been a blast to build thus far :D
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

OOOOH! yours looks NICE! :D I don't think my box looks as good, I ended up using what I could find, laminated wood cabinet parts and acrylic! It still looks pretty good, even though i'm not done with it yet.
 

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Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

very cool I just went by what you all were talkin about early in the gb and I said to myself ooh plexiglass is a good idea so I stoled you all's idea ::)
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Mike on the back of the 30 volt switching power supply, :) if thats what your talking about the little black box is the fuses Oh mike I found a Scientech 362 power/energy meter for $29.00 on ebay thanks for the info, I need to make a sensor like Chris was talking about I have one of those 127 p things I got from Kenom through my brother from buying some krytons from him i guess he gives those out with his lasers?
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Well, the PWMs are finally done! As you can see in the attached picture it's quite small! What you do is solder the wallwort-wires or whatever you want to use for the PWM-drive and the PWM-wires from the laser-driver onto the small PCB and then you can adjust the dutycycle from 0-100%. Turned fully clockwise is 100%.
I will post better pictures describing which wire goes where. As you can see on the O-scope in the backgruond the frequency is about 23.8kHz. I think this will do. It works in the range (2 - 5.5V).

I'll ship them off tomorrow!


/Tottish  
 

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Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Very nice work Tottish, that will make the laser go from tingle to POW!!! lol thanks I like the little nerald knob for turning it up:D
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Yeah, Ifiguered I'd make it small so you guys can put together a bigger knob if you feel the need to. Since all the components are SMD the backside of the single-sided PCB is electrically neutral and can be glued on to anything.


Here's the pinout by the way. Hope you don't mind some msPaint-art and some nasty spelling. :D
 

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Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Wow, this is quite an amazing field of electronics.
I have been interested in acquiring a CO[sub]2[/sub] laser for quite a long time, but couldn't figure out how to get such a fragile CO[sub]2[/sub] tube over to South Africa without paying a fortune.
What would I need for a complete, working kit? I would like to fiddle around, but I don't have any experience with RF and I know it is dangerous.
Is it safe to have an unshielded RF source such as this?
Nightstick and Disma, yours are looking great, keep up the good work.
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

The HF frequency of ~27.1 MHz isn't too bad to be around if you don't touch the antenna on the tube ;D Some have learned. The assemblies aren't as fragile as those water cooled tubes on ebay.

I put my MFJ antenna analyzer on my tube today. I can't find a dip in the SWR across the spectrum. The SWR meter stays pinned high (way over 3:1) . load resistance goes from about 0 to 100 ohms. At 27 MHz, its about 20 ohms driven by 50 ohm coax. Strange antenna on there.

Mike
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

the mfj antenna analyzer uses less than 10 mw doesn't it? :-? it would never be enough to ionize the gas, try a regular swr meter inline between the amp and the laser tube. What frequency is it at 50 ohms?
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

Disma ---

I Posted on Friday that my Bird Thruline watt meter said 230 WATTS forward power and 80 WATTS reflected.  To me, that's too much SWR but maybe typical of this system.  This is at the driver's set output of 27.1 MHz.    The MFJ test was done to see if there is a close range to tune for lower SWR.  That might lower input current and driver heating giving greater efficiency.

I'm looking to build a Starwars SS rifle but the final design hinges on batteries and their size.  Bluefusion said that 18650's will put out 15 amps -- maybe.   I'm still on the bench doing measurements.

Mike

Oh -- Disma -- you opened my eyes here. If the tube isn't ionized, the load picture is different... good point --- Oh well ..............
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

OOOPS! I remember you had said that a while back, sorry bout that, all I was thinking about is the mfj not having any power behind it... the second of my l.t. battery's is no good, the cells all had .001 volts in them! :( Now i'm considering trying it with just the 8 good ones...
 
Re: GB ROUND 2 OPEN for 10W RF EXCITED CO2 LASERS!

When the tube ionizes the effective capacitance of the load goes way up. Strange things happen with RF + plasma!!! As they say in the Wizard of Oz 'We're not in Kansas anymore"

Yes Co2 lasers tend to have a relatively high SWR compared to standard RF transmission gear. This is due to the plasma coupling and mirroring the RF.

Mike try tuning the load coil in the head with a chopstick or plastic hook tool while it's running and see if you can get a lower SWR.
 





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