Co2 laser powered by zvs driver?

Hi all,
Im new here, ive been lurking around for quite a while (about a year or so i think) but never really felt the need to make a thread up until now.

I've handled a few fairly high power DPSS greens, made countless numbers of dvd writer sourced 200-300mw red lasers and recently made my first 1.5w or so 445nm blue. I always excersise appropriate caution when working with these lasers and always wear goggles when necessary. Im now interested in a co2 laser after seeing many fairly cheap 40w tubes on ebay.

My question is:
Could a co2 laser like that mentioned above be powered by somthing like a zvs flyback driver easily? The power requirements of the tubes I have seen seem to match that of a zvs driver, does anyone have any experiance with this method of powering a co2 laser? Several forum searches seem to return nothing in this area.

On a side note; The jump from a 1.5w blue to a 40w far infra-red laser seems massive, the idea of this invisable beam of light shooting accross my room that will happily make a hole in pretty much anything i put in its path both scares and interests me. Im currently 16 and have been interested in lasers since i was about 10. Think i can handle a co2 laser based on my previous experience?

Oh and also, im not sure if this should be in the gas lasers or the drivers section?

Thanks in advance,
Matt.

Yes, it can be done. Many (most?) stock PSUs have flybacks as their main driving elements. I'm not sure about the specifics, but be sure to observe the current limitations of the tube.

Also, they don't really make holes in things, they just set them on fire. You NEED a beam dump such as a brick for them.

Don't know if this helps any:
Diane's Laser Page

@Cyparagon
I always thought they used flybacks from the look of the transformers in them, i was wondering if they use some sort of special driving method? E.g. Does the tube need some kind of special waveform or is high frequency pulsed DC good enough?
Yeah the making holes in things is a bit optimistic without a focusing lense of some form. About the beam-stop, i was thinking a house brick?

@Anselm
Great link, thanks The laser featured seems to be almost exactly the same as the ones ive been looking into.

Yeah, most any brick will be fine. They prefer smooth DC, but they'll work with just about any wave shape including AC. Just at reduced life span.
Smooth it if you can, it should be easier at high frequency anyway.

Ok great, thanks. I'll go mess around with zvs drivers for a bit then order a tube if i think i can power it...
For measuring current would sticking a 1ohm resistor in series with the ground line then messuring the voltage accross it do? eg 1mv = 1ma?

Just to be safe, polycarbonate eye protection goggles/glasses will help stop the laser from blinding me right?

Flyback refers to the topology of circuit, not the physical appearance of the transformer. A flyback transformer is driven single ended, the switching device closes and "charges" up the core with magnetic flux. When the switch opens the field collapses and induces a high voltage spike in the windings. This is good for lower power applications and you get significantly higher voltage out than the turns ratio would imply. I would expect CO2 supplies to be driven push-pull. The ZVS driver is a form of Royer oscillator. I've built a couple of them and have been impressed by the performance. I see no reason why the circuit wouldn't work well for a CO2 laser, but you will probably have to wind your own transformer to get sufficient current. The core salvaged from a flyback ought to work pretty well.

James, I do understand that the true meaning of flyback means the driving method of a transformer rather than the actaul style of transformer. I usually refer to high voltage, high frequency, ferrite-core based step-up transformers as 'flyback' transformers out oh habbit as that is the method usually used to drive them. That and others usually understand what im talking about. Thanks for clearing that up though.
Oh and winding my own transformer seems like it could take quite a while based on the number of windings needed... I was kind of hoping i would come across a flyback tranformer from a CRT tv/monitor that does roughly the right voltage and can handle the current.

I orderd the tube a few days ago as they seemed to be going up in price again, i hope it arrives one piece...
I can post my luck with driving it here if anyone is interested.

@pieznice29 yes i'd be interested in your experiments with the CO2. its something i have been thinking about myself (getting a cheap chinese CO2 tube and PSU). let us know how it goes!

@plexus Ok sure i'll post pics and things when it comes...
I wanted to buy a laser with power supply like you but just couldnt afford the power supply, so i thought i'd have a go at making my own.

Pieznice29 said:

James, I do understand that the true meaning of flyback means the driving method of a transformer rather than the actaul style of transformer. I usually refer to high voltage, high frequency, ferrite-core based step-up transformers as 'flyback' transformers out oh habbit as that is the method usually used to drive them. That and others usually understand what im talking about. Thanks for clearing that up though.
Oh and winding my own transformer seems like it could take quite a while based on the number of windings needed... I was kind of hoping i would come across a flyback tranformer from a CRT tv/monitor that does roughly the right voltage and can handle the current.

I orderd the tube a few days ago as they seemed to be going up in price again, i hope it arrives one piece...
I can post my luck with driving it here if anyone is interested.

Click to expand...

Winding high frequency HV transformers is easier than it sounds. You can have a lot more volts per turn / fewer turns per volt than with mains frequency iron transformers. See here: _-= Uzzors2k =-_ Project Site

Thanks for the link Huh, it does seem a lot easier than i imagined. If i havent got a transformer that does what i need i'll probably have a go at winding one myself then.

Update:
Driver progress:
Parts for my ZVS driver arrived today, it seems to be doing about 50% more power than i got from 555 timer + single mosfet designs ive played around with before. I still need to experiment with capacitor and inductor values though, especially capacitor, the one im using right now gets really hot really fast...

Video of it running at 12v (Video was made in a bit of a rush as im sure you can tell)

Playing with the arcs (12v un-ballasted)

Laser progress:
40W CO2 Laser tube was orderd several days ago, i expect it to arive on monday or tuesday

Laser has arived
All in one piece too
I'll try powering it up when I get a chance...

First light (< click it)

nice! congrats!