PLUG & PLAY CO2 BURNING LASERS only $150 DELIVERED

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

The scientech power meter sensor is very easy to build since all it is is a 127 couple peltier cooler ran backwards, one side on a heat sink, the other with a thin black painted aluminum or copper plate bonded to it.

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

nightstick:
No probs man, I would build one for myself anyways. About running at a 18650: It shouldn't be a problem, The processor works down to 2V so the question is how much voltage you would need over the optocoupler (and resistor) for it to actually register. I will tst it out when I get my PS but basically the module should work fine with any wallwort that works without the module. :-? In other words: The module works "rail-to-rail", it has no voltagedrop.
Oh, and a standard 18650-cell should last about 80 hours.

Mike:
OK, be sure to post if/when you've done the scope-reading.

heruusciences:
Oh thats a neat design! What kind of precission would you expect out of such a meter?

/Tottish

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

3V delivered to the opto is fine.

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

thanks Mike Tottish and Chris, Im learning 80 hours would be Great 10 would be great on one charge probably get rid of the wallwort. I was going to trim my plexiglass box with 1/2 x1/2 angle aluminum I was wondering if it would affect the tunning? the strips of aluminum will be about 2 1/2 inches from the antenna :-/

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

Chris I have a 127 peltier should dielecctric grease be used or just glue for the aluminum and then I guess the pos and neg just connects to the back of the meter?

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

WOW -- What an ulgy cloud of noise we have !!!  My PWM goes nutz... I need more shielding and bypass caps !!!

Also, Mine draws 9.97 amps while the GEL cells are good -- Watch out -- as they poop out I started reading over 14 Amps.  I shut down immediately.  That's where excess heating comes from.  I'm using a DC AMP clamp on the input leads.  Looks like I have a sick Gel Cell.

Mike

Chris -- I hear a relay in the power supply -- what's that do ?

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

My O'scope test on my PWM showed a little HF noise on the base line -- Ground.  Long clip leads on the bench are going to be a problem because of inductive impedance - it's an antenna.
As I turned up the PWM, I quickly got about 1 V P/P noise on the output which gets worse quickly as the power output reading simply jumped from almost nothing to max.

This PWM thing isn't going to be as easy as I hoped  

Mike

Perhaps some ferrite "prayer blocks" are needed here.

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

you can do it man

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

"Perhaps some ferrite "prayer blocks" are needed here."
;D ;D ;D

I'm having the same kind of thing happen here, a friend said I should try using a cmos 4001 nor gate chip instead of the 555. I haven't tried it yet though... gotta find a schematic for that one.

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

The RF cloud around the circuit is so bad I can't even read battery voltage with my DMM Some of you guys have entered a different world of electronics with this RF excited laser. This could be a bigger challenge than the old DDL driver ;D

The step from basic DC to AC and RF is a major jump. All the rules change --- forever......... CMOS may use higher voltages but it is still suseptable to RF coupling and interference. Remember that the antenna has high voltage nodes on it. 3 volts, 5 volts or 15 -- it won't matter much.

Mike

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

Yeah Mike, thats just what I've been told, RF is a bitch . I'm however new to the phenomenon but at least I have a good O-scope so that I can test if my "improvements" help.
So what do you think about getting the PWM-cable shielded?
Is it the emitter on the laser-module that produce all the statics or can some RF/HF-static be expected to come from the driver?
As I said earlier my PWM-signal didn't look very good (lots of static) on the o-scope with the laser turned on but from what I could tell, burning some paper, it worked perfectly. Maybe I picked up some of the static in the probe/probe-cable and the signal wasn't so nasty after all... ?  :-?
Maybe I should wait for my real PS and perform some thourogh benchtests before shipping off the PWM-modules...


/Tottish


EDIT:
So, both Mikes and my own O-scope readings indicate that this is one noisy SOB. Guess thats to be expected from a 10W+ RFtransmitter huh : ? Do you guys really think it would be such a bad idea to (Faraday-)cage this beast? Could it hurt the laser if the tuning goes out the window or is the momentary performance the only victim? If thats the case I think it would be great if one of you guys with the lasers up'n'running tried to put on a proper shielding and we'll se what happens. As I said earlier, it feels like the natural thing to do to attack the problem at its source...
EDIT2: Nevermind... Chris wrote the post under this one while I was Editing...

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

About 3-5 turns on a ferrite bead plus a .01uf bypass cap on both sides of the input to the pwm will stop the RF from turning the opto on, but allow the pwm to work ok

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

Prayer blocks to the rescue  ;D   Shield wires probably will help but selecting a ground for the shield may take a few trys.

Mike

I'm charging GelCells tonight

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

Im working on mounting my power supply to the plexiglass laser case, I didn't notice any power difference with aluminum corner trim on the box this laser is a real burner at 30 volts smooth

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

Hey, nightstick, could you possibly measure the current@30V? Since it seems to be around 10A@28V and 14+A@<26V it would be quite interesting to see the rating at 30V. Also it would help me not to worry to much about my ~32V 9.7A PS that I've ordered not being enough.

PWM-status:
I have made the first prototype on PCB and almost completely ported the code from the µC it was developed on to the one we're actually going to use in our modules. Back to work on these babies, then! I'll probably report the progress later on today. (10:40AM here)

/Tottish

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

At 10 amps:   27.1 Mhz @ 220 Watts of drive.   My reflected power is 80 watts however.  

Mike

Readings taken with an HP Freq counter and Bird Wattmeter.