SELEM 2009 - FS / Trade Table Goodies List

[mophead]

I'll be bringing:

JDSU 2214-40MLA head
JDSU 2214B-40MLA power supply and blower

Lexel 95 and powersupply


lots of pulled pork BBQ

[daedal]

OK -

I'm REALLY not planning on going broke during / after this meet like I have others in the past, but the offers of argon lasers, diffraction gratings, etc. are making it difficult....

Just a thought on building materials -

Anyone driving that might need to offload some reasonable sized / priced 1/4" aluminum plate might find a market for it at SELEM.

What kind of size are we looking at? I have a nice plate I'm willing to part with... its even anodized... It's got a few tapped holes in it, but nothing that would ruin a new setup...

--DDL

[Stuka]

What kind of size are we looking at? I have a nice plate I'm willing to part with... its even anodized... It's got a few tapped holes in it, but nothing that would ruin a new setup...

--DDL

Right now, I personally would be more interested in smaller "raw" pieces that could be cut down as needed for individual laser & scanner mounts.

However, if it fits in the trunk of your car, since you're heading that way already...

[Stuka]

Crap, crap, son of a ....

Thanks to my impeccable timing, I have managed to turn my nice dual set of Maxyz 660's into little more than a bulky low-power pointer that probably wouldn't even get my cats excited...

So, do any of my fellow SELEM attendees have any interest in bringing these back to life? I know we wouldn't have time do rebuild them there, but if anyone would be interested in taking this on as a side project, I could tote them along.

FYI - quick story of the demise:

While testing out my interlock circuit, I decided to do a real-time laser-in-the-loop test with my Maxyz. Works great, except for one small detail -
if you stick to the interlock / emergency stop design which only kills power to laser power supplies, you potentially leave an active modulation signal going to unpowered laser modules.
Maxyz apparently don't like that!!

Looks like I'll be digging out my back-up set of MechEng duals, and try to get them installed in place of the Maxyz - which should kill the time I hoped to spend on the Jolly Green project...

Damn, this sucks!!

[allthatwhichis]

I have one MechEng still going and a plastic insulator board that has holes drilled in it for two modules if you need it.

[DZ]

Hey Stuka, sorry to hear about the dead maxyz. I happen to have 2 open can diode sleds sitting on my shelf here. I can replace them in both your maxyz in about an hour. Drop in replacements will net only about 170mW each, I have figured out how to change the maxy driver current, so I may be able to bump them up to 220mW each. If you can ship them to me, I'll have them fixed before SELEM, otherwise, I can fix them up friday, maybe right before the dinner thing.

[Stuka]

Thanks for the assist, guys!!

PM sent, DZ!!

[buffo]

if you stick to the interlock / emergency stop design which only kills power to laser power supplies, you potentially leave an active modulation signal going to unpowered laser modules.
Maxyz apparently don't like that!!

Er - I dissagree Randy. My Maxyz modules are wired the same way. When the Interlock is broken, the +9 volts to the Maxyz modules goes away, but the modulation signal is still present.

I've never had a problem with this, and it's been wired this way since May of 2008.

I think the difference may be that I don't actually kill the DC power supply each time the interlock trips. Rather, my interlock just opens a relay that connects DC power to the lasers. The DC power supply is powered up all the time. That way there is no way for a power-on spike from the power supply turning on to get to the lasers. (Remember too that my projector requires the operator to push the RUN button to engage the relay both on intial power up *AND* after any interlock trip... So it's impossible for a power-on spike to make it past the main relay.)

I think what happened is that you tripped the interlock while a show was playing. Then when you reset the interlock, the driver already had +5 volts on the modulation input, which means that the driver was ready to conduct as soon as DC power was restored. So if there was a power spike for a split second on power-up (say 150% over-voltage or so), it could have caused the driver to output enough current to blow the diodes.

The good news is that DZ has the repairing of Maxyz modules down to a science. So no worries - he can get you running in no time.

Adam

[Stuka]

Er - I dissagree Randy. My Maxyz modules are wired the same way. When the Interlock is broken, the +9 volts to the Maxyz modules goes away, but the modulation signal is still present.

I've never had a problem with this, and it's been wired this way since May of 2008.

I think the difference may be that I don't actually kill the DC power supply each time the interlock trips. Rather, my interlock just opens a relay that connects DC power to the lasers. The DC power supply is powered up all the time. That way there is no way for a power-on spike from the power supply turning on to get to the lasers. (Remember too that my projector requires the operator to push the RUN button to engage the relay both on intial power up *AND* after any interlock trip... So it's impossible for a power-on spike to make it past the main relay.)

I think what happened is that you tripped the interlock while a show was playing. Then when you reset the interlock, the driver already had +5 volts on the modulation input, which means that the driver was ready to conduct as soon as DC power was restored. So if there was a power spike for a split second on power-up (say 150% over-voltage or so), it could have caused the driver to output enough current to blow the diodes.

The good news is that DZ has the repairing of Maxyz modules down to a science. So no worries - he can get you running in no time.

Adam

Yep, I'm wired the same way - I'm just cutting the supply to the lasers themselves, but not to the actual power supplies. The power supplies all stay "hot" after the key switch is turned on.

After mentally going through several "WTF " scenarios, and eliminating reverse polarity, short circuits, etc. as the cause, your comment about a possible spike on power-up seems most likely: I was using my bench modulation source (regulated 5V supply with variable modulation output) as my modulation source during the test. And yep, it was pumping out the full 5V modulation voltage when the power to the Maxyz was enabled.
Time for a BIG yellow warning label inside the projector case!!
Crap...

Anyhow -

Sorry for hijacking this thread, but I thought this "event" might be of interest to others out there, so let my demise be a lesson to you!!

And DZ - thanks for the bailout offer - I'll definitely be picking up part of your SELEM bar tab!!

[300EVIL]

I changed out my Maxyz with a long die open can diode. I'm very happy with the results, and I'm sure you will be too, Randy.

If anyone is interested in purchasing/trading a 4W RF pumped CO2 laser, I'll bring it.



Gonna need a 35V@6A, 12V@3A and 5V@1A power supply to power it though....