Opinions/options re: power loss on Lasever blue DPSS

[buffo]

Do you know if it's drawing less than it did at that output when the mod input set it there when it was working right?

Hi Doc;

I'm not sure... It does support analog blanking, but neither Fred nor I had a chance (or bothered) to check the current draw at anything other than full power (with +5 volts on the blanking lead) before this current problem (no pun intended ) manifested itself.

If I apply less voltage to the blanking lead now, the laser power goes down just like it should. I haven't bothered to plot a complete power-to-voltage curve or anything (and I suspect that even if I did the results would not be 100 % linear), but I can say that the analog blanking circuit is working more or less as it's supposed to.

When I run the laser with the Pangolin QM-32 board, I get beautiful hues of blue, teal, purple, pink, etc... They're just a bit dimmer than they ought to be.

I honestly don't know what the proper current draw should be for this laser when it's operating at 40 mw of output power. I only know that when it was making 110 mw +, it was drawing nearly 5 amps, and now it draws 3.6 to 3.7 amps and makes 40 mw max.

Adam

[marconi]

Hi Adam..

That diode should draw at least draw over an amp..being a 1watt diode
And theres no easy way to measure it without taking the connector apart or adding a test cable.
You need an IR temp meter with the unit open to really figure whats happening...really.
Hard to blame it on the diode just as yet, no mode-ing.
But it can still be weak.

I have a LBO crystal from a CNI blue that showed no hints of it going bad, No mode hopping
but had a hairline crack in the center when viewed under the microscope.

Something else I would do..and others should do as well on these.
Since there is NO overvolt protection or regulation for the rail on these Lasever power supplies (4 pot unit).
I would wire in a BIG 5.6volt zener across the supply leads.
The one I got from MechEng for his green apparently got spiked and took out his diode along with 2 tantalum (tantrum) caps in the supply.

He was using a regulated 5v supply to so dont know how it happend.
Go figure!!!
Yeah, These things can drink you to drink if you think about them long enough..heh.

[marconi]

Hehe, PL froze
It made a double post
First time for me...

[Astroguy]

I have Pm`ed and e-mailed David at lasever and am waiting for a reply. We will get this taken care of ASAP.

[buffo]

Fred, you've been more than helpful through this! I don't expect instant service; I know we'll get it sorted eventually. And in the mean time, I've still got a working RGB rig - even if the power is low.

Marconi: That's a good idea re: the 5.6 volt zeiner across the input leads to protect against a spike. Got a good source to recommend? (I'm thinking Allied Electronics, or.?.) I'll put one across the inputs to the green driver too, just to be safe.

As far as any futher troubleshooting, you're getting into things that are beyond my comfort zone. While I'm sure I could work through the tests with your help, I'm not really ready to crack the head on this thing - especially since it's still under warranty. But it's nice to know that you've got the knowledge if I ever do have a problem with one of my older units and have no choice but to get into the guts. (Translation: your number is going into my rolodex under "Emergency Laser Advice Contacts" ... Sorry about that!)

Seriously though - I appreciate your input! Thanks.

Adam

[marconi]

hehe,,... No problem

I like challenges ..

Yeap..put one on each power input as well as the analog inputs right at the driver. Cant hurt any..
5.6v 1/2watt zener should work (digi-key or ebay)..the worst that can happen is crowbar the supply into shut-down if your using a switcher supply if it gets accidently hit by a dragging wire (yes, ive done it) it wont take out the lasers.
And if your not using a switcher than its just maybe a blown fuse or kills the supply, better than the laser dying.

One customer swore his laser just quit and started smoking., didnt know why
either...turns out he accidently had one leg of the AC mains connected.
oops

Ah well.. After receiving the laser back the reverse polarity diode and regulator was smoked (evaporated) but the rest of the circuit was fine. all because I added a zener at the output of the regulator...justa thing I do just in case...saves face..

[p1t8ull]

I honestly don't know what the proper current draw should be for this laser when it's operating at 40 mw of output power. I only know that when it was making 110 mw +, it was drawing nearly 5 amps, and now it draws 3.6 to 3.7 amps and makes 40 mw max.

Adam, my "U" series lasever blue draws 2.72 amps LD current @ it's max output of 120mw.

hth,

Pit.

[Astroguy]

As of today I have not heard back from David at lasever.

[dave]

You probably wont hear anything till Monday, being that China has a public holiday finishing on Monday..

[Astroguy]

As of today I have not heard back from David at lasever.

I have now heard from David and he and Adam are in touch to work this out.
I do feel responsible since I sold it to Adam so what ever happens I will stand behind anything I sell.