Green 150mW Repair (Work in Progress)

[hobbybob]

Hi All,

Just a short update about the green 150mW Green Lasever repair.
Today i received 3 packages:
1.
DDL's package (containing the nice blank Diode housings, gratings (don't know what they do, but they looked funny and nice, so i ordered), glasslenses and 2 very tiny small red laserdiodes (wow, they are small)....
And the LASORBS (3 x red, 1 for Blue/ray)

2.
Snoctony's 2W 808nm diode
This diode was looking almost the same as the Lasever one, only color was more copperlike while the other was gold. But the diode seemed to have the output on the exact same spot. This is what i'll be using to repair my green Lasever.
It was packed in a antistatic bag and put in bubble wrap.

3.
Chris Leubners 2W 808 diode
This diode didn't resemble my diode and i could not see where the light would exit. I will try to use this with a laser cavity (housing and crystals) i bought on ebay.
The laser was packed nice in a antistatic bag , which was wrapped in bubble wrap and was placed in a nice box. All if fair, packing was very good. Didn't have time to built it in, since the laser looked like it will exit the diode on a different spot, but is very hard to see. So maybe it WILL enter the same spot. Will use this diode with the other green cavity. To build yet another green and will buy a driver of Robin to power it.

Anyways.... All where nicely packed, DDL's package was the fastest, i just ordered this on wednesday and it the others i ordered a few days before. Chris' diode nicely had a small note packed with it with Voltage amperes and such.

Ok, but on to the repair...since that's all what you're here for...pictures !
First i took a antistatic mat, wristband, and took out the old broken diode:


You can see nicely in the middle of the "cup" a small indentation indicating the middle. This was really handy aligning the new diode, you can watch from the top and i positioned it and only touching it by a pair of tweezers.
Then when i thought it was smack dead in the center i fastened it.


Here you see the old, broken diode (Gold, left) and Snoctony's new diode. I cut the strip a bit to fit in the cup else it was touching the borders.
Since the positive was the cup i need to make sure it wasn't touching the housing.


So i carefully soldered (still wearing ESD wristband) and a clamp on the diode cup, the black wire to the metal strip which was very flexible. Before i put the diode in, i cut the strip to the exact (almost) same length as the old diode and i bended it to look exactly the same as the old gold diode. Then i soldered it quick to not kill the diode by heat.

Then i put the optics on, but didn't know if the optics path was right, so just pointed the whole upwards and place the optic cavity containing crystal and lens on top.

Connected driver to laser, then powersupply to driver and finally the mains to the powersupply.
I prayed to the lasergods, for holy photons and low and behold:


Thank you gods of light... it turned on and immediately gave nice bright green light ! YES ! Immediately i turned it off since it was not in the heatsink (the TEC was working but there was not hotplate/housing etc.

Looking up the ceiling i saw this:

The dot was not focussed yet, but was round and bright. The head containing a small lens was not yet on and the front lens which is adjustable (as i know, read one of my first posts about it turning loose on a rock concert making the laser go waaaaay out of focus)...

Suddenly it went offf......NOOOOOO !!! I looked at Lasever powersupply LSR-PS-1 the red led was on... It was the auto shut off....
Ok after cooling down, i tried it on very shortly and it still worked (pfew).
Then i glued the optics with very, very little glue to the cup.
Then turned on again shortly to see if i didn't f... it up with the glue (i searched and searched and then found some universal superglue....)
I really wanted to glue this so it can dry...
Turned it on after gluing... wow. only a nice dot, not the interference we saw on the picture above !!! NICE going....

Tomorrow i will continue , for now i will let it dry. Now i need to see how to fit the lasorb (this housing doesn't really is fit for mounting a lasorb).

I have seen a similar lasever laser (i think it was Jem's ?) mounted on a aluminium block. The lens was still on , but this was excellent cooling.

Anyway , will be continued....

[MechEng3]

Good job. Hope it all works out and stays green for you. The next one may not go so easy. I have worked for hours to get everything right and properly tuned. The time spent on some repairs is just not worth it. Easier to get a new 532 or just build a red unit.

[mikkojay]

Cool! Nice pics & details- thanks for sharing the experience

[ElektroFreak]

Good job. Hope it all works out and stays green for you. The next one may not go so easy. I have worked for hours to get everything right and properly tuned.

Me too, and I suspect that hobbybob could probably tweak the output of that system to get even more power, but I would doubt that it's really worth it if it's doing that well as it is. Fortunately for him it's a very straightforward design..

Nice work hobbybob! Very impressed..

[hobbybob]

Thanks for all your kind replies, i just got home from work, tonight i will try to finalize it.
And i have to work on the case for my other (Big) green laser, which i want to bring to UKLEM, since the case is now in parts.... it's not really finished but at least it's housed then.... Bye

Dimitri

[hobbybob]

Well it's very late, but i managed to put it all back together.
I wrapped PTFE tape around the TEC+diodecasing+optics, shoved the cylinder with lens on it, put arctic silver on the back of the tec coolplate and screwed it in the lasever housing. After turning it on a round dot appeared. I could play for around 45 seconds and then it shut off.
Then after a few seconds the red led goes off, and a few seconds after that the green light comes on and the laser also, then 10 seconds on and red light again.
The red light on the PSR-1 is the overheating, the housing gets warmer.
Turning the pot for the cooler doesn't help much. I think i need to add more peltiers ?

I did remember seeing a build / projector from someone here on PL, containing a silver Lasever housing, but it was mounted on a big block of ally, not in the original housing. Seemed like a much better construction, only cannot find the picture anymore.

I wanted to know the diode current as well, after inspecting the pcb i found a resistor (SMD) with a value of 1003. so i thought: hey thats probably 1 Ohm, so 1 volt across is 1 AMP. And indeed measuring when the laser was on read 2.13V, so 2.13Amps through diode. Cool it's rated for 2.2A so the previous diode was also 2Amp.

Now only to find out how to adjust it so it won't have a duty cycle of 50 percent (10 seconds on, 10 seconds of...) hahaha

If anyone knows i'd love to know !

[ElektroFreak]

You could try adjusting the TEC pot on your driver. You should be able to make it cooler, which should help stabilise the system. You could also reduce the current to the diode to help control the heat. As I have not worked on that particular laser myself, all I can do is offer possibilities..

[hobbybob]

Hi ElectroFreak,

Thanks for the suggestions, i have tried pot RW2, anticlockwise should cool the laser says the manual. But that doesn't work. RW3 is to change the current of pump diode, couldn't see a difference when i turned it measuring voltage across the 1Ohm resistor in the end, it kept saying 2.13V when i measured across it, turning RW3 didn't change this. As it's really late now, i will try tomorrow, or bring the thing to UKLEM, maybe i can try using a tec to cool it more.....

Hopefully someone knows about who was the owner of the Modified lasever on a ally coolblock....

[ElektroFreak]

I kind of suspect that the resistor you are reading current from might not be suitable for that, but I don't know for sure. Also, changes to the TEC temperature will take time to register, as long as 5 minutes in my experience.

[p1t8ull]

Check the peltier itself, is it open circuit? it's possibly been over driven and popped along with the diode when you powered the laser with a 473nm driver