How to turn a GB diode into an open can!

[chimo]

How to turn a Senkat GB LD into an open can version.

OK, I had this one in my flashlight mod. I tried using teflon tape to tighten up the thread slop in the module, but the tape became shredded and made its way down to the LD.  It caused some damage to the coating on the LD window and made the LD unusable.  

At first, I thought I had COD, but the damage looked to be only on the window.  So, I carefully removed the top of the can and discarded it.  I hooked up the LD again to power and it works fine.

Unfortunately, I did not take any photos of the beam prior to doing this little operation.

 

[Gazoo]

Chimo, thanks for the pics. If it would have been an open can in the first place you would have been SOL. It is nice to know teflon tape is not a good idea.

I wonder if with the top cut off, if the diode will run a little cooler and put out a little more light. Also the pics confirm that there are slightly differences in the guts of a closed can vs an open can diode:

Credit goes to VaThink for the above picture.

 

[paper183]

Let us know if the beam quality is nice and if it seems to output more power ! pretty nice macro pictures by the way !

 

[chimo]

Let us know if the beam quality is nice and if it seems to output more power ! pretty nice macro pictures by the way !

I have to repare the LD anode leg - it got severed in the fun. The beam appeared the same as a "normal" LD.

Thanks on the macro shots - that's as good as I could get hand-holding the camera.

Gazoo, in a closed environment, I don't think it would matter much for cooling.  

If you consider the path the heat must flow to get from the LD chip to the case, the flat, heat-sink mounted LDs are much better configured to remove heat faster.

Purple - LD chip to pedestal
Green - pedestal to base
Red - base to module housing
Blue - and you still have to get heat away from the module!

 

[laserrod]

Great photography man.

What special lens and cam did U use?

Man U fried the Teflon good! ;D

Windows are glued in those cans, I'm not impressed with that at all.
Better than unprotected hair thin lead wires?

 

[chimo]

Great photography man.

What special lens and cam did U use?

Thanks.

Canon A620, macro mode. Hand held with no additional lens.

 

[Gazoo]

Good point about heat dissipation chimo. It would be nice to know why the open can diodes hold up better than the closed can diodes....there is a big difference in the design somewhere. Maybe it is the LD chip and this is the sole reason.

But I have often wondered why they were made open instead of closed....was it to cut costs or is there something else going on with this we don't know about?

 

[chimo]

Good point about heat dissipation chimo. It would be nice to know why the open can diodes hold up better than the closed can diodes....there is a big difference in the design somewhere. Maybe it is the LD chip and this is the sole reason.

But I have often wondered why they were made open instead of closed....was it to cut costs or is there something else going on with this we don't know about?

Could be the larger pedestal. It can be larger (as it appears to be in your photo) and thus should provide a better thermal path to the base.

 

[Kenom]

How in gods name did you get the can off that? I also have damaged just the glass on one of my GB diodes and would love to salvage it but am afraid of doing damage to the wires running to the cathode or anode. ah, nevermind. by the time you reply I will have torn it apart and destroyed it I'm sure. hehe.

 

[chimo]

I used a diamond wheel on a dremel tool an dwas very careful. I didn't cut all the way through all around - just part way and peeled the rest off. And I guess I was lucky as well.

How in gods name did you get the can off that?  I also have damaged just the glass on one of my GB diodes and would love to salvage it but am afraid of doing damage to the wires running to the cathode or anode.   ah, nevermind.  by the time you reply I will have torn it apart and destroyed it I'm sure.  hehe.

 

[Daedal]

[quote author=Laserrod link=1189268933/0#4 date=1189283734]Great photography man.

What special lens and cam did U use?

Thanks.

Canon A620, macro mode. Hand held with no additional lens.
[/quote]

Cannon all the way... WOOO ;D

--DDL

 

[Daedal]

And I guess I was lucky as well.

That, my friend, is not luck alone... you have a very steady hand and a lot of patience. Both of which are amazing things to have.

Great work on that diode Chimo. Hats off to you...

--DDL

 

[Daedal]

We really need some more smilies in here... Something with a hat off... or something! :

--DDL

 

[chimo]

Thanks DDL.

Here are some more Macro shots of the anode wire repair.

The anode wire broke off flush with the base.  

The base was masked with kapton tape. A dot of flux was added to the anode contact and I pre-tinned it.  The replacement wire was pre-tinned as well.

Replacement wire soldered.


Kapton removed.


The solder joint is very small and will not be strong so it must be re-inforced.  I used JB Weld.



Here are some shots of a dead SLD1236VL.  
Dead SLD1236VL. Note that there is no photo-diode - don't worry about shorting it out to the case.  The cathode wire was not broken removing the can - it was melted.

Extreme macro.  I used a loupe in front of the camera lens for the next two. Image is larger but PQ is poorer.

 

[Gazoo]

I admit I have never owned a digital camera. But I have been looking around for one. When I first saw some of your pictures I thought man that is one awesome camera...must cost some big bucks. So I looked it up and found it is affordable, and I am really impressed by the close ups.

Regarding the wire that acted as a fuse.... ;D I assume the diode is completely dead and not even an LED. How much current did you run into it to cause it to melt?

 

[chimo]

Regarding the wire that acted as a fuse.... ;D I assume the diode is completely dead and not even an LED. How much current did you run into it to cause it to melt?

Probably between 1-2 amps.