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ArcticMyst Security by Avery

How to cook a Sony (SenKat GB) diode - with pics

Joined
Nov 24, 2007
Messages
321
Points
16
It is with deep sadness that I wish to report the passing of my first Sony diode. :'(

It was in an instant - and then it was gone. Here's what happened so that you, dear reader, shall not need to suffer the slings and arrows of suffering and remorse as have I this foggy eve.

I had mounted the diode in a three pin transistor socket, and had previously noted that the leads weren't quite long enough to fully engage the socket, but it was pretty secure, so I let it be.

As I was focusing the beam this evening in the fog (pretty!!!!!), the diode slipped for only a fraction of a second out of the socket - probably only one pin. The pressure of my focusing it live caused it to slip out - and then immediately back in. It died instantly.

What happened? It seems that the driver circuit - probably true with them all - goes to full Vcc (in my case, 6vdc) when there is no load. The capacitor, attached as a spike preventor, then charges to full Vcc. The diode, on reinsertion, then gets a full 6v discharge from the cap - plus the driver circuit. I would guess that in the ~ 30ms that the diode disconnected for, the cap charged to 6v, and subsequently dumped 6v at well over an amp to the diode for a ms or so, effectively turning my beautiful sony laser diode into a dim at best regular LED.

The moral of the story is this: Even when prototyping, SOLDER your diode into the circuit to prevent disconnection/reconnection. I socket things because I like to keep leads pristine until installation in a finished product. Not worth it. SOlder, leave the leads at maximum length.

NEVER reconnect a diode into the driver circuit until you have shorted the cap and outputs of the driver circuit.

Buy spares! I did... and now I will go REMOVE that damn socket and SOLDER in a new diode!

I just hope the next one burns as well as the one I just cooked. That thing ROCKED! I was burning holes in everything!

:exclamation Learn from my mistakes!!!! :)

Dave
 





Joined
Nov 9, 2007
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Re: How to cook a Sony (SenKat GB) diode

Yep that was it ive learned to solder everything before i even start to play with it, the cap did charge and and effectifly sent 6v to it and untold amps which fried it. Dont throw away that diode tho if it still lights up with a dim led like glow. You can use it to test other circuits because it draws the same ma as one that is alive because it still is an ld but one of the mirrors that reflect the light back causing it to be polarized broke from the power (cod..Catostrophical Optical Damadge)


Although it might have broken it completely from the whole cap dischargin into it.

...lazer... ;D ;D ;D
 
Joined
Nov 24, 2007
Messages
321
Points
16
Re: How to cook a Sony (SenKat GB) diode

Yeah - still glows a little - but gets damn hot out of the Aixiz housing!

Good idea to use as a test load - thanks!

D
 
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Aug 15, 2007
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Re: How to cook a Sony (SenKat GB) diode

Sometimes the entire semiconductor chip simply goes poof. If it gives any optical output at all, I'd say COD, though.
 
Joined
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Re: How to cook a Sony (SenKat GB) diode

Yeah i know now i realize why they say dont use them out of the housings, man that got hot. I even was able to pop a baloon with one of my dead diodes, i turned it on and touched it to a baloon and it pops it ;D So they have a few uses after their dead.

..lazer... ;D ;D ;D
 
Joined
Nov 24, 2007
Messages
321
Points
16
Re: How to cook a Sony (SenKat GB) diode

Here's a pic of the "revision 2" laser protoboard... note the nomenclature on the photo.

Hopefully this one will remain living to the point of me installing it in the housing unit I am making for it (along with all the related goodies it will be going in with - a multipurpose device for sure!)
 

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Joined
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Re: How to cook a Sony (SenKat GB) diode - with pi

I would definantly not recomend 4aa's, the regulator starts dropping out below 6v and you lose alot of your power, i used to use 4aa's in mine and i would have to change them so often because they would go below 6v and wouldnt get much power, i would suggest a 6v or 7.2v ni-mh racing pack (the kind in remote control cars) dont go any higher than that tho because you would need a heatsink for any higher voltage.

(Im gona stop posting now so i dont fill up the whole first page :p)

..lazer...
 
Joined
Nov 24, 2007
Messages
321
Points
16
Re: How to cook a Sony (SenKat GB) diode - with pi

4 AAAs are for the proto unit only - and so far they have held up very respectably. One diode down - still going on the original AAAs - and I have inscribed a LOT of things with those AAA cells!

The finished unit will have a large Li-Ion rechargable 7.2v battery that will power a bunch of simultaneous loads. I'm not too worried about size anymore as the laser portion of this thing will be the smallest of the guts, but it will still be a compact unit. Think Star Trek; The Next Generation! :)

Dave
 

Gazoo

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Joined
Jun 9, 2007
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Re: How to cook a Sony (SenKat GB) diode - with pi

xanatos,
I am sorry to read about the passing of your diode.. :'( But thanks for sharing your experience. I killed a few diodes using a plug...never again...I will always solder everything.

It is very possible the regulator might be dropping out with the batteries you are using. Just remember before you hook up your li-ion battery, to turn the pot to the most resistance... and then re-adjust.
 




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