Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

445nm Diode Reverse Connection

Garoq

Garoq

0
Joined
Aug 27, 2010
Messages
1,525
Points
83
I've recently accidentally soldered two 445nm diodes to 1.25A drivers in reverse, and applied power a few times for several seconds before realizing what happened. I then hooked them up correctly and they worked just fine.

I found that someone on PL had the same experience:

445 Damage

Anyone else had the same or a different result? I did a quick search on LPF and didn't find anything.
 





GBD

GBD

0
Joined
Oct 25, 2010
Messages
783
Points
0
Yep.. seems the 445nms have some form of reverse bias protection... do that with any other common diode and you see death. Among other things too, makes this diode pretty noob friendly and hard to screw up.
 
Last edited:
Cyparagon

Cyparagon

0
Joined
Sep 12, 2007
Messages
9,399
Points
113
As long as the voltage isn't too high in reverse, they'll take it all day long. It is a diode, after all.
 
DrSid

DrSid

0
Joined
Jul 17, 2010
Messages
1,506
Points
48
I've did it with direct drive, and had no problems. But drivers can increase the voltage to get onto preset current .. that is usually the problem. Still yeah, those diodes are pretty tough.
 
benmwv

benmwv

0
Joined
Sep 10, 2010
Messages
1,380
Points
48
I have done this with a few different diodes... I have never had a diode damaged because of reverse connection. I never really believed the notion that connecting it wrong would damage a diode, as cyparagon said, they are diodes. Not to say that I connect expensive diodes so carelessly, just that I have connected a couple reds backwards before and no harm done.
 
Garoq

Garoq

0
Joined
Aug 27, 2010
Messages
1,525
Points
83
OK, so I'll ask the question differently: Has anyone ever killed a diode as a result of a reverse connection? First hand experience.
 
Fenzir

Fenzir

0
Joined
Jan 25, 2011
Messages
699
Points
0
Garoq said:
OK, so I'll ask the question differently: Has anyone ever killed a diode as a result of a reverse connection? First hand experience.
Click to expand...

PHR 803t dead. They are more sensitive.
 
Wolfman29

Wolfman29

0
Joined
Jan 14, 2011
Messages
3,816
Points
63
Must have been some hella high voltage then. I should think that these should be able to take their lasing voltage in reverse, considering they are diodes. Maybe someone should set up a murder fund to find out some of these diodes' breakdown voltage?
 
Kevlar

Kevlar

0
Joined
Apr 26, 2010
Messages
1,353
Points
48
Fenzir said:
PHR 803t dead. They are more sensitive.
Click to expand...

Are you positive it was because of reverse connection? It could have been ESD, they are, as you said, "more sensitive". :na:

Seriously though, it could have been something else, just saying.
 
Bluefan

Bluefan

0
Joined
Aug 15, 2009
Messages
1,443
Points
48
I've degraded a A130 diode to half output with ~7V reverse bias for a few seconds. I've killed a cheap red pointer instantly.
 
Garoq

Garoq

0
Joined
Aug 27, 2010
Messages
1,525
Points
83
Bluefan said:
I've degraded a A130 diode to half output with ~7V reverse bias for a few seconds. I've killed a cheap red pointer instantly.
Click to expand...

Very interesting, thanks. According to the Nichia NDB7352 data sheet the absolute maximum rated reverse voltage is 5V.
 
Last edited:
DrSid

DrSid

0
Joined
Jul 17, 2010
Messages
1,506
Points
48
5V ? That sounds reasonable .. my direct driving with 4.5V was bellow this .. but if I used flexdrive, it could easily jump over it.
 
Garoq

Garoq

0
Joined
Aug 27, 2010
Messages
1,525
Points
83
DrSid said:
5V ? That sounds reasonable .. my direct driving with 4.5V was bellow this .. but if I used flexdrive, it could easily jump over it.
Click to expand...

Of course, the maximum rated forward current is 1.2A. :eg:
 
You must log in or register to reply here.




Top