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

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

445nm Diode Reverse Connection

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.
 





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:
As long as the voltage isn't too high in reverse, they'll take it all day long. It is a diode, after all.
 
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.
 
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.
 
OK, so I'll ask the question differently: Has anyone ever killed a diode as a result of a reverse connection? First hand experience.
 
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?
 
PHR 803t dead. They are more sensitive.

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.
 
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.
 
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.

Very interesting, thanks. According to the Nichia NDB7352 data sheet the absolute maximum rated reverse voltage is 5V.
 
Last edited:
5V ? That sounds reasonable .. my direct driving with 4.5V was bellow this .. but if I used flexdrive, it could easily jump over it.
 
5V ? That sounds reasonable .. my direct driving with 4.5V was bellow this .. but if I used flexdrive, it could easily jump over it.

Of course, the maximum rated forward current is 1.2A. :eg:
 


Back
Top