shorted diode

[browniebob]

I have a shorted diode in my system and I cannot fix it on time to test. Are shorted diodes usually reliably 'short' or do they behave oddly under certain conditions? (Its okay if its short so long as it stays short...)

BB

 

[IRstuff]

As a general rule, a shorted diode will stay shorted... unless it then opens ;-)

A shorted diode can be caused by a couple of mechanisms, only one of which is known to be permanent: a metal spike through the junction is invariably a permanent short.

On the other hand, other shorts might be caused by intermetallic "whiskers" that might break free and clear the short. Or, some other part of the series path might open for completely unrelated and irrelevant reasons.

Philosophically, either a component is required or it's not. If the diode is a "don't care," then it shouldn't be there in the first place. If it had a function, then the failure of the diode potentially stresses some other, more critical, part of the system and you'll have an accident, or catastrophe, waiting to happen.

TTFN

 

[jraef]

I couldn't agree more. I'd be interested to see what type of system this is on that it is OK to be shorted. Being that you posted this question in the Motor Controls forum I can't think of any application where a shorted diode would be OK.

"Venditori de oleum-vipera non vigere excordis populi"

 

[Skogsgurra]

A reverse power protection diode? Perhaps?

Gunnar Englund

http://www.gke.org