🚀 go-pugleaf

In sci.electronics, legrady@ug.cs.dal.ca (Tom Legrady) writes:

>I don't know about the exact relationship of heat and lifetime for
>electronics comnponents, but there is an inverse exponential effect on
>the life of high-intensity lamps, such as the ones used for stage
>lighting. I have to fudge the exact numbers, since I've been out of
>theatre for a number of years, but dropping a lamp to 90% full
>intensity generally doubles the expected life of a lamp. Dropping to
>80% results in an unlimited expected life. Since our reaction to light
>is non-linear, dropping to 90% has little effect on preceived
>brightness. Since the lamps used cost $30 - $50  or more apiece and
>have an expected life ranging from 300 - 2000 hours, doubling the life
>is a desirable things to do. Of course, if you drop it, it still dies. 

>I would suspect ( but without any evidence ) that similar effects hold
>with electronics, that a relatively minor reduction in heat would have
>a great effect on life and operation.


>Tom Legrady

As a matter of fact this does indeed occur. One rough rule-of-thumb
at least for silicon devices (most applications) says that lifetime
is roughly doubled for every 10 degree drop in temp.

disclaimer: please, folks, this is only a rule-of-thumb, so please
don't respond with all the various reasons why this relation is
not completely accurate!

Stan Bischof
HPSR

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As usual, this is purely personal opinion and in no way is a statement
of the opinions of my employer, Hewlett-Packard.
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