>
> +AD4-
> I understand that its needed if the psu droops but does this happen that
> often in reality?
>
> YES YES YES YES. Brownouts are caused by many events on power lines -
> switching, reclosers, temporary short circuits, fried squrrels that pick the
> wrong two conductors to jump between, Birds with birdbrains, other people
> turning on their Dr. Frankenstien 2000 amp arc generators, and so on. We
> nearly had a recall of a product which was not brownout proof, and caused
> headaches whenever one of these events occurred.
>
> Every time the wind blows hard, sticks, squirrels, birds, and other detritus
> touches power lines. If these sticks and squirrels are wet (usually) they
> make a short circuit. Big circuit breakers, called reclosers, are located
> in substations around the power network. These babies will interrupt the
> power for a few milliseconds, hoping the fault will clear itself, whenever
> Rocky tries to surf on both power lines. Generally, Rocky is roast after a
> few milliseconds, and falls to his doom. If the recloser turns back on, and
> still finds a short circuit, it interrupts power for a longer period, maybe
> 1 second. Most reclosers are programmed to try a third time, and interrupt
> for up to 7 seconds. Every power company programs their reclosers
> differently, for different numbers of seconds and different number of tries.
> Your product has to survive this abuse. No AC powered product should be
> without brownout protection in some form.
>
> Check my web page for more diatribes on brownouts:
>
http://members.socket.net/+AH4-llile/acad1.htm
>
> -- Lawrence Lile
>
> +ACo- For non-US readers: Rocky the Squirrel is a famous US cartoon character.
>
> --
>
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