Re: New Monitor: Power Supply Design

Ahem, I forgot to mention the fuses. If the rectifier fails shorted, it
won't take long to fail open or blow a fuse. In any case the circuit could
handle huge voltage swings with no problem. The output (display) would get
(literally) very ugly, but a fuse or two would generally blow before
that(due to the excessive current required to swing a cap full rail). If a
cap was conveniently missing or open at that point, well, there's always a
fire extinguisher around right? Just kidding. the bus could handle the
swings. A shorted cap will blow a fuse too.

At my real job, we deal with these problems all the time. You should see
how interesting this gets when your power supply is capable of delivering
200,000 volts at 100-200 amps intermittant!

Thanks
James

----- Original Message -----
From: David Shoemaker <davids@oz.net>
To: <vectorlist@lists.cc.utexas.edu>
Sent: Saturday, November 13, 1999 4:11 AM
Subject: Re: New Monitor: Power Supply Design

> One thought. Look at the likely failure modes of this and how it could
> effect the rest of the board.
>
> With the rectifier what happens if it melts down and you get a 48V ac into
> the rest of the system? What happens if you lose half wave rectification?
>
> What if a cap shorts? Opens?
>
>
> Etc. I have no idea how to answer these but they are what I would think
> about.
>
> David
> ----- Original Message -----
> From: James Nelson <nelsonjjjj@didactics.com>
> To: <vectorlist@lists.cc.utexas.edu>
> Sent: Friday, November 12, 1999 8:16 PM
> Subject: New Monitor: Power Supply Design
>
>
> > The power supply will consist of the following:
> >
> > 48V center tapped transformer
> > Bridge Rectifier package
> > 2 Electrolytic capactiors rated at 6800 uF.
> > Some 0.47 uF caps for higher freq noise.
> >
> > That's it Dead simple, and should be good & reliable.
> >
> > As far as regulation goes, there will be none. It should be unnecessary
> due
> > to the superior low frequency noise rejection characteristics of the
> LM3886.
> >
> > I did find a good source for the 48V center tapped transformers.
> >
> > James
> >
>
>
Received on Sat Nov 13 06:30:45 1999