For student use I always put a diode in the + 12v input and I put a
resetable fuse in the -12v supply. I also use a 7805 when 78L05 would do.
Wally Barnacle

>From: Alex Kilpatrick <AlexK@HCITRAINING.COM>
>Reply-To: pic microcontroller discussion list <PICLIST@MITVMA.MIT.EDU>
>To: PICLIST@MITVMA.MIT.EDU
>Subject: Re: [PIC]: Newbie Queston: Electrical protection for PICs
>Date: Mon, 22 Sep 2003 20:59:40 -0500
>
>Kelly.
>
>I don't think that is a stupid question at all.  I have seen many
>questions that were far stupider here.  I'm interested in the answer as
>well.
>
>However, it will help if you classify your question by putting in the
>proper tag.  (I've put it in for this reply)  Otherwise, many folks will
>not see it.  The two most common ones are:
>
>[EE]: for general electrical question, not about PICs specifically
>[PIC]: for pic-related questions.
>
>ALex
>
> > -----Original Message-----
> > From: Kelly Miller [mailto:fkmiller@COMCAST.NET]
> > Sent: Monday, September 22, 2003 8:25 PM
> > To: PICLIST@MITVMA.MIT.EDU
> > Subject: Newbie Queston: Electrical protection for PICs
> >
> >
> > Please don't "flame" me for asking what will likely sound
> > like the stupidest question yet on PICs and electronics.  I
> > am a "newbie" at
> > electronics (but not so with systems and programming).   I'm busy
> > studying basic electricity, electronics, and microcontrollers
> > and have a question from a "best practices" perspective:
> >
> > I understand that 5 volt PICs work with what seems low
> > voltage and limited current.  Is it a good idea to put some
> > sort of electrical "fusing" between a regulated 5 volt power
> > supply and the PIC input pin(s)?  (There is a 3 Amp circuit
> > breaker in the upstream 12-16 volt power supply that I
> > regulated down to 5 volts.)  Would it serve to protect the
> > PIC, associated components, and possibly safety?
> >
> > It doesn't sound to me like anyone does this, so I'm sure it
> > is a flawed idea.  Why?  If it is a good idea, what is an
> > example of some component to use.  I want to keep the magic
> > blue smoke contained in the shiny little components.  :-o
> >
> > Thanks, Kelly
> >
> > --
> > http://www.piclist.com#nomail Going offline? Don't AutoReply
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> >
>
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