From: James Meyer
Subject: Re: automotive protection circuit needed
X-Newsreader: Forte Agent 1.91/32.564
Date: Sun, 08 Sep 2002 17:44:35 GMT
NNTP-Posting-Date: Sun, 08 Sep 2002 13:44:35 EDT
On Sun, 08 Sep 2002 15:54:49 GMT, "lqqkin" wrote:
>Does anybody have any simple protection circuit ideas for protecting my pic
>in an automotive circuit. It will be kind of harsh its going in a drag car.
>Zeneers , diodes, maybe.... but where ? Any input would be appreciated..Any
>experiences ? It will also be controlling a solenoid. "At the very least put
If you power the PIC from it's own battery and put the PIC and the
battery in a metal box with no wires or other connections passing outside the
box, then you don't need any protection at all.
If you want to power the PIC from the car's battery, then I think you
should use an isolated DC/DC converter to develop the PIC's supply voltage.
Many converters are already protected from spikes and such sufficiently to need
no extra protection.
If you want to connect any part of the PIC to something else in the car,
then you will need to protect those connections. How you protect them depends
on where they are connected and the types of signals present. Heavy filtering
will protect most connections but heavy filtering will also reduce the speed of
the connection, perhaps making it so slow that it won't fail but it won't do the
How many wires or connections will you have?