hyper 7148

[Tom Hussey]

Suggest you look at Harris AN9312.3. It will put the right kind of
caution into you ;-)

Cheers,
Tom

Andrew K. Mattei wrote:
> 
> Dave Z wrote:
> >
> > GCAR came from one of you chaps? I thought that was canadian ;-)
> 
> Even though I stuck a copy of it on my web page, I got it from a
> canadian - so I guess that really is its origin :P I played around
> with
> it, compiled my own versions a few times, and then put up that web
> page
> with "all I knew". :) That was about a year (or more?) ago.
> 
> >
> > I have an HC11 based monitor circuit I made.. very flexible and
> > expandable, always growing very slowly though. Imagine the GCAR
> board
> > with display capability and a 232 port.
> 
> I've been thinking of something similar... Possibly using a PIC,
> though... I've got thoughts of using a LCD (I have a few displays), a
> keypad, and the PIC to decode the data and supply the LCD with the
> text.
> 
> And now, so I don't post multiple times, on to Tom's reply to me - and
> a
> question about transient suppression. What do ya'll think is required
> to
> properly shield the ECM? The way I have my board working, I'm powering
> it off of the cigarette lighter. The laptop I'm using has a dead
> battery, so I just plugged it in to the wall of the garage. ;) The
> only
> "protection" I really have is a capacitor (don't recall what value I
> used... 20uF, I think) on the high side of the 7805 voltage regulator.
> Nothing on the input line to the ECM (other than the resistors and
> transistors). Any suggestions on what else I could use? I do have the
> grounds (DC-) hooked all the way through from the computer to the car.
> I
> realize opto isolation would be best, but... I don't think I have any
> of
> those chips laying around (everything I build, I build from scrap
> parts
> - I recycle ;^D).
> 
> Thanks!
> 
> -Andrew