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7805 reg and CAN wiring.

Posted: Thu Oct 02, 2008 7:50 pm
by devojet
Would there be any problem in using a LM7805 regulator instead of the LM2937 regulator? The LM7805 has the same pin out but is rated for 1A. I only ask as I have 7805's already at home.

Is there any special requirements for the CAN wiring? i.e. twisted pairs, shielding, or will any two wires do? I was just using two wires on the bench previously which worked, but wasn't sure if I should be doing anything special when I go to install a GPIO into a car.

cheers

Daniel.

Re: 7805 reg and CAN wiring.

Posted: Fri Oct 03, 2008 7:15 am
by Bernard Fife
Daniel,

The 7805 *should* be okay. Even though it not a low drop out regulator, the trans hardware doesn't do much while cranking anyhow (presumably the cranking is with the shift lever in neutral/park).

I use twisted pairs for the CAN wiring (20 or 22 gauge, I don't remember exactly) - I just twisted two wires together with a pitch of about 10mm - so nothing special. I have about 2 feet of this on my test bench, and have been completely unable to induce CAN comm errors using all sorts of 'noise generators' (my favourite is an old 120VAC drill that messes lots of other things up when it's running!).

Lance.,