Danpatgal wrote:

> If I really understood what the controller was doing, there would probably
> be only a few possible problems that could cause it to work for 40
> seconds, then quit.  Maybe it is a heat problem, not that the entire thing
> is over-heating, but that some small component is over-heating and
> tripping the thermistor.  Once it cools off, I can go again.

Two possibilities immediately come to mind; one is that something is 
overheating and so you can go for another little while after allowing things to 
rest and cool off for a bit, the other is that you have a capacitor that is 
being charged through a high resistance, and so when you use the controller, 
the cap discharges faster than it can recharge such that after some shortish 
amount of time, its voltage drops too low for the controller to remain 
operating and you have to leave the car sit until the cap is able to charge 
back up sufficiently.

Since you suggest that the first time the controller runs longer before cutting 
out, and although it comes back to life after sitting for a bit, it lasts less 
long before shutting down again, it sounds more like a thermal issue, although 
both of these scenarios are still possibilities.  If the issue is a high 
resistance connection to the KSI input, for instance, it might just be that you 
simply aren't allowing a long enough rest period for the caps to charge as 
fully as they were initially, and so the controller shuts down sooner than on 
the first attempt.

> I don't know if it matters, but I decided since I wasn't using the A2
> terminal, that I would just take it off - so I did that, along with the
> copper shield that connects to the three doides on the side.  But, maybe
> it's not that simple ...

My first thought is to check the external connections to the controller to 
ensure that you don't have some high resistance in the connection to the 
controller KSI input.  Resistance in the B+ connection could cause similar 
behaviour, but I wouldn't expect the vehicle to move very far/long at all 
before the controller shuts down, and I would expect the controller to 
'recover' after a very short rest.

Next, I would undo the A2 modification.  It is possible that by removing the 
"unused" bits that you have, that you have removed some critical heatsinking 
from those 3 diodes.  Just because you are not explicitly connecting the A2 
terminal doesn't necessarily mean that those diodes aren't used by the 
controller in normal operation.

Good luck!

Roger.

_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA 
(http://groups.yahoo.com/group/NEDRA)

Reply via email to