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Old 08-23-2013, 02:13 PM   #6220 (permalink)
jyanof
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Quote:
Originally Posted by SEBART PL View Post
I think it is important on 50/50 current and temperature three actions:

1sudden overload=current rise=temperature rise (series motor take huge current even with slow motion temperature on mosfets rise very quickly especially if you have only ten mosfets)

2,then/or
sudden blown up mosfets cause shortcircuit/sticking drain and source=current rise out of control=motor run out of control (only main contactor can stop motor)

or
3environment temperature rise = boiling mosfets (very sunny day, traffic jam often starts and stops)
then 2

Just to review some history of this design and its many applications, there are many instances of the controller's thermal cutback algorithms working correctly and saving the controller from failure. I won't search through the past posts, but there are several cases that come to mind where the user didn't initially realized the importance of a heatsink. The controller would overheat and power would be reduced as expected. I recall another case where in addition to limited heatsinking, the motor was undersized forcing the controller to output max current (500A) for long periods of time.

In any event, the original thermal design of this controller should be adequate for normal use. I myself use the controller in my EV during the hot Arizona summers where ambient temperature can be 50C (especially in the sun). Actually, just this year, I got the a/c working and currently all the hot air from the condensor gets dumped into the engine bay under the hood.

A thermal sensor under the hood indicates that the ambient air temp under the hood can get up to 60C with the a/c on and the controller still works fine! (knock on wood).

I see the pictures previously posted of your controller design in this post. The power section does not appear to be similar to the original Revolt design.

The Open Revolt software and hardware are designed to work together. While changing the software to work better with the current hardware you have may work, you might consider changing the hardware to match the original design intent. There are many more things to consider in the power board layout other than thermal performance - changing to a proven design may end up being more effective than trying to develop software mods which may continue to result in blown up hardware.

Good luck in your efforts!
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ReVolt AZ testing thread:

http://ecomodder.com/forum/showthrea...ting-9325.html
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