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Old 09-07-2010, 01:08 PM   #3729 (permalink)
Join Date: Feb 2009
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Originally Posted by princeton View Post
I'm new to the thread. I've been trying to work on a controller at home but after reading this thread, mine seems way too simple. Why does it have to be this complicated? Are all the features that necessary?
Some hardware features that add complexity and what value they add (IMO):

1. hardware overcurrent protection: saves the power section while testing out new software. one wrong line of code could command the controller to fully turn on unregulated and blow things up (or result in a runaway car).

2. serial output: nice to help troubleshoot software by looking at the output so you know what the controller is doing. also allows an easy way of updating software, changing controller settings, and add-on software (see adam's RTDexplorer).

3. Opto isolation: this is pretty important. it allows the high current power section to operate without any electrical link to the control board. This greatly reduces noise that could screw up the micro or ADC conversions or whatever.

4. power section undervotlage protection: keeps the mosfets from turning on if the gate-driving-voltage is too low (from the output of the DCDC converter). If they only turn partway on, they'd heat up quickly and result in a blown powersection and possibly a runaway vehicle.

5. thermal protection: in the right setup and driving style, it won't be necessary. but, just in case, it'd be a shame if the controller blew up (possibly resulting in a runaway vehicle) because it overheated and didn't automatically reduce output power.

6. current sensing: this probably should have been first. it's way too easy to get ridiculously high currents in an EV motor. the output current must be regulated through some sort of feedback system.

hm, are there other hardware features? there's a ton of software features that aren't really necessary, but are nice to have. writing code is free, though.
ReVolt AZ testing thread:
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deodeo (03-28-2012), Nevyn (09-07-2010), princeton (09-07-2010)