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Unread 19-11-2012, 23:47
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Tom Line Tom Line is offline
Raptors can't turn doorknobs.
FRC #1718 (The Fighting Pi)
Team Role: Mentor
 
Join Date: Jan 2007
Rookie Year: 1999
Location: Armada, Michigan
Posts: 2,537
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Re: New Talon Speed Controller

I wanted to follow up on our promise to toast the Talon. We didn't really accomplish it the way we meant to. First, we ran the Talon without a fan. We connected 2 cims to the output, and 4 inputs from the PD board. We locked the drivetrain in place, and then started ramping up the voltage.

Initially, we thought we had an infant mortality when the Talon dropped out at around 60 amps. The truth of the matter (after disassembly and testing back at the manufacturer) was that the Talon got SO hot that it desoldered components from the board. That's what happens when you run 60 amps through an uncooled speed controller for an extended period. It still didn't actually smoke for us, though I understand it did when it had cooled and resoldered some of the joints at the manufacturer.

Today we retested the Talon with a fan on it. We hooked it up to 1 cim, 2 inputs, and ramped the amperage up. In this case, we had a borrowed Cross The Road engineer with a datalogger in-line with the input to the Talon, so we know exactly how much amperage we were running. We couldn't kill it. We ramped up to 74 amps continous (for an extended period). The silly thing just wouldn't die.

The Victor provided equally good results in both cases. The bottom line is that there is NO way an FRC team should be able to fry either one of these with a fan on.

We have one more 'test' we'd like to try: we're going to bolt a talon to an aluminum bar (simulating a chassis bar) and see if it sinks enough heat to keep the Talon happy over extended periods at high amperage. I think that will wrap up our Beta season this year.