Speed controllers....

we have blown up 5 or something speed controllers (the first ones )in the last year… we are currently thinking about going for “homemade” or buying some from somewhere nearby…
however when they are costing around £150 (~ 250 dollars) and we will need 2 or 4 of them… we are unsure of what to do…
ideas?

I’m pretty sure you can’t use homemade speed controllers in the FIRST competition. You shouldn’t be blowing up your speed controllers it does happen but it shouldn’t happen that often. Running straight into the ball corral doesn’t help either lol.

For as long as I’ve been in FIRST, the only speed controllers a team can use, are the Innovation FIRST speed controllers, provided in the Kit of Parts, or speed controllers of that same model purchased from Innovation FIRST. (For example, this year only Victor 884s could be used, not the 883s of previous years)

If you’re having problems blowing speed controllers up, make sure to read the Victor 884 Users Manual and look at the **Installation Info **to make sure everything is hooked up right, with the correct wiring.

You can buy new speed controllers **here **from the Innovation FIRST Website for $115 each.

Its been my experience that the IFI speed controllers are pretty robust. We’ve done a lot of stupid things over the years and not had too many issues with the IFI parts. Are you sure you are not doing something wrong in how you are using/connecting the speed controllers?

One thing that is a source of failures is for metal chips to get inside and short out the speed controller. Is it possible that you have been generating chips too close to your speed controllers?

Maybe if you explain how the failures are occurring it would be possible for people in the forum to give more specific help.

Ken

I’ve never ever seen one “blow up” in 4 years of doing robotics.

I have VERY rarely heard of them failing in mysterious ways.

Double check all your wiring, make sure it’s all right, nothing’s shorting out, etc etc

Years ago, in 1999, Woburn had some trouble with (what was believed to be) metal filings at the base of the FETs. A few Victor 883s failed that way. Also, in 2003, one unexplained faulty 884 turned up in West Michigan. It may have failed for the same reason (since preventative measures weren’t really taken to avoid debris).

I’d say that this is the most likely explanation for the issue. Do you typically cover the Victors before performing metal work?

Here’s a crazy idea: self-resetting fuses. Maybe it’s not in the kit, but you’d think that you could get approval for something as budget-saving as this… :confused:

5 Victors sure is worth a lot…

You have the fans hooked up to the input side, right?

If they’re hooked up to the output, they will not be funninf at full power most of the time.

Self Resetting fuses are in the kits.

Sweet. The last time I was on a FIRST team was in 2001.

If you have killed that many, you are either the most unlucky team on the face of the robosphere and you have some how managed to incite a fiery vengence against you from the robot gods or you are doing somehtign wrong. I have put those thigns through alot of abuse including running them at about 20 volts instead of 12, dropping them etc and have never had any problem.

Make sure there is nothing in the way of the fans, like wires or tye-wraps. I assume when a speed controller blows up, it might have been the result of it overheating. Also be careful of where you place the speed controller on the system, make sure there is a lot of space for the fans to work.

Actually, they’ve been part of the kit as long as I’ve been in FIRST; see this from the 1999 kit, on page 4.

seppuku?

I have to say, in 5 years, I only seen one bad speed controller. Last year we got one that would not produce output, but IFI replaced it quickly.

On a side note, if you want some to experiment with, I have some older 883’s that my team would part with cheaply. (the money going back into the teams funding) They are not competition legal, but might be better to test out the problem then frying new legal ones.