Re: CIM Motor Capacitors
 

Yep, that explains why our "off switch" has a red reset button. :P I guess it's just another safety feature built into the system.

Re: CIM Motor Capacitors, voltage issues, dropouts
 

This is a great thread.

I'd like to add a note that 1712's and several others converters 12v - 5v for the Dlink, failed.

It failed by providing only 4.1 volts.
Once you have tried all of the above advice, try tracking the 5v in at the Dlink and make sure its OK all the time.

Dropouts are happening in other areas of the robots this year and they are hard to diagnose, so look at the threads on Jaguars and encoders next as well.

Re: CIM Motor Capacitors
 

It is a breaker - a short circuit breaker. The other breakers down line from the main one are the real ones that do all of the work to prevent component damage. Ever wonder why we end up having like a pound worth for the whole system?

measurements, getting to the heart of it
 

One thing I learned early on, in robotics what you get is what you don't see.

Use meters to reveal things.
Voltage is easy.
DC Current is thought to be hard, but check out the Kussmaul Electronics 091-8 strap on ammeter. (inductive ammeter)

If you are overloading the main or subcircuits, this will pinpoint the problem for less than $20 and without disconnecting any wires.

Snap-on Tools has similar meters, but they are pretty expensive.

Re: CIM Motor Capacitors
 

Not really.

The snap action breakers are the real protection circuits while the 120 amp breaker acts as a single point emergency switch for anyone who needs it and as a catastrophic short protection.

In the 9 years I've been in FIRST, I've never seen one trip, not have I seen a need for it to trip (except this years 1519 minibot ... which has no breaker :P )

main breaker, or switch ?
 

Its required by the rules.

What I would like to say here is that in my 11 years with FIRST I have seen three of these fail.

Only one was a complete open and you could feel that it was broken beacuse the lever was floppy.

The other two would fail to 'snap' on, although they looked to be on,
about 2 out of 5 times, which created havoc until we figured it out and replaced it.



Onboard diagnostics ? Voltmeters ? Operators watching the displayed voltage ?

Re: CIM Motor Capacitors
 

Guys,
The breaker is rated for switch use, so in our application it is fine. Please remember where it is in the circuit. If there would be a short on the PD, or any wiring feeding it, the main breaker is intended to trip to prevent fire. While I have a had few reports of teams tripping this breaker, I have not personally witnessed any that tripped on the field. I have seen several over the years that were damaged in manufacture and needed replacement.