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Unread 15-02-2011, 13:58
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Re: Question from a ROOKIE Team

Quote:
Originally Posted by Matt Krass View Post
If it's a slow blink, you're almost certainly looking at debris, the question is whether or not it is causing a transient problem or if your FETs have already fried.
I have never seen the "slow blink" due to a debris problem. If there has been a debris issue it almost always causes instant failure of a Jaguar. From the document that I referenced earlier:
"Fault Conditions
A slow flashing Red LED indicates that the MDL-BDC detected one of the following fault conditions:
�� Power supply under-voltage
�� Over temperature
�� Over current
�� Limit switch activated in the current direction of motion
When a fault condition occurs, the motor shuts down and the LED indicates a fault state during the
fault condition and for 3 seconds after the fault cause is cleared (except for the limit switch fault,
which is cleared instantly). A slow flashing Yellow LED indicates that the MDL-BDC is not receiving a
valid control signal."

Quote:
Originally Posted by Matt Krass View Post
This statement is an oxymoron.
Hotwiring motors is not a safe proposition, no matter how steady your hands are. There is a reason FIRST has us use circuit breakers and reliable connections, and it's not to cost people money or time, it's a SAFETY FEATURE.
I'm sure there are many different ways someone could "hotwire" a motor. What I was referring to above (and why I put in the words "please exercise safety") is to use common sense*. I can think of several ways to "hotwire" a motor without having to have a "steady hands" requirement, such as:
-If the motor is not installed on a robot, put it on a table and clamp it down.
-Use a circuit breaker inline with the power connection. All Circuit Breakers that attach to the PD Board are compatible with a standard female 12 AWG connector.

Can anyone else think of some ways to safely "hotwire" a motor?
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Last edited by DavidGitz : 15-02-2011 at 13:59. Reason: formatting