Thread: Jaguar Meltdown
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Unread 29-01-2010, 19:46
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Talking Re: Jaguar Meltdown

Quote:
Originally Posted by Team2191 View Post
Where should we send broken Jaguars?
You can find instructions here on how to RMA a jaguar.

We had this exact same problem last year. In the report Luminary Micro released. They say the problem is Excessive heat in MDL‐BDC MOSFET(s) with the symptoms of Excessive current draw by MDL‐BDC with the visuals of Single low‐side MOSFET melt‐down with damage to plastic ring Possible blown or fractured PCB traces. To prevent this Luminary Micro reccomends Mitigate risk for swarf (for example, avoid using ring terminals; take extreme precaution when creating metal debris), avoid positioning module for direct impact vulnerability during competition.

Two days ago we had another Jaguar fail the status led flashed red and BDC-COMM reported a VOLTAGE BUS error. Which is most likely "Voltage regulator Failure (REG): Failures of the 3.3 V or 5.0 V linear regulator could be due to one of two conditions. The most likely root cause is excessive current draw from the power rail at the interface connector. The regulator is specified to shut down internally under these conditions; however, our testing has shown that this regulator feature does not work correctly. The second possible root cause is input over-voltage. The regulators have a maximum input voltage of 15 V, which is reflected in the absolute maximum rating of the Jaguar module. Bench tests have shown that the regulators function beyond 15 V with no degradation or failures at less than 17 V. Although there is no measured data showing DC supply voltages greater than 15 V, there is speculation that the supply could exceed this under certain regenerative conditions. Efforts to replicate this failure on the bench using a motor in full-regeneration were unsuccessful. Despite lack of correlation with bench testing, this is the only reasonable explanation for certain regulator failures, and because of the range of installations, not every condition can be reasonably replicated. Luminary Micro will use a regulator with an increased voltage range and functional over-current protection in future revisions of this design."

-Sean