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BrianG · 11.14.2009, 02:24 PM

Cool info Patrick. I wonder what causes this current "shoot through"? Could it be a timing issue with the H-bridge on the servo driver circuit? I suppose it doesn't matter since there is little that can be done short of getting a new servo. I just hope adding a delay doesn't mask a true problem because repeated current bursts from a legitimate condition could overheat the BEC and eventually cause a true failure. The BEC looks like it has foldback current limiting, so that's good. Adding a simple capacitor to an unused servo port on the receiver is an easy and cheap solution IMO. Anything between 1000uF and 4700uF @ 10v rating should be sufficient. Any higher capacitance may actually trip the BEC's overcurrent protection when the cap intitially charges. And even though the BEC output is virtually noise-free from the MMPros I've looked at, a cap would also filter any noise which some receivers are sensitive to.

The same thing could happen to any servo really. Or, it could happen if a servo stalled because of radio EPA set too high, simply a faulty servo.

	(#56)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	11.14.2009, 02:24 PM Cool info Patrick. I wonder what causes this current "shoot through"? Could it be a timing issue with the H-bridge on the servo driver circuit? I suppose it doesn't matter since there is little that can be done short of getting a new servo. I just hope adding a delay doesn't mask a true problem because repeated current bursts from a legitimate condition could overheat the BEC and eventually cause a true failure. The BEC looks like it has foldback current limiting, so that's good. Adding a simple capacitor to an unused servo port on the receiver is an easy and cheap solution IMO. Anything between 1000uF and 4700uF @ 10v rating should be sufficient. Any higher capacitance may actually trip the BEC's overcurrent protection when the cap intitially charges. And even though the BEC output is virtually noise-free from the MMPros I've looked at, a cap would also filter any noise which some receivers are sensitive to. The same thing could happen to any servo really. Or, it could happen if a servo stalled because of radio EPA set too high, simply a faulty servo.