Overload controller and ultimate bec?

davidleitch · Mar 19, 2003, 06:02 PM

Lets say you have a 40 amp controller and are using the UBEC.

Now for some reason (you run 80 amps through it) the controller shuts down, will the UBEC continue to function?

I am actually only running 60-70 amps according to Motocalc (hacker b407L 15x10 and 8x1700). Since it will only be on for 10-15 seconds it should be allright, but sure don't want to lose any more planes due to equipment failure.

txs
dave

Doc Data · Mar 19, 2003, 08:11 PM

Yes, the UBEC will continue. It has nothing to do with the controller and is actually a bypass circuit that is a direct feed, stepped down to Rx voltage, directly from the battery pack to the Rx.

Dave

Daveairway · Mar 19, 2003, 09:24 PM

"Now for some reason (you run 80 amps through it) the controller shuts down, will the UBEC continue to function? "

It depends on why the controller shut down. Thermal protection or a short ?

I have used an "old rule of thumb" that anything over 40 amps (was 20, then 30, now 40 amps) should use a rec battery, not BEC. Even a UBEC may be applicable.

My concern, is that as the amps increase, failures are more likely for the batt pack, esc, or motor. A dead batt pack will still cause the UBEC to quit.

I have had a brake FET short in a brushed ESC that dumped the battery really fast, but this happened on the bench and not in the air. So as I watched the batt smoke I realized there was a problem.

If you use a BEC or UBEC and the motor seems low on power, shut the throttle off and land.

It is a tough call,
Dave

Mar 19, 2003, 06:02 PM	#1
davidleitch Tragic case Sydney Australia Joined Feb 2002 5,858 Posts	Overload controller and ultimate bec? Lets say you have a 40 amp controller and are using the UBEC. Now for some reason (you run 80 amps through it) the controller shuts down, will the UBEC continue to function? I am actually only running 60-70 amps according to Motocalc (hacker b407L 15x10 and 8x1700). Since it will only be on for 10-15 seconds it should be allright, but sure don't want to lose any more planes due to equipment failure. txs dave

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Mar 19, 2003, 08:11 PM	#2
Doc Data Registered User United States, FL, Starke Joined Apr 2002 2,251 Posts	Yes, the UBEC will continue. It has nothing to do with the controller and is actually a bypass circuit that is a direct feed, stepped down to Rx voltage, directly from the battery pack to the Rx. Dave

Mar 19, 2003, 09:24 PM	#3
Daveairway Registered User Santa Rosa, Northern CA, USA Joined Oct 1999 2,459 Posts	"Now for some reason (you run 80 amps through it) the controller shuts down, will the UBEC continue to function? " It depends on why the controller shut down. Thermal protection or a short ? I have used an "old rule of thumb" that anything over 40 amps (was 20, then 30, now 40 amps) should use a rec battery, not BEC. Even a UBEC may be applicable. My concern, is that as the amps increase, failures are more likely for the batt pack, esc, or motor. A dead batt pack will still cause the UBEC to quit. I have had a brake FET short in a brushed ESC that dumped the battery really fast, but this happened on the bench and not in the air. So as I watched the batt smoke I realized there was a problem. If you use a BEC or UBEC and the motor seems low on power, shut the throttle off and land. It is a tough call, Dave