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Old Dec 18, 2012, 05:45 PM
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rcroadtrain's Avatar
Australia, NSW, Marsfield
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I left mine in...
and I've left them in on my hex, too..(skywalker 20A escs)

havent had an issue...(that I can tell, anyway..)

(maybe Im just lucky..)
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Old Dec 18, 2012, 06:06 PM
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T J Gilbert's Avatar
United States, MS, Ridgeland
Joined Feb 2009
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BECs

Quote:
Originally Posted by rcroadtrain View Post
I left mine in...
and I've left them in on my hex, too..(skywalker 20A escs)

havent had an issue...(that I can tell, anyway..)

(maybe Im just lucky..)
You really never know.
Sometimes BECs play well together, sometimes they don't.
There have been many pages written about this.

From what I've seen, here's the bottom line:

If the BECs are not supplying identical voltages, it's like two batteries of slightly different voltage being in parallel.
An "average" or "leveled" voltage results.
Since the BECs are actively adjusting and regulating their output voltages, a conflict ensues as each tries to adjust for the other.
This conflict causes overheating and potential damage to the BECs.

This sounds reasonable to me, so I disconnect all red wires but one when two or more BECs are in parallel.
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Last edited by T J Gilbert; Dec 18, 2012 at 06:21 PM.
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Old Dec 18, 2012, 09:30 PM
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United States, WA, Redmond
Joined Dec 2011
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Quote:
Originally Posted by T J Gilbert View Post
You really never know.
Sometimes BECs play well together, sometimes they don't.
There have been many pages written about this.

From what I've seen, here's the bottom line:

If the BECs are not supplying identical voltages, it's like two batteries of slightly different voltage being in parallel.
An "average" or "leveled" voltage results.
Since the BECs are actively adjusting and regulating their output voltages, a conflict ensues as each tries to adjust for the other.
This conflict causes overheating and potential damage to the BECs.

This sounds reasonable to me, so I disconnect all red wires but one when two or more BECs are in parallel.
Its not really about them supplying different voltages. They all supply the same voltage. A switching reg uses transistors, which are voltage controlled switches. They have an input, an output, and a gate, which controls the switch. When the voltage rises above a certain threshold, the gate opens, and lets current flow, dropping the voltage, and this happens many times per sec. If that gate voltage is fluctuating, because of other BEC's in parallel, it will be switching even more than it has to as well as having to deal with current surges and peaks, which could cause it to burn up.

Most of the time the effects are probably unnoticeable, but in some cases its bad. So effectively, TJ is right.
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Last edited by Cervanchez; Dec 19, 2012 at 10:16 PM. Reason: clarification of gate voltage, had it backwards
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Old Dec 18, 2012, 10:59 PM
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Australia, NSW, Marsfield
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this is probably why I havent had a problem, the BEC in the skywalker 20's is linear....
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Old Dec 19, 2012, 12:20 AM
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Quote:
Originally Posted by T J Gilbert View Post
You are correct.
Power the Naza ONLY through the VU.
Maybe the TBE can be used by other FC than Naza which should have one ESC connected ....
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Old Dec 19, 2012, 02:34 AM
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United Kingdom, Norwich
Joined Jun 2004
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I've been having my own fun and games getting a matched set of non DJI ESC's working..... can't understand why ESC's sold as 'multirotor' have a BEC anyway.....just pulling the red wire doesnt stop the regulator from working of course, switching or linear, so that just wastes power, and if it's a switching regulator, then that's four (at least) interference noise producing circuits whistling away as well.....
I cut the red wire where it exits the ESC to minimise 6 inches of 'aerial' radiating too......

The only use I can think of is using one (or two?) of the BEC to power the gimbal servos independant of the NAZA

http://s197.beta.photobucket.com/use...nny/story/6175
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Last edited by jetstuff; Dec 19, 2012 at 02:40 AM.
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Old Dec 19, 2012, 05:51 AM
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United Kingdom, Norwich
Joined Jun 2004
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A quick qestion for you......has anyone deciphered and understood page 14 of the latest manual?? My new Axi's with RC Timers flashed ESC's won't start together unless I select high Motor Idle Speed setting....even then one of the motors doesn't run properly till nearly lift off throttle.
Also where do you all set the throttle trim position on your Tx when calibrating....low, middle or high??

THANKS!
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Old Dec 19, 2012, 07:15 AM
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What Are You Saying?

Quote:
Originally Posted by tritan View Post
Maybe the TBE can be used by other FC than Naza which should have one ESC connected ....
If I translate this correctly...
"Maybe the Toilet Bowl Effect can be used by other Flight Controllers than Naza which should have one Electronic Speed Controllers connected..."
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Old Dec 19, 2012, 07:22 AM
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Quote:
Originally Posted by jetstuff View Post
A quick qestion for you......has anyone deciphered and understood page 14 of the latest manual?? My new Axi's with RC Timers flashed ESC's won't start together unless I select high Motor Idle Speed setting....even then one of the motors doesn't run properly till nearly lift off throttle.
Also where do you all set the throttle trim position on your Tx when calibrating....low, middle or high??

THANKS!
Page 14 relates pulse width to throttle position with a formula based on the pulse width output of your particular transmitter.
I don't think it helps your problem.
The irregular start-up seems to just be an annoyance.
(As previously posted by several.)
Always keep your trims at zero.
The reasons why are back in the threads for your searching.
There's some stuff about trims on my blog...
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Old Dec 19, 2012, 08:33 AM
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Quote:
Originally Posted by T J Gilbert View Post
If I translate this correctly...
"Maybe the Toilet Bowl Effect can be used by other Flight Controllers than Naza which should have one Electronic Speed Controllers connected..."
He, he ...!

Well, TBE can be confusing, To Be Expired ?

No, with TBE I was refering to the multi with that name - or similar name?
EDIT: should be TBS .........
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Old Dec 19, 2012, 08:42 AM
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Acronyms

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Originally Posted by tritan View Post
He, he ...!

Well, TBE can be confusing, To Be Expired ?

No, with TBE I was refering to the multi with that name - or similar name?
EDIT: should be TBS .........
We throw out so many acronyms in our posts, it's a wonder newbies haven't asked for a dictionary...
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Old Dec 19, 2012, 10:17 AM
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Quote:
Originally Posted by T J Gilbert View Post
We throw out so many acronyms in our posts, it's a wonder newbies haven't asked for a dictionary...
We could start with RTFM
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Old Dec 19, 2012, 10:21 AM
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Huh?
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Old Dec 19, 2012, 10:43 AM
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Rtfm

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Originally Posted by Bill Glover View Post
We could start with RTFM
You mean "Read The Fantastic Manual"?
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Old Dec 19, 2012, 10:45 AM
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Quote:
Originally Posted by T J Gilbert View Post
You mean "Read The Fantastic Manual"?
http://www.youtube.com/watch?feature...&v=sZrgxHvNNUc
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