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› how can an esc with a internal bec thats pulling 15a do so through a servo connector?
06-21-2014 04:43 AM  4 years agoPost 1
charleshodge

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spring hill fl

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Supposedly a servo plug can handle 5 amps but people use internal becs from there scorpion and kontronik ESC.even with a bec pro,its pulling 20 amps and it is doing so through two servo plugs ,how is that?I'm between either running a straight lipo or running an internal from a talon 120 with a scorpion back up guard.just making sure I got things figured out.also can someone fill me in on exactly how to setup a RX pack that stays charged as backup and kicks in when there is a bec failure.?I hear how people run these buffer packs with their escs running internals and the pack stays topped by flight pack or bec or whatever,but I thought you couldn't have two power sourses and its really bad?is there a way to wire where the bec is primary and if voltage drops RX pack kicks in? Can't figure it outor find it online.building a goblin 700 comp and wanna play it safe.iI do run 3 610 and 650 align off a 6.6 life 10amp pack through two servo plugs but I would think 4 HV servos at 7.4 or 8.4v would be pulling more then 10@ with the FBI.trying to have a really clean setup with minimal wires so I'm really not trying to run a regulator to my RX to FBI and all that.also Don mind extra weight,just want it safe and clean

charles hodge

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06-23-2014 07:02 PM  4 years agoPost 2
Gregor99

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Western Wa

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Current ratings are based on temperature rise. How long can the connect sustain a specified current without getting so hot that the contacts degrade or the housing fails.

The current from servos is very "peaky" with sustained levels averaging far lower values than the peak rating. The connector may briefly exceed the 5 amp rating. But as long as its not sustained, the heat does not have a chance to build up and cause issues.

Also if you look closely, or better yet test, the current rating on BECs, its not black and white. For example, the CC BEC is rated at 20 amps, but that is peak. The continuous rating using a 48v source is only 8 amps. It goes up to 13 amps using a 24v source.

For running a buffer pack you need an a device that can handle the charging and switching. The Optipower UltraGuard will this. There are also some Kontronic ESCs that have this capability. The Scorpion device has its only internal battery that does this as well. But it may not have a high enough current rating for large power hungry servos.

Revolectrix Beta Team

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06-23-2014 11:08 PM  4 years agoPost 3
FireNWater

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Collierville, TN

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but I would think 4 HV servos at 7.4 or 8.4v would be pulling more then 10@ with the FBI.
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And there is the problem. Nobody actually measures how many amps their radio system draws, they just guess. And everyone wants to "guess" higher than the next guy.
.
I've connected an Eagle Tree system and measured actual amp draw in flight. I couldn't get more than 3.5 amps on the bench leaning all of my weight into all four servos, draw in flight was much less.
.
Yes, I know this is for a 600, but it uses the same servos (Align 610's) as the 700.
.

Buy Cheap, Buy Twice . . .

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06-24-2014 01:16 AM  4 years agoPost 4
Gregor99

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Western Wa

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And there is the problem. Nobody actually measures how many amps their radio system draws, they just guess.
Precisely. Actually I did measure my Align 610s and was able to get 5 amps. At 5 amps, the BEC I was using at the time just briefly shut off until the load was lifted. That was also on a 600. I moved to a 10 amp BEC and that solved it.

Revolectrix Beta Team

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