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Old May 09, 2012, 07:26 PM
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A question about mulitple esc's on a multirotor

If I have 4 esc's connected to a quad board and each esc is rated for 2 amps, will the maximum amperage delivered be 8 amps or at least more than 2?
The reason I am asking is that when I was running all 4 esc's into the board it was working fine.
But I was told to run a ubec instead so I went with a 3 amp 5v ubec. Now, intermittently, I get a total "power out" situation to all 4 motors
I'm flying this with a DX7 and 7010 RX.
The esc's are rc timer 30amp programmable and 2212/850kv motors. Any ideas?
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Old May 09, 2012, 09:01 PM
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I assume you mean the BEC in each ESC is rated for 2 amps? Normally, that type BEC doesn't share well with others, which is why a separate BEC was recommended.

Did you disable the BEC output from each ESC before installing the external BEC? If not, there could be an overheating condition, and they all overheat and shut down.

Is the BEC you installed a switching type? If not, and you are using 3S or higher battery voltage, that would also explain the power shutting off.
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Old May 09, 2012, 09:11 PM
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I plugged in only the signal wires before installing the ubec. And the ubec is not a switching type.
It's this one.
http://www.ebay.com/itm/Hobbywing-3A...item46038743dd
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Old May 09, 2012, 10:19 PM
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So, only the ground and signal wires connected, with the center red wire turned back? Or, only the signal wires? If you only connected the one signal wire, without the ground, it wouldn't take much noise in the ESCs to confuse the controller chips.

It appears that the data sheet in the first photo on that site does say it is a switch mode BEC. Did you get the same data sheet?
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Old May 09, 2012, 11:24 PM
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Yes I only connected the signal wires without the grounds. I just flipped the plugs over so that only the signals were plugged in.
The "switch" the ubec sheet refers to is a jumper that will let you do either 5 or 6 volts. I have one of these coming. It's twice the amperage.
http://www.ebay.com/itm/270968011654...84.m1497.l2649
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Old May 10, 2012, 05:55 AM
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The first one is actually a switching ubec and should work fine, but needs the ground wire on the ESCs connected as Wintr says.
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Old May 10, 2012, 02:34 PM
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Connect the grounds as well as the signal coming from ESC.
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Old May 10, 2012, 10:21 PM
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The reason you need the ground wire, too, is the input circuit of the ESC has to measure the pulse on the signal wire; without a reference ground to compare it to, except the indirect one through the battery and BEC, it could have trouble doing that.

You can extract the contact with the red wire from the connector, using a sharp blade, like an Xacto, to lift the plastic tab that holds it in. Then, just tape it back, so it won't short.
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Old May 11, 2012, 09:38 PM
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Ah ok. I wasn't aware of that. Thanks for the info.
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