Is that thing an external BEC ??

[offtom]

Just wondering and I know this is the place for answers.

Searching around and I've started noticing some of the larger ESC's have this little gizmo attached to them. It almost looks like an external BEC. Only thing that tells me it isn't is the three wires running back into the ESC itself.

Anybody know what that thing is?

[Wildflyer]

I would guess it is a bec. They may be doing it to get away from the heat of the ESC.

As far as the three wires on both sides, the unit still needs the battery voltage to work, so that is the red & black between the units, and the control lead, the white wire, has to run into the main ESC to tell it what to do. The white wire probably just runs straight through the small bec.

The smaller unit is just a voltage reg, so if the ESC burns up, cut off the reg and see if it still works. if it still does, you have a UBEC.

[offtom]

I was guessing it was an external when I first saw them but then I got to thinking that every external I've ever put in a plane just had the red and black wires that I attached to the battery wires going into the ESC.

Never played with a third wire on any of them.

[slipstick]

Originally Posted by offtom

Never played with a third wire on any of them.

But that's because you usually have two separate leads and the signal wire is only needed in one of them. In this case the BEC (and that's what I'm guessing it is) is inline in the only lead....the signal needs to pass through it to get to the main part of the ESC somehow .

Steve

[offtom]

Not to argue or anything, but the third wire in this case still has me baffled somewhat. I can understand signal wire and all with the servos, but then a BEC just supplies power to the receiver doesn't it?? I don't know why it would need the signal wire to do that.

Sure wish they would explain what that gizmo is. The more I look at it I'm starting to think it's to make it look like a complex piece of engineering that does the same thing the previous model did, but they can charge more for it because it looks "High tech"

[kyleservicetech]

Originally Posted by offtom

Just wondering and I know this is the place for answers.

Searching around and I've started noticing some of the larger ESC's have this little gizmo attached to them. It almost looks like an external BEC. Only thing that tells me it isn't is the three wires running back into the ESC itself.

Anybody know what that thing is?

That looks very much like a uBEC (Switching Power Supply BEC). One way to quickly find out, is to power up the ESC, and measure the voltage between the red and black wires coming out of the "thingy". If you find 5.0 Volts DC, then it's a uBEC.

As for the white wire, you might find its not connected to anything inside the uBEC. Why? IMHO, it's better to use all three wires in the battery cable to the receiver, making it less susceptable to falling out due to vibration on those glow/gasser models that don't use electric power. You can verify that after verifying the 5 VDC on the red and black wires, measure the voltage between the black and white wires, then between the red and white wires.

If it's zero, (or if the voltage is floating) it's probably not connected to anything. Digital meters are quite sensitive, and these meters can measure stray voltages when they're not connected to anything.

Don't know how carefully the red/black wires for the uBEC are secured inside the ESC. It might be a good idea to put a little wire tie on the red/black wires securing them to the red/black power wires of the ESC.

Let us know what you find.

[slipstick]

Originally Posted by offtom

Not to argue or anything, but the third wire in this case still has me baffled somewhat. I can understand signal wire and all with the servos, but then a BEC just supplies power to the receiver doesn't it?? I don't know why it would need the signal wire to do that.

Seems pretty simple to me. The BEC (if that's what it is) is connected via those 3 wires to the RX (throttle channel) and to the ESC. The ESC needs a signal to control the throttle and there are no other wires connecting it to the RX. What's not to understand ?

Steve

[offtom]

Originally Posted by kyleservicetech

Let us know what you find.

Oh I'm not going to get one. Was thinking about it when I first saw them because I was thinking it would take the hassle out of trying to hook up an external BEC in one of my bigger planes.

Originally Posted by slipstick

Seems pretty simple to me. The BEC (if that's what it is) is connected via those 3 wires to the RX (throttle channel) and to the ESC. The ESC needs a signal to control the throttle and there are no other wires connecting it to the RX. What's not to understand ?

Steve

Sorry Steve, I'm thinking we're on two different trains of thought. I understand what you're saying, but my question was if it was setup like an external BEC where all it did was provide power to the receiever, and plugged into a totally different channel than the throttle channel.

Seeing as it only has one three strand wire from the entire ESC to plug into the receiver I'm thinking it's not what I originally thought it was. It may in fact be an external BEC, but it's still an all in one package that would not suit my needs right now.

Thanks all for helping me sound out this quandry. I think we figured it out.

[slipstick]

Terminology is getting in our way isn't it ? It certainly appears to be a BEC and it's definitely external to the main ESC.

But it's not a separate standalone BEC which I guess is what you are thinking of.

Apart from anything else I imagine the internal circuits of the ESC rely on the power produced in that BEC which means you couldn't easily just cut it loose and use the two parts separately .

Steve

[gramps2161]

I have one it plugs into channel 3 and powers everything like a normal ESC. I never used it except to test motor directions and setting up servos. That little square piece gets pretty warm just having a battery plugged into the ESC never would trust it in a plane.

Anyone want to sacrifice a plane and try it?

[offtom]

Originally Posted by slipstick

Terminology is getting in our way isn't it ? It certainly appears to be a BEC and it's definitely external to the main ESC.

But it's not a separate standalone BEC which I guess is what you are thinking of.

Apart from anything else I imagine the internal circuits of the ESC rely on the power produced in that BEC which means you couldn't easily just cut it loose and use the two parts separately .

Steve

Yes the English language and forums do have a conflict at times don't they. Appreciated your input though.

Originally Posted by gramps2161

Anyone want to sacrifice a plane and try it?

Well, since you've already got one of the things, looks like you might have already volunteered.