BEC 101 Video

[Pinecone]

wrong thread

[msaeger]

Why would someone use a different BEC if their speed control has it built in ?

[fireup]

Why would someone use a different BEC if their speed control has it built in ?
Here are some:

1. You're internal BEC only works on 3s and you want to run 4s or higher.
2. You're internal BEC puts out only 5V and you want to run 6V
4. You're intarnal BEC don't put out enough current for all you servos.

[CaptDen]

Bob,

I was wondering if you have heard of this. I just switched from a 72 to a Spektrum 2.4 based receiver on my Trex 450. I did this because it seemed like I had some cliches at the beginning of a new battery. What I have found out is that it looks like there is an issue with the ESC that is an over power issue that causes the Spektrum receiver to reset. I am wondering if it is better to go with a new ESC or to go the other way with a BEC to correct this. I have read from other forms how Spektrum is real touchy with voltage and by changing to a BEC might be better because it's soul reason is to feed the reciever and servo's and it regulates better than a ESC.

[Finless]

I fly nothing but Align ESC's and the Spektrum Rx's on my 450 and I don't have a problem. You have some other problem going on like a binding servos or something that is causing more amp draw thus causng the Spektrum RX to reset or shut off... FIND IT as this is NOT the norm!

Bob

[Pinecone]

A Spektrum Rx is good to 9 volts. It is senstive to LOW voltage, but my testing (in the 2.4 Radio Section) shows that most are good down to 3 volts.

So you most likley have some other problem.

But a BEC may solve that also.

But you need to know what is going on.

[CaptDen]

Thanks for the response. You bring a good point as far as a possible binding going on bring a drop in volts. I don't this is the issue in that the shut off happened 1 in. off the ground with the heli hovering well. I was also thinking that maybe a short caused the issue. But I have checked all the wires and connectors and all seems ok. What really interested me was that when the battery pack was run longer (reduced in power) there was no power issue. I am feeling that the issue is an over power and not under power. So I bet it is a bad ESC. I will switch this out.
But my real wonder here is the setup. Is having a BEC a more secure environment when power is critical. As you indicated servo binding and low battery can cause issues with a reset on the receiver, does a BEC offer a better/wider safety margin in case one of these things happen?

[Lottomunch]

This whole BEC thing has bothered me since I started flying my first Trex 2 years ago. I'm currently running a Sport BEC on my spektrum setup and haven't had a single problem. It's probablly overkill and another weak link but I'm happy.

What cracks me up is this.

Why do we always go with so much headroom on our ESC's (most everybody runs 35 ampers while most of us probably never exceed 25 amps burst let alone 35).

Why do we all ask WAY more outta our BEC's than the manufacturer recommends. (they all state 2 servos on 3S packs yet we're all running 4 plus a gyro and many of us have all digitals).

Just a thought.

Daniel

[dogfart]

Two years from now, will someone rename this thread "OLD-BEC 101 Video?" (Maybe it would be a good idea to replace the word "NEW" with a date.)

[Finless]

I use NEW in front of threads here to let people know this is a NEW topic in my forum here.... Eventually I remove the NEW from the front of the thread.

Bob

[HeliBurns]

Bob, just received the PCB's today....they look damn nice,,,

I need a better cam to do justice......

[Spek]

Just put my BEC on my Trex, the extra plug extension with the 5.1 sticker on the back needs to be plugged inline also or is that for a special set up?

[Finless]

???? No clue what your asking.....

Bob

[Spek]

No worries Bob, I did word that pretty bad:wink:. After I wrote it I figured out it was a regulater harness wire to use incase the tail sevo couldn't handle the 6 volts, you could use the adapter to got down to 5.1.

[bonanza34g]

The WWW is great, I came here to post a question about this and found a thread on it!

I have a Trx 450 with an Align ESC (BL35G) a DX7 Trans and AR6100 Rec. I guess my bottom line question is why do I need a BEC?

I'm having an issue with the receiver shutting down and resetting (takes about 5 seconds at which point it has crashed). I called Horizon and they said put in a BEC, but shucks if the ESC has one why add another?

I looked back in this thread and saw the possibility of binding causing a glitch, but I can't find anything wrong with linkages or servos, the thing flys great until the damm thing decides to shut down. I crash enough on my own, I don't need it to crash on its own!! :arggg:

[Pinecone]

The problem is, some BECs in the ESC have limited capacity, especially when running 3S packs. It sems that some are rated at 2S, not 3S, and linear regualtors have LESS capacity as the input voltage goes up.

So the voltage can rop under load.

BUT, this time of year, due to driness, you could be running into ESD (static/spark) problems.

[bonanza34g]

Well dang, I installed the BEC and 2 minutes into the next flight, the glitch happend again with the usual crash landing.

What else might be going on, could the battery be bad?

[dogfart]

Will the name of this thread still include the word "New" years from now?

[Montana_Reefer]

Bob,
I'm more confused now than ever. I have a 450se V2 w/ DS285MG and a 401 w/ 3400g. From what I have read I can possibly draw more amps than my stock ESC can deliver to the rx. I bought a CC BEC a month ago but have not installed it yet. I did check it out and it is a new one that dose not cause a binding issue w/ the AR6200. Should I install this or not and do I need to remove the power wire from the ESC?

[Finless]

TO install it or not is up to you! If you feel worried about the internal BEC then go for it. Yes you would need to pull the red wire from your ESC as you dont want two BEC's driving the RX especially if they are outputting a different voltage like 5V vs 6V.

Bob

[Montana_Reefer]

Thanks Bob,
I think what I've been worried about is the glitch in the 2.4 systems and pulling too much power because of the digital servo's causing it to initialize again. Are you saying don't worry about it? Has this been a problem of servo binding and not realy the ESC/BEC? If there is no reason to use the BEC I'll save it for the the next heli.

[Finless]

I have never needed a external BEC on a 450 but I am also not running those servos. Best to ask in the Trex450 forum.

Bob

[cybinary]

Bob, quick question about the last thing you touched on in this video...

You said that if I needed to I could pull the red wire from the ESC and plug in the red wire from the BEC to join the two connectors together right?

You also said that since the ESC had a signal wire it needed the ground going to the Rx for refrence, so we can't remove the ground from the ESC and have both black+red from BEC joined with Signal from ESC right?

But the BEC doesn't have a signal wire so does it need a ground? If we take the red wire from the BEC and plug it into the ESCs connector then can't we just shrink-cover the BECs ground and leave it unconnected?

Just curious, I have a 9Ch receiver so I have plenty of slots for my BEC. :D

:banana

[Pinecone]

BEC still needs the ground wire connected. Think about it, how well does a battery work with only one terminal connected? Electricity flows in a circle, so you need both leads.

If you run out of slots, use a Y connector to hook the BEC up to any slot. If you use the ESC slot, you can cut the red wire in the Y connector on the leg connected to the ESC.

Do realize, some ESCs require all three wires hooked up since they actually get their power from the BEC also (the power to run the electronics of the ESC, not to run the motor).

[chasenichals]

Guys im new here,first post...and im downloading and watching all of these vids but i do have a question,I also build edf jets along with my helis,the current edf im building requires a 4s pack and there for i need an rx pack or a bec,the latter being lighter.the plane is a twinn,is the connection method in this video the same for my edf as well,also i only need one bec even though its a twinn,right.and does it matter which side i connect the bec to.thanks..Chase