BEC 101 Video

[dogfart]

Originally Posted by fireup

On ESC that don't have BEC, you don't have to cut the red/middle wire. On ESC that do have an onboard BEC you should cut the wire or else that voltage will conflict with your external BEC specially if you want to run 6V on your external BEC and your onboard is putting out 5V.

Okay, that makes sense. Do you know how many Volts the BEC contained within the Align 35A ESC (for the Trex 450) puts out?

[Finless]

Align has 2 versions of the 35. The 35G which puts out 5V. It has a GOLD colored heat sink. The Align 35X which puts out 6V and has a blue heat sink.

Dogfart dude... this is documented on the Align web site and the instructions you get with the ESC! Not to harass you man but have you READ the freakin instructions that came with yours?

Bob

[HeliBurns]

Wow, this BEC thread is gaining momentum....

[Finless]

Originally Posted by HeliBurns

Wow, this BEC thread is gaining momentum....

Yea I am kind of surprised too... I had no idea that this BEC / ESC stuff was that confusing to people???? I shot this video kind of ADHOC on a request and I may have to do it again to cover all the questions!

Interesting for sure....

Bob

[HeliBurns]

Bob, I think it is a good thing....I think it's a subject that has been overlooked
for a long time.....

Our servo manufacturers are very vague on what max(or even average) current might be needed...and perhaps rightly so, as they can't predict what load is appropriate for everyone.....

I just wish they could spec at least the stall current so that we can "guesstimate" what we need from a BEC depending on what servos we are using...I tend to want to overspec by at least 50% just for piece of mind, even though it might not be necessary...but that's just me...

What is surprising to me is that linear regulators are even used at all, given the state of the tech. art of today's switchers....but again, who am I to judge...

I'm a happy camper.....just received my TR500...
Can't believe what a small box it is.......

[HeliBurns]

Bob, I also forgot to add this....

Perhaps a video could be made....that discussed ESD precautions that we must be careful of when handing sensitive circuitry.....I don't mean to burden you with
extra work, but you be the man...and people will listen to you......

[Finless]

Well me being a field rep for years and understanding ESD I would agree BUT I think you might be a bit over zealous on this one. You cant expect most guys to go out and buy a freaking ESD wrist strap and pad to work on their helis!
Honestly I have worked with CMOS for a lot of years and handled 100,000 circuit boards in my 30 years or so... In fact I have probably modified 10,000 astro CCD cameras and never had a failure due to ESD.
Look at this web page and what i was doing for a long time before I gt back into RC helis:
http://home.socal.rr.com/hotweb/vesta/vesta.html
The home page is here too if you want to look
http://home.socal.rr.com

Anyway I am NOT disagreeing that ESD is a problem I am just saying that I think some people are way to paranoid about it!

I don;t see an ESD video in my list of videos to do anytime soon... If you think it is that important go for it... These are consumer devices and as a consumer I SHOULDN'T need a class on ESD to use them... Sorry dude...

Bob

[dogfart]

Originally Posted by Finless

Align has 2 versions of the 35. The 35G which puts out 5V. It has a GOLD colored heat sink. The Align 35X which puts out 6V and has a blue heat sink.

Dogfart dude... this is documented on the Align web site and the instructions you get with the ESC! Not to harass you man but have you READ the freakin instructions that came with yours?

Bob

Call me a 'tard. I am pretty sure that I had read the instructions, but I did not see the answer there. It did not occur to me to try the website though.

EDIT: By the way, thanks for the answer though.

[HeliBurns]

Bob, while you're experience in the handling of CCD devices over your distiguished career is outstanding.......having said that, I am totally amazed
that you make such statements that discount any ESD effects....

If your point of view is such that it's too much of a hassle for the average person
to take care with respect to ESD..then you are inadvertently doing people a diservice...one can simply ground themselves with a PC power cord......

Bob, you go ahead and handle circuitry in the manner that you are familiar with....
but please don't discount how your mishandling of such circuitry is of no consequence to the end user...

'Nuff said

[da.tsun]

Can anybody tell me how to download videos I click and all I can see message from members

Thanks

[Pinecone]

wrong thread

[msaeger]

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

[fireup]

Originally Posted by msaeger

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