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Old Sep 30, 2015, 09:32 PM
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How can you tell the Amp draw rating of this esc?

It's an old esc but still working. Not sure if this is 20amps or 30amps.

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Old Sep 30, 2015, 09:36 PM
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The other side
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Old Sep 30, 2015, 10:23 PM
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Just a guess, but that looks like a part number in the first photo: HL30VA14. Don't know if that indicates 30A or 14A, or doesn't mean anything.
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Old Sep 30, 2015, 10:49 PM
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Technically no way to tell just from examination. That's like looking at a unlabelled computer motherboard and knowing how fast the computer is. If you have a temperature gun that would probably let you know with some test runs.
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Old Sep 30, 2015, 11:29 PM
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Geez.. i thought it was easy as counting the number of chips in there.

Quote:
Just a guess, but that looks like a part number in the first photo: HL30VA14. Don't know if that indicates 30A or 14A, or doesn't mean anything.
make sense.. Could be 30A for 14V? HL30AV14

though still not sure.
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Old Sep 30, 2015, 11:38 PM
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I'd say it's a 4S 30A ESC. Scrape the goo off the FETs so we can see the PNs and maybe there's more that can be said...

The three chips on the right side of the second picture are IR2003 bridge-drivers. They control the FETs on the other side of the board, as seen in picture 1.
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Old Oct 01, 2015, 12:30 AM
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Quote:
Originally Posted by DYORD View Post
It's an old esc but still working. Not sure if this is 20amps or 30amps.

Help
I have some old ones with missing labels ... and what I do is use them on lesser jobs ... if they start to run hot ... I know its being pushed to limits.

Trying to determine original amp rating is near impossible.

Nigel
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Old Oct 01, 2015, 08:58 AM
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I'm with Nigel, put a load on it with a prop and battery you want or intend to use and hold it between your fingers.

When the MOSFET field gets almost too hot to hold (130F/54C) you are approaching a sensible continuous load limit. But if the temperature is still rising you may be on the way to eventual self destruction with a fried MOSFET.

Most MOSFET are rated for continuous operation up around 80-100C or so. But when they are mounted and packaged in a typical wrapping, and you are judging heat from the outside, you don't want to find that temperature there. So backing off at 130F/54C or a little more becomes a sensible point to do it at. If you are using a real time temperature sensor and have the probe inside the heat shrink in the MOSFET field you can judge the temp of the field itself better and run it up closer to the MOSFET's limit.

Almost any ESC can be run at higher than the recommended voltage as long as that voltage does not exceed the limits of a built in BEC. That is especially so if it is a linear BEC. If you do not use the BEC (pull the red wire from the throttle/BEC lead) you can often run a ESC rated for 3S at 4S or maybe even higher.

Jack
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Old Oct 05, 2015, 12:15 PM
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As noted before, remove the goo on top of the MOSFETs and read off the part number. Find the datasheet on that part number and look for drain current rating. There are typically two values provided for low temperature and high temperature operation. Take the high temperature value and double it. That should be the max current you can put through your ESC. The reason you're doubling it is because you have two MOSFETs in parallel for positive and two for negative switching for each motor connection.
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Old Oct 05, 2015, 01:26 PM
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Quote:
Originally Posted by rocketsled666 View Post
I'd say it's a 4S 30A ESC...
I'd agree on the current rating of 30A, but would say "V14" is for 14 volts, which would limit it to 3S.
I don't think I'd try this on 4S.
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Old Oct 05, 2015, 10:25 PM
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Maybe. But manufacturers are generally lazy (I know, I am one). "V14" is fewer characters than "V14.8". And "V14" is every bit as unambiguous as "14.8". Markings like this are rarely exact reflections of operating specs, sometimes markings don't reflect anything about the operating spec, you have to look up the model # to figure it out. But when manufacturers do mark products they tend to use markings exact enough to accurately differentiate model types and no more. 2S would be "07", 3S would be "12", 4S would be "14", etc. etc...

You buy a 4S ESC and it says "14.8V" and that's not right, either. A fully charged 4S pack is 16.8V, so a "14.8V" ESC is actually rated for 16.8V.

Getting the part numbers on the FETs would help answer this more definitively though.
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Old Oct 06, 2015, 07:37 AM
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Quote:
Originally Posted by rocketsled666 View Post
Maybe...
You buy a 4S ESC and it says "14.8V" and that's not right, either. A fully charged 4S pack is 16.8V, so a "14.8V" ESC is actually rated for 16.8V.

Getting the part numbers on the FETs would help answer this more definitively though.
I see what you're saying, and agree. Since fully charged 3S is 12.6V, and "V14" is greater than that, it could be 4S capable. I guess I've never looked at the labeling on any of my ESCs to see if they say "14.8V" on them.

But, yes, the best way to be sure would be to look up the data sheet of the FETs...

:cheers:
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Old Oct 06, 2015, 08:26 AM
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We can argue about it but, generally speaking, I think the best way to make the determination here is to put a motor and some voltage on it, using a servo tester as a throttle, and slowly and carefully bring up the load on it while checking for heat.

The real danger spots will be the BEC, especially so if it is a linear BEC and not a switching BEC, so I would not load the BEC at all and use an external BEC for the testing. Handle it as you test or use visible temperature displays and sensors and let the heat decide it all.

There are a number of ESC's on the market that have proven themselves as perfectly useable at higher than the rated input voltage as long as the BEC is not used at the higher voltage. A good example of ESCs that are like that are the older Castle Creations Thunderbird and Phonix ESCs.

Jack
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Old Oct 06, 2015, 09:01 AM
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Knowing the transistor specs would certainly give the true maximum voltage; even without a load, exceed that limit and the parts could fail catastrophically. But, yeah, I would expect a much higher true limit than whatever the builder specified, except for the BEC. That round thing on the component side looks like a toroid for a switcher, but there could be other reasons for its presence, e.g.: drive voltage for the FETs.
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Old Oct 08, 2015, 12:40 PM
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hello
i am new for making quadcopter ..
it is my first quad-copter ..
my first target is ondly to fly
quadcopter up - down
i don't want to ( forward-back or left-
right ) ( i hope i will do it latter )
For controlling i have to ( want to)
use arduino ..
As my way of thinking working of quadcopter is :-
The transmitter transmits the singnal which receiver receives and gives it to arduino
(Arduino is pre-programed)
So according singnal received arduino generate PWM singnals
Which gives to ESC &
According to that ESC will run the motor ..
My question is :-
There is need of gyro ?
If yes .. Than why ? & How?

I really need help for these ..
I request you to answer me as soon
as possible as well as briefly
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