420A 24S ESC by aliens

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bearing   10 kW

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420A 24S ESC by aliens

Post by bearing » Oct 23 2012 5:04am

Spotted these on eBay.
Alien Power Systems.

Controllers are for RC, but are supposed to work on bikes too. PC interface for settings.
I can supply 200, 250, 300, 350 and 400A, with a battery voltage from 2 to 24s Li po, with firmware for heli, boat, car or e-bike, and cooling system for air, street and boat.

If you require any customisation, such a different amp, power, different application, specific parts (capacitors, mosfeet ext.) then please ask as i can provide these.
Air cooled 420A 24s
http://www.ebay.co.uk/itm/420A-4-24S-ES ... 3f1da2436e

Watercooled 420A 24s
http://www.ebay.co.uk/itm/420A-4-24S-Bo ... 3f1dc24e45

EDIT: Links are dead. New link:
http://alienpowersystem.com/product-cat ... sc/ev-esc/


EDIT 2013-11-22
420A Controller has been tested by liveforphysics!

http://endless-sphere.com/forums/viewto ... 35#p825135



EDIT 2013-05-22:
Later in this thread a member gets a 420A controller after volunteering to make a proper test of it. The test has not been done yet. So if you read through the entire thread expecting to find the results of the test, there is a good chance that you will become frustrated, disappointed and start expressing that in different ways, which is what the later half of this thread currently contains.

Pictures of some hardware to be used during the test, and a discussion of how the test should be performed starts at the post linked below.
http://endless-sphere.com/forums/viewto ... 65#p700565

If I'm still around when the test is made, I will add a link to it. If not, I'm sure a moderator will do it instead of me.

Some people have stated success of using different Alien controllers in practice, with both wheel hub motors and RC motors. I don't have the time/interest to find those posts and put the links here, but if someone hands me the links, I'll paste them here.
Last edited by bearing on Nov 26 2013 4:38am, edited 6 times in total.

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Re: 420A 24S ESC by aliens

Post by nieles » Oct 23 2012 7:57am

i am not 100% sure, but it looks like a re-branded fighercat controller to me

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Re: 420A 24S ESC by aliens

Post by bearing » Oct 23 2012 8:43am

Thank you, I suspected that it would be a rebranded product, but wasn't able to find the original source.

So this is the original source?
http://fliermodel.en.alibaba.com

The closest model I can find is this one. It has the same weight and appearance, but not the same voltage and current.
http://fliermodel.en.alibaba.com/produc ... 5_Car.html
630gram, 350A, 8s.

Maybe he gets them custom made with 100V FETs and capacitors. If they can handle 350A with 8s, it isn't really believable that they can handle 420A with 24s, though. But who knows, the newest surface mount power mosfets are almost as good as an IRF4110, and you can fit a lot more of them in the available space.

Found this video
http://www.youtube.com/watch?v=J5zE4o0TE-M

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Re: 420A 24S ESC by aliens

Post by nieles » Oct 23 2012 12:51pm

there used to be a fightercat website. but i cant find any controllers on that website anymore.

http://www.fightercatracing.com

about the rating on the controller. what i find a 200a controller could be a 400a controller to a Chinese vendor.
since it is not specified for how long the controller has to last at 400a. could be 1 sec. could be 20 sec. who knows.

all i know from my rc days is this: never trust the rating on any rc controller/motor/whatever, especially if it comes from china/hong kong

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Re: 420A 24S ESC by aliens

Post by neptronix » Oct 23 2012 1:22pm

420A for how long, a second? :mrgreen:

Nothing this size is capable of pushing out that kind of power for long. I would bet that it's capable of 50A-75A continuous, on a nice cold day..

Look how large multi hundred amp controllers are. Maybe if this thing consisted of 3 solid blocks of copper, it could transmit 3 phases of 420A, but it sure ain't!
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Re: 420A 24S ESC by aliens

Post by liveforphysics » Oct 23 2012 1:32pm

bearing wrote: But who knows, the newest surface mount power mosfets are almost as good as an IRF4110, and you can fit a lot more of them in the available space.
There are datasheets for SMT parts that to a fool make them look radically better than other legged part offerings. The issue with them has nothing to do with how amazing the dice in the packages, or even how well it can transfer heat into a PCB, the problem is if you're using a PCB to cool the part, it's doomed. If it's made with new super amazing dice with 1/4 the resistance of the previous best stuff, it just lives about 4x longer before it turns to plasma.
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Re: 420A 24S ESC by aliens

Post by bearing » Oct 23 2012 1:45pm

I have been writing with the guy who sells these today, and I think he is from Europe, probably Italy. He knows some electronics, and has chosen the FETs and the capacitors himself, and possible some other components. He offers rewinding of RC-motors too, and you can see in the video above that the 80100 he is using is rewound. Not to the highest fill factor, it looks, though.

From our letters:
bearing wrote: ...
Have you tested the controller at 400A?
Sorry to be a bit skeptic, but I work as an electronics engineer, and I know that it's hard to make electronics capable of 400A.
...
If the motor is used at 400A 50% duty, then the capacitors will see 200A, which is 50A each. They are probably able to handle that current for a short time, but I think they will heat up very fast.
...
bruno6168 wrote: Don't worry. I can understand. I'm not an engeneering but is long time that i do electronics thing. You are right about the capacitors but always the theory and the ptactice are little bit different. The last test i have done with the 400Amp model was 250Amp, 74V in load for 5 minutes. No issue. About 3 weeks ago the test was 450Amp, 96V for 1 minute. No load. Everything fine

Anyway when you start a project is a lots of things to consider. The item is covered of full warranty exept any wrong use or modification.

All the people that buy it are very impressed. Let me know if you need more info. I will be happy to help you. Regards
I don't know what to believe about the testing, but if they are only at no load, they aren't of much use, of course. It could be a typo though, i.e, he meant "no issue". To me he doesn't look like a liar. And he does offer a warranty. I feel like ordering one to try out, and maybe put through a test with an 80100. I'll decide after he gives me some info on the FETs.
liveforphysics wrote:the problem is if you're using a PCB to cool the part, it's doomed
You can get one sided PCB's on an aluminum core. If you put the FET's on one side, and a heatsink on the other side, I think it could provide as much cooling as a TO220 mounted to a heatsink.

I doubt that this ESC is using an aluminum core though, but it could be SMD FETs with a source connection on top. The source connection has a decent thermal resistance to the core too.

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Re: 420A 24S ESC by aliens

Post by liveforphysics » Oct 23 2012 1:53pm

Say its all aluminum core PCBs. Where does the heat go?

I have a video of the latest greatest fighter cat 100v esc (claiming some hundreds of amps number) blowing up after 20seconds of 100amp battery current.

450amps will melt the solder off a pair of 8awg wires in less than a minute. This guy is full of shit.
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Re: 420A 24S ESC by aliens

Post by Miles » Oct 23 2012 1:57pm

They're possibly made by this company: http://www.sunrisemodel.com/pro.asp as the Fighter Cat ones were...

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Re: 420A 24S ESC by aliens

Post by neptronix » Oct 23 2012 2:07pm

Well, you said it better than i could :mrgreen:

The gauge of wire coming out of something is very telling as to what it's capable of. At least when you sell me an underperforming ESC, gimme the right gauge/length of copper for the job. Then maybe it's worth $3 at the scrap recyclers instead of $0 ;)
liveforphysics wrote:Say its all aluminum core PCBs. Where does the heat go?

I have a video of the latest greatest fighter cat 100v esc (claiming some hundreds of amps number) blowing up after 20seconds of 100amp battery current.

450amps will melt the solder off a pair of 8awg wires in less than a minute. This guy is full of shit.
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Re: 420A 24S ESC by aliens

Post by nicobie » Oct 23 2012 2:10pm

Maybe he is talking about phase amps?

I can't see where that fan would do any good as I don't see any exit vents.
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Re: 420A 24S ESC by aliens

Post by neptronix » Oct 23 2012 2:15pm

( skip to 5:05 to see the ESC blow it's magic smoke )

Think about the duration of peak load that a little 2-20 pound RC car puts on a controller. Probably hundreds of amps for half a second, at the most. This thing couldn't stand up to the guy punching the throttle at very low voltage for about 1 second very occasionally.

How long do you think it would last driving something that is 200-300lbs with about a 100x larger aerodynamic footprint?
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Re: 420A 24S ESC by aliens

Post by Punx0r » Oct 23 2012 3:49pm

bearing wrote: ...
If the motor is used at 400A 50% duty, then the capacitors will see 200A, which is 50A each. They are probably able to handle that current for a short time, but I think they will heat up very fast.
...
Maybe I'm just being dense, but the above makes absolutely no sense to me :?:

400A @ 50% duty cycle is 400A. 400A @ 1% duty is still 400A. That duty cycle could cover an hour, a day...

I assume the capacitors he mentions are the input caps? What has their discharge capability got to do with this controller's ability to handle 400A?

The test of it would surely be powering a resistive coil in a bucket of water...

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Re: 420A 24S ESC by aliens

Post by Jeremy Harris » Oct 23 2012 4:08pm

Punx0r wrote:
bearing wrote: ...
If the motor is used at 400A 50% duty, then the capacitors will see 200A, which is 50A each. They are probably able to handle that current for a short time, but I think they will heat up very fast.
...
Maybe I'm just being dense, but the above makes absolutely no sense to me :?:

400A @ 50% duty cycle is 400A. 400A @ 1% duty is still 400A. That duty cycle could cover an hour, a day...

I assume the capacitors he mentions are the input caps? What has their discharge capability got to do with this controller's ability to handle 400A?

The test of it would surely be powering a resistive coil in a bucket of water...
400A at 50% duty cycle is indeed 200A average. As it's heat that blows these things (specifically FET die temperature or bond wire temperature) then the heat is proportional to the duty cycle and the current.

The capacitors are commutation capacitors. They carry substantial ripple current and need a low ESR to function, both of which tend to be a function of value as well as physical construction method. They won't see the phase current, just the current induced by the ripple voltage on the rails. If the capacitors have a high ESR then the ripple will be high and the ripple current will also potentially be high. Generally low ESR is associated with capacitors with a high peak discharge rate.
Please ask questions on the forum, rather than by PM, as it helps others and you'll get a better range of answers.

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Re: 420A 24S ESC by aliens

Post by bearing » Oct 23 2012 4:15pm

Punx0r wrote:
bearing wrote: ...
If the motor is used at 400A 50% duty, then the capacitors will see 200A, which is 50A each. They are probably able to handle that current for a short time, but I think they will heat up very fast.
...
Maybe I'm just being dense, but the above makes absolutely no sense to me :?:

400A @ 50% duty cycle is 400A. 400A @ 1% duty is still 400A. That duty cycle could cover an hour, a day...

I assume the capacitors he mentions are the input caps? What has their discharge capability got to do with this controller's ability to handle 400A?

The test of it would surely be powering a resistive coil in a bucket of water...
That quote is from a message from me to the seller, and was leading to a question about the nominal current limit. He didn't answer that, but did answer that he had used it at 250A for 5 minutes.

If the motor consumes 400A at 50% duty of the switching frequency, the input caps will discharge at 200A when MOSFETs are on, and be charged from the battery with 200A when MOSFETs are off. This is the worst case, and means that the RMS current which heats the ESR in cap is 200A.

He wrote that the ESC has 4 caps, and I calculated the heat generated in each cap to be 90W. He may have mixed his controllers up though, because the auction says 6 caps. That makes it 40W per cap. Still way too much for continuous use. I've read that the ESR gets lower as it's electrolyte heats up, so in practice it may not be 40W of losses in the cap, but still, it's not going to handle 400A continuously. I don't need my ESC to handle 400A continuously though, I'll need about 250A peak and probably less than 100A on average.

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Re: 420A 24S ESC by aliens

Post by Punx0r » Oct 23 2012 5:45pm

Ah, right. PWM duty, not motor duty like I was thinking...

I clearly have some learning to do. I thought the only caps in a brushless controller were the smoothing ones on the input.

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Re: 420A 24S ESC by aliens

Post by bearing » Oct 23 2012 6:05pm

This is about those caps. They will be beaten to death at half max speed and max load (up a hill for example). In a normal acceleration from zero to full speed, they are only heated for a short time, since there is no ripple current at max speed. When cruising at half speed, the current is low. But on on a race track for example, you'll probably accelerate hard from like 40% to 80% of max speed out of most corners, which will destroy an under dimensioned set of caps eventually.

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Re: 420A 24S ESC by aliens

Post by neptronix » Oct 23 2012 6:26pm

You two are missing the biggest part of the equation - the FETs, the traces, the other bits and pices, and the extreme lack of heatsinking.

I have not heard of a single RC ESC that lives up to it's claims. ebike/ecar/emotorcycle controllers are rated for a certain constant current, but it seems that RC ESCs are rated all at peak current and it's expected that said peak current will last a few seconds or less - not minutes.

This reminds me of the ultrafire cell argument. :lol:
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Re: 420A 24S ESC by aliens

Post by bearing » Oct 23 2012 7:02pm

He told me which caps he's using, that's the background to this side discussion about the caps. If he gives me the part number of the FETs, it shouldn't be too hard to judge if they are enough for the application.

This ESC can of course never be used at 400 amps continuously, but that doesn't matter to me, because the motor can't handle that. The motor probably can't handle more than 100A continuously, and 250A peak. I need a 100V ESC which commutates the motor properly, and has the same peak capability as the motor. This is the best I have found so far, for the money. It's not a 100g RC controller, the weight is 650g, so it has to contain some good stuff at least.

I don't get why you say it has an extreme lack of heatsinking. It has two heatsinks with fans. Even though they are small, they could be enough if the rest is done right. I think it's odd though, that there are two heatsinks. Should be either one per phase, or one common. My guess is that it has one brain, and two powerboards, in parallel, each with it's own heatsink. The powerboard is probably the same as in the 200A version. Maybe the same board as in video that you posted... =) the one that blew up.
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Re: 420A 24S ESC by aliens

Post by liveforphysics » Oct 24 2012 12:15am

This is a controller rated for 350amps for 2minutes when bolted to a huge 5lbs heatsink.
It's got 42 mosfets in it. It's got 24 big ass low ESR caps positioned between each row of FETs that have an excellent thermal path to the heat sink.
It's got massive fat high current busses running all over the place.


Image
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RC controllers are for toys.
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Re: 420A 24S ESC by aliens

Post by Arlo1 » Oct 24 2012 1:18am

Sorry bearing I would have answered same as luke but toolman is all over me for my opinion on kellys lately.
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Re: 420A 24S ESC by aliens

Post by Jeremy Harris » Oct 24 2012 4:10am

Punx0r wrote:I thought the only caps in a brushless controller were the smoothing ones on the input.
Those are the commutation caps. Their function is primarily to keep the ripple on the FET supply rails as low as possible, so that high voltage spikes from commutation don't cause the FETs to fail, either from over-voltage or from dV/dT failure. They have a tough job, as they are working at fairly high frequencies (for an electrolytic capacitor) and are carrying fairly high ripple currents. This is why capacitors with a low ESR (Equivalent Series Resistance) over the operating frequency range of the controller are important.
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Re: 420A 24S ESC by aliens

Post by bearing » Oct 24 2012 7:13am

liveforphysics wrote:This is a controller rated for 350amps for 2minutes when bolted to a huge 5lbs heatsink.
It's got 42 mosfets in it. It's got 24 big ass low ESR caps positioned between each row of FETs that have an excellent thermal path to the heat sink.
It's got massive fat high current busses running all over the place.
Thats a nice piece.
liveforphysics wrote:RC controllers are for toys.
Most of them probably are. But I want to argue, that if done properly, you can make something very powerful in a small package like the ESC in question.

Lets make a rough comparison.

The Sevcon has 7 FETs in parallel. I don't know which FETs they are, so I'm going to assume IRFB4115. They have an RDS of 9 mohm, which is doubled at high temperatures - 18 mohm. 7 in parallel makes 2,5mohm. The switching losses on these through hole FETs are quite high. On 120V they are probably roughly the same as the conduction losses, so I'm going to count that as a doubled RDS - 5mohm. The high side and low side are in series - 10mohm. Now it's easy to estimate the heat losses:
At nominal 140A: 140A^2 * 10mohm = 200W
At 350A: 350A^2 * 10mohm = 1200W

I don't know which heatsink Sevcon is using, so I'm assuming something similar to this 300x300x40mm, which is 0,28K/W (natural convection). This puts the heatsink at 56K above ambient at nominal current, and would put it at 340K above ambient if used continously at 350A. The thermal mass of the heatsink makes it possible to use it for 2 minutes. If the mass is 2500g aluminum, then the sink would rise about (1200 - 200)W * 120s / (2500g * 0,9J/(g*K)) = 53K above the nominal temperature, but in practice less, since the heatsink moves more heat as the temp diff to ambient increases. I'm too lazy to solve the equation. 14 FETs with a thermal resistance junction to case of 0,4 K/W is 0,03K/W. At 350A, the FETs will get 1200W * 0,03k/W = 36K hotter than the heatsink.

It looks like the FETs junctions are approaching their maximum temp (175°C) after 2 min of 350A. However, at 50A per FET, the max allowed temp is about 125°C. My numbers are probably a bit worse than reality, but I think they are in the right ballpark. With some airflow around the heatsink, it gets better.


The SMD ESC could have 10 FETs in parallel, or more. I'm going to assume IRF7769. They have an RDS of 3 mohm, which is doubled at high temperatures - 6 mohm. 10 in parallel makes 0,6mohm. The switching losses on these smd FETs are not very high. On 80V they are probably roughly 30% of the conduction losses, so I'm going to count that as a 1,3 times the RDS - 0,8mohm. The high side and low side are in series - 1,6mohm. Heat losses:
At 140A: 140A^2 * 1,6mohm = 32W
At 350A: 350A^2 * 1,6mohm = 200W


Again, I don't know what heatsinks they are, so I'm assuming something similar to this 40x40x16mm, which is 1.93K/W (forced convection). With two of them, it's about 1K/W. This puts the heatsinks at 32K above ambient at 140A, and would put it at 200K above ambient if used continously at 350A. The thermal mass isn't much on these heatsinks, they are 21g each, so about 40g aluminum total. If we allow the sink to rise 60K above above the nominal temperature, we will be able to use 350A for (40 * 0,9J/(g*K)) * 60K / (200W - 32W) = 12s , and in practice more, since the heatsink moves more heat as the temp diff to ambient increases. 20 FETs with a thermal resistance junction to drain of 0,5 K/W is 0,025K/W. At 350A, the FETs will get 200W * 0,025K/W = 5K hotter than the heatsink. This is assuming they are soldered to an aluminum PCB, and the heatsink is mounted on the other side of the PCB.

12 seconds of 350A is not much, but if you increase heatsink mass from 40g to 400g, then you have 120 seconds, which is on par with the Sevcon.

To me it looks like the SMD stuff could compete with the through hole stuff, if done properly. I have yet not seen it done properly.

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Re: 420A 24S ESC by aliens

Post by toolman2 » Oct 24 2012 8:00am

Arlo1 wrote:Sorry bearing I would have answered same as luke but toolman is all over me for my opinion on kellys lately.
:lol: spose thats true, but i would have cut you some slack on this one. :wink:

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Re: 420A 24S ESC by aliens

Post by Jeremy Harris » Oct 24 2012 8:17am

bearing wrote: The Sevcon has 7 FETs in parallel. I don't know which FETs they are, so I'm going to assume IRFB4115. They have an RDS of 9 mohm, which is doubled at high temperatures - 18 mohm. 7 in parallel makes 2,5mohm. The switching losses on these through hole FETs are quite high. On 120V they are probably roughly the same as the conduction losses, so I'm going to count that as a doubled RDS - 5mohm. The high side and low side are in series - 10mohm. Now it's easy to estimate the heat losses:
At nominal 140A: 140A^2 * 10mohm = 200W
At 350A: 350A^2 * 10mohm = 1200W

I don't know which heatsink Sevcon is using, so I'm assuming something similar to this 300x300x40mm, which is 0,28K/W (natural convection). This puts the heatsink at 56K above ambient at nominal current, and would put it at 340K above ambient if used continously at 350A. The thermal mass of the heatsink makes it possible to use it for 2 minutes. If the mass is 2500g aluminum, then the sink would rise about (1200 - 200)W * 120s / (2500g * 0,9J/(g*K)) = 53K above the nominal temperature, but in practice less, since the heatsink moves more heat as the temp diff to ambient increases. I'm too lazy to solve the equation. 14 FETs with a thermal resistance junction to case of 0,4 K/W is 0,03K/W. At 350A, the FETs will get 1200W * 0,03k/W = 36K hotter than the heatsink.

It looks like the FETs junctions are approaching their maximum temp (175°C) after 2 min of 350A. However, at 50A per FET, the max allowed temp is about 125°C. My numbers are probably a bit worse than reality, but I think they are in the right ballpark. With some airflow around the heatsink, it gets better.
The Sevcon in the photo above seems to have IRFB3077s, so Rdson is 3.3 mohm max (2.8mohm average), not 9mohm. Makes a pretty big difference to the heat calcs, but also means this isn't a high voltage controller, probably around 60V max (the 3077s are rated at 75V absolute max). FWIW, the 3077s are my favourite FET for this sort of voltage, relatively low switching losses when driven reasonably well and very low Rdson.
Please ask questions on the forum, rather than by PM, as it helps others and you'll get a better range of answers.

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