# most powrfull 48V brusless controller?



## hardwired (Sep 11, 2007)

helps to read title of post before responding


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## niko (May 1, 2010)

edit : yes , it's nor brushless


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## frodus (Apr 12, 2008)

that alltrax is not a brushless controller.


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## 9852 (Jan 17, 2010)

well, some people on this forum, dont like it, but Logisystems has a 48v 700amp controller with a continous rating of 375amps. i use it in my car now and have about 1000 miles with no problems. it cost $345.00 and has a curtis1205 footprint, here is a couple of pics of it


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## niko (May 1, 2010)

thansk
same , looks nice , but is it for Brushless?


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## major (Apr 4, 2008)

niko said:


> Hello,
> I'm looking for a brushless controller which has to be very reliable and which could handle 500A continuous @48V. Or even more if that exists
> motor going on it
> Kv étoile = 35 rpm/V Rm = 0.016 ohm Io = 4.8A @ 40V
> ...


Hi niko,

Can you post a picture of this motor? I'd really like to see what you're talking about.

I have never seen a BLDC controller capable of 500A continuous (or even 400) at 48 volts. This product would be in that neighborhood for rated current, but needs a much higher voltage. It is possible that the inverter could be altered to run on low voltage. But you are looking at a $40k product. 

http://www.uqm.com/pdfs/PP150 Spec Sheet 4.21.10.pdf 

Regards,

major


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## frodus (Apr 12, 2008)

Aside from Major, no one has posted anything relating to a BRUSHLESS controller. I don't think they're actually reading your thread....

Basically, for 48V, you're looking at Sevcon or Kelly, and neither of them will do 500A continuous....

if you want that kind of power (24kw), start looking at higher voltage.


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## 9852 (Jan 17, 2010)

sorry, I guess I cant read, I dont think it is for a brushless motor.


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## niko (May 1, 2010)

motor is Douchka 2 from parawatt http://www.razeebuss.com/_wp_generated/wp158bb801.png
It comes with a controller
But controller till now in aircraft applications is the weakpoint. And this engine will go on a ultralight able of 1 hour and more of fligh and in spite controller is given for 200A continuous (making 10kW which is enough for continuous stall) I wish a safety margin . Aircraft is not like a car and controler failure can have consequences (previous flights with cricri lead to critical situations according to his pilot) 
I would be really confortable with 20kW continuous (400A) , or at least 300A
what is you opinion about Kelly's ? http://www.newkellycontroller.com/product_info.php?cPath=23_45&products_id=259


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## frodus (Apr 12, 2008)

Don't just arbitrarily chose a current.... you need to make sure that the motor can even HANDLE 500A continuous. Match the motor AND controller. I know you want some overhead.... but at some point, you lose because you can't use the extra power without overheating the motor.

Kelly are "ok", but not the best. Some people have no issues, other people have had many problems. They're overrated (if you want 500A, get a 1000A controller). The controller you linked to "Motor Current Limit, continuous: 250A.", so even though its 500A, its only 250A continuous. Some people have also noticed heating in the BLDC motors, and this might be because of the switching frequency of the controller.


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## major (Apr 4, 2008)

niko said:


> what is you opinion about Kelly's ?


No personal experience here. But I've heard they are over rated by like a factor of 2, at least. And I have seen multiple reports of failures and poor company support. A few guys here and there turn out to be pleased with their products.


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## Amberwolf (May 29, 2009)

There are some folks over at Endless Sphere forums working on a BLDC (PM) controller to do several hundred amps continuous at even higher voltages than 48; but I expect it'll be some time before they have a viable design worked out.


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## niko (May 1, 2010)

Hello,
a few monthes later , we are still trying to find another very reliable brushless controller 48-72V , able to support 400A or more continuous (meaning rated 800-1000A peak)
price doesn't mind (a few thousand $) , it's for an experimental aircraft . Even developper offers are welcome 
If you hear about something please report here ! thanks


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## DavidDymaxion (Dec 1, 2008)

Does an airplane really need a controller? Don't airplanes like to run fairly constant rpm, the peak of this being a constant speed prop. I'm just curious what is driving the design decision for a brushless controller, instead of a simple shunt motor.


niko said:


> Hello,
> a few monthes later , we are still trying to find another very reliable brushless controller 48-72V , able to support 400A or more continuous (meaning rated 800-1000A peak)
> price doesn't mind (a few thousand $) , it's for an experimental aircraft . Even developper offers are welcome
> If you hear about something please report here ! thanks


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## niko (May 1, 2010)

absolutly.
Any brushless motor needs a controller
DC motors are not reliable enough for this purpose (I know some do with it but we want a more performant system)


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## DavidDymaxion (Dec 1, 2008)

How did you decide brushless is more reliable? (Note I'm not saying one or the other is more reliable, just want to learn the data behind that.) A brushless motor and controller has many more points of failure than a DC motor with a switch, plus there are many real life controller failures, so it's one of those things that's not obvious to me.


niko said:


> absolutly.
> Any brushless motor needs a controller
> DC motors are not reliable enough for this purpose (I know some do with it but we want a more performant system)


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## sunworksco (Sep 8, 2008)

Here are a couple of very successfull EV aircrafts.
Regards,
John


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## frodus (Apr 12, 2008)

And it looks like every single one of them is brushed!!!


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## sunworksco (Sep 8, 2008)

If you are building an ultra-light aircraft with a brush-less motor you might look at this combo.This one may need a prop reduction of around 3 to 1 ratio.
I'm using this combo : http://www.thunderstruck-ev.com/index.php?dispatch=products.view&product_id=55

Regards,
John


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## niko (May 1, 2010)

lol , this won't help a lot 
here is our project









we already invested a lot in it. We know that brushless is not the easy way , but this is the one we chose , even though many more projects are running on DC
DC don't seem able to run several hours in these conditions. brushes have burned after 1 hour in many of these projects.
In brushless , weak point is controller , and we try to find another evolution of the one we have on it now









pilot and builder is Jean Luc Soullier ; I'm the one on the right
http://forum.pegase.tv/viewtopic.php?t=4978&postdays=0&postorder=asc&start=570
As now we have more than 1 hour autonomy , switch to H2 cells with carbon tanks will bring us to several hours (6) and JL is aiming to make a cross
Problem with the controler is that it shuts at 320A and even if we have probably the most watt efficient aircraft in europe (65kg , around 100kg with 8kWh kokam !!!) taking off with an "agressive" prop step (necessary for flying efficient) leads to approach dangerously this 320A limit. And JL touched it 2 days ago at 30 ft alt taking off , it became hot
Next step beeing a inflight adjustable prop linked to wattmeter , we also want to explore another option for controller


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## sunworksco (Sep 8, 2008)

You may want to look into the www.alulight.com aluminum foam sandwich panels in place of the wood panels.They are structural and can be welded together.Much stronger and resist magnetic radiation.The only material that is lighter is CF.Your aircraft is wonderful , especially the drive-train!
Brush-less is the best way to build for aircraft use and is a little more resistant to moisture and longer continuous running capability.
You may consider using a small pc tablet for connectivity to the components , especially the controller for better programming during flight.This would measure the watts and create your gauge cluster , too with the proper software.
May I download your blueprint of the airframe ?
Regards and brilliant flying,
John


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## niko (May 1, 2010)

all the work is Jean Luc , I'm only a technical associate 
You can find blueprints at colomban (MC30 Luciole) 
Brushless and controller are allready programmable and controller is a prototype , which is directly optimised by an ingeneer from Werner Eck , it's already a very advanced solution ; but here in europe we probably reached the limit , and by coming here I had the hope that some teams could have worked on it and got some even better amps
We have now an working telemetric measurment of all parameters , and of course a wattmeter onboard
a light mode S transponder (1.5 kgs) has also been put recently to be complete
landing is the normal landing gear , I just found lighter wheels (nylon , 320mm , 60mm width) on which we are starting to adapt light disk brakes to try to gain 1 more kg 
A new set of wings based on carbon rectangular beam will allow probably a total gain of 20 lbs , that we will use for next project too
Your aluminium foam is a really interesting product I take a look at it! this kind of material (together with carbon of course) will be usefull for next step (2011) (behind luciole which were at this time with temporary green stickers)









As you can guess at this point we are looking for a controller specialist to definitly solve this hard point. in case anyone hear about a product , a developper etc.. (in the range 48-72V)
this controller would also fit the Douchka 2 that we never tryed so far (I personaly believe in this engine offering an easier and quicker way to adapt adjustable prop due to empty axle)
thannkkss!


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## sunworksco (Sep 8, 2008)

Here is a specification sheet for the aluminum foam sandwich panel.
Regards,
John


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