Connector for high current

[Zik Saleeba]

I'm designing a small VTOL UAV which runs on brushless DC motors. The
maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
applications like this use Deans Ultra plugs but they're not rated for this
kind of current (info is scarces but some sites claim they're rated at 60A).

http://www.wsdeans.com/products/plugs/ultra_plug.html

I was wondering if anyone had a suggestion of a good polarised 200+ amp
power connector which is light in weight and reasonably easily attached and
detached. Any ideas?

Thanks,
Zik
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Richard Prosser]

Zik,

There's an Anderson power pole connector rated at 350A. I wouldn't say
it's easy to connect/disconnect but probably reasonable considering -
especially if one side is fixed to something moderately immovable.

<http://www.andersonpower.com/products/multipole-sb.html>

RP


2008/6/17 Zik Saleeba <zik@...>:

> I'm designing a small VTOL UAV which runs on brushless DC motors. The
> maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
> applications like this use Deans Ultra plugs but they're not rated for this
> kind of current (info is scarces but some sites claim they're rated at 60A).
>
> http://www.wsdeans.com/products/plugs/ultra_plug.html
>
> I was wondering if anyone had a suggestion of a good polarised 200+ amp
> power connector which is light in weight and reasonably easily attached and
> detached. Any ideas?
>
> Thanks,
> Zik
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Marcel Duchamp]

I don't have the connector info you asked for but am curious about your
design.  Are there any websites with info on this particular plane? My
calcs show that to be 4.66 kw. Wow. I'm impressed!  I'd like to see it.
  Will you use a pic to control any parts of it?

Zik Saleeba wrote:

> I'm designing a small VTOL UAV which runs on brushless DC motors. The
> maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
> applications like this use Deans Ultra plugs but they're not rated for this
> kind of current (info is scarces but some sites claim they're rated at 60A).
>
> http://www.wsdeans.com/products/plugs/ultra_plug.html
>
> I was wondering if anyone had a suggestion of a good polarised 200+ amp
> power connector which is light in weight and reasonably easily attached and
> detached. Any ideas?
>
> Thanks,
> Zik

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Zik Saleeba]

Thanks Richard. That looks like a nice connector but maybe a little large
and heavy for my application. The plane will have a total weight of about
4.5kg. The total weight budget for the airframe and payload is less than 2kg
on a 2m wingspan plane. That means every gram counts (or oz if you're
American). The total assembly there is 18cm long which is about 17cm longer
than the Deans plugs. That's going to be a size and weight issue for me.
Thanks for the pointer though.

Cheers,
Zik

On Tue, Jun 17, 2008 at 9:50 AM, Richard Prosser <rhprosser@...>
wrote:

> Zik,
>
> There's an Anderson power pole connector rated at 350A. I wouldn't say
> it's easy to connect/disconnect but probably reasonable considering -
> especially if one side is fixed to something moderately immovable.
>
> <http://www.andersonpower.com/products/multipole-sb.html>
>
> RP
>
>
> 2008/6/17 Zik Saleeba <zik@...>:
> > I'm designing a small VTOL UAV which runs on brushless DC motors. The
> > maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
> > applications like this use Deans Ultra plugs but they're not rated for
> this
> > kind of current (info is scarces but some sites claim they're rated at
> 60A).
> >
> > http://www.wsdeans.com/products/plugs/ultra_plug.html
> >
> > I was wondering if anyone had a suggestion of a good polarised 200+ amp
> > power connector which is light in weight and reasonably easily attached
> and
> > detached. Any ideas?
> >
> > Thanks,
> > Zik
> > --
> > http://www.piclist.com PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Zik Saleeba]

On Tue, Jun 17, 2008 at 9:57 AM, Marcel Duchamp <
marcel.duchamp@...> wrote:

> I don't have the connector info you asked for but am curious about your
> design.  Are there any websites with info on this particular plane? My
> calcs show that to be 4.66 kw. Wow. I'm impressed!  I'd like to see it.
>  Will you use a pic to control any parts of it?


I'm designing it as a demonstrator of my UAV autopilot. The autopilot is
based on an AT91SAM7 processor, but it does have an auxiliary PIC16F687 to
help with some of the I/O. The autopilot is pretty close to completion.

The plane itself is an unusual design with a swept-forward wing and three
ducted fans providing approximately 6kg of thrust. At the moment it's just a
concept. I'm making a smaller scale R/C version to test the idea first.

Cheers,
Zik
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Steve Smith-2]

Try Anderson power products... The SBS50 is about 3" long as an assembled
pair and are rated at 50A continuously and during mating. The copper mating
surface is about 5x the area of a deans plug and burst mode they are good
for 250+A total weight is about 2 oz and most of that is copper. The
termination pins accept either 6mm or 16mm cable depending on which one you
go for... I know they are bigger than deans but they are well up to the job
. The power pole 30A (PP30) are used for racing cars and are ok to about
100A peak they are about equivalent to the deans plugs but a bit bigger they
could be parallel connected as they stack...


Steve

-----Original Message-----
From: piclist-bounces@... [mailto:piclist-bounces@...] On Behalf Of
Zik Saleeba
Sent: 17 June 2008 00:36
To: Microcontroller discussion list - Public.
Subject: [EE] Connector for high current

I'm designing a small VTOL UAV which runs on brushless DC motors. The
maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
applications like this use Deans Ultra plugs but they're not rated for this
kind of current (info is scarces but some sites claim they're rated at 60A).

http://www.wsdeans.com/products/plugs/ultra_plug.html

I was wondering if anyone had a suggestion of a good polarised 200+ amp
power connector which is light in weight and reasonably easily attached and
detached. Any ideas?

Thanks,
Zik
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist


--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Olin Lathrop]

Zik Saleeba wrote:
> providing approximately 6kg of thrust.

Not likely since Kg is not a measure of force.

********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
[phone].  Gold level PIC consultants since 2000.
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Apptech]

> Zik Saleeba wrote:
>> providing approximately 6kg of thrust.

> Not likely since Kg is not a measure of force.

PICy picky :-).
While that is strictly true, there are many exceptions to
such general usage that allow such nominally "lazy"
statements to be made in polite and even informed company.

eg the pound mass is not a valid unit but is embedded in the
psyche of the US and UK community. What Y'All think is a
pound is actually 1/g th of a slug, but slugs never caught
on. Slugs are to pounds force what Kilograms are to Newtons,
which is Olin's point.

And, properly, one should ask for sold-by-weight material by
it's force value rather than it's mass. Which the lbf is.
But I am not aware of anywhere in the world (though such
perverse places may exist) where eg dead fish is sold by the
Newton.

And even steely eyed rocket men have haggled for countless
thousands of hours over many many decades over the
proprietary of mixing force and mass units in certain
classical instances. eg the unit of merit of a rocket motor
and propellant combination is Isp = "specific impulse".
Some, indeed many, declare the units thereof to be "seconds"
as it is eg the number of seconds that a pound mass of
propellant will produce a pound force of thrust, OR,
pertinent here, the amount of time for which a kgm or
propellant will produce a kgf of thrust. Cancel the units of
eg kgm/kgf and you get seconds. Many argue volubly, as
would, perhaps, Olin,  about the impropriety of such a
cancellation of mixed units. But seconds is "easier" than
saying lbm/lbf or kgm/kgf.

So, mass units as force units is a time honoured aberration
in the thrust using community and, interestingly, more
understood by the general public than the use of the
"correct" units. If Zik had said that his UAV would produce
about 60 Newton of thrust fewer would have understood the
order of force involved. Or, that to be VTOL capable that it
would probably need to "weigh" less than 6 kilogram (even
though kilogram is NOT a valid weight unit :-) * ).

* "It masses about xxx kg" is one way around this.
I haven't met anything being said to eg "mass under 0.4
slug", as Zik's UAV will.

        Russell




--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Wouter van Ooijen]

Apptech wrote:
>> Zik Saleeba wrote:
>>> providing approximately 6kg of thrust.
>
>> Not likely since Kg is not a measure of force.
>
> PICy picky :-).
> While that is strictly true, there are many exceptions to
> such general usage that allow such nominally "lazy"
> statements to be made in polite and even informed company.

Made yes, and hanging someone for making such statements would be out of
bounds, but criticism is certainly justified. IM(H?)O criticizing such
criticism is [self-censorship kicks in].

> And, properly, one should ask for sold-by-weight material by
> it's force value rather than it's mass.

no, definitely by its mass. weighting instruments used are calibrated to
read the mass *at the place they were calibrated*, so nothing wrong with
asking for mass. It even prepares for interstellar trade.

Glimpse from my 6-y old son trying to understand our sometimes confusing
world: kilo is a synonym for 1000, as in km. but it is also a synonym
for 1000g. He is (rightly?) blaming the world for being illogical. He is
in for an interesting life.

--

Wouter van Ooijen

-- -------------------------------------------
Van Ooijen Technische Informatica: www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: www.voti.nl/hvu

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Olin Lathrop]

Apptech wrote:
>> Not likely since Kg is not a measure of force.
>
> PICy picky :-).

Not that picky.  Sloppiness and inattention to detail are the source of many
problems in firmware and electronics.  If he'd said "Kg force" as a short
form of "the weight of 1 Kg at nominal earth gravity", that would have been
fine.  There is enough confusion about physical measures and units that
errors should be stomped on quickly and hard when they pop up.  Ask Nasa
about that satellite...

> eg the pound mass is not a valid unit but is embedded in the
> psyche of the US and UK community.

As long as you say "pound mass", it's clear enough what you mean and it
shows you're not confused about the physics.  "Pound mass" as short for "the
mass of something that weighs 1 pound at nominal earth gravity" is
acceptable.  But saying "pound" when referring to mass is wrong.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
[phone].  Gold level PIC consultants since 2000.
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Tomás Ó hÉilidhe-2]

> Glimpse from my 6-y old son trying to understand our sometimes confusing
> world: kilo is a synonym for 1000, as in km. but it is also a synonym
> for 1000g. He is (rightly?) blaming the world for being illogical. He is
> in for an interesting life.

To be honest I don't see this as any different from saying:

    Give money to the poor

instead of:

    Give money to the poor people

Adjectives being used as nouns, stuff getting shortened, redundant stuff
removed. Plus it helps for newspaper headings:

KILO OF HEROIN SEIZED

:-P

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Jake Anderson-2]

Wouter van Ooijen wrote:

> Apptech wrote:
>  
>>> Zik Saleeba wrote:
>>>      
>>>> providing approximately 6kg of thrust.
>>>>        
>>> Not likely since Kg is not a measure of force.
>>>      
>> PICy picky :-).
>> While that is strictly true, there are many exceptions to
>> such general usage that allow such nominally "lazy"
>> statements to be made in polite and even informed company.
>>    
>
> Made yes, and hanging someone for making such statements would be out of
> bounds, but criticism is certainly justified. IM(H?)O criticizing such
> criticism is [self-censorship kicks in].
>  

I dunno, in terms of giving a ball park figure that's understandable Kg
force seems pretty good to me.
First thing I do when judging the "force" of something in that size
region is mentally divide by 10 to get kilograms and compare that to
cartons of milk. (which works out to a buttload of thrust for a model
sized contraption, its gonna be zippy)

If the OP was making a post about the physics of something then I'd
expect to see it in newtons.

> Glimpse from my 6-y old son trying to understand our sometimes confusing
> world: kilo is a synonym for 1000, as in km. but it is also a synonym
> for 1000g. He is (rightly?) blaming the world for being illogical. He is
> in for an interesting life.
>
>  
The Kilo Gram is an odd unit of measurement, it is actually 1000 grams,
but it "works" better than measuring everything in grams.


--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Apptech]

>>> Not likely since Kg is not a measure of force.

>> PICy picky :-).
>> While that is strictly true, there are many exceptions to
>> such general usage that allow such nominally "lazy"
>> statements to be made in polite and even informed
>> company.

> Made yes, and hanging someone for making such statements
> would be out of
> bounds, but criticism is certainly justified. IM(H?)O
> criticizing such
> criticism is [self-censorship kicks in].

You are being, for you, unusually inconsistent :-). I KNOW
you know what you are talking about and I understand your
point. But it is in practice violated in everyday use in
much of the world to the extent that people are unaware of
the "correct" usage at almost all levels. Weighing units
whose mechanism works by measuring force MAY be calibrated
in mass units on their scale (although a vast number are not
*) but they MEASURE force, as you know. One could argue that
a mass/mass balance is a mass measurer as the two masses
generate forces which are related by the (almost) common
gravity field that they reside in, as I know you know. A
rare example of a true mass measurer is the Space Shuttle's
astronaut weigher which uses AFAIR period of oscillation of
an arm to determine mass. * Pounds are not, as I know you
know, units of mass. Even pounds-mass are not a real unit
(he said dangerously). The real unit is, as I said and as I
know you know, the slug which is the mass which "weighs" g
pounds or about 32 pounds. I have yet to see a mass
measuring device, or a force measuring device, calibrated in
slugs, but there are countless many calibrated in the force
unit pounds, which is the force exerted in a one g field by
the non existent 1 pound mass. ie in the imperial system the
overwhelming common usage is to use force units to represent
both mass and force, and only a scientist, an engineer or a
pedant does otherwise. (I being all 3 ... ;-) ).
For the mksa / SI system the opposite everyday convention
applies and the norm is for both mass and force to be
commonly represented by mass units, leaving poor old Sir
Isaac to the realm of aforesaid scientists, engineers and
pedants. (I being all 3 ...). Which is where we came in.

>> And, properly, one should ask for sold-by-weight material
>> by
>> it's force value rather than it's mass.

> no, definitely by its mass. weighting instruments used are
> calibrated to
> read the mass *at the place they were calibrated*, so
> nothing wrong with
> asking for mass. It even prepares for interstellar trade.

As above.
Slugs just don't cut it.

And re my discourse on Isp. That argument really has gone on
for decades and is unlikely to ever be resolved. In that
case it's almost only the pedants who get it "correct". Some
give up, multiply Isp by g and call it exhaust velocity.
Which it sort of is, but it is far less evocative.

> Glimpse from my 6-y old son trying to understand our
> sometimes confusing
> world: kilo is a synonym for 1000, as in km. but it is
> also a synonym
> for 1000g. He is (rightly?) blaming the world for being
> illogical. He is
> in for an interesting life.

Indeed :-)


        Russell

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Martin Klingensmith]

Zik Saleeba wrote:

> I'm designing a small VTOL UAV which runs on brushless DC motors. The
> maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
> applications like this use Deans Ultra plugs but they're not rated for this
> kind of current (info is scarces but some sites claim they're rated at 60A).
>
> http://www.wsdeans.com/products/plugs/ultra_plug.html
>
> I was wondering if anyone had a suggestion of a good polarised 200+ amp
> power connector which is light in weight and reasonably easily attached and
> detached. Any ideas?
>
> Thanks,
> Zik

I doubt you'll be drawing 200 amps for very long, right? A minute or
two? You should be fine with something like a powerpole connector. There
are no light-weight easily-attached connectors that are rated for 200
amps. Electric vehicles routinely use Anderson connectors rated for a
few hundred amps, at very high peak currents.

-
Martin
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Gerhard Fiedler]

Jake Anderson wrote:

> Wouter van Ooijen wrote:
>> Glimpse from my 6-y old son trying to understand our sometimes confusing
>> world: kilo is a synonym for 1000, as in km. but it is also a synonym
>> for 1000g.

Only a "synonym", as in "everyday language", otherwise it would be
something like "kilogram". I think he's probably old enough to start
understanding the difference between exact definitions and "normal"
language.

> The Kilo Gram is an odd unit of measurement, it is actually 1000 grams,
> but it "works" better than measuring everything in grams.

That has historical reasons, because the units meter and gram (and many
others) were there before the SI and its precursors like CGS were formed.
They picked the base units among what was already there, considering
convenience over consistency.
<http://physics.nist.gov/cuu/Units/history.html>

Gerhard

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Zik Saleeba]

Thanks guys - powerpoles seem to definitely be the favored choice. I'll have
to look into just how far I can reasonably push the specs to get as small
and light a version as possible into my plane.

Cheers,
Zik

On Wed, Jun 18, 2008 at 12:49 AM, Martin <martin@...> wrote:

> Zik Saleeba wrote:
> > I'm designing a small VTOL UAV which runs on brushless DC motors. The
> > maximum current draw at the LiPo battery is 210A (at 22.2V). Normally R/C
> > applications like this use Deans Ultra plugs but they're not rated for
> this
> > kind of current (info is scarces but some sites claim they're rated at
> 60A).
> >
> > http://www.wsdeans.com/products/plugs/ultra_plug.html
> >
> > I was wondering if anyone had a suggestion of a good polarised 200+ amp
> > power connector which is light in weight and reasonably easily attached
> and
> > detached. Any ideas?
> >
> > Thanks,
> > Zik
>
> I doubt you'll be drawing 200 amps for very long, right? A minute or
> two? You should be fine with something like a powerpole connector. There
> are no light-weight easily-attached connectors that are rated for 200
> amps. Electric vehicles routinely use Anderson connectors rated for a
> few hundred amps, at very high peak currents.
>
> -
> Martin
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>

--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Zik Saleeba]

Who'd have thought that I'd wake up this morning to a nice flame war on the
piclist which apparently I started by simply referring to thrust in units of
kg. Now I know why I love this place.

Incidentally the manufacturer of the ducted fan I'm using themselves quote
the thrust in grams:

http://oos.modelengines.com.au/command/servlet/Command?command=display_item_pub&pkey=meng&itemid=HIM-DF96

Sloppy use of units is pretty common in the R/C world. I'm not going to try
to justify it. In the end it's all about the most effective form of
communication for the medium. Let's face it - even Olin knew what I meant
and he's the one who made the fuss in the first place. If I'd given the
thrust in Newtons how many people would have taken the time to think it
through? Of course if I'd been writing a formal spec rather than a casual
email I'd probably have expressed it differently.

Cheers,
Zik
PS. I bet James is glad he un-moderated Olin
--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

[Apptech]

> I'm designing a small VTOL UAV which runs on brushless DC
> motors. The
> maximum current draw at the LiPo battery is 210A (at
> 22.2V). Normally R/C
> applications like this use Deans Ultra plugs but they're
> not rated for this
> kind of current (info is scarces but some sites claim
> they're rated at 60A).
>
>