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From: acannell on 7 Oct 2009 19:00
oh you guys are gonna like this one...

so i bought a winch for my jeep but it didnt come with a controller
box.

so i need a way to connect the 12V from the jeep battery to the winch
ON and OFF like....and reverse it...so I can reverse the winch
direction

thats it!

needs to be controlled with a rocker switch, or two switches, whatever

the maximum steady-state current of the winch is about 300A, so the
switching circuit needs to handle that

and of course the winch is an enormous DC motor

so...whats a fun way to do this? bank of mosfets? something else?

i know i can just by a big relay/contactor, but i want to make this
myself...

suggestions?



From: Joerg on 7 Oct 2009 19:26
acannell(a)wwc.com wrote:
> oh you guys are gonna like this one...
>
> so i bought a winch for my jeep but it didnt come with a controller
> box.
>
> so i need a way to connect the 12V from the jeep battery to the winch
> ON and OFF like....and reverse it...so I can reverse the winch
> direction
>
> thats it!
>
> needs to be controlled with a rocker switch, or two switches, whatever
>
> the maximum steady-state current of the winch is about 300A, so the
> switching circuit needs to handle that
>
> and of course the winch is an enormous DC motor
>
> so...whats a fun way to do this? bank of mosfets? something else?
>
> i know i can just by a big relay/contactor, but i want to make this
> myself...
>
> suggestions?
>

I would use a huge contactor. If it absolutely has to be electronic
you'll need an H-bridge driver with integrated charge pump, like this:

http://www.freescale.com/files/analog/doc/data_sheet/MC33883.pdf

Then probably 8 or 12 of those, plus some discrete parts:

http://ixdev.ixys.com/DataSheet/DS99630A(IXTH-TQ280N055T).pdf

As you can see this gets a tad expensive. Also, you need to have some
safety shut-down feature to cut power when the MOSFETs weld themselves
shut. Or in case of a contactor if the contacts weld together. After
all, you don't want the winch to keep cranking and then pulling your
Jeep up a tree :-)

Remember, you do this on your own risk, 300 amps and so much power is
dangerous.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
From: acannell on 7 Oct 2009 19:41
On Oct 7, 4:26 pm, Joerg <inva...(a)invalid.invalid> wrote:
> acann...(a)wwc.com wrote:
> > oh you guys are gonna like this one...
>
> > so i bought a winch for my jeep but it didnt come with a controller
> > box.
>
> > so i need a way to connect the 12V from the jeep battery to the winch
> > ON and OFF like....and reverse it...so I can reverse the winch
> > direction
>
> > thats it!
>
> > needs to be controlled with a rocker switch, or two switches, whatever
>
> > the maximum steady-state current of the winch is about 300A, so the
> > switching circuit needs to handle that
>
> > and of course the winch is an enormous DC motor
>
> > so...whats a fun way to do this? bank of mosfets? something else?
>
> > i know i can just by a big relay/contactor, but i want to make this
> > myself...
>
> > suggestions?
>
> I would use a huge contactor. If it absolutely has to be electronic
> you'll need an H-bridge driver with integrated charge pump, like this:
>
> http://www.freescale.com/files/analog/doc/data_sheet/MC33883.pdf
>
> Then probably 8 or 12 of those, plus some discrete parts:
>
> http://ixdev.ixys.com/DataSheet/DS99630A(IXTH-TQ280N055T).pdf
>
> As you can see this gets a tad expensive. Also, you need to have some
> safety shut-down feature to cut power when the MOSFETs weld themselves
> shut. Or in case of a contactor if the contacts weld together. After
> all, you don't want the winch to keep cranking and then pulling your
> Jeep up a tree :-)
>
> Remember, you do this on your own risk, 300 amps and so much power is
> dangerous.
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.

the fun begins!

why did you pick out a fet with a relatively low Ids? some of those
ixys parts go up to 700A+. is a bank of fets better than a single fet?
From: Joerg on 7 Oct 2009 20:04
acannell(a)wwc.com wrote:
> On Oct 7, 4:26 pm, Joerg <inva...(a)invalid.invalid> wrote:
>> acann...(a)wwc.com wrote:
>>> oh you guys are gonna like this one...
>>> so i bought a winch for my jeep but it didnt come with a controller
>>> box.
>>> so i need a way to connect the 12V from the jeep battery to the winch
>>> ON and OFF like....and reverse it...so I can reverse the winch
>>> direction
>>> thats it!
>>> needs to be controlled with a rocker switch, or two switches, whatever
>>> the maximum steady-state current of the winch is about 300A, so the
>>> switching circuit needs to handle that
>>> and of course the winch is an enormous DC motor
>>> so...whats a fun way to do this? bank of mosfets? something else?
>>> i know i can just by a big relay/contactor, but i want to make this
>>> myself...
>>> suggestions?
>> I would use a huge contactor. If it absolutely has to be electronic
>> you'll need an H-bridge driver with integrated charge pump, like this:
>>
>> http://www.freescale.com/files/analog/doc/data_sheet/MC33883.pdf
>>
>> Then probably 8 or 12 of those, plus some discrete parts:
>>
>> http://ixdev.ixys.com/DataSheet/DS99630A(IXTH-TQ280N055T).pdf
>>
>> As you can see this gets a tad expensive. Also, you need to have some
>> safety shut-down feature to cut power when the MOSFETs weld themselves
>> shut. Or in case of a contactor if the contacts weld together. After
>> all, you don't want the winch to keep cranking and then pulling your
>> Jeep up a tree :-)
>>
>> Remember, you do this on your own risk, 300 amps and so much power is
>> dangerous.
>>
>> --
>> Regards, Joerg
>>
>> http://www.analogconsultants.com/
>>
>> "gmail" domain blocked because of excessive spam.
>> Use another domain or send PM.
>
> the fun begins!
>
> why did you pick out a fet with a relatively low Ids? some of those
> ixys parts go up to 700A+. is a bank of fets better than a single fet?


That depends on the size of your wallet, lottery winnings and such. The
FETs I suggested are slightly above $4 a piece. Four of these would also
suffice but it'll come to a grand total of 1100 bucks because they cost
$275 each:

http://www.microsemi.com/datasheets/APTM10UM01FAG-Rev1.pdf

Or this one for the "bargain price" of $150 a pop, ouch:

http://ixdev.ixys.com/DataSheet/L286.pdf

And then you do some outdoors stuff, get into a rain storm, lightning
.... *PHUT* ... hundreds of bucks gone.

I have paralleled FETs many, many times and the reason was always the
same: $$$. However, you may need resistors in series with each gate,
usually something around 10ohms.

Personally I'd use the traditional big old contactor :-)

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.
From: acannell on 7 Oct 2009 20:31
On Oct 7, 5:04 pm, Joerg <inva...(a)invalid.invalid> wrote:
> acann...(a)wwc.com wrote:
> > On Oct 7, 4:26 pm, Joerg <inva...(a)invalid.invalid> wrote:
> >> acann...(a)wwc.com wrote:
> >>> oh you guys are gonna like this one...
> >>> so i bought a winch for my jeep but it didnt come with a controller
> >>> box.
> >>> so i need a way to connect the 12V from the jeep battery to the winch
> >>> ON and OFF like....and reverse it...so I can reverse the winch
> >>> direction
> >>> thats it!
> >>> needs to be controlled with a rocker switch, or two switches, whatever
> >>> the maximum steady-state current of the winch is about 300A, so the
> >>> switching circuit needs to handle that
> >>> and of course the winch is an enormous DC motor
> >>> so...whats a fun way to do this? bank of mosfets? something else?
> >>> i know i can just by a big relay/contactor, but i want to make this
> >>> myself...
> >>> suggestions?
> >> I would use a huge contactor. If it absolutely has to be electronic
> >> you'll need an H-bridge driver with integrated charge pump, like this:
>
> >>http://www.freescale.com/files/analog/doc/data_sheet/MC33883.pdf
>
> >> Then probably 8 or 12 of those, plus some discrete parts:
>
> >>http://ixdev.ixys.com/DataSheet/DS99630A(IXTH-TQ280N055T).pdf
>
> >> As you can see this gets a tad expensive. Also, you need to have some
> >> safety shut-down feature to cut power when the MOSFETs weld themselves
> >> shut. Or in case of a contactor if the contacts weld together. After
> >> all, you don't want the winch to keep cranking and then pulling your
> >> Jeep up a tree :-)
>
> >> Remember, you do this on your own risk, 300 amps and so much power is
> >> dangerous.
>
> >> --
> >> Regards, Joerg
>
> >>http://www.analogconsultants.com/
>
> >> "gmail" domain blocked because of excessive spam.
> >> Use another domain or send PM.
>
> > the fun begins!
>
> > why did you pick out a fet with a relatively low Ids? some of those
> > ixys parts go up to 700A+. is a bank of fets better than a single fet?
>
> That depends on the size of your wallet, lottery winnings and such. The
> FETs I suggested are slightly above $4 a piece. Four of these would also
> suffice but it'll come to a grand total of 1100 bucks because they cost
> $275 each:
>
> http://www.microsemi.com/datasheets/APTM10UM01FAG-Rev1.pdf
>
> Or this one for the "bargain price" of $150 a pop, ouch:
>
> http://ixdev.ixys.com/DataSheet/L286.pdf
>
> And then you do some outdoors stuff, get into a rain storm, lightning
> ... *PHUT* ... hundreds of bucks gone.
>
> I have paralleled FETs many, many times and the reason was always the
> same: $$$. However, you may need resistors in series with each gate,
> usually something around 10ohms.
>
> Personally I'd use the traditional big old contactor :-)
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/
>
> "gmail" domain blocked because of excessive spam.
> Use another domain or send PM.

Oooooh..

I'm thinking the design problems are:

Being able to turn on the fets fast enough so they dont dissipate any
energy in their linear region. (requires some kind of high current
driver, like the one you suggested)
Being able to handle whatever inductive spikes the motor might throw
our way. (not sure how to do this. (can the fet body diodes take care
of this?)
Handling the current

Anything else?

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