fun h bridge for winch control
in [Design]
|
From: Joerg on 7 Oct 2009 20:55 acannell(a)wwc.com wrote: > 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? > That's pretty much it I believe. The body diode ratings are in the datasheets. They are usually very staunch, I use the body diodes in my designs a lot. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Paul Hovnanian P.E. on 8 Oct 2009 01:25 Joerg wrote: > > 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 :-) Contactors. Four of them. Unless the OP's winch uses a reveres gear to change directions. Or four groups of FETs. Either way, most winches are series DC motors, with the field leads brought out separately from the armature so as to facilitate reversing polarity. -- Paul Hovnanian mailto:Paul(a)Hovnanian.com ------------------------------------------------------------------ Who is General Failure and why is he reading my hard drive?
From: PeterD on 8 Oct 2009 09:03 On Wed, 7 Oct 2009 16:00:41 -0700 (PDT), "acannell(a)wwc.com" <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? > > Go to Warn's site, and download the schematics from one of their winch controllers, they are simple, using four 'starter relays' of the Ford variety, a simple switch (SPDT center off), and not much else... Resist the urge to go solid-state... Those 'starter relays' are about $10 each at the parts store.
From: George Herold on 8 Oct 2009 09:24 On Oct 7, 7:00 pm, "acann...(a)wwc.com" <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? 300 amps sems like a lot! I thought the alternator only put out 60A or so? I guess they put bigger alternators in trucks and such. I've got a small winch on my truck and just use a big rocker switch. What's wrong with a even bigger switch? It's simple. George H.
From: acannell on 8 Oct 2009 13:46
On Oct 8, 6:24 am, George Herold <ggher...(a)gmail.com> wrote: > On Oct 7, 7:00 pm, "acann...(a)wwc.com" <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? > > 300 amps sems like a lot! I thought the alternator only put out 60A > or so? I guess they put bigger alternators in trucks and such. I've > got a small winch on my truck and just use a big rocker switch. > What's wrong with a even bigger switch? It's simple. > > George H. The battery and the alternator work together to supply the current to the winch.. My winch only draws 30A under no load. But under full load (8000lbs) draws 280A. How big of a rocker switch?? Jeez how often do you use it? Most hand operated switches would not be able to handle winch current. |