Re: [PSUBS-MAILIST] Re: Motor controller...

[ROUFFIGNAC Laurent <laurent_rouffignac@yahoo.com>]

Thanks Ken for the answers... It might be very helpful
for many of us to have an 'universal' electric motor
controller for small subs.
Laurent

--- Subscuba@aol.com wrote:
> Laurent, I copied your post and can answer some of
> your questions below.
> 
> Ken Martindale
> 
> 
> > 
> > Hi John,
> > I started working on your schematic and I have a
> few
> > questions for you:
> > - Why did you add extra flyback diodes , the IXFK
> > serie already have some in their package?
> 
> All Power Fets have body diodes which can be used
> but there are difficulties 
> with body diode recovery times and I didn't want to
> deal with the potential 
> destructive effects of using the body diodes.
> 
> > - Is there any specific reason why you used a H
> bridge
> > with only N-channel Mosfet instead of both N and
> > P-channel Mosfet?
> 
> I cannot get P channel FETs to handle the currents
> involved.
> 
> > - I have some concerns about the heat sink
> dimensions.
> > Are you currently using the hull of your sub to
> cool
> > them? :-)
> > -I was also interrested in using Minn Kota motors.
> Do
> > you have any specs on these? Are you already using
> > them? 
> > I plan to use 4 of them (2 for the main prop and 2
> for
> > up/down & left/right) but i'm still working on the
> > mechanical design so I still don't know what are
> my
> > power requirements. Looks like I'll be very close
> to
> > Ken's needs.
> > 
> > Laurent
> > 
> > 
> 
> 


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