[Date Prev][Date Next] [Chronological] [Thread] [Top]

Re: Speed control

Dave,
Thanks very much for the link.  I found a PWM (it happens to use MOSFET's
though) which will supply a 12vdc motor with up to 35 amps for only $63.  I
don't suppose you think even $63 is high for such a device, do you?  I had
found a surplus unit available for $25 but the source was soon to dry up
(can't use a "dried up" controller on an underwater propulsion unit now can
we!) and I was expecting the normal price of a similar unit to be over $100.
Now I feel a bit more comfortable designing around the variable speed
concept.  I have high hopes of making an underwater propulsion unit which can
be marketed at significantly less cost than those currently for sale.
Quantities will likely be low for at least awhile so an off the shelf item is
very nice to deal with.
Thanks again,
Dick Morrisson

Dave Everett wrote:

> At 09:34 15-05-99 -0700, Dick Morrisson wrote:
> >Could these
> >IGBT's be used in a 12vdc, 30 amp PWM cost effectively?  A simple answer
> >will suffice for now, details could follow later if appropriate.
>
> The short answer is yes. IGBT's are generally much cheaper than equivalent
> Power MOSFET's.
>
> If you're looking for a ready made controller, you could try:
> http://www.4QD.co.uk/
>
> There are some good references there as well.
>
> Dave Everett.