The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: firstname.lastname@example.org (Bill Allison)
Subject: Re: Help - Power mosfets - difficult load
Date: 25 Oct 2002 03:40:59 -0700
References: <email@example.com> <firstname.lastname@example.org> <email@example.com> <firstname.lastname@example.org> <email@example.com>
NNTP-Posting-Date: 25 Oct 2002 10:40:59 GMT
"Phil Allison" wrote in message news:...
> "Bill Allison" wrote in message
> > For the benefit of new participants, I'm not that concerned about
> > motor or battery efficiency as the winch, currently equipped with
> > crude tension sensor driving on/off relay, has power to spare. My main
> > concern is keeping within the (expensive) fets' ratings.
> ** And you have studiously ignored advice on exactly that point.
No - questioned, debated (sure - ignorantly and unwisely or with
tongue in cheek on occasions) but absolutely *not* ignored it.
> > I'm not using a permanent magnet motor.
> ** So ???
Sorry - I should have asked the question explicitly - It's natural (to
this f**wit at least)) to wonder what difference it might make to a
pulse driven motor's behaviour to have a permanent rather than pulsed
It's prompted me to wonder, for example, whether, at the low pulse
frequency it's convenient for me to use :) differences in inductance
between armature and stator windings, might result in magnetic field
pulses in one leading or lagging the other and whether therefore I
might benefit from adjusting the timing (i.e. rotating brush pack
relative to stator) to compensate for that?
> > To all - this has generated such interest and controversy that I feel
> > obliged, once construction is complete and assuming (!!??) success, to
> > post oscillograms somewhere (somebody suggest where?) to quantify just
> > how much of a problem operating at 50Hz turned out to be. So keep an
> > eye open for this thread re-awakening in a few weeks.
> ** Keep all the blown fets and post a picture later on will you.
I refuse to be unfriendly back! I'll assume there's an invisible
smiley at the end of your sentence :)
> .. . . . . ............... Phil
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup