Date:         Sun, 7 Aug 2005 12:12:18 -0400
Reply-To:     Tom Miller <tmiller@VCMAILS.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tom Miller <tmiller@VCMAILS.COM>
Subject:      Re: Mechanical Geniuses please note! (NVC)
Comments: To: John Rodgers <inua@CHARTER.NET>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
              reply-type=response

You can use a variable fequency AC drive controller but the torque of the
motor will also vary with speed.  If constant torque is needed across the
speed range, use a flux vector or vector duty AC drive controller which
boosts the voltage as the frequency is reduced to maintain torque down to
zero speed.  You may need to order a vector duty motor though since the
cooling fan on the motor shaft will not be turning fast enough at low speed
to handle full load torque current.  Search Google for AC drives.  They are
sized by HP and line voltage available.
TEMiller

----- Original Message -----
From: "John Rodgers" <inua@CHARTER.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, August 07, 2005 8:51 AM
Subject: Mechanical Geniuses please note! (NVC)


> Fella's - and Ladies .... I need a little help.
>
> I  need to  build a  machine that uses a 1 HP Capacitor start 120v
> electric motor that turns at 3350 rpm. The motor - by way of pulleys -
> will drive a shaft whose rotational speed  should have a controllable
> range from 0 to 200 RPM.
>
> I'm hoping that some of you folk out there know about such stuff and can
> help me with suggestions on how to get it done.  - speed controllers,
> variable diameter pulleys, or what ever. I am open to suggestions.
> Specifics and specifications would be of a big help.
>
> I would appreciate any input.
>
> Thanks.
>
> Regards,
>
> John Rodgers
> 88 GL driver
>