Re: Controllers

["prasad" <zilliondreams@yahoo.com>]

Hi James and all,
Thanks for the support. Motor spec is as follows -
Voltage - 24V DC
Continuous rated current - 15A
power - 1/2 hp
rpm - 1500
Type - compound, with the field ON all the time.

Looks like a very BAD choice, but that is all I could find from a junkyard, I hate it when money is a constraint.

Anybody who can provide me with a circuit off the list, kindly write to me at the addresses mentioned below.

Thank you all.

Prasad
aquariangenius@yahoo.com
aquariangenie@hotmail.com
_________________________________________________________________________________________
Obstacles are placed across our path in life not to be boggled at but to be surmounted.
_________________________________________________________________________________________



----- Original Message -----
From: <jcmassey@netspace.net.au>
To: <zilliondreams@yahoo.com>
Sent: Friday, June 29, 2001 4:47 PM
Subject: Controllers


Hi Prasad

A bit more info would be needed to discuss your motor accurately on-list.
It may be a compound motor with a field that is on all the time, or it
could be a motor that is effectively a series motor with interpole
windings. Interpoles are secondary fields used to 'push' the magnetic field
in the motor back and forward to keep it aligned with the brush position
(the magnetic field normally changes position for forward to reverse, brush
position is normally optimum only in one direction).

Motor specs, please:
What voltage is the motor?
hp, RPM, etc?

It is quite reasonable to build a 'home made' electronic controller for,
say, 72V at 250A, but quite another matter at higher volts and amps. Most
electronics people (Take it from one) havent a CLUE about motors, so being
a good electronic tech doesn't mean you can design and build controllers.
Relays are a big no-no for PWM from. They were not used in the '20s let
alone the '60s. Depending on what you hope to do with this motor there are
quite a few options. Be a good idea to forget relays and re-post to the
list with a description of the motor and what you hope to achieve. Some
good advice should follow, but if this is an ex-forklift motor most
list-ers seem to be against them (not me though).

Have a look at http://www.ca.com.au/~sccs/EVCA/coltconv.htm

Regards


James Massey





_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com