Re: Impressions of the Gold Coast line

["Chris Downs" <cvdowns@ozemail.com.au>]

I thought a chopper literally chopped the current off for a short period of
time and this was done many times per second.  More current's chopped out when
starting giving the same effect as burning "excess" current with resistors.
As the train accelerates the chopper stops current for shorter periods of time
(like switching through resistors) until the point is reached where continuous
current flows, i.e. the chopper is off.

Chris

jjjim <jjjim@bigpond.com> wrote in message
3A5D7CE4.8501FC55@bigpond.com">news:3A5D7CE4.8501FC55@bigpond.com...
> im form an electronics backround . sorry to confuse,  I see a chopper as
> something creating an AC waveform of different freqency to the mains
> 50Hertz, (or the same in the case of an inverter for use in your home) .
> So inverter / chopper to me,
>
> Rob Kearey wrote:
>
> > David Johnson wrote:
> >
> > > > Dean all the SMUs run AC traction, and IMU's,  just the smu2's are
> > > > slightly differennt choppers,
> >
> > > I was under the impression that Choppers were used for DC motors.
> >
> > I think he means inverters.
> >
> > > David Johnson
> >
> > --
> > Rob K
> > http://members.optushome.com.au/mammal
>