Re: [CAD_CAM_EDM_DRO] Re: Power supply transformer setup questions...

At 21:30 10/09/2003 +0000, you wrote:

>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Lloyd Leung" <lloyd@l...>
>wrote:
> > Not that I doubt you, but can you explain why then it is suggested
>that I
> > use 2/3rd of the sum of the motor amperages then?
> >
> > The setup will be using 3 G201 drives, connected to three motors.
> > One 3A/3V motor, and two 3.5A/4.2V motors.
> >
> > I would have thought that a 6.7Amp rated transformer is required.
>
>
>Lloyd,
>
>look at the total watts of the motors.
>
>The chopper drivers cannot supply more, even if you have such an over
>sized power supply.
>
>one motor is 9 watts
>the other 2 total 29.4 watts for a grand total of 38.4 watts.

You've lost a factor of 2 here - both coils get energised in each motor, so
the right number is 76.8 Watts.

Regards,
Tony

>if you run at 60 volts, then the required current is 2.04 amps for
>ALL 3 motors.

Not quite - not sure where that came from. Current is Watts divided by
Volts. So 76.8/60 or 1.28 Amps is nearer the mark.

>If you want to run 6.7 amps, you will have pleanty reserve.
>

That's certainly true!


Regards,
Tony