PSU for my first project

Hi all,

Although a newbie to the world of CNC and electronics I am going to
attempt to CNC an old lathe I have.

I have been viewing the excellent advice given on the group and have
tried to collate the info I need to build a power supply. I would be
grateful is somebody would look at my proposed shopping list and
tell me if I am on the right track.

UK voltage.

I plan to use 4 x Gecko G210 drives to power 4 x Sanyo "H" Series
Stepper motors. I have not decided on the spec of all four yet, but
will try a Size 34 double stack 4A/phase 4 lead 4.91Nm to start (for
the lathe carriage) and then increase/decrease spec to suit.

I have been told that I will need a power supply producing around 60
to 65Vdc and that 1 Amp for each motor should be allowed. I have
also been told that I need a linear power supply e.g. transformer,
bridge rectifier, smoothing capacitors (with discharge resistor).

With this in mind I plan to buy the following.

Toroidal Transformer
2 x 60V Sec (or should I buy 2 x 30 Secs?) I do understand what is
meant by the rating VA. They seem to range from about 50VA up to
1000VA, is there a formula for calculating my requirements. I am
guessing I need about an 8A supply?

Bridge Rectifier

400V PIV 35A 280V RMS ?

Capacitor(s)

100V 15000uF from Bridge rectifier
100V 470uF across power terminals on each driver

Volt meter display

I guess these are pretty standard specs ?

Heat sinks

Will I need heat sinks for the Gecko's ?

Discharge resistor

Not sure about this one !

Any links to schematics would be appreciated, although the one
posted recently on the Gecko site looks pretty straight forward.

Thanks in advance, and apologies for the basic questions. I did a
search on Toroidal but did not come up with much.

Regards,

Ian