Re: Power Supply & Gecko's

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "smith67au" <thdsmith@b...> wrote:

> Hi All,
>
> This is my first post and I'm hoping I can get some advice.
>
> I have a retrofit bidgeport mill runing on steppers with Gecko
> 201/210's.
>
> Current settings are two at 7.0 amps and one at 3.5 amps.
>
> I have been driving the mill with a 24V 25 Amp regulated power supply,
> for a few years.
>
> I wanted to upgrade the power supply, so I've built one similar to the
> "Simple Power Supply" in the files section, using a transformer I had
> laying about.
>
> I have 48VAC out of the transformer going through the bridge rectifier
> (35A 400V) and then paralleled with a 22,000 uf Cap.
> Result is I am getting around 70VDC as expected.
> I am also measuring quite a bit of AC (around 150V), but it might be
> because my multimeter is a cheap one (the 24 VDC power supply I have
> been using for a long time also has an AC voltage (30VAC).
>
> My problem starts when I connect up the Gecko's.
> The 5A fuses blow instantly every time (are they big enough?)

Where in the circuit is the fuse ?

If you have two motors at 7 amps and one at 3.5 amps, you have 18 amps
but you have a 5 amp fuse ?

If the fuse is on the AC side, it is blowing from the inrush of the
transformer, try this experiment, put a lightbulb and a switch in
parallel with the fuse.

when you turn on power, the light will light and then dim, at that
point, the transformer and cap will have charged. turn off the light
and leave the fuse in the circuit.

If it is just the inrush, you *should* be able to run normally.

But, tell us where the fuse(s) are in the circuit.

Dave