Re: gecko's and voltage - For Mariss

Mariss:

Just saw this posting, Your words are art.

Reagrds,
Jeff
(also an EE)


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Mariss Freimanis"
<mariss92705@y...> wrote:

> Kim,
>
> I try to produce good drives. I am a designer and I put my best

into

> it. I have the privelege of being a gradutate EE and having spent

30+

> years in designing power analog circuit circuits. I eat, dream and
> sleep with this stuff. I also have seen everything when it comes

to

> motor drives. There is also nothing new to me when things go wrong.
>
> Being a practicing EE I'm also aware of everything that's out

there

> and I can work out the complex matrixies of how how price and
> performance integrates with the final product.
>
> A good design is an inticate dance that delivers the expected
> performance while using the minimal possible parts. It is a Zen or
> Haiku poem kind of a thing. It delivers to the customer the lowest
> possible price a product while giving the best possible

performance.

> If done right, it is balancing things on a knife's edge.
>
> What that means is every little resistor, capacitor, diode and
> transistor is working for you. You have paid for them and you

expect

> that. Like a Haiku poem it is sparse, interconnected and necessary

to

> the whole. Nothing is wasted, nothing is wanting.
>
> Being that way, it cannot be disturbed without destroying it. It
> cannot be made to run at 100VDC or 120VDC. If it could, I would

have

> cheated my customers by having this unrevealed but paid for

ability.

> I would haved failed as an engineer.
>
> You say you are a EE. I would guess you are young and have not yet
> learned all your craft has to offer. It is a beautiful proffession
> that can teach you so much if you have the humility and an

openness

> of mind to recieve all it has to teach. It is subtle and intricate
> beyond belief. Like nature, its mother, it speaks quietly and

doesn't

> care if you didn't listen.
>
> Mariss
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Kim Lux <lux@d...> wrote:
> > On Sun, 2003-07-06 at 09:40, mmurray701 wrote:
> > > > This situation is NOT a matter of petitioning, but
> > > > rather a matter of considering the end user requirement.

Yes,

> > > using a
> > > > larger voltage transistor may increase the price of the

driver

> by
> > > $10 or
> > > > $40, but it will decrease the transformer cost by $100-

$200.

> > > Every try
> > > > to buy a 1.8KV oddball voltage transformer ?
> > >
> > > Well, instead of using a huge oddball oddball transformer,
> >
> > Stepdown transformers are not oddball. Hammond for one makes

them.

> Go
> > to any electrical wholesaler and they can get you one. Nothing
> oddball
> > about that, right ?
> >
> >
> > > why not
> > > use a bunch of smaller more common ones? MPJA has 24v 10a
> > > transformers for $17.99. Two of these in series will give 48v

AC

> and
> > > roughly 67V DC when rectified.
> >
> > 1.8KVA / 240VA = 8 transformers, not, not 6. I'd have to

double

> the
> > size of my CNC electrical box.
> >
> > > This is what I plan to use for my
> > > Gecko servo system. Did I miss anything? Should work fine

right?

> If
> > > you need more than 10a (sounds like you do) just add

additionaly

> > > sets of whats described above. If you were to go with 3 sets

of 2

> (6
> > > total) that would give you a 67v 30a supply (2.0KW) and all 6
> > > transformers would still only cost $107. Dont seem too

expensive

> to
> > > me.
> >
> > That is an ugly solution. When was the last time you went into a
> > commercial piece of equipment and found 6 transformers ?
> >
> > > > We ? Does that mean you work for Gecko ? If I guarantee my
> > > supply will
> > > > never exceed 100V ie use a zener protection circuit set at

90V,

> > > can I
> > > > use a G320 at 87V ?
> > >
> > > Mariss is the designer of the Geckodrives. Any advice received
> from
> > > him should be strongly considered. He really knows his stuff.
> Good
> > > luck.
> > >
> > > Mark
> > >
> > >
> > >
> > >
> > >
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> > --
> > Kim Lux <lux@d...>