Re: Bleed Resistor... Do geckos need a fan?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "AbbyKatt" <cnc@a...> wrote:

> I was wondering..
>
> Power supply is all nice and working now, and am about to hook it

all up

> to the geckos.
> I was wondering: Do I need a bleed resistor across my cap? What

happens

> if I neglect to put one in?

Absolutly not required or important.

Think of a bleed resistor as an energy dump that is on all the time.

Think of the Gecko as a powered device that is on all the time.

The Gecko will blead the power supply orders of magnitude faster than
the resistor.


Also, what is the reason for the power supply to be fully
discharged ? is your box exposed ? do you need to get into it
often ?

If you wanna secondary power drain, add a light or a fan. Both will
offer some benifit and will drain your power supply considderably
faster than a resistor.

> Also, do I need a fan for geckos, I'm only going to be doing a peak

of

> 12 amps @ 50V, and I have it already bolted to some nice aluminium.

Will

> I need thermal paste?

Not sure what you mean. A Gecko is rated for a maximu of 7 amps and
the manual says you must use a heat sink over 3 amps. Either you
need a large heat sink or heat sink and a fan. Whichever is easir
for you.


But, that does bring up another question.

We have watched the Gecko evolve since it's origional incarnation.

Added are features like the ability to select microstepping and also
a power reduction if not stepping.

Also, Mariss has mentioned the Vampire unit and a unit that will have
minimal motor heating.

What advanced in the Gecko have changed the need for heat sinks ?

Is the circuitry similar to the origional or has Mariss changed it to
a FPGA ?CPLD ? Rabbit ???

Mariss, wanna give us an update ??

Dave