The closer it is to the opposite polarity or ground (the floor in this case=
 I =

guess), the higher the field strength on the tip of the carbon fibres becom=
es =

and the lower the actual corona discharge voltage becomes.

Another option might be to use an active device. I have seen a couple of =

chinese small, rather chaep, piezo based dischargers and, a bit depending o=
n =

how big the charge on the robot is and how fast it is generated, the result=
ing =

voltage on the robot could be well below 100V. These devices are usually us=
ed =

together with a fan in order to discharge a larger surface, like a workbenc=
h =

when working with electronics assembly. They are also used in air nozzles t=
o =

reduce any charge buildup when blowing with compressed air.

A new thing I have not seen before is USB ionizers. A small USB powered ion=
izer =

that looks like a thumbdrive. They only seem to produce negative ions thoug=
h =

(probably just rectified the output).

/Ruben

> Well, I did actually try both antistatic garland and a few simple
> needles and they made very little difference below 3kV. I had not
> heard of this carbon fiber brush but I will look into it. I find it
> hard to believe that it is going to be able to reduce the corona
> threshold to below 1kV (which we would need), but I will look.
> =

> Thanks,
> =

> Sean
> =

> =

> 2010/3/25 Ruben J=F6nsson <ruben@pp.sbbs.se>:
> >>
> >> Alternately, coat the machine with needles pointing outwards and let
> >> the static dissipate through air discharge. ;-D
> >>
> >
> > This was my thought also. Perhaps you can use carbon fibre antistatic b=
rushes,
> > like this: <http://www.amstat.com/solutions/passive.html> at suitable p=
laces on
> > the robot. Note that the brush should not touch the ground.
> >
> > Normally these brushes are connected to ground potential and located cl=
ose to a
> > charged surface. Since the carbon fibres are so thin, the field strengt=
h around
> > them becomes high enough to ionize the air through corona discharges lo=
ng
> > before the breakdown voltage in air is reached (which would cause a spa=
rk
> > instead).
> >
> > /Ruben
> >
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D
> > Ruben J=F6nsson
> > AB Liros Electronic
> > Box 9124, 200 39 Malm=F6, Sweden
> > TEL INT +46 40142078
> > FAX INT +46 40947388
> > ruben@pp.sbbs.se
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D
> >
> > --
> > http://www.piclist.com PIC/SX FAQ & list archive
> > View/change your membership options at
> > http://mailman.mit.edu/mailman/listinfo/piclist
> >
> =

> -- =

> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
> =


=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124, 200 39 Malm=F6, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
ruben@pp.sbbs.se
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

-- =

http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist