An Electrostatic Levitator for high-temperature containerless materials
processing in 1-g. Won-Kyu Rhim, et al., Rev. Sci. Intstrum.
64 (10), Oct. 1993
Summary: This paper presents continuing research utilizing the
levitator described in the 1985 paper by Dr. Rhim. This levitator
has a six electrode configuration. This configuration provides active damping
in three dimensions, but only in 1-g. This paper also discusses position
control system logic. There is a detailed discussion on capacitive
charging and its effect on the launch voltage. There are very good
graphs showing the required launch voltage for different sphere masses.
From this paper (and the 1985 paper) we get a starting point for the range
of variables and expected results.
Development of an electrostatic positioner for space materials processing.
W. K. Rhim, et al., Rev. Sci. Instrum. 56 (2), February 1985
Summary: This paper featured three electrode configurations:
Dish type, Ring and Disk, and Tetrahedral. Dish type, which will
be our first prototype, only has active control in one dimension.
This electrode configuration only works in 1-g, and damping in the radial
direction is only due to the viscosity of the gas surrounding the sphere.
Ring and Disk type has similar performance to the Dish type, with the addition
of passive damping in the radial direction. This paper presents basic
PID control system algorithms. A high-voltage amplifier schematic
is included which can be used to build your own. Charging and
launching are also discussed in some detail.
A Novel Method for Near-Critical Viscosity Measurements in 1-g and
in Microgravity. Ralph S. Budwig, Anthony R. H. Goodwin
Summary: This was a proposal sent to NASA requesting a grant
for research. They were denied, but this paper created the motivation
for our experiment, that being, if we could develop the apparatus described
in this paper, that there would be a better chance receiving a grant when
the paper is resubmitted. The ultimate goal of this research is to
conduct precision viscosity measurement on gasses at the critical point
in zero-g. Our apparatus and experiment requirements are taken from
Direct Electrostatic Levitation and Propulsion. Ju Jin,
Toshiro Higuchi, IEEE Transactions on Industrial Electronics. Vol.
44, No. 2, 1997
Summary: This paper presents suggestions for high voltage safety
and avoiding electrostatic discharge. It also presents concepts in