Patent ID: 6930487

Claim:
A method of adding damping to an electrostatic positioner by electronic means comprising the steps of: (a) applying a control voltage driving said electrostatic positioner to control a physical position of said electroctatic positioner, and (b) producing a first voltage proportional to the total current passing through said electrostatic positioner in response to said control voltage, and (c) producing a second voltage proportional to the current passing through the static capacitance of said electrostatic positioner, and (d) subtracting said second voltage from said first voltage to produce a third voltage proportional to the current produced by the velocity of the moving plate of said electrostatic positioner, and (e) amplifying or attenuating said third voltage to obtain the desired degree of damping, and (f) applying said amplified or attenuated third voltage to increase said control voltage when said movable plate is moving away from the stationary plate, whereby a negative feedback effect is produced that inhibits the velocity of said movable plate thereby producing the effect of damping added to said electrostatic positioner by electronic means.