Patent ID: 6820493
Filing Date: 2004-11-23
Classification: G01B,G01L

Abstract:
A precision Multi-dimensional capacitive transducer comprising:a plurality of drive plates, said plates being composed of electrically conductive material; pickup electrode means movably mounted relative to said drive plates; further including: electrical circuit means for applying electrical drive pulses said drive plates, said drive plates being operatively grouped into pairs, said pulses to having a frequency F, and a pulse width T of approximately 1/F divided by the total number of drive plates, said drive pulses being grouped into one main channel per operative drive plate pair, each main channel comprising two sub-channel pulses, one sub-channel pulse of said main channel operative on a first drive plate of said drive plate pair, with remaining sub-channel pulse of said main channel simultaneously operative on remaining drive plate of said drive plate pair, with said main channels being multiplexed to sequentially apply said pulses to said drive plates with each main channel dedicated to a particular drive plate pair, and with said main channels being spaced apart in time by approximately the pulse width T; sampling means for synchronously demodulating and demultiplexing the signal on the pickup electrode means into one channel per drive plate pair, each channel comprising two sub-channel signals, each channel operatively associated with a particular drive plate pair; timing means for controlling said sampling means such that each first sub-channel is sampled during the time period that the drive pulse is applied to the corresponding drive plate pair and each second sub-channel is sampled after the drive pulse corresponding to that drive plate has ended, and before the drive pulse corresponding to the next channel in said multiplexed sequence is applied; storage means for each sub-channel; and differential amplifier means to convert each of the sub-channel signal pairs into single main channel signals.