Patent ID: 11965757
Assignee: GUILIN GUANGLU MEASURING INSTRUMENT CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 6:
7. The hybrid positioning electromagnetic induction displacement sensor according to claim 1, comprising
an analog switch group (6) forming a three-stage switch series structure, and completes selection, exchanging and sampling of a phrase voltage for an input three-phase voltage sequentially: first-stage switches (S1-S6) are configured as three pairs: {S1, S4}, {S2, S5} and {S3, S6}, which respectively select phase voltage pairs {uA, uB}, {uA, uC} and {uB, uC}; second-stage switches (S7-S8) exchange, as required, a sequence of the phase voltage pairs selected by the first-stage switches; third-stage switches (S9-S10) sample a pair of phase voltages output by the second-stage switches, and save results in the sample-and-hold capacitors (C1, C2) respectively; and
a differential amplifier (7) performing a subtraction operation and amplification on two phase voltage samples saved in the sample-and-hold capacitors (C1, C2), to obtain a corresponding line voltage sample and zero-order hold signal; under the control of an output signal of the signal generator, a line voltage cyclic scanning sampling in the order of A-B, A-C, B-C, B-A, C-A, C-B is obtained sequentially, and input three-phase voltage that does not change with time (when the sensor is not moving), but changes periodically with a measured position, of the three-phase receiver winding is synthesized into a discrete time sinusoidal signal (us(n)), and a spatial phase of the measured position within the pitch of the three-phase receiver winding is converted into an initial phase of the discrete time sinusoidal signal (us(n)).