| 摘要 |
1,136,247. Position digitizers. HOLLANDSE SIGNAALAPPARATEN N.V. 21 Dec., 1965 [23 Dec., 1964], No. 54162/65. Heading G4H. An oscillator 101 feeds a frequency divider 102 which steps a ring counter ABC providing a 3-phase input to the primary windings of transformers 116, 119. The rotor of transformer 119 is fixed at a reference position whereas the rotor 115 of transformer is rotated by a movable member, the position of which is to be measured. The output of low-pass filter 117 is an A.C. signal, the phase of which represents the position of rotor 115, and low-pass filter 120 provides a reference phase signal. The zero-crossing of these signals sets and resets trigger 124 so as to pass pulses to a counter 128 for an interval representing the position of rotor 115 with respect to the reference position determined by transformer 119. A counter RST allows counting to take place only in every third cycle of the reference phase signal, the other two cycles being used for read-out and resetting of counter 128. Fig. 3 (not shown), illustrates an alternative circuitry for the part below line SL. Similar, partly common, circuits may be used for coarse and fine or independent inputs. The use of a number of phases other than three, particularly two, is described. |
