High resolution position sensing apparatus with linear variable differential transformers having phase-shifted energizing signals
First Claim
1. Apparatus for sensing the position of a movable member, comprising:
- a plurality of position transducer means each comprising a magnetic core coupled to said movable member, a primary coil and two series-connected secondary coils;
input means for providing an energizing signal to said primary coil of each transducer means, said energizing signals having the same frequency but having differing relative phases and being operative to induce in said secondary coils secondary voltages of differing relative phases; and
output means for detecting the peak value and polarity of each half cycle of said secondary voltages of differing phases and providing a composite output signal representative of said peak values and polarities, said output signal indicating the position of said movable member at a rate of n times the frequency of said energizing signal where n is the number of said transducer means.
1 Assignment
0 Petitions
Accused Products
Abstract
Apparatus for high resolution sensing of the position of a rapidly moving member. The apparatus includes at least two linear variable differential transformers (LVDT'"'"'s) each having a magnetic core coupled to the movable member. A signal source and a phase shifter provide energizing signals to the primary coil of each LVDT. The energizing signals have the same frequency but are phase shifted relative to each other. The induced secondary voltages of the LVDT'"'"'s are sampled by synchronous detectors, the outputs of which are combined by an adder into a high resolution output signal. When two LVDT'"'"'s are utilized, the energizing signals have a relative phase shift of 90° and the effective position sampling rate is doubled. The apparatus can be used to sense the operating frequency of a tunable magnetron.
39 Citations
9 Claims
-
1. Apparatus for sensing the position of a movable member, comprising:
-
a plurality of position transducer means each comprising a magnetic core coupled to said movable member, a primary coil and two series-connected secondary coils; input means for providing an energizing signal to said primary coil of each transducer means, said energizing signals having the same frequency but having differing relative phases and being operative to induce in said secondary coils secondary voltages of differing relative phases; and output means for detecting the peak value and polarity of each half cycle of said secondary voltages of differing phases and providing a composite output signal representative of said peak values and polarities, said output signal indicating the position of said movable member at a rate of n times the frequency of said energizing signal where n is the number of said transducer means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification