Position transducer arrangement
AssigneeDavy-Loewy Limited
InventorRoy Clegg
Life of this patent
Estimating the term…
Abstract
In a position transducer arrangement one or more AC operable position transducers are energised by the output of a variable amplitude oscillator. The output signals from the oscillator and the or each transducer are demodulated, or detected in turn by the same demodulator and the demodulated oscillator signal is compared with a reference signal to produce a difference signal. The difference signal is used to adjust the amplitude of the oscillator signal in the sense to reduce the difference signal to zero.
Claims11
A position transducer circuit comprising at least one AC position transducer having an input and an output, a variable amplitude oscillator connected to the input of the transducer, the output of the oscillator and the output of the transducer connected to respective switch inputs of a demodulator, the output of the demodulator connected through separate output switches to respective stores, means for switching said demodulator input and output switches together and in sequence to connect said oscillator and the transducer in turn through the demodulator to said respective stores, means for comparing the signal in said oscillator signal store with a reference signal to produce a difference signal and means in the oscillator responsive to said difference signal to adjust the output of the oscillator in the sense to reduce said difference signal substantially to zero.
The combination of a position transducer circuit as claimed in claim 8 in which the position transducer indicates the position of a first member movable with respect to a second member, and which further includes, a position control system capable of moving said first member with respect to the second member, said position control system including means for receiving and comparing a signal representative of the desired position of the first member, and the demodulated signal of the position transducer to produce an error signal which is employed to move the first member in the sense to reduce said error signal substantially to zero.
A position transducer arrangement comprising
- at least one A.C. position transducer having an input and one output,
- an oscillator having means for adjusting the amplitude of its oscillations, said oscillations being supplied to said input of the transducer,
- a demodulator having an input and an output,
- first switching means for switching the output of the oscillator and the output of the transducer repeatedly in turn to the input of the demodulator,
- first and second electronic stores,
- second switching means operable in synchronism with the first switching means for switching the demodulated oscillator output and the demodulated transducer output from the demodulator repeatedly in turn to the first and second stores respectively, and
- comparison circuit means for continuously comparing the contents of the first store and a reference signal to produce an error signal, said error signal being applied to the oscillator adjusting means to adjust the amplitude of the oscillator in the sense to reduce said error signal to zero.
A position transducer arrangement comprising
- an oscillator having an output and the amplitude of the signals from which can vary;
- at least one A.C. position transducer having an output;
- means connecting the output of the oscillator to the transducer to energize the transducer;
- demodular means for producing an output signal indicative of the amplitude of an oscillating signal at its input, said demodulator means having an output;
- means for connecting the output of the oscillator and the transducer repeatedly and in turn to the input of said demodulator means;
- a reference voltage;
- comparing means for comparing the output of the demodulator means resulting from connection of the oscillator to the demodulator input with the reference voltage to produce a difference signal;
- means responsive to said difference signal to adjust the amplitude of the oscillator output in the sense to reduce said difference signal to substantially zero so that the demodulated output signal of the transducer is essentially constant for a particular condition of the transducer.
Dependencies are inferred from the claim text.