Measuring and control device using the damping effect of a resistive effect element on the inductor of a tuned circuit
OwnerRodger T. Lovrenichinventor
Life of this patent
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Abstract
A detection type device that includes an arrangement for detecting the energy absorbed by a resistive effect element in proximity to the inductor of a resonant circuit. The resonant circuit uses a direct current source to alternatively charge it and then let it ring through a switch connected between the direct current source and the resonant circuit. Two different parameters of the same oscillating signal generated by the resonant circuit are detected and compared. The difference is the result of a ratio of these parameters that accurately reflects the energy absorbed by the resistive effect element. This difference is used for measurement and control purposes.
Claims17
A measuring and control device that measures or controls by detecting the energy absorbed by an energy absorbing resistive effect element in proximity to the magnetic field of an inductance means, comprising:
- power supply means;
- resonant circuit means including inductance means and capacitance means electrically coupled for oscillation and electrically connected to said power supply means;
- detection and comparison circuit means electrically connected to said resonant circuit means for receiving an oscillating signal from said resonant circuit means when said resonant circuit means is oscillating and comparing the values of different parameters of the same oscillating signal to provide a ratio of said parameter values that indicates the damping effect upon said signal caused by the presence of said resistive effect element in the magnetic field of said inductance means for measurement and control purposes without using a separate reference value;
- switching means electrically connected to said power supply means and said resonant circuit means for alternately completing the circuit between said resonant circuit means and said power supply means for energizing said resonant circuit means and then breaking the circuit between said power supply means and said resonant circuit means whereupon said resonant circuit means passes an oscillating signal to said detection and comparison circuit means;
- and
- actuating means for actuating and deactuating said switching means at a frequency that is independent of the frequency of oscillation of said resonant circuit means.
Dependencies are inferred from the claim text.