In order to telemeter data from a moving body to a fixed recorder, a unidirectional voltage representing the data is converted by means of circuitry to frequency modulated pulses which are fed to a transmitting coil which sets up an induction magnetic field; the circuitry and the coil are both mounted on the moving body. A fixed recording system includes a receiver having an antenna located in the induction field of the transmitting coil. The receiver converts the pulses picked up to a unidirectional voltage which provides the input for the recorder.
A system for transmitting signals between stationary and movable portions of a machine without utilizing any direct electrical contacts. An alternating supply source for the system is provided on the stationary portion and is connected to a stationary coupling member of an inductive coupling. A movable coupling member of the inductive coupling is arranged on the movable portion of the machine. A pulse generator connected to the movable coupling member receives its alternating supply voltage through the inductive coupling and generates a pulse during each period of the supply. A temperature dependent resistor controls the pulse generating device so that the phase portion of the pulse in relation to the zero passage of the supply voltage is dependent on the sensed temperature. The pulses are fed back through the inductive coupling to a measuring device arranged on the stationary portion of the machine.
The present invention relates to a signal transmission and control system wherein a signal is transmitted from one member of co-acting members to another member; the signal being transmitted without mechanical contact -- and being transmitted regardless of the spatial relation, the angular relation, or the relative motion of the members. The present invention may be designed to transmit various types of signals; and may be used as a remote control for controlling any of a variety of systems.
Apparatus and method for detecting rotation of a shaft include a first antenna for transmitting electromagnetic energy into the shaft, a second antenna disposed for rotation with the shaft for modulating electromagnetic energy passing through the shaft in relation to the shaft rotational speed, and a detector for detecting the modulated electromagnetic energy that passes through the shaft.
A smart structure comprising a rotatable shaft, and a sensor integrated with the shaft, a resonant detector circuit integrated with the structure for detecting a sensor output, and an external exciter circuit; the detector circuit having first coil means and the exciter circuit having second coil means magnetically coupled to the first coil means when aligned across a gap; and control means exterior the shaft for producing an output that corresponds to the sensor output compensated for the gap.
A gauging apparatus for fluid containers such as fuel tanks includes a capacitance disposed in the container that changes value based on the volume of fluid in the container; a first antenna disposed below an outer surface of the container and coupled to the capacitance; a second antenna magnetically coupled with the first antenna across a coreless gap; and a gauging circuit coupled to the second antenna and comprising an oscillator for applying an excitation signal at a number of different frequencies to the second antenna, and a signal processing circuit that detects current in the second antenna caused by the excitation signal and by current in the first antenna related to the capacitance value.
