Advanced transducers. Phase A - Investigation of digital transducers and digital compatibility techniques
Digital transducers and digital compatibility - analog-to-digital conversion techniques
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Digital transducers and digital compatibility - analog-to-digital conversion techniques
The term digital transducer normally implies the combination of conventional analog sensors with encoders or analog-to-digital converters. Because of the objectionable characteristics of most digital transducers, a program was instituted to investigate the possibility of producing a transducer that is inherently digital, instead of a transducer that is digital in the usual sense. Such a device would have improved accuracy and reliability and would have reduced power and bulk requirements because two processes, sensing and conditioning, would be combined into one processes. A Curie-point-temperature sensor is described that represents realization of the stated goal. Also, a metal-insulator semiconductor is described that does not conform precisely to the program goals but that appears to have applications as a new and interesting transduction device.
Digital transducer principles and potential applications in analog to digital data processing systems
Direct, indirect, quasi and A to D digital transducers principles and features
Physical phenomena and tunneling theory for design of digital transducers
Dielectrics, titanium dioxides, and vapor deposition of thin films for digital metal-insulator-silicon tranducers
Thin film transport in polymer dielectrics, fabrication of semiconductor devices having digital or discontinuous responses, and chemical vapor deposition of exotic dielectric films
Charge transport in thin polymer films based on field emission or thermal emission
Charge transport mechanism in thin silicon nitride films
Thin film titanium dioxide by high temperature vapor deposition
Charge transport mechanism in metal semiconductor polymer thin films
Cadmium sulfide photodielectric effect at cryogenic temperatures with bibliography
Dielectric properties of thin films of polymerized oil-metal-silicon structures
Digital liquid level transducer for ultrasonic binary measurements
Specifications and performance tests for digital pressure transducers designed for spacecraft application
A new digital magnetic temperature transducer is reported. The device utilizes the discontinuous behavior of the initial permeability with temperature at the Curie temperature of some magnetic materials. Since the Curie temperature is determined by the chemical and crystallographic composition of the particular material only, the transducer requires no calibration and has extremely high stability and reproducibility with time. The output of the transducer is inherently digital and, therefore, is directly compatible with the digital information processing and control without A/D conversion. The temperature-sensing portion of the transducer consists only of magnetic cores and wire and, therefore, has extremely high reliability, is shock and radiation insensitive, small, and virtually indestructible.
A study has been made of the feasibility of using the discontinuous permeability versus temperature characteristics of some magnetic materials for a digital temperature transducer and a thermally controlled ON-OFF switch. Simple logic converts the number of output pulse to a digital word recognizable by the system. Efforts have been concentrated on materials with Curie temperatures between 0 and 100 C. One compound has the composition Mn(5-x)Fe(x)Ge3 where the amount of iron determines the transition temperature. The other compound is Ni-Zn ferrite and has the compositon Ni(1-x)Zn(x)Fe(1.95)O4 where the nickel: zinc ratio determines the transition temperature. A detailed report of materials prepared is presented. Toroidal inductors of the material have been constructed and the change in inductance with temperature measured. In view of these initial measurements, it is felt that a transducer utilizing the permeability versus temperature characteristics of these materials has promise as a reliable and sensitive solid state digital temperature transducer.
A novel concept for a digital optical position tranducer is presented. This compact and rugged device is electrically passive and requires only a dual-fiber optical link. Wavelength division of a broad-spectrum semiconductor light source is employed to multiplex the channels of a 10-bit digital position encoder. A preliminary design was evaluated and found to have a 10-dB on-off contrast ratio and a 12-dB insertion loss.