General Electric Company

Edwin C Underkoffler

Michael Gdula

Jagdish T Gajjar

Craig Alan Wroblewski

John T Adamchick

Michael F Roman

John C Sicko

Raymond J Hodsoll

A binary gas analyzer instrument and analysis method for determining percent composition of a cooling gas within a turbine generator is disclosed. The instrument includes a measurement block having a plurality of cells therein, some of which comprise sealed cells containing a known reference gas. One of the cells comprises a measurement cell and contains the binary gas mixture to be evaluated. Each of the cells contains a thermistor and a heater is provided for keeping the cells at a substantially constant temperature. An electric current supply provides a constant current to each thermistor for selfheating, and the gas within each cell conducts heat away from the thermistor at a distinctive rate. Measuring apparatus is selectably connectable across each cell thermistor to measure the voltage drop across said thermistors, and computational apparatus is provided to automatically translate the measured voltage drop across the measurement cell thermistor into a percent compositional reading of the binary gas constituents. Translation is accomplished by the computational apparatus with reference to the voltage drop across at least one of the reference cell thermistors.

Binary gas analyzer instrument and analysis method

A device for visually presenting communications information, communicated over the telephone network by a pair of sequential dual-tone-matrix-frequency (DTMF) signals to a hearing-impaired person's location, includes an integrated circuit filter for separating the dual tones into one high-frequency-group tone and one low-frequency-group tones for concurrent presentation to a decoder. The decoder presents a four-bit signal to a microprocessor programmed to recognize the pair of sequentially-decoded DTMF signals as one of a set of alphanumeric symbols and to the parallel-format this character information. the character information is coupled to display drivers and associated displays, to present a plurality of sequential alphanumeric characters upon a visible display, in scrolled fashion, whereby the hearing-impaired person views visible information converted from audible tones. Only the recipient need have the communications device of the present invention, whereby a hearing-impaired recipient can receive information from any tone-encoded telephone instrument, without the requirement for the sender of information to possess special equipment.

Telephone communications device for hearing-impaired person

A reference generator, providing a plurality of precisely-phased output signals, utilizes a microprocessor having a table of values for the output waveforms stored in a read-only memory thereof. The table entries include a multiplicity of values for providing a stepwise representation of each of the desired waveforms, which may have constant angular increments therebetween. The incremental tabular values are consecutively read responsive to the count in a timer, integral in the microcomputer, which is sequentially advanced by the pulse output of a voltage-to-frequency converter receiving a rate signal. The tabular values are converted to analog polyphase reference signals by a like number, equal to the number of phases, of digital-to-analog converters and associated low-pass filters. The output waveform peak amplitude is established by a dual-polarity reference voltage generator, responsive to a variable level signal. Essentially instantaneous reversal of the polyphase waveforms is provided by 'angle complement' control of the present point utilized within the tables. The timer circuit provides steps of increasing size through the lookup-table to provide a gradual degradation in the number of steps in the output waveform when the rate signal exceeds the microcomputer execution speed upper limit.

Polyphase reference generator

A microcomputer controller for a printer, and apparatus for facilitating direct memory access to the microcomputer, includes a central processing unit (CPU) with a known set-up time at the beginning of each machine cycle. A memory, associated with the CPU, has an access time less than the CPU set-up time. A pair of three-state buffers are utilized on the address bus to, and the data bus to and from, the memory from each of the CPU and a direct memory access (DMA) port. A DMA control circuit is coupled to the three-state buffers to facilitate direct access to the memory, from the DMA port, during CPU set-up time intervals and also returns control of memory access to the CPU when the set-up, or synchronization, time interval ends. The microcomputer controller is utilized with additional memory, of the read-only type, and shift registers for realizing a printer controller capable of receiving print character data from the DMA port and causing that data to be printed as the associated symbol, indicia and the like, in a print font selected responsive to incoming data.

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Schenectady, NY, United States of America

Edwin C Underkoffler