Ming Deng

Application of Embedded Technology for Induced Polarization Instrument

Induced polarization method is one of common methods for electrical prospecting of geophysical. The paper is to analyses and research application of embedded technology for induced polarization instrument and design multifunctional transceiver instrument. The paper is to realize hardware part of induced polarization instrument by regarding ARM processor as hardware core by combination of current intelligent power module (IPM), induced polarization analog signal processing and 24-digit △-∑ high-precision A/D conversion chip (CS5532), etc. It can transplant embedded operation system (uClinux) on embedded ARM processor and formulate drive program which matches hardware circuit and application program to fulfils various functions including data acquisition, data processing & display, data storage & transmission required by induced polarization instrument under uClinux system management.

A 1-V recycling current OTA with improved gain-bandwidth and input/output range

A novel bulk-driven technique is adopted to improve the gain-bandwidth of the conventional recycling current OTA, without requiring any additional power dissipation. Also, the threshold voltage of the transistors is reduced because of bulk-biasing technique, leading to the input/output voltage range extended. To compare the performance advantages of the proposed OTA versus the conventional one, two OTAs were designed in a 1-V 0.18 μm CMOS process. Results show that the proposed OTA’s unit-gain bandwidth is improved by 55% and the input/output voltage range is increased by 140/110 mV. Also, the dc gain is enhanced almost 6 dB.

Dynamic Data Transmission Technique for Expendable Current Profiler

As an expendable profiler in marine environment, XCP (Expendable Current Profiler) is mainly to measure current speed, direction and temperature. The paper is to research dynamic sinking data transmission technique for XCP. Data transmission medium is a varnished wire with diameter of 0.1mm, length of 1,800m and two parallel wires. Transmission characteristics of varnished wires can be tested by experiment and computation. The paper is to research and design a kind of base band transmission system and analyze its characteristics and performance. By utilizing digital base band signaling transmission technique, indoor and marine testing results show that designed data transmission system can reach 1,800m on varnished wires with diameter of 0.1mm if XCP probe sinks dynamically by speed of 4m/s and transmission speed is 2,400bps.

Low-voltage bulk-driven OTA with enhanced transconductance and dc gain

A novel low-voltage bulk-driven operational transconductance amplifier (OTA) with enhanced transconductance and dc gain is presented. Based on the current-recycling structure and partial positive feedback technique, the effective transconductance of the bulk-driven input stage is improved. Also, the bulk-biasing technique is proposed to the composite transistor to achieve the dc gain enhancement. The proposed OTA is designed to operate with a 1 V supply using the CSMC 0.18 µm CMOS process. Results confirm that the gain–bandwidth achieves 29.6 MHz and the dc gain is higher than 86.1 dB when the load is 25.0 pF. The figure of merit is above 370, which demonstrates the proposed OTA has a significant boost compared to prior arts.

Design of data acquisition system based on SoPC and LabVIEW

The paper introduces a design scheme to quickly build data acquisition system based on SoPC and LabVIEW technology. The slave computer of the acquisition system in the design adopts the EP3C10 chip of the CycloneIII series produced by Altera as the main control chip for digital control on A/D converter chip CS5550, digital signal after A/D conversion will be sent to the host computer through RS232 after conversion by EP3C10 chip. The host computer uses the graphical programming language LabVIEW for development of man-machine interactive interface software. The system designed in this paper has many advantages such as rapid development, simple operation, availability for secondary development, strong maintainability and more humanized man-machine graphical interface etc.

Realization of High-Speed Data Transmission in Seismic Data Acquisition

Data transmission is one of key techniques of acquisition station for seismic data acquisition system. With the development of electronics, computer science and communication science, a good realization method has become available for seismic data transmission. The paper focused on the independent design & development of Manchester encoding module, Manchester decoding module and parallel/serial and serial/parallel conversion module by hardware description language (HDL) with FPGA as main control unit and Manchester code and low-voltage differential signaling as theoretical basis. It can realize data transmission speed of 16Mbps between seismic data acquisition stations. Testing results showed low error rate during data transmission to ensure that seismic data acquisition station can read commands sent by power station and convey seismic data correctly.

A high DC-gain low-power current recycling amplifier in deep sub-micron technology

A high DC-gain low-power current recycling amplifier using positive-feedback technique is presented. In the proposed amplifier, the positive-feedback signal used to enhance the DC-gain is derived from the extra nodes created by cascoding. Positive-feedback offers the ability of obtaining a very high DC-gain, ideally infinite gain, without affecting high frequency performance and stability. Under the SMIC standard 65 nm process, the proposed amplifier was implemented. Simulation results show that the DC-gain of 104.5 dB is achieved with only power consumption of 25.5μA and the bandwidth is not limited.

The Application of Circular Magnetic Grid Sensor in Automatic Viscometer for Measuring Viscosity of Liquid Material Based on Fluid Mechanics

Viscometer is analysis instrument which is available in measuring viscosity of liquid material. The viscometer is widely used in food, inks, paints, solvents, petroleum products and various fields of industrial production. In the field of oil drilling, viscometer is mainly used for evaluation rheological parameter of drilling fluid that is beneficial to safety, fast and scientific drilling. Circular magnetic grid could improve precision and stability when it is applied in torque measurement of automatic viscometer, and its non-contact measurement and high antipollution characteristics meet the design requirements of viscometer. The improved automatic viscometer has strong stability, good consistency and automatic reading function. According to needs of users, it would automatically draw various rheological curves.