Non-electrical signal to the sensor signals into the circuit a total follow-up measurement and analysis， measurement and control system is an indispensable component， it is the nature of various non-electrical signal conversion and signal mutual In the monitoring and control system， the quality and characteristics of the sensor affect the performance of the entire Temperature measurement in the area of negative temperature coefficient (NTC) thermistor in its response has been fast and wide measurement range， the advantages of cheap occupy certain market However， different series of thermistor resistance difference between the thermistor and the same series of individual differences seriously affect the actual use of the Subject to the single-chip microcomputer as the core design of AVR NTC temperature characteristics tester， in the design of high-precision temperature sensor PT100 thermal resistance of the heating environment in which real-time accurate measurement， the use of constant current source circuit as a sensor drive circuit， through the TLC2543 to be the temperature of high-speed data At the same time bridge the use of constant current source of the resistance of the thermistor measured the output signal through the bridge with the PGA-type △ ∑ A / D converter AD7705 is converted to digital From these single-chip temperature， the corresponding value recorded and the data sent through the serial port to the PC， in this way to measure the temperature characteristics of thermistor
SummaryHDB3 code (that is， the third order high-density bipolar code) is a modern transport system in the most common code， application is very The main content of this article is based on the CPLD HDB3 encoder First of all on HDB3 codes and CPLDs development are discussed in this article， and to the software used and the introduction of VHDL language MaxPlusII; finally a detailed analysis of the principle of coding HDB3 codes and VHDL HDB3 codes by coding theory analysis， this design on HDB3 encoder design are divided into three modules step-by-step implementation (Plug-and-V module modeling and implementing the modeling and implementing module B， polar transform module modeling and implementation) Complete the design content in software MaxPlus2 on simulation， testing results and design ideas at the start of the match， so the simulation is correct， complete based on the CPLD HDB3 encoder
PickHDB3 yards ( third-order high-density dual polarity yards) is the most commonly used in modern transmission system is one of the MaXing， is widely This study is based on the main content of the HDB3 yards encoder CPLD device First of HDB3 yards and CPLD application and research status were introduced， This paper used to MaxPlusII and VHDL language software， Finally HDB3 yards are analyzed in detail by VHDL language encoding principle and realization Based on the principle of coding HDB3 yards， the paper analyzes the design scheme of HDB3 code design mainly divided into three coder realized module ( insert V module， modeling and realize the modeling and realization， B module modeling and realize polarity transform module) After completion， the software design in the simulation， MaxPlus2 test results and the design idea of early， so right， completed based on simulation HDB3 code design of CPLD Keywords: HDB3， VHDL， Polarity transformation
This subject introduces a kind of nc dc voltage stabilizer， the power supply， by simulation showed circuit， control circuit and digital-to-analog circuit， amplifying circuit four parts， mainly is a set of singlechip intelligent dc power Accurate analog power is to provide power， digital chip， amplifiers， microcontroller is the voltage required by A/D sampling data output voltage， and comparison， if there is A deviation is the limit， adjust output signal output and closure， alarm， The working process of the working status， manostat by SCM outputs drive LED display， Display circuit used to display the size of the output voltage of While the digital technology and the simulation analysis of the concept of technical This topic is a kind of based on singlechip intelligent high-precision dc power supply of simple design， this power can use digital adjustment， the closed-loop real-time monitoring， high precision， and the output of both double overload protection and alarm functions， applicable to all have high accuracy requirements of the It compared with traditional manostat with easy operation， high stability of power and its output voltage size using digital display
Abstract Non-electrical signal to the sensor signals into the circuit a total follow-up measurement and analysis， measurement and control system is an indispensable component， it is the nature of various non-electrical signal conversion and signal mutual In the monitoring and control system， the quality and characteristics of the sensor affect the performance of the entire Temperature measurement in the area of negative temperature coefficient (NTC) thermistor in its response has been fast and wide measurement range， the advantages of cheap occupy certain market However， different series of thermistor resistance difference between the thermistor and the same series of individual differences seriously affect the actual use of the Subject to the single-chip microcomputer as the core design of AVR NTC temperature characteristics tester， in the design of high-precision temperature sensor PT100 thermal resistance of the heating environment in which real-time accurate measurement， the use of constant current source circuit as a sensor drive circuit， through the TLC2543 to be the temperature of high-speed data At the same time bridge the use of constant current source of the resistance of the thermistor measured the output signal through the bridge with the PGA-type △ ∑ A / D converter AD7705 is converted to digital From these single-chip temperature， the corresponding value recorded and the data sent through the serial port to the PC， in this way to measure the temperature characteristics of Key words: SCM; PT100; constant current source bridge; resistance measurement
