上游文通大学 2.1 Functional Elements of an Instrument SHANGHAI JIAO TONG UNIVERSITY Bourdon tube, Bourdon tube data conversion Fig.2.3 Pressure Thermometer Linkage gearing, data manipulation Measured mediur Bulb,sensing variable conversion Pointer scale, Tube,data transmission data presentation 上游充通大学 SHANGHAI JIAO TONG UNIVERSITY 2.1 Functional Elements of an Instrument Ac power Variable conversion: line electrical pulses(电脉冲)to mechanical reciprocation(机械往复运动) Sensing arm Solenoid Micro- switch 003427 Switch. Rororing Variable conversion Mechanical shaft counter Fig.2.4 Digital Revolution Counter Counter: variable conversion Camlike(凸形)Projection+sensing arm, variable manipulation sensing variable conversion data presentation
2.1 Functional Elements of an Instrument Fig. 2.3 Pressure Thermometer Measured medium Bulb, sensing + variable conversion Tube, data transmission Bourdon tube, data conversion Pointer + scale, data presentation Linkage & gearing, data manipulation 2.1 Functional Elements of an Instrument Fig. 2.4 Digital Revolution Counter Camlike (凸形) Projection + sensing arm, sensing + variable conversion Counter: variable conversion + variable manipulation + data presentation Variable conversion: electrical pulses (电脉冲) to mechanical reciprocation (机械往复运动) Switch, Variable conversion
上海充通大学 2.2 Active &Passive Transducers SHANGHAI JIAO TONG UNIVERSITY Transducer definition in technical paper:a device that converts one type of energy to another. In this book,transducer does not necessarily means energy conversion. Passive Transducer:A component whose output energy is supplied entirely or almost entirely by its input signal. e.g.Pressure Thermometer shown in Figure 2.3 Active Transducer:It has an auxiliary source of power which supplies a major part of the output power while the input signal supplies only an insignificant portion. e.g.Digital Revolution Counter shown in Figure 2.4,2.6,2.7 n practical,an instrument may have passive active transducers,it is considered as an active transducer as an entire. 上泽充冠大学 SHANGHAI JIAO TONG UNIVERSITY 2.2 Active &Passive Transducers Auxiliory Auxiliary power power Motor +。 0 0 e Amplifier esl Torque direction for ee positive -Slide wire Auxiliary Fig 2.7 powe Instrument Servomechanism "Black box" Mix of passive active transducers
2.2 Active ＆Passive Transducers Transducer definition in technical paper: a device that converts one type of energy to another. In this book, transducer does not necessarily means energy conversion. Passive Transducer: A component whose output energy is supplied entirely or almost entirely by its input signal. e.g. Pressure Thermometer shown in Figure 2.3 Active Transducer: It has an auxiliary source of power which supplies a major part of the output power while the input signal supplies only an insignificant portion. e.g. Digital Revolution Counter shown in Figure 2.4，2.6， 2.7 In practical, an instrument may have passive & active transducers, it is considered as an active transducer as an entire. 2.2 Active ＆Passive Transducers Fig 2.7 Instrument Servomechanism Mix of passive & active transducers