Ch. 13 AC Measurements (교류측정ks.ac.kr/kimbh/KSU-Lectures/Lecture2005/SE028-ch13... · 2005. 5. 17. · AC Meters (교류계측기) • AC Meters (교류계측기) – Moving-coil

Ch. 13 AC Measurements (교류측정)

May 20, 2005

Outline

• AC Meters (교류계측기)

• Oscilloscopes (오실로스코프)

• Frequency Counters (주파수카운터)

• Bode Plotter (보드플로터)

Objectives

• Identify the types of meters available for AC measurements.(교류측정을위한계측기의종류)

• Identify the types of meter movements used to make AC measurements. (교류측정에사용되는계측기의동작형태)

• Explain the function of an oscilloscope. (오실로스코프의기능)

• Identify the basic parts of an oscilloscope and explain their functions. (오실로스코프의주요부분및기능)

Objectives

• Demonstrate the proper setup of an oscilloscope.(오실로스코프의조정방법)

• Describe how to use an oscilloscope to make a measurement. (오실로스코프의사용방법)

• Explain how a counter works. (주파수카운터의동작)

• Identify the basic parts of a counter. (주파수카운터의주요부분)

AC Meters (교류계측기)

• AC Meters (교류계측기)– Moving-coil meter movement. (가동코일형계측기)

• Referred to as d’Arsonval meter movement. (다아손발계측기)• Designed to measure DC current. (직류전류측정) • AC current must be converted to DC current to be measured. (교류전류

직류전류로변환)• The process is called rectification. (정류기)• The rectifiers convert the sine wave into a pulsating DC current.

(정류기 : 정현파전류 맥동직류전류로변환)

– Analog meter as one of moving-coil meter movement : Fig. 13-1– Digital meter : Fig. 13-2– Rectifier (정류기) : Fig. 13-3

– Fig. 13-1 Fig. 13-2

– Fig. 13-3

• Iron-vane meter movement (가동철편형계측기)– Does not require the conversion of AC to DC. (AC DC 변환이필요없슴)

– Consists of two iron vanes within a coil. (코일안쪽에두개의철편이사용됨)

• One stationary vane. (고정형철편)• One movable vane. (가동형철편 : 코일에흐르는전류에비례하여회전)

– Used primarily for 60 hertz applications. (60Hz 정도의응용)

• Clamp-on meter (클램프온미터)– Uses a split-core transformer. (스플릿코어변압기사용)– Used for measuring high values of AC current. (높은교류전류측정)

Oscilloscopes (오실로스코프)

• Oscilloscopes : Fig. 13-6 – Most versatile piece of test equipment available for working on

electronic equipment and circuits. (가장많이사용되는전기전자장치의회로동작을시험하는장비)

– Provides a visual display of what is occurring in the circuit.(시각적으로회로의신호형태를파악하는데효과적임)

– The frequency of a signal. (신호의주파수)– The duration of a signal. (신호의주기)– The phase relationship between signal waveforms. (신호파형의위상관계)

– The shape of a signal’s waveform. (신호파형의모양)– The amplitude of a signal. (신호의진폭크기)

– Fig. 13-6

• Basic parts of an oscilloscope (오실로스코프의기본적인구성요소)– A cathode ray tube (CRT). (음극선관)– A sweep generator. (스위프발생기)

• 톱니파입력을수평편향증폭기에공급)– Horizontal and vertical deflection

amplifiers. (수평/수직편향증폭기)• 음극선관의전자빔이적절한편향레벨로증가하도록입력전압

증폭)– Power supplies. (전원공급기)

• Cathode-ray tube (CRT) (음극선관)– A phosphor screen. (형광스크린: 전자가스크린에충돌할때발산)– Deflection plates. (편향판: 전자빔이스크린에도달할때편향판에의해전자빔의방향이바뀜)

– An electron gun. (전자총: 스크린에충돌하는전자빔을발생)

• Faceplate (눈금판)– Marked in centimeters along the vertical and horizontal axis.

(가로/세로눈금)– Can be calibrated with a known voltage before testing an unknown

signal. (임의의전압범위로조정하여사용가능)– Called a graticule, and is separate from the oscilloscope. Mounted in

front of the CRT. (화면의외부표면에계수선표시)

• Power switch (전원스위치)– Usually on the front panel. (전면에위치)– May be a toggle, push-button or rotary switch. (토글, 푸시버튼, 로터리스위치)

– Mounted separately or with another switch. (독립적으로, 또는다른스위치와함께동작)

– Used to apply line voltage to operate the oscilloscope. (전압인가)

• Intensity switch (휘도(밝기) 스위치)– Also called brightness.– Controls the electron beam within the CRT.– It is a rotary control.– Too much intensity for too long can burn a hole or etch a line in the

phosphor screen.

• Focus and astigmatism controls (초점및비점수차조절)– Connected to the electron gun.– Used to adjust the electron beam size and shape.– Rotary controls.

• Horizontal and vertical position controls (수평/수직위치조절)– Rotary controls.– Allows the electron beam to be positioned anywhere on the face of

the CRT.

Frequency Counters (주파수카운터)

• Frequency counters– Measures frequency by comparing a known frequency against an

input frequency. (미리알고있는주파수와비교하여입력주파수를측정하는장치)

– Consist of:• A time base. (시간조정회로)• An input-signal conditioner. (입력신호조절기)• A gate-control circuit. (게이트제어회로)• A main gate. (주게이트회로)• A decade counter. (십진카운터)• A display. (디스플레이)

• The electronic counter is used in/on (사용처)– Electronics repair shops. (전자제품수리점)– Engineering departments. (공학관련학부)– Ham radio shacks. (무선기기점)– Industrial production lines. (산업생산라인)

Bode Plotter (보드플로터)

• Bode Plots (보드선도)– Named for H.W. Bode.– Used for studying amplifier feedback. (증폭기의피드백연구: 신호의주파수응답분석, 즉진폭과위상각분석)

– Required semi-log graph paper. (세미로그그래프활용)– Required two graphs.

• Gain in decibels. (데시벨단위의이득표시)• Phase shift in degrees. (각도크기의위상천이표시)

– Useful in analyzing filter circuits. (필터회로해석에활용)