oscilloscopes: 2 types , analog,digitial see appendix i

Oscilloscopes: 2 TYPES, ANALOG,DIGITIALSEE APPENDIX i

ANALOG:DIRECTLY APPLIES THE VOLTAGE BEING MEASURED TO AN ELECTRON BEAM WHICH MOVES UP, DOWN AND ACROSS THE CRT SCREEN.

DIGITIAL: SAMPLES INPUT WAVEFORM AND USES A TO D CONVERTER TO CHANGE VOTLAGE INTO DIGITAL INFORMATION.

DIGITAL OSCOPES HAVE MOSTLY REPLACEDANALOG SCOPES.SMALLER,LIGHT WEIGHT4 CHANNELMULTIPLE MENU.

LIGHTWEIGT DIGTIAL LCD OSCOPE, GREAT FOR TROUBLESHOOTING IN CRAMPED SPACES

Illustration showing the interior of a cathode-ray tube for use in an oscilloscope. Numbers in The picture indicate:

1.Deflection voltage electrodes 2.Electron gun

3.Electron beam 4.Focusing coil

5.Phosphor-coated inner side of the screen

MAKE presents: The Oscilloscope http://www.youtube.com/watch?v=SxZWcku_Sw0

Old school analog

CYCLE P.203: ONE WAVEFORM THAT DOES NOT REPEAT ITSELF

½ CYCLE

PERIOD (T) : TIME TO COMPLETE ONE CYCLE.( IN THIS CASE .25 SECONDS)

.25 S

SAME THING

FREQUENCY( f ) : # OF CYCLES/SECOND

Time (sec) FOR THIS WAVEFORM f = 1 CYCLES/SEC

HERTZ: UNIT OF FREQUENCY . FOR THE ABOVE WAVEFORM f = 1 Hz f =1/T OR f =1/λ

AMPLITUDE: (a) HEIGTH OF THEWAVEFORM.

=1/T = 1/20ms = 1/.002 = 500Hz

EXAMPLE: FIND THE FREQUENCY FOR THE WAVE FORM BELOW.

ANALOG SCOPES MAKE 2 BASIC MEASUREMENTS, AMPLITUDE AND TIME.

TYPICAL WAVEFORMS THAT CAN BE SEEN ON AN OSCOPE

TRIGGERING: USES THE SAME TRIGGER POINT ON A CONTINUOUS WAVE FORM TO CREATE A STABLE DISPLAY.

You tube: Oscilloscope Tutorial Part 1 - Choosing an oscilloscope http://www.youtube.com/watch?v=qIfo_-d82Co

TYPES OF PROBES

TIMES ONE PROBE( X1) (SHIELDED WIRE)

TIMES TEN PROBE (X10)(LOW CAPACITANCE PROBE)

YOU TUBE: Oscilloscope Tutorial Part 2 - Basic usage http://www.youtube.com/watch?v=hUIgAu3QQWQ

FUNCTION GENERATOR

BASIC MEASUREMENTS WITH OSCOPESVPP=# OF VERTICAL DIVISIONS x VOLT/DIVISIONT (PW) = # OF HORIZONAL DIVISIONS x SECOND/DIVISION

f = 1/T VRMS =VPP/2 X .707

PW: PULSE WITDHNONSINUSOIDAL WAVE FORMS (PULSES)PULSEWIDTH

prt

PULSE REPETITION TIME (prt)

PULSE REPETITION FREQUENCY (prf)

prf = 1/prt

SCOPE SETTINGSX: SEC/DIV = 0.2 MS/DIVY:VOLT/DIV = 0.5 V/DIV

SET SIG. GEN. TO SAWTOOTHF =1KHz AT 1.7 Vp AMPLITUDE

FROM SCOPE SCREEN COUNT VpK SHOULD BE 3.4 VERTICAL DIV X 0.5V/DIV VpK=1.7VVPP=2xVPK=2X1.7V=3.4V

T = 5 HORZ. DIV X 0.2MS/DIV = 1ms

f = 1/T =1/1ms =1KHz

.5

1.0

1.5

2.0FIND Vpp, T ,f OF THE DISPLAYED WAVEFORM

.2 .4 .6 .8 X

Y

YOU TUBE: Oscilloscope Tutorial Part 3 - Advanced functions http://www.youtube.com/watch?v=g_KuGEh0PyA

3.4

FROM SCOPE FIND PW, prt, Vpk

SET SIG. GEN. TO SQUARE WAVEAMPLITUDE = 20VF = 125 KHz

SCOPE SETTINGX: SEC/DIV = 1us/DIVY: V/DIV = 5V/DIV

PW = 4 HORZ. DIV X 1us/DIV = 4us

prt = 9.6 HORZ. DIV X 1us/DIV = 8us

KHzfHzxf

Hzxf

usprtf

1251025.1

10125.

8/1/1

5

6

us1 2 3 4

5

10

15

20

YOU CAN CONFIRM THIS RESULT

LISSAJOUS PATTERNSARE MADE BY APPLYING TWO AC SIGNALS TO THE HORZ. AND VERT. INPUTS OF AN OSCOPEAT THE SAME TIME. SET THE TIME DIVISION SWITCH TO X/Y POSITION ON THE OSCOPEWITH THE TWO FUNCTION GENERATORS SET TO THE SAME FREQUENCY, A CIRCLE SHOULDAPPEAR ON YOUR OSCOPE.

1:1

YOU TUBE: Function Generator Tutorial http://www.youtube.com/watch?v=mLKPwWGBtIw

WITH 1FUNCTION GENERATOR

WITH 2 FUNCTION GENERATORS

Basics of Lissajous Patterns on an Oscilloscope http://www.youtube.com/watch?v=t6nGiBzGLD8

http://www.youtube.com/watch?v=U8bXpzppdR0Oscilloscope for iPad, iPhone and iPod touch

FREQUENCY RATIO