OPERATING
INSTRUCTIONS
GENERAL
METHODSOF
OPERATION
A
waveformtobeviewedisfedtoV.
INPUT
terminals(1)
andGND(2)or(2)andDCterminal(3).Adjustthe
controls
VERT.ATT
(4)andV.GAIN(11)sothatthe
displayedwaveformis40to60mmhighonthevertical
axis.
Foradjustments,refertotheitems4 and11ofthe
operatingprocedureoutlinedonthepanel.Thenobtainan
appropriatenumberofwaveformpeaksbyadjustingthe
controls
SWEEP
RANGE
(6)and
VAR/H.GAIN
(10).The
displayedwaveformmustbesynchronizedtoa steady
state.
Ifthewaveformcontainsonlya singlecomplete
cycle
onCRT,itmeansthatthetimebasefrequencyis
identical
with
thefrequencyofthesignalbeingdisplayed.
Incontrast
with
this,ifthewaveformcontainsfive
peaks,
thetimebasefrequencyis1/5ofthefrequencybeing
displayed.
Waveformsdisplayed
with
frequenciesaslowas
below50Hzmay
cause
flickeringonCRTduetotheslow
movementofspot.
This
phenomenoniseliminatedasthetimebasefrequency
getshigherthan50Hz.ByusingtheV.
INPUT
DC
terminal,theDCcomponentofdisplayedwaveformcanbe
measured
orfrequenciesbelow10Hzcanbeviewed.When
observingACcomponentonly,theV.
INPUT
ACterminal
is
used.
The
polarityofdisplayedwaveformispositiveintheupper
directionofCRTandintheright-directionwhenviewedin
thehorizontaldirection.
The
positionofthewaveformonCRTcanbecenteredby
adjustingthecontrols(9)and(12).
Since
thewaveform
shifts
upordowndependingonthepolarityoftheDC
component,it'mustbecorrectedbyadjustingthecontrol
(12).
Ifthewaveformcannotbesetinthecenterofthe
screen
evenaftertheadjustmentofthecontrol(12),itisan
indicationthattheDCcomponentistoohighand,
therefore,thecontrols(4)and(11)mustbeadjusted
appropriately
until
thewaveformiscentered.
To
measurethevoltageofthedisplayedwaveform,
cali-
bratetheamplitudeofthewaveformappropriatelyusing
the
scale
onthescreenasa guideandreadthesensitivity
obtained.
Amplitude Amplitude
(Positive
squarewave)
With
AC-DC
selectorswitch
set
atpositionDC.
Calculate
the
voltage
according
tothe
equation
below.
Voltage= Amplitudex sensitivity
As
an alternative,thevoltagecanbeobtainedbya
proportionalcalculationmethodusinga waveformofa
knownvoltage;forexample,iftheamplitudeofthesignal
having3Vppofvoltageis4 cm(thesensitivityofthe
oscilloscope
is3Vpp-f4 cm= 0.75V/cm)andtheampli-
tudeofunknownwaveformis6 cm,then:
3VppXVpp3Vppx 6cm
—_
= —_so„ — = XVpp
4cm6 cm4 cm
Therefore,
X = 4.5Vpp
Alllevelsontheoscilloscopeareinpeak-to-peakvaluesand,
therefore,mustbeconverted
into
correspondingeffective
values
sinceeffectivevaluesarecommonlyusedinpractice.
Inthisconversion,however,itshouldbenotedthatthe
relationshipbetweentheeffectivevalueandtheamplitude
varies
accordingtothetypeofwaveform.Sometypical
relationshipsbetweentwoaregivenforreference:
Waveforms
Effective
values
(rms)
Y=0.5A
2/3"
0.288A
Fig.
2 MeasurementofACandDCcomponents
6
"7?
=0707A
275=0.354A
A
y
=
0.5A
l
In
With
AC-DC
selectorswitch
set
atpositionAC.
