Tektronix 2221 User Manual

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Basic
Applications
.--
2221
Operators
1. Set
the time
duration
of
the
reference
signal
to an
exact
number
of
horizontal
divisions
by
adjusting the
SEC / DIV switch and the SEC / DIV Variable control .
The time
duration
of the
unknown signat can then
be
computed
by substituting
values in the
formula :
Time
Duration
68.5 us / div x 7 div
=
480
us
1
2.
Establish a
horizontal
conversion
factor
,
using
the
following formula ( reference - signal time duration must be
known ) :
The frequency of the unknown signal is then calculated :
1
Frequency
2.083 kHz
480
us
Horizontal
Conversion
Factor
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1
Reference
Signal
Time
Duration
(
Seconds
)
Horizontal
Distance
SEC
/ DIV
Х
(
Divisions
)
Switch
Setting
22
SLOPE
L
3. For the unknown signal , adjust the SEC / DIV switch
to a setting that provides sufficient horizontal deflection to
make an accurate measurement . Do not readjust the
SEC / DIV Variable control .
The slope of a particular portion of a waveform is the
rate of change of voltage with respect to time . The follow
ing procedure is useful for making the measurements
required
to
determine
the
slope of a
portion of a
waveform .
u
4.
Establish an
arbitrary
deflection
factor ,
using the
fol
lowing
formula
:
1. Preset instrument controls and obtain a baseline
trace ,
Arbitrary
Deflection
Factor
Horizontal SEC / DIV
Conversion X
Switch
Factor
Setting
2. Set the VOLTS / DIV switch to obtain about 5 divi
sions of
vertical
amplitude .
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5.
Measure the
horizontal
distance of the
unknown sig
nal in
divisions
and
calculate its time
duration
using
the
fol
lowing
formula :
3. Set the
SEC / DIV
switch
to
horizontally
spread
the
portion of the waveform to be measured across the width
of the
graticule area ( see
Figure 6-11 ) .
U
Time
Duration
Arbitrary
Horizontal
Deflection
X
Distance
Factor
( Divisions )
4. Read the voltage difference between the waveform
points of
interest .
L
EXAMPLE : The
reference
signal time
duration
is
2.19
ms
, the
SEC
/ DIV
switch
setting
is
0.2 ms
, and the
SEC
/
DIV
Variable
control is
adjusted
to
provide a
hor
izontal
distance of
exactly 8
divisions .
บ
100
90
Substituting the given values in the horizontal conver
sion factor formula :
VOLTAGE
CHANGE
Horizontal
Conversion Factor
2.19
ms
8
div x
0.2
ms
/
div
1.37
10
1
04
1V
Sms
For the
unknown signal the
SEC / DIV switch
setting is
50 us , and one complete cycle spans seven horizontal divi
sions . The
arbitrary
deflection
factor
is
then
determined by
substituting values
in the formula
:
TIME
CHANGE
1
( 5301-19 ) 6530-39
Arbitrary
Deflection
Factor
1.37 X
50 us
/
div
68.5
us /
div
Figure
6-11
.
Slope
.
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6-12

Tektronix 2221 Specifications

General

Brand	Tektronix
Model	2221
Category	Test Equipment
Language	English