dual trace oscilloscope

2. OSCILLOSCOPE:
The device which convert any electrical signal
to visual.(waveform)
The graph, usually called the trace, is drawn by a beam of
electrons striking the phosphor coating of the screen making it
emit light, usually green or blue. This is similar to the way a
television picture is produced.
WHY DUAL TRACE?
Unlike single trace oscilloscope,dual trace oscilloscope can display
two traces on the screen, allowing you to easily compare the
input and output .
FOREXAMPLE: input and output of an amplifier.

3. Amplifier input Amplifier output

4. Input and output comparison on DTO

5. Single trace oscilloscope

6. Difference Between DTO and Dual Beam
Oscilloscope
A dual-trace oscilloscope should not be confused with a dual-
beam oscilloscope.
Dual-beam oscilloscopes produce two separate electron
beams on a single scope, which can be individually or jointly
controlled.
Dual-trace refers to a single beam in a CRT that is shared by
two channels.

7. DTO WORKING MODES:
VERT MODE TRIGGER SIGNAL
SOURCE
CH 1 CH 1
CH 2 CH 2
ALT Switches between CH1 and
CH2 input signals after each
sweep
CHOP Switches between Ch1 and
CH2 input signal for each
sweep
ADD Combined signal of CH1 and
CH2

8. Front panel

9. FRONT PANEL
CAL TERMINAL
INTENSITY CONTROL
FOCUS
POSITION CONTROL
VOLTS/DIV
INPUT JACK
CH1
CH2
ALT
CHOP
ADD

10. Dual Trace Oscilloscope Works
In Following Two Modes
alternate mode
chopped mode

11. Alternate mode
In alternate mode an electronic switch alternates
between signal A & B.

12. In this the electronic switch alternates between channels A and
B, letting each through for one cycle of the horizontal sweep.
The display is blanked during the flyback and hold-off periods,
as in a conventional oscilloscope.
The screen will show a stable display of both the waveform at
channels A and B.
The alternate mode cannot be used for displaying very low
frequency signals.

13. Chopped mode
In the chopped mode the switch free runs at very
high frequency.

14. In this mode the electronic switch free runs at a high
frequency of the order of 100 kHz to 500 kHz.
The result is that small segments from channels A and B are
connected alternately to the vertical amplifier, and displayed on
the screen.
If the chopping rate is much faster than the horizontal sweep
rate, the display will show a continuous line for each channel.
If the sweep rate approaches the chopping rate then the
individual segments will be visible, and the alternate mode
should now be used.

16. Typical Applications
Troubleshoot electrooptical and electrical systems.
Observe a triggered event separately or relative to the
trigger itself.
Use with analog light meter output to visualize
intensity of a source.
Check response of a silicon, InGaAs, or avalanche photo
diode.
Analyze signals produced by function generators.
Evaluate system performance.

17. THANK
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