Oscilloscope principles

1. OSCILLOSCOPE
AND ITS
APPLICATIONS
Taif Aied Faisal
M.Sc. Laser and Optoelectronics Engineering

2. Introduction Oscilloscope (scope) is
a visual voltmeter with a
timer (clock) that shows
when a voltage changes.
An analog scope uses a
cathode ray tube (CRT)
similar to a television screen
to display voltage patterns.

3. Types of Oscilloscope
• Analogue Oscilloscope
• Digital Storage Oscilloscope
• Digital Phosphor Oscilloscope
• Digital Sampling Oscilloscope

4. Analogue Scope
Digital Storage Scope

5. Digital
Phosphor
Scope
Digital
Sampling
Scope

6. Scope Panel
and Probe

7. Wavestypes

8. Analog and digital scope

9. Scope
Division
Screen

10. Scope
Integration

11. Phase Shift Measurements
 The difference in timing between two otherwise
identical periodic signals is to use XY mode to
measure the phase shift.
 This measurement technique involves inputting
one signal into the vertical system as usual and
then another signal into the horizontal system .
 It’s called an XY measurement because both the X
and Y axis are tracing voltages, the waveform
that results from this arrangement is called a
Lissajous pattern.
 From the shape of the Lissajous pattern, you can
tell the phase difference between the two signals.
You can also tell their frequency ratio.

12. Lissajous patterns for various frequency
ratios and phase shifts

13. X-Y
Operation
δ Sweep generator to produce one cycle of
a sawtooth waveform when it receives a
pulse at its input.
δ PG to produce periodical pulses with a
period ofT, which is equal to the period of
the input signal.

14. Measuring
light on
photocell
 A sensor creates electrical signal in response to physical
stimuli; such as sound, mechanical stress, pressure, light, or
heat.
 The photocell converts light intensity into electrical signal.
Scientific data can be gathered by scope

15. Signal
parameters

16. Structure and main components of a CRT
Face plane of the CRO screen

17.  Electron gun provides a sharply
focused electron beam directed
toward the fluorescent-coated
screen.
 The thermally heated cathode emits
electrons in many directions.
 The control grid provides an axial
direction for the electron beam and
controls the number and speed of
electrons in the beam.

18.  It consists of two pairs of
parallel plates referred to as
the vertical and horizontal
deflection plates.
 One of the plates in each set is
permanently connected to the
ground (0V), whereas the
other plate of each set is
connected to input signals or
triggering signal of the CRO.

19. A +V is applied toY I/p
e-beam deflect
vertically upward
A –V is applied toY I/p
e-beam deflect
vertically downward.
The same is for X I/p.

20. Applied Voltage Examples
=sin(t)