The Control Functions of Oscilloscope

1
The Control Functions of Oscilloscope
2
Objectives

• At the end of this chapter, the students should
  be able to
• describe the basic control functions of an
  oscilloscope.
• practice their knowledge in using an
  oscilloscope to display various electrical
  signals.

3
Introduction

• The Oscilloscope is nothing more than just an
  instrument for displaying electrical signals in
  the TIME domain. Meaning that, you can view
  waveforms on it.
• Some of the uses of the scope may not be obvious
  but if you already possessed one, then you will
  most probably regard it as the most useful tool
  on your workbench.
• So, what is actually an oscilloscope?

4
Basic Oscilloscope

• A basic Oscilloscope is as shown below.

5
Basic Oscilloscope

• The basic controls are
• Bright To adjust the intensity of display.
• Focus To adjust the focusing of display.
• Grat (Graticule) To illuminate a scale used
  to measure a trace.
• Trigger To select a trigger source.
• Trace To select which trace is to be
  displayed.

6
Basic Oscilloscope

• Timebase To select the speed which the trace
  moves across the tube face.
• Input Level- To adjust the input level.
• Pos (Position) To set the position of the
  trace on the display.

7
Brightness

• This is self-explanatory, it controls the
  intensity of the display. It is well worth
  remembering that one cannot execute screen-saver
  programs on an oscilloscope, so leaving the scope
  with a high brilliance will certainly burn the
  trace into the tube face.
• If you must leave your scope switched ON for any
  length of time then turn the brilliance control
  down.

8
Focus

• The focus control is also quite
  self-explanatory but most "scopes" seem to adjust
  a single spot from a short horizontal to a
  vertical line.
• A single horizontal line is therefore not the
  best waveform to adjust the focusing, this is
  best done whilst viewing a waveform.

9
Trace

• Selects which trace is to be displayed.
• There are usually two or more selections
  possible
• A - Selects trace A only (single channel).
• B - Selects trace B only (single channel).
• AB - Selects both trace A and trace B (dual
  channel).
• ADD - Both channel inputs are added and
  displayed as a single trace.

10
Timebase

• The speed the spot travels across the screen
  of the tube may be varied by means of the
  Timebase selector switch.
• This is calibrated in Seconds (S),
  MilliSeconds (mS 0.001 seconds) or MicroSeconds
  (uS 0.000001 seconds).

11
Conclusion

• We have learned at brief about the control
  functions of a basic oscilloscope.
• Various control buttons on the oscilloscope
  serve their own purpose in control.