In this article we will discuss about the Application of CRO and their working . we will also learn about the main application or CRO.
Application Of CRO
The modern cathode ray oscilloscope provides a powerful tool
for solving problems in electrical measurements. Some important applications of
CRO are.
1. Examination of wave forms
2. Voltage measurement
3. Frequency measurement
1. Examination of waveform:
One of the important use of CRO is
to observe the wave shapes of voltages in various types of electronic circuit
circuits. For this purpose the single under study is applied to vertical input (vertical
deflection plates) terminals of the oscilloscope. The sweep circuit is set to
internal so that saw tooth wave is applied to the horizontal input that is
horizontal deflection plates. Then various controls are adjusted to obtain
sharp and well defined signal wave form on the screen.these are main application of CRO.
2. Voltage measurement
As discussed before, if the signal is applied to the
vertical deflection plates only, a vertical line appears s on the screen. The
height of the line is proportional to peak to peak voltage of the applied
signal. The following procedure is adopted for measuring voltages type
application of cro. By this application of cro these can do...
1. Shut off the internal horizontal sweep generator.
2. Attach a transparent plastic screen to the face of
oscilloscope. Mark off the screen with vertical and horizontal lines in the
form of graph.
3. Now, calibrate the oscilloscope against a known voltage.
Apply the known voltage; say 10V, to the vertical input terminals of the
oscilloscope. Since the sweep circuit is shut off, you will get a vertical
line. Adjust the vertical gain till a good deflection is obtained. Let the
deflection sensitivity be V volts /mm.
4. Keeping the
vertical gain unchanged and apply the unknown voltage to be measured to the
vertical input terminals of CRO.
5. Measure the length of the vertical the obtained
Let it be l mm.
The, unknown voltage = L x V volts.
3. Frequency measurement
The unknown frequency can be accurately determined with the
help of a CRO. The steps of the procedure are as under. which are basic application of CRO.
1. A known frequency is applied to horizontal input and unknown
frequency to the vertical input.
2. The various controls are adjusted
3. A pattern with loops cut by the horizontal line gives the
frequency on the vertical plates and the number of loops curt by the vertical
lien gives the frequency on the horizontal plates.
Working of CRO ( Cathode ray oscilloscope).
The oscilloscope is an electronic measuring device which provides a visual presentation of any wave form applied to the input terminals.
Cathode Ray tube (CRT) like a television tube provides the
visual display of the signal applied as a waveform on the front screen. It is
also known as cathode Tay oscilloscope (CRO).
Block Diagram of CRO
For better understand CRO working and application we need to
know about the block diagram of CRO.
Block Diagram of CRO
For knowing about CRO working and application we required to
also know about the block diagram of CRO.
The Block diagram of CRO is shown below. It consists of
various elements which must be known to us to understand the proper functioning
of CRO.
1. Attenuator
The input signal should be
attenuated to a suitable magnitude before
it is applied to the
amplifier. The attenuators are employed at the input of both vertical and
horizontal amplifiers.2. Amplifier
The amplifiers of an oscilloscope consist of a vertical
amplifier and a horizontal amplifier. The vertical amplifiers amplify the
vertical input signal before it is applied to the Y-plates. The horizontal
amplifier amplifies the signal, before it is connected to the X-plates.
3. Saw-tooth Generator
For better know about CRO working and application we
required to know about Saw-tooth generator.
The measuring signal of any shape is connected to the
Y-input (plates) and then it appears on the screen. The signal on X-plates
should be such that the image on the screen is similar to that on the Y-plates.
Hence, a saw tooth signal is required to be connected to the x-plates which make
the image on the screen like the signal connected at the vertical plate.
The saw-tooth signal is called the time base signal, and is produced
by the saw-tooth generator. The shape of the saw-tooth signal is shown in figure.
The time base signal consists of trace, retrace and hood-off period.
4. Gate Amplifier or Z-amplifier
It is desirable that the image seen on the screen of the CRT
must be continuous. The electron beam is desired to appear only in the trace
period of the time base signal. The retrace period of the electron beam must
not be visible on the screen. Therefore, the gate amplifier is required to
control the electron beam in order that it’s appears only in the trace period. It
is very important for CRO working and application.
5. Trigger (Gate Amplifier Output)
As mentioned earlier, the measuring signal waveform is
connected to Y-input, which appears on the screen.
In order to make the waveform stationary on the screen, it
is required that the starting point of the time base signal has to be fixed
related to the signal connected to the Y-input. This is known as
synchronization.
There are three forms of triggering in an oscilloscope. For
better know about CRO working and application we need to know about this.
1. Internal triggering
The signal which is supplied to the trigger is the internal
signal of the CRO produced by using the signal form the vertical input signal.
2. External triggering
The signal which is supplied to the trigger is the external
signal, produced by using the signal from the external synchronous.
3. Line Triggering
The signal which is supplied to the trigger is the signal
from the power supply of CRO (not shown).
Switches are provided to select the form of triggers as
required. In a CRO, suitable timing can be selected that causes the image on
the screen to be stationary.
Application of CRO
1. Measurement of current
2. Measurement of voltage
3. Measurement of frequency
4. Measurement of inductance
5. Measurement of admittance
6. Measurement of power factor
7. Measurement of resistance.
Hence it is the main application of CRO and their working. If you
will find any incorrect above please comment below in comment box.
For knowing more about the application of CRO.
you must watch this video.
you must watch this video.