Question

draw the block diagram of the CRO and explain the different components

Answer 1

Ques:

Ans:

Block Diagram of CRO :- Cathode Ray Oscilloscope (CRO) consists a set of blocks. Those are vertical amplifier, delay line, trigger circuit, time base generator, horizontal amplifier, Cathode Ray Tube (CRT) & power supply. The block diagram of CRO is shown in below figure.

The function of each block of CRO is mentioned below.

1. Vertical Amplifier − It amplifies the input signal, which is to be displayed on the screen of CRT.
2. Delay Line − It provides some amount of delay to the signal, which is obtained at the output of vertical amplifier. This delayed signal is then applied to vertical deflection plates of CRT.
3. Trigger Circuit − It produces a triggering signal in order to synchronize both horizontal and vertical deflections of electron beam.
4. Time base Generator − It produces a sawtooth signal, which is useful for horizontal deflection of electron beam.
5. Horizontal Amplifier − It amplifies the sawtooth signal and then connects it to the horizontal deflection plates of CRT.
6. Power supply − It produces both high and low voltages. The negative high voltage and positive low voltage are applied to CRT and other circuits respectively.
7. Cathode Ray Tube (CRT) − It is the major important block of CRO and mainly consists of four parts. Those are electron gun, vertical deflection plates, horizontal deflection plates and fluorescent screen.

The electron beam, which is produced by an electron gun gets deflected in both vertical and horizontal directions by a pair of vertical deflection plates and a pair of horizontal deflection plates respectively. Finally, the deflected beam will appear as a spot on the fluorescent screen.

In this way, CRO will display the applied input signal on the screen of CRT. So, we can analyse the signals in time domain by using CRO.