Cathode Ray Oscilloscope

CRO abbreviated as Cathode Ray Oscilloscope. The block diagram of oscilloscope is shown below which contains of many equipments, these are listed below

1.Cathode Ray Tube (CRT):

CRT displays the visual signal. When electrons dispatch from electron gun strikes the phosphor screen of CRT. So CRT is also named as heart of oscilloscope.

2.Vertical Amplifier:

An amplifier is used to strengthen the weak signal the similar action is performed by vertical amplifier, it amplifies input signals in vertical sections so the amplified signal drive the deflection plates.

3.Delay Line:

Delay Line circuit provides better performance at output. The input of delay line circuit is obtained from vertical amplifier output. The vertical amplifier output is taken by horizontal amplifier. At this process some delay time is arises due to this trace of leading edge of input waveform will be missed, to avoid this delay line circuit is used between vertical amplifier and vertical deflection plates.

4.Trigger circuit:

The trigger circuit is used for converting incoming signal into triggering pulses. It is required to synchronize the input signal with sweep frequency.

5.Time Base Circuit:

From the output of trigger circuit the pulses reaches the time base circuit. In this circuit the sawtooth waveform is generated which is used to deflect the beam in horizontal section. In time base circuit the waveform is generated by unijunction transistor.

6.Horizontal amplifier:

The operation is similar to vertical amplifier but the only difference is it amplifies the sawtooth voltage produced by time base circuit. The signal later transfers to deflection plates.

7.Power supply:

Power supply consists of negative high voltage and positive low voltage. The range of negative high voltage is -1000V to -1500V, similarly the range of positive low voltage is 300V to 400V. The high voltage supply generates high power to accelerate and deflect the electron beam.

USES:

1.These are used in sciences, medicine, engineering and telecom industry.

2.These are used in electrocardiogram for displaying heart beat waveforms.

3.These are used in electronic mixes, electronic oscillators, amplifiers.

4.Used for testing newly designed circuit.