OPERATION OF Cathode ray oscilloscope

a.       Major subsystems of a CRO consists of:

b.      Cathode ray tubes

c.       Vertical amplifier

d.      Channel Delay

e.      Time base generator

f.        Horizontal amplifier

g.       Trigger circuit

h.      Resources

Cathode ray tube (CRT) is the heart of the oscilloscope, with the rest of the CRO consists of a series in order to operate the CRT. Basically the CRT electron beam to produce a sharply focused and accelerated to a very high speed. Files that are concentrated and accelerated this move from the source (electron gun) to the front of the CRT, which hit the material CRT attached fluorescence to the inner surface with sufficient energy to make lights screen in a tiny spot. Electron beam through a pair between two plate a pair of vertical deflection and horizontal deflection plates. Voltage that is inserted into the vertical deflection plate can move the beam in the horizontal plane and CRT spots move up and down. Voltage that is inserted into the vertical deflection plate can move the beam in the horizontal plane and the CRT spot is from left to right. These movements are not mutually dependent to each other so that the CRT spots can be placed at any place on the screen by connecting the input voltage corresponding vertical and horizontal simultaneously.

Waveform signal to be observed on the CRT screen connected to the vertical amplifier input. This amplifier in the set of the entries have been calibrated attenuation commonly marked

VOLT / DIV. Push pull output of the amplifier is returned to the plate deflection through the so-called delay line with sufficient force to control the CRT spot in the vertical direction.

Time base generator or sweep generator generating a sawtooth wave voltage is used as the horizontal deflection in CRTs. Sawtooth wave part that led to positive is linear, and the rate of increase of the sawtooth voltage is restored to the horizontal amplifier. It contains an inverting amplifier phase and produce two waves, two simultaneous output of the sawtooth is returned to the horizontal amplifier. It contains an inverting amplifier phase and produces two simultaneous output waveform is a sawtooth toward negative, while leading a positive sawtooth plate inserted into the right side of the CRT horizontal deflection and the sawtooth deflection towards the negative to the left of the plate. These stresses cause the CRT electron beam across the screen from left to right, in units of time are controlled by the TIME / DIV.

Entered into two voltage deflection plate pairs simultaneously CRT causes spots on leaves loyal shadow file, this is shown pepper drawing 4-2 in which a sawtooth voltage or voltage sweeper inserted into the horizontal plate and the sine wave signal into a vertical peat. because
horizontal sweep voltage increases linearly with time, spots CRT moves across the screen at a constant speed from left to right. At the end of sweeping, when the sawtooth voltage is suddenly decreased from the maximum price to zero, CRT spot to return quickly to its initial position is now the screen section and remain there until a new sweep is started.  When an input signal is inserted simultaneously with the voltage sweep started. When an input signal voltage is inserted simultaneously with sweeping horizontal to vertical deflection plates, the electron beam by two styles, namely one for the horizontal field of dots moving along the CRT screen at a rate which is linear, and one track in the vertical plane that drives the CRT to the top spots and down according to the magnitude and polarity of the vertical input signals on the CRT as a function of time.

                If the input signal has a repetitive ,  CRT displays can be maintained stable by the start of each horizontal sweep at the same point on the wave signal. To achieve this sample is returned to the input wave triggers a wave that generates a trigger pulse at a selected point on the wave input. Trigger pulse is used to turn on the time base generator,  which in turn initiate sweeping spots CRT horizontally from left to right screen.

                Input wave transmission occurs initially used to activate the trigger generator to generate a trigger pulse and start sweeping. This event lasts until a time interval 0.15 μs, so sweeping is not started until after the first wave on the screen. The purpose of the channel delay is slowing the arrival of the input wave on the vertical deflection plates to the trigger circuit and the circuit time base has had the opportunity to start a sweeping beam. Channel delay resulted in a total delay of 0.25 μs, the vertical deflection channel so that the first wave can be seen while it is used to trigger sweeping.

The resources consist of the high voltage to operate the CRT, low voltage electronic circuits for supplying the oscilloscope