The cathode ray is a beam of electrons which are emitted by the heated cathode (negative electrode) and accelerated toward the fluorescent screen.
The range of positive voltage supply is from 300V to 400V. The voltage of negative high voltage supply is from -1000V to -1500V. Power supply - The voltages required by CRT, horizontal amplifier, and vertical amplifier are provided by the power supply block. Hence input signal and the sweep frequency can be synchronized. Trigger Circuit - The signals which are used to activate the trigger circuit are converted to trigger pulses for the precision sweep operation whose amplitude is uniform. Horizontal Amplifier - The saw tooth voltage produced by the time base circuit is amplified by the horizontal amplifier before it is applied to horizontal deflection plates. The spot is deflected by the saw tooth voltage at a constant time dependent rate. The saw tooth voltage produced by the time base circuit is required to deflect the beam in the horizontal section.
DIGITAL CATHODE RAY OSCILLOSCOPE GENERATOR
Time Base (Sweep) Generator - Time base circuit uses a uni-junction transistor, which is used to produce the sweep. Therefore, the input signal is delayed by a period of time. The input signal is not applied directly to the vertical plates because the part of the signal gets lost, when the delay time is not used. Usually, the vertical amplifier is a wide band amplifier which passes the entire band of frequencies.ĭelay Line - As the name suggests, this circuit is used to delay the signal for a period of time in the vertical section of CRT.
Vertical Amplifier - The input signals are amplified by the vertical amplifier. When the electrons emitted by the electron gun strikes the phosphor screen, a visual signal is displayed on the CRT. Figure shows the basic block diagram of a general purpose CR oscilloscope.Ī general purpose oscilloscope consists of the following parts:Ĭathode Ray Tube - It is the heart of the oscilloscope. Its reliability, stability, and ease of operation makes it suitable as a general purpose laboratory instrument. The cathode-ray oscilloscope (CRO) is a common laboratory instrument that provides accurate time and amplitude measurements of voltage signals over a wide range of frequencies.
0 kommentar(er)
