When most of the air was evacuated from the tube, an electrical charge could be seen jumping across the gap between the two electrodes. Early ExperimentationĮarly experiments to solve the riddle of electricity often included the use of anode-cathode tubes (glass tubes that contained an anode at one end and a cathode at the other). Great scientists like Henri Becquerel (1820-1891 French chemist and an authority on luminescent, or light caused by radiant energy, phenomena), Marie Curie (1867-1934 Polish-born French physicist who worked extensively with radium) and Thomas Young (1773-1829 English physician and physicist) led the way. Phenomena that had never before been truly understood, such as light, heat, and electricity, were systematically explored. This pulse turns on the sweep generator, initiating the sawtooth wave form.In the mid to late 1800s, the world experienced a scientific revolution. however The sweep trigger then generates a pulse coincident with a selected point in the cycle of the triggering signal. A portion of the signal in the vertical amplifier is impose to the sweep trigger as a triggering signal. Cathode Ray Oscilloscope CRO Operation:Ī simple block diagram of a oscilloscope is in Fig 3 In general, the instrument is operats in the manner The signal in display increases the amplitude by the vertical amplifier and impose to the verical deflection plates of the CRT. The horizontal deflection of the beam repeats periodically, the frequency of this periodicity is adjustable by external controls. When the voltage suddenly falls to zero, as at points (a) (b) (c), etc…., the end of each sweep – the beam flies back to its initial position. Application of one cycle of this voltage difference, which increases linearly with time, to the horizontal plates causes the beam which deflects linearly with time across the tube face.
CATHODE RAY EXPERIMENT VIDEO GENERATOR
The voltage output of such a generator is that of a sawtooth wave as shown in Fig. The linear deflection or sweep of the beam horizontally is accomplish by use of a sweep generator that is incorporated in the oscilloscope circuitry.
The signal impose to the vertical plates is thus displays on the screen as a function of time and The horizontal axis serves as a uniform time scale. In the most common use of the oscilloscope the signal is first amplifies and impose to the vertical (deflection) plates to deflect the beam vertically and at the same time a voltage which increases linearly with time is apply to the horizontal deflection plates thus cause the beam to deflect horizontally at a constant rate. This coversion of electron energy into light allows us to write with points or lines of light on an otherwise darkened screen. then Wherever the electron beam hits the screen, the phosphor excits and light emits from that point. moreover The combination of these two deflections allows the beam to reach any portion of the fluorescent screen. The plates are thus refer to as the horizontal and vertical deflection plates. Between the electron gun and the fluorescent screen are two pair of metal plates – one orients to provide horizontal deflection of the beam and one pair oriented ot give vertical deflection to the beam.
0 kommentar(er)
