09-10-2012, 05:48 PM
Presentation of cathode ray oscilloscope
[attachment=35865]
Basic introduction of CRO
The oscilloscope counts among the important measuring instruments in experimental physics. It makes it
possible to observe and to measure quantitatively the course of an electric voltage UY as a function of time
t or as a function of voltage UX in „real-time“. The temporal course of all physical quantities that can be
converted to an electrical voltage using a suitable sensor can be displayed with an oscilloscope1. There
are few restrictions regarding the amplitude and frequency of the measurable signals: if you are prepared
to spend enough money, you will certainly find an oscilloscope which meets the requirements.
During the introductory laboratory course, too, the oscilloscope is a frequently used measuring
instrument. In some experiments it is a fundamental component of the experimental set-up and yields the
quantitative data required for the analysis. In other experiments it is used for qualitative control, i.e.,
whether a circuit has been correctly set up and is operative, if a sensor is providing the correct signal, ... .
In order to perform the following experiments successfully, a thorough knowledge of the oscilloscope is
imperative. . The experiments described in this document are divided into two laboratory sessions.
Electron Gun:
In the electron gun of the CRT, electrons are emitted, converted into a sharp beam and focused upon the fluorescent screen. The electron beam consists of an indirectly heated cathode, a control grid, an accelerating electrode and a focusing anode. The electrodes are connected to the base pins. The cathode emitting the electrons is surrounded by a control grid with a fine hole at its centre. The accelerated electron beam passes through the fine hole. The negative voltage at the control grid controls the flow of electrons in the electron beam, and consequently, the brightness of the spot on the CRO screen is controlled.
Uses
Oscilloscopes are commonly used when it is desired to observe the exact wave shape of an electrical signal.
In addition to the amplitude of the signal, an oscilloscope can show distortion and measure frequency, time between two events (such as pulse width or pulse rise time), and relative timing of two related signals.
Advantages
One of the advantages of a scope is that it can graphically show signals: where a voltmeter may show a totally unexpected voltage, a scope may reveal that the circuit is oscillating.
Digital electronics usually operate from a clock, so a dual-trace scope which shows both the clock signal and a test signal dependent upon the clock is useful.
Storage scopes are helpful for "capturing" rare electronic events that cause defective operation.
[attachment=35865]
Basic introduction of CRO
The oscilloscope counts among the important measuring instruments in experimental physics. It makes it
possible to observe and to measure quantitatively the course of an electric voltage UY as a function of time
t or as a function of voltage UX in „real-time“. The temporal course of all physical quantities that can be
converted to an electrical voltage using a suitable sensor can be displayed with an oscilloscope1. There
are few restrictions regarding the amplitude and frequency of the measurable signals: if you are prepared
to spend enough money, you will certainly find an oscilloscope which meets the requirements.
During the introductory laboratory course, too, the oscilloscope is a frequently used measuring
instrument. In some experiments it is a fundamental component of the experimental set-up and yields the
quantitative data required for the analysis. In other experiments it is used for qualitative control, i.e.,
whether a circuit has been correctly set up and is operative, if a sensor is providing the correct signal, ... .
In order to perform the following experiments successfully, a thorough knowledge of the oscilloscope is
imperative. . The experiments described in this document are divided into two laboratory sessions.
Electron Gun:
In the electron gun of the CRT, electrons are emitted, converted into a sharp beam and focused upon the fluorescent screen. The electron beam consists of an indirectly heated cathode, a control grid, an accelerating electrode and a focusing anode. The electrodes are connected to the base pins. The cathode emitting the electrons is surrounded by a control grid with a fine hole at its centre. The accelerated electron beam passes through the fine hole. The negative voltage at the control grid controls the flow of electrons in the electron beam, and consequently, the brightness of the spot on the CRO screen is controlled.
Uses
Oscilloscopes are commonly used when it is desired to observe the exact wave shape of an electrical signal.
In addition to the amplitude of the signal, an oscilloscope can show distortion and measure frequency, time between two events (such as pulse width or pulse rise time), and relative timing of two related signals.
Advantages
One of the advantages of a scope is that it can graphically show signals: where a voltmeter may show a totally unexpected voltage, a scope may reveal that the circuit is oscillating.
Digital electronics usually operate from a clock, so a dual-trace scope which shows both the clock signal and a test signal dependent upon the clock is useful.
Storage scopes are helpful for "capturing" rare electronic events that cause defective operation.