O s c i l l o s c o p e


Oscillopscope is electronic equipment that displays the voltage multisignals in luminous waveforms. It is like a medium to read the complex light modulation.



Understanding the basic concepts of the basic operation


What does oscilloscope measure?

It measures sounds/signals electronic waves. Like the ocean wave, earthquakes wave, sonic boom, explosion, sound through air, or the natural frequency of a body in motion. Energy, vibrating particles and other invisible forces pervade our physical universe. Even light part particle, part wave has a fundamental frequency, which can be observed as color. Sensors can convert these forces into electrical signals that you can observe and study with an oscilloscope.

Oscilloscopes enable scientists, engineers, technicians, educators and others to see events that change over time.
The usefulness of an oscilloscope is not limited to the world of electronics

They are indispensable tools for anyone designing, manufacturing or repairing electronic equipment. Engineers need to solve their measurement challenges quickly and accurately. They are used from physicists to television repair technicians. An automotive engineer uses an oscilloscope to measure engine vibrations. A medical researcher uses an oscilloscope to measure brain waves. The possibilities are endless. As the eyes of the engineer, oscilloscopes are the key to meeting todays demanding measurement challenges.

Types

There have two categories/or classifications:

Analog and Digital
Both of them can be used depending on the applications.


Analog oscilloscope
It works with continuous variable voltages. The analog measures the signals voltage to the vertical axis of an electron beam that moves left to right across the screen. Usually the cathode ray tube (CRT) is where the electrons run by. The more frequently the beam hits a particular location, the more bright it glows. The CRT limits the range of frequency that can be displayed. At very low frequencies the signals appear very bright. At high frequency the CRT's writing limit defines the limit. So when the signals frequency exceeds this limit, the display becomes too dim to see. The fastest it can display frequency is 1 GHz.
It is the one in ITP (see specifics descriptions)link.
Digital oscilloscope means that the oscilloscope can display any frequency within its range with stability, brightness, and clarity. It works with binary numbers that represents voltages samples. Digital is classified in three: digital storage (DSO); digital phosphor (DPO); and sampling oscilloscope.
Describing how Analog oscilloscopes works

The probe (which has power and ground output) is connected to a circuit where the voltage travels through the vertical system of the oscilloscope.

The voltage is applied to some deflections of the signals causing glowing dots to move across the screen. An electron beam that hits the luminous phosphor inside the CRT creates this glowing dot.

The dot will travels in a horizontal system; when trigged it causes the horizontal time base to move the dot across the screen. At higher speeds, the dot may sweep across the screen up to 500.000 times/second.


The horizontal sweeping and vertical deflection trace a graph of the signal. (It is like x/y)

Apart from the capability of probe measurement, oscilloscopes come with channel inputs (BNC) that enable external signal inputs from devices that carry these.

The signal will be displayed in different forms depending on some set ups are set on the control interface.

For more info visit
http://www.cs.tcd.ie/courses/baict/bac/jf/labs/scope/oscilloscope.html

Systems and Controls


The oscilloscope consists of four different systems to each kind of specific measurement required; important to remember that each system contributes to the oscilloscopes ability to accurately reconstruct a signal:

Vertical

It allows to position and to scale the waveform vertically.

The volts/div control = voltage per division/ has a control that works as an attenuator to reduces or increases the amplitude of signal voltage varying the size of the waveform on the screen.

It can displays signals levels from about 4 milivolts to 40 volts

Can be also used to set the input coupling and other signal conditioning.


The time base use the sec/div control to set the amount of time/division represented horizontally across the screen

Horizontal

Can be used to position the to scale the waveform horizontally.

It is most closely associate to the its acquisition of an input signal (like sample rate and record length)



Trigger

The trigger level is used to stabilize a repeating signal or to trigger a single event.

It synchronizes the horizontal sweep at the correct point of the signal, essential for clear signal characterization.

It makes repetitive waveform appear static on the oscilloscope display by repeatedly displaying the same portion of the input signal.

Trigger position control is only available on digital oscilloscopes. It allows us to capture what a signal did before a trigger event, know as a pre-trigger viewing.



Display system and controls

An oscilloscopeÕs panel includes a display screen and the knobs, buttons, switches and indicators used to control signal acquisition and display. As mentioned above it is divided in sections. It also includes input connectors. Each one is different but we provided the specs on the ITP's oscilloscope.


Probe

It functions in conjunction with the oscilloscope as part of the measurement system. Precision measurements start at the probe tip. Probes actually became part of the circuit.

The XY Mode lets you display an input signal, rather than the time base, on the horizontal axis.

Also some of these controls differ between analog and digital

For more info go to

www.tektronix.com.