How to use an oscilloscope

Tektronix
Tektronix
265 هزار بار بازدید - 13 سال پیش - Tony and Ian from Tektronix
Tony and Ian from Tektronix walk through what is an oscilloscope, how to use an oscilloscope, and other oscilloscope basics. You'll see how you might use an oscilloscope to look at an RC circuit, something many engineers encounter early in their studies. From there, learn about the most important oscilloscope controls and how to use them.

What is an Oscilloscope?
At its heart, an oscilloscope is a device that shows how a signal changes over time -- often, that means looking at how voltage changes over time.

For example, say you had a simple RC circuit consisting of a battery, a resistor, and a capacitor. If you attach an oscilloscope probe to the leads of the capacitor and then connect the battery, a correctly configured oscilloscope will show the way the voltage across the capacitor changes over time.

Here are some oscilloscope basics:

Oscilloscope Display
An oscilloscope can measure four analog channels at a time. Each channel has its own independent set of vertical controls, which allows you to position all four signals however you like on the oscilloscope screen.

What Are Vertical Controls?
The vertical position knob moves the signal up or down the screen. The vertical scale knob stretches or shrinks the signal vertically.

What Does Vertical Scale Mean?
Vertical scale is expressed in volts per division. In the example, the scale is set to 5 volts per division. Because this oscilloscope has 8 vertical divisions, it can fit a signal of up to 40 V peak-to-peak on the screen in this configuration

What Are Horizontal Controls?
All of the oscilloscope's four analog inputs share a common set of horizontal controls. When you change the horizontal settings, all of the waveforms on screen will move together. Turning the horizontal position knob moves the trigger position left or right. This causes all the waveforms on screen to move left or right together, allowing you to see earlier or later parts of a signal. The horizontal scale control causes the scope to acquire data for a longer or shorter period of time--which in turn stretches or shrinks the waveform horizontally.

What does Horizontal Scale Mean?
Horizontal scale is expressed in seconds per division. If an oscilloscope is configured to show 1 second per division, the entire screen is 10 divisions wide and can fit 10 seconds of data.

What are Trigger Controls?
The triggering system determines when the scope begins displaying data. Modern oscilloscope triggers are very sophisticated. Today we'll only be looking at the basics of triggering. The most important trigger control is the trigger level knob.

What Does Trigger Level Mean?
With the basic trigger model (known as edge triggering), the trigger level determines what voltage a signal must reach before the oscilloscope will display it.

What Does Triggering Do?
Without triggering, the oscilloscope will acquire and display data arbitrarily. Since there's no synchronization going on, your signal appears to start at a different voltage each time the scope displays it. The result is a blurred, flickering waveform on the screen. With triggering, the oscilloscope starts displaying data at the same point in your signal, every time it updates the display. The result is an easy-to-view waveform.

For more oscilloscope tutorial support, check out: http://www.tektronix.com/learning/osc...

To learn more about oscilloscopes: https://www.tek.com/blog/what-is-an-o...
13 سال پیش در تاریخ 1390/03/20 منتشر شده است.
265,046 بـار بازدید شده
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