JA303Oscilloscope

RAJA PUTRA NASRULLAH B RAJA KAMARUL ZAHARI ( 15BAD11F2020 )

SYAMSUL AZWAN MAULA ISMAIL ( 15BAD11F2023 )

GANESHKUMAR A/L GUNASUNDREM ( 15BAD11F2042 )

KUMARESAN A/L BALAKRISHNAN (15BAD11F2033)

Why do we need an oscilloscope?

Display Screen Displays an input

signal with respect to time.

Control Panel Adjusts how the

input signal is displayed.

The purpose of an oscilloscope is to measure a voltage that changes with time and show it in a graphical format

1) Here is the oscilloscope

-Notice the X-Y axes

2) Here is our alternating voltage signal from before

3) If we measure our signal with the scope, it would look like this!

What must the X-Axis represent? What must the Y-Axis represent?

TIME

VOLTAGE

• So…what do the dials do?

• Notice that the screen has ruled divisions both horizontally and vertically.

• The axes can be scaled, for example…

• If each vertical division is worth 5 seconds, what time is represented by this point?

• If each horizontal line represents 1 volt, what voltage is represented by this point?

• The section to the right of the screen contains the controls necessary to adjust how the waveform is displayed on the screen.

• The controls allow you to alter the sweep time, amplitude, and triggering method. (Note, these topics will be discussed later)

• How do we get the voltage into the scope?• This area is broken into two parts

– Left Half for Channel 1 (X)– Right Half for Channel 2 (Y)

• In the center is a switch that determines which channel will serve as the input to the scope: 1, 2, Dual or Add.

• Why would we want more than 1 channel?

Channel 1 Channel 2

Purpose: Produces waves of different Shapes (sinusoidal,

square, etc.) Amplitude Frequency

Several available in the lab, but we will use the one built into the Instek Oscilloscope. (Shown)

A scope is a device that has measures the voltage across its input at a fixed rate. The scopes you will be using take a voltage measurement every ns s, which it stores in its memory (has room for 2500 measurements). It stores it with 8 bits of precision (1/28=0.004). It then makes a graph of voltage versus time. The graph is refreshed whenever it receives a “trigger”. You set how which measurements it should display relative to the trigger time.

The trigger is a condition you set on a signal fed into the signal input. When the signal satisfies the conditions, the display is refreshed. Often, you feed the same signal into the display input and the trigger input, but not always (you’ll see tomorrow an example of when you would want different inputs).

In this section, we will power on the oscilloscope and set it up to display a signal connected to the CH1 input.

Is this signal changing over time?

What do we call this type of signal?If we made a chart at the different time

intervals…

X=TIME (seconds)

Y=VO

LTAG

E (v

olts

)

5 10 15 20

5

2.5

-2.5

-5

• Press the POWER button located below the bottom right corner of the Oscilloscope’s screen.

• Set the Channel Mode to CH1.

• Set the Trigger Mode to AUTO.

• A green line or dot should appear on the screen.

• If not, try adjusting the Intensity or Position dials.

Press Power

Set Trigger ToAuto

Set Mode to CH1

• The oscilloscope is capable of measuring voltages from two different sources.

• The channel mode switch is used to alternate between these sources.

• For this lab, we will be using Channel 1, so set the switch to the CH1 position.

We will use three types of connecters in this lab. BNC Banana Mini-Grabber

Obtain a BNC cable, Mini-Grabber attachment and connection them together.

Connect the free end of the BNC cable to CH1 on the oscilloscope

Find the Time/Div dial on the oscilloscope. This dial controls the amount of time per centimeter division.

Adjust to dial to 2 milliseconds per centimeter.

Adjust the Position dial for Channel 1 to center the horizontal line.

• If the display is difficult or out of focus, the Intensity and Focus dials can be used to adjust it.

• The INTEN dial controls the brightness of the line.

• The FOCUS dial controls the sharpness of the line.

• Take a moment to adjust each one and notice the difference.

• The channel mode should be set to 1.• The TIME/DIV should be set to 2mS per

centimeter.• A BNC cable should be connected to the

channel 1 input. The other end should have a free Mini-Grabber connection.

• The Trigger Mode should be set to AUTO.• The Oscilloscope should be ON.• The intensity and focus should be adjusted so

the line is clear to see.• The channel 1 position dial should be adjusted

so that the green line is centered on the screen.