Exp#7:RMS value of an AC waveform

By: Eng.Tamar Jomaa

Practical wok:

I will use new simulation program called Proteus.

Do not worry, I do not want you to learn the program only analysis the results.

Part#1:

1) Connect the circuit as shown:

Part#1:

2) Draw the direct voltage (appeared on ch1) using oscilloscope.

3) Vary the potentiometer and notice the movement of the dot on Ch2 while varying, then draw the waveform.

Part#1:

At 5% of 1KΩ potentiometer, Ch2 result:

Part#1:

In the report calculate the value of the previous

voltage, if you know the configuration of oscilloscope

as shown:

Part#1:

Remember:

The value of voltage = # of square x scale of ch

So the solution of the previous voltage is

V= - 0.9 x 5 = - 4.5 volte

At 25% of 1KΩ potentiometer:

Part#1:

Ch2 result, in report calculate the value of voltage?

At 55% of 1KΩ potentiometer the result of Ch2:

At 80% of 1KΩ potentiometer the result of Ch2:

At 100% of 1KΩ potentiometer the result of Ch2:

At 5% of 1KΩ potentiometer the result of Ch1:

At 25% of 1KΩ potentiometer the result of Ch1:

At 55% of 1KΩ potentiometer the result of Ch1:

At 80% of 1KΩ potentiometer the result of Ch1:

At 100% of 1KΩ potentiometer the result of Ch1:

Now fill this table according your results:

Ch2 voltageCh1 voltageVariable resistor

5% of 1KΩ

25% of 1KΩ

55% of 1KΩ

80% of 1KΩ

100% of 1KΩ

Note:

Insert your calculation in each part.

Part#2:

1) Connect the circuit as shown:

Part#2:

2) switch link to the left. The lamp should be one.

Notice the intensity of the lamp.

Part#2:

The value of channel A:

Part#2:

3) Switch the link to the right and adjust the amplitude

of the function generator until the intensity is nearly

the same as before.

Part#2:

The value of Channel B

Part#2:

4- Find the value of the output rms value then should

equal to 5V. From the oscilloscope, determine Vpeak.

Vrms=………..

Vpeak=………

5- obtain the peak factor=

Note:In each part show your calculations.

Be free to ask any question