ac procedure

7/28/2019 AC Procedure

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Procedure 1: Creating and Measuring AC Voltages

In this procedure the Function Generator was connected to the oscilloscope to provide AC

voltage signals, each time with different shape: sinusoidal wave or square wave or triangle

wave, also each with different settings for the frequency, the offset voltage and for the peak-to-peak amplitude. Then, the mathematical equation describing the signal produced was

recorded. Afterwards, the display of the signal's wave on the oscilloscope's screen was

adjusted to view a specified number of cycles of the signal. Measurements regarding the

signal produced were recorded using two ways. First, the values of the horizontal setting,

vertical setting, period, frequency, amplitude and offset were taken from the oscilloscope's

screen and were recorded. Second, measurements of the period, the frequency, the amplitude

and the offset voltage were taken from the "Quick Measure" option provided by the

oscilloscope and were also recorded. Eventually, the percentage error of the frequency and the

amplitude for each signal was calculated.

Results and Discussions:

The 1st

signal produced was for a sinusoidal wave with a frequency of 200Hz, no offset

voltage, and peak-to-peak amplitude of 4Vpp. The mathematical equation describing the

voltage signal was written as the following:

V(t)= 2sin((400)t)

The measurements taken from the oscilloscope's screen were recorded in table (1.1). Whereas,

the measurements received from the "Quick Measure" option were recorded in table (1.2).


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It's noticeable that the values in both tables are close to each other and almost equivalent to

the specified settings. However, the values in table (1.2) show more precise measurements

compared to the values in table (1.1). For example, the period's value in both tables equals 5

but the resolution/error (least count) is better when using quick measure with a value of 0.001while using the screen gives a resolution of 0.2. Also, it's obvious in the case of the amplitude

(peak to peak) which shows in table (1.1) a resolution of 0.25 while a resolution of 0.01 is

shown in table (1.2). On the other hand, the offset's value in table (1.1) is more accurate.

Signal of Procedure 1.1

( Screen)Measurement

error

(Resolution) Units

Wave shape sin wave -

Oscilloscope Horizontal

Setting 1 0.2 MsOscilloscope Vertical Setting 1 0.25 V

Period 5 0.2 Ms

Frequency 0.2 - KHz

Amplitude (peak to peak) 4 0.25 V

Offset 0 0.25 V

Signal of Procedure 1.1 ( Quick

measure)Measurement

error

(Resolution) Units

Wave shape sin wave -Period 5 0.001 ms

Frequency 200 0.1 Hz

Amplitude (peak to peak) 4.06 0.01 v

Offset (avg) 156 1 mv


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The 2nd signal produced was for a square wave with a frequency of 2000Hz, no offset voltage,and peak-to-peak amplitude of 4Vpp. It was described by the following mathematicalequation:

In table (1.3) the measurements shown were taken from the screen. While, the measurementsprovided by the "Quick Measure" option were recorded in table (1.4).

Signal of Procedure 1.4 ( Screen) Measurement error (Resolution)

Units

Wave shape Square wave -

Oscilloscope Horizontal Setting 200 40 s

Oscilloscope Vertical Setting 1 0.25 v

Period 500 40 s

Frequency 0.002 - Hz

Amplitude (peak to peak) 4 0.25 v

Offset 0.25 0.25 v

As seen in table (1.3) the period's resolution is the same as the horizontal setting's resolution

and equals 40 s. This is due to the fact that the period's value is taken from the horizontal

axis, whereas, when using the quick measure the settings for the horizontal and the vertical

aren't needed.

The two tables show similar values for the period and the frequency. The slightest difference

is noticed in the values of the amplitude and the offset where in table (1.3) the amplitude is

equivalent to the specified settings provided by the function generator which is 4Vpp.

However, since there's no offset for this signal table (1.4) gives a close value to zero

compared to table (1.3).


( Quick measure)Measurement

error

(Resolution) Units

Wave shape square wave -

Period 500 1 s

Frequency 2 0.01 KHz


Offset 156 1 mv

500

2

500:2

2

5000:2

)(t

t

tV


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The 3rd signal produced was for a triangle wave with a frequency of 100Hz, 2V offset, andpeak-to-peak amplitude of 4Vpp. The mathematical equation describing the produced signalwas recorded as the following:

Measurements using the screen were recorded in table (1.5), while, measurements using quickmeasure were recorded in table (1.6).


( Screen)

Measurement

error

(Resolution)/least

count

Units

Wave shape Triangle wave -

Oscilloscope Horizontal Setting 2 0.4 ms


Period 10 0.4 ms

Frequency 0.1 - KHz

Amplitude (peak to peak) 4 0.25 V

Offset 2 0.25 v

Once again the values in both tables are close to each other. But, it can be noted that using

the screen as in tables (1.5) provides values that are much closer to the specified setting

produced by the function generator and this is mostly noticeable in the value of the offset

which is exactly 2, whereas, it's 2.163 in table (1.6).



error

(Resolution) Units

Wave shape Triangle wave -

Period 10.01 0.01 ms

Frequency 99.9 0.1 Hz


Offset 2.163 0.001 v

104

30:2)10(

4/10

2

4

30

4

10:2)

2

10(

4/10

2

4

100:2

4/10

2

)(

tt

tt

tt

tV


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The 4th and the last signal produced was also for a square wave and had a frequency of450Hz, an offset voltage of 2.5V, and peak-to-peak amplitude of 5.5Vpp. It was described bythe following mathematical equation:

The measurements taken from the screen were recorded in table (1.7). While, the

measurements provided by quick measure were recorded in table (1.8).



error

(Resolution) Units

Wave shape square wave -

Period 2.22 0.01 ms

Frequency 450.5 0.1 Hz

Amplitude (peak to peak) 5.5 0.1 V

Offset 2.62 0.01 V

The most noticeable values when comparing the two tables are the values of the frequencyand the offset. In table (1.7) the frequency equals approximately 0.0004545 Hz which equals

454.5 Hz, while, the frequency in table (1.8) equals 450.5 Hz and is closer to the actual value.However, the value of the offset in table (1.7) is 2.5 V, whereas, it's 2.62 V in table (1.8). In

this case the value of the offset in table (1.7) is equivalent to the actual value.

Signal of Procedure 1.10 ( Screen) Measurement

error

(Resolution) Units

Wave shape Square wave -

Oscilloscope Horizontal Setting 500 100 s


Period 2200 100 s

Frequency 0.0004545 - Hz

Amplitude (peak to peak) 5.5 0.25 V

Offset 2.5 0.25 V

22002

2200:75.2

2

22000:75.2

)(

t

t

tV

ac procedure

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