TITLE : AC VOLTAGE MEASUREMENT

OBJECTIVES : The purpose of this practical lab is to get an AC waveform on an oscilloscope and to be able to draw waveform of an AC sinusoidal signal , measure the peak voltage, peak-to peak voltage, periodic time and frequency of AC waveform and lastly calculate the rms (effective) and average value voltage.

EQUIPMENTS

1. Oscilloscope

2. Function generator

3. Multi meter

Procedures :

1. The multi meter must be set to AC button and voltage range to 20V

2. Multi meter is connected to function generator at terminal output 50 ohms

3. The function generator is set to sine wave function and sine duty and offset terminal in OFF condition

4. The range is selected from Hz to 1Khz, then the frequency selector is tuned to 0.6 in order to get 600Khz as output frequency

5. AMPL selector is adjusted (amplitude voltage) until the multi meter display 6vrms (voltage must be in AC voltage )

6. The formula is used to calculate the peak and average voltage ( Vp and Vave )

7. Calibrating the oscilloscope

8. Volt/DIV CH 1 is set to 2V range and MAIN TIME /DIV to 0.5ms

9. Sine wave that display on the oscilloscope is drew on the Graph 1 as well as the measurement for the peak voltage, peak to peak voltage, periodic time (T) and frequency (f),

10. The procedure 5 and 6 is repeated for output voltage 4Vrms and 2Vrms.

11. The result is shown in the Graph 2 and Graph 3

Conclusion, at the end of this practical lab we had learnt how to proceed the procedures in systematic way to get the AC voltage’s waveform on the oscilloscope display screen. We also noticed that Sinusoidal wave is only formed on the oscilloscope display when the voltage is set to AC voltage which shows the changing polarity of the current flows.