Ac amplitude measurement, Electrical Engineering

1. Introduction:

Theory: Amplitude is defined as the magnitude of the change in the oscillating variable with each oscillation within an oscillating system. It is calculated as the maximum distance between the extreme points of a curve and the equilibrium value. Following figures shows the peak-to-peak amplitude.

2429_AC Amplitude Measurement.png

Peak-to-peak amplitude is the change between peak (highest amplitude value) and trough (lowest amplitude value, which can be negative). The peak value is defined as the amplitude measured between the horizontal axis and either of the peak values.

Peak value = (1/2) Peak-to-peak value

Material Required: Oscilloscope, Frequency generator, connecting wires, resistor, multimeter.

Description and Aim: To measure the amplitude of an AC waveform using an oscilloscope.

An AC waveform has to be generated from the frequency generator. This waveform is displayed at the oscilloscope and the no of vertical divisions covering the extremes of the waveform are cautiously measured. These extremes give the value of V(pk-pk).

2- Method:

Step 1) Turn on the Oscilloscope and use all the fundamental ports.

Step 2) Use terminal ports to connect generator to DC/AC waveforms circuit clock. Use a two port connector to connect generator source (GEN) to resistor R1.

Step 3) Turn on the generator. Set frequency to 60 Hz at oscilloscope. Adjust the Channel 1 vertical coupling to AC and Channel 1 attenuator to 0.1 V/div. Also set the horizontal time base control to 2ms/div.

Step 4) Connect channel 1 probe of oscilloscope across R1. Adjust generator amplitude to produce a sine wave with height equivalent to 6 divisions. The higher number of divisions ensures better accuracy in the measurement. Try to use the knobs in case there are some distortions coming on the oscilloscope to stabilize them. Peak to Peak voltage of displayed waveform (Vr1) is now 6 Vpk-pk

Step 5) Now disconnect X10 probe from the circuit. Turn on the multi-meter and set it for AC voltage measurement. To measure voltage, make sure that multi-meter is connected across R1 and then voltage is measured.

Step 6) Take the readings and then remove the circuit connections. Switch off the oscilloscope.

3 - Results:

Frequency of oscilloscope = 60 Hz

V(pk-pk) = 6 V

Peak voltage = Vpk  = Vpk-pk / 2  = 6/2  = 3 V

V(rms) = Vpk * 0.707  = 2.121 V

V(avg)= Vpk * 0.637 = 1.911 V

4 - Discussion:

The major factors which affected our results are the waveform generated from the frequency generator. Secondly, the resistor should not be changed in between the experiments as it also decides the final voltage been displayed at the oscilloscope. Lastly, the waveform was enlarged to include maximum no of divisions on oscilloscope. This helps us to take accurate readings. The theoretical and measured results were found almost similar.

Posted Date: 3/2/2013 12:50:41 AM | Location : United States







Related Discussions:- Ac amplitude measurement, Assignment Help, Ask Question on Ac amplitude measurement, Get Answer, Expert's Help, Ac amplitude measurement Discussions

Write discussion on Ac amplitude measurement
Your posts are moderated
Related Questions
Input output The parallelogram symbol  is used to represent the input output  process as shown  below.                 IN01H

A capacitor is charged to 100 V and then discharged by a 50 kΩ resistor. If the time constant of the circuit is 0.8 s, verify: (a)  The value of the capacitor, (b)  The time

Q. Briefly discuss about ‘Cascaded Amplifier' using a diagram? Amplifiers are cascaded when the output of the first is the input to the second. The combined gain is whe

What is the purpose of control word written to control register in 8255? The control words written to control register state an I/O function for every I.O port. The bit D7 of t

coding for vehicle tracking system using gsm in avr atmega16 microcontroller

V-I Characteristics  In the  normal  mode of  operation of an IGBT  a positive  voltage is applied to the collector relative to emitter. When  the gate is at zero potential wi

Q. For the configurations of the coupled coils shown in Figure, obtain the voltage equations for v 1 and v 2 .

i am Eectrical engineer and i want to teach students on line mode. let me know the procedure. thanks pushpendra

Q. A 20-kVA, 2200:220-V, 60-Hz, single-phase transformer has these parameters: Resistance of the 2200-V winding R1 = 2.50  Resistance of the 220-V winding R2 = 0.03  Lea

Q. Find the frequency of oscillation, amplifier gain ? The transfer function is found to be where the equation is written as a Laplace transform (s=jw). Analysis of thi