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
I want to know whether the circuits for both methods(linear polarization resistance and electrochemical impedance spectroscopy) are same or not?

Q. Show Elementary Synchronous Machines? The polyphase synchronous machine operates with direct current supplied to the field winding (assumed to be on the rotor, which is usua

Q. Two charges of equal magnitude 5µC but opposite sign are separated by a distance of 10 m. Find the net force experienced by a positive charge q = 2 µC that is placed midway betw

Role of Consumers in Distribution Reform In the reforms procedure, mandatory metering for all consumers is being implemented.  Consumers should implement this measure. Public

Distribution Loss Reduction and Efficiency Improvement You are well aware of the fact in which all energy supplied to a distribution utility does not reach the end consumers.

Q. Find the parameter values V T and I DSS for a p- channel MOSFET with i D = 0 when v GS ≤-3 V, and i D = 5 mA when v GS = v DS =-8V.You may neglect the effect of v DS on

A three-phase, four-pole, 220-V, 60-Hz induction machine with a per-phase resistance of 0.5  is operating at rated voltage as a generator at a slip of -0.04, delivering 12 A of li

Q. What do you mean by Frequency Response? As with all electronic circuits, op amps have limited frequency response. Because of the negative feedback of the circuit, the passba

Q. DTL AND TTL LOGIC CIRCUITs? Bipolar transistorswere the first solid-state switching devices commonly used to implement digital logic circuits in the 1950s and 1960s. These c

Q. Implement the following Boolean functions by employing 8-to-1multiplexers. (a) F 1 (A,B,C) = Σ m i (0, 2, 4, 6) (b) F 2 (A,B,C) = Σ m i (1, 3, 7)