The 6th lab on 2012-2-16

This lab, we observe the spectrum of chaotic behavior.

It shows the spectrum with source voltage of 2V VPP at the resonance frequency of 90Hz (diode D1N4002). X axis represents frequency and Y axis represents the amplitude of the voltage across the resistor. From the lab result (left), the harmonic at 90KHz has the largest amplitude and other harmonics has really small amplitude. As noise has a huge effect on the lab result, Pspice simulation might be more accurate. According pspice simulation (right), the spectrum is discrete and only has one obvious harmonic at 90KHz.

  

 It shows the spectrum with source voltage of 6V VPP at the resonance frequency of 90Hz (diode D1N4002). X axis represents frequency and Y axis represents the amplitude of the voltage across the resistor. From the lab result (left), the amplitude of the harmonic at approximately 200KHz and 300KHz increases, though the amplitude of the harmonic at 90KHz still has the largest amplitude. In addition, the number of harmonics increases.

According pspice simulation (right), the spectrum is discrete and only has one obvious harmonic at 90KHz.

 It shows the spectrum with source voltage of 6V VPP at the resonance frequency of 90Hz (diode D1N4002). X axis represents frequency and Y axis represents the amplitude of the voltage across the resistor.The spectrum are continuous.