Poster

Here is our poster.

The 7th lab on 2012-2-20

This lab, we write the sustainability report.

Here is our sustainability report.

Sustainable Development Aspects of the Design

Group 47

Jinqi Liang (ID 200750871) Xin, Wang (ID 200838825)

Department of Electrical Engineering and Electronics

14th February 2012

1 Regulatory considerations

RoHS and WEEE Regulations are two most important part of sustainability legislations. RoHs represents Restriction of Hazardous Substances (RoHS) and this regulation requires all manufacturers of electronic and electrical equipment sold on EU market to ensure that their products contain less than agreed levels of hazardous substances including cadmium, lead, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl (PBDE) .WEEE stands for Waste electrical and electronic equipment and legislations relating WEEE provide how to recycle end-of-life electronic components and devices.

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.

  

The 5th lab on 2012-2-13

This lab, we first observed the non-chaotic and non-chaotic behavior of RLD circuit and then replaced the diode with capacitor to prove that the non-chaotic behavior of RLD circuit is right. Next, we observed the relationship between the chaotic behavior with frequency using analogue oscilloscope. Finally, we observed the relationship between chaotic circuit with amplitude using analogue oscilloscope. 

Part1 Non-chaotic behavior

Phase plot of non-chaotic circuit(diode D14002, 90.9KHz, 184mV )

The 4th lab on 2012-2-10

This lab, we replaced the diode with capacitor to observe non-chaotic behavior. It can be found that the behavior is still non-chaotic when we change both amplitude and frequency.

The third Lab on 2012-2-6

Today is the third lab day. What we have done are observering the chaotic waveforms on the digital oscilloscope. In order to obtain clearer waveforms, the resistor is changed to 820hm.

Chaotic waveform of diode 1N4004  with different amplitude


According to the results, as the amplitude increases, the chaotic behavior become more obvious.

Figure1:Chaotic waveforms with input signal 2V at 90KHz (Diedie 1N4004)

Second Lab

Capacitance of diodes

From data sheet, the Cj0 of D1N4002 and D1N4004 are both 15pF.

Figure 1: datasheet of diodes

For Pispice, Cj0 of D1N4002 is 51.17pF.

According to lab results, Cj0 of D1N4002 is 61.8pF.

Cj0 of D1N4004 is 58 pF.

We do not know why there is a huge difference among the Cj0 of Pspice, datasheet and measurement.

2012-1-30 First Lab

Today is the first day we operated with all equipment and components. The following problems were met during the experiment;
1. How to display the signals on the oscilloscope.
In this case, we use X-Y mode to get the waveforms, where X input is the signal measured across the vlotage source and Y input is the signal measured across the resistor.

2. How to measure the capacitance of diodes.
This problem has not been solved yet. Impedance bridge has been tried.

3. Is the resonance frequency relate to parameter of resistor.
By measured and simulated, the resonance frequency changed a little while using 100K ohms and 10K ohms resistor.

And what have done are:
1. The circuit has been built.
2. The resonance frequency has been measured and simulated.
3. The chaotic waves have been obtained from oscilloscope.