Study and Build Chaotic Circuits: 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.

Electronic component used in our project are resistors, diodes, capacitors and inductors. All electronic components are provided by Farnell Company. Farnell strictly obey Environmental legislations and the EU RoHS, the WEEE and the Dodd-Frank Wall Street Regulation are three most important pieces of legislation [1] Besides these, Farnell take energy efficiency as an essential part of sustainable design into consideration to prolong the lifetime of electronic device. Many electronic components provided by Farnell can prevent the electronic circuit from critical events including power surges voltage spikes and therefore components of the circuit can be used for longer time.

Diodes used in this experiment are PN junction diode. This type of diode is mainly made of silicon, boron and phosphorus and therefore does not contain hazardous chemicals. PN junction diode will be break down under high voltage. So, the voltage range across the diode should be controlled and the diodes that do not break down can be recycled.

Capacitors used are electrolytic capacitors. If it is not marked on the back, the capacitor is considered to contain PBCs (polychlorinated biphenyls). PCBs were banned in capacitors in 1978, but stocks containing PCBs are still allowed to be sold [2]. When capacitors are recycled, it is necessary to see if there are markings on the back. If not, the capacitors should be set aside to distinguish capacitors containing PCBs from capacitors containing no hazardous substance.

Resistors are the most common electronic components. If the resistor is put on the breadboard, it can be recycled directly. If the resistor is fixed in the PCB (print circuit board), it can be recycled after desoldering.

Appliance Recycling is another important part of industry sustainability. Recycling appliances are valuable sources of scrap metal when they become obsolete or are no longer needed. However, some of the components in appliances contain materials that can cause health or environmental problems if they are not removed and properly managed prior to recycling.

2 Consideration of potential use of product

This project has three stages: manufacture of components, building the circuit and recycling components. When producing the diode, chlorine is used, which is toxic gas. When the circuit works, the circuit causes electric energy loss. Electric energy is mainly produced from the burning of fossil fuels, which cause the emission of carbon dioxide. Recycling electronic components and devices has been discussed in the first part.

Memristor, which is a portmanteau of memory resistor, is envisioned as a fundamental non-linear circuit element. And it is used in Chua’s circuits to cause chaotic behavior. It is a passive two-terminal electrical component relating charge and magnetic flux linkage. Nowadays, memristor has become a significant part in electronic field. According to Kanellos, memristor can be fashioned into non-volatile solid-state memory, which is similar to DRAM, allows greater density of data than the existing hard drives with access times potentially [3]. As Markoff stated, it can improve the speed to one-tenth of DRAM [4]. In the last few years, patents which related to memristors have occurred in many fields like programmable logic, signal processing, neural networks, control systems, reconfigurable computing, Brain-computer interfaces, and RFID. With these advantages, surely, memristor will lead a new revolution of electronics industry.

Information security becomes an increasing important societal issue. When you purchase goods on the internet, check your bank statement or pay using online credit card, all these actions involve with information security. Generally, some specific software is used for protecting your private information. However, using chaotic circuit to encrypt digital information is a creative way to ensure information security [5].

3 Opportunities for specific design improvements

The component of our project do not contain hazardous substance expect capacitor. The project should use capacitors without PCBs instead of capacitors containing PCBs. Almost all electronic components and devices can be recycled after use. Our project is related memristor, which has a huge potential market. Chaotic circuit also can be used for encryption to ensure information security. Study the chaotic circuit where diode is replaced by memristor and how to encrypt signal will be studied in further study.

Reference

Harriet G, Premier Farnell sustainability report

http://www.premierfarnell.com/premier_farnell/csr/environmentpolicy/

Leonaed E. Electronic devices and Electronic devices dismantling Sacramento California 2011

www.dtsc.ca.gov/HazardousWaste/.../E-Waste_Q-A.pdf