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 **__EE 413-01 __**  **__Design Idea: Circuit Protection for Outdoor LED Lighting __** URL: [] **__Sustainability Analysis of a Metal Oxide Varistor [MOV] __**

“…waste is basically stupid [1].” These are the words spoken by the architect and designer William McDonough in the documentary video “Waste = Food.” As much as society acknowledges this truth, it is often ignored as the Earth’s resources are continuously taken for granted and more waste is successively produced every year. Moreover, humanity helps to generate more waste even when destroying the environment a **little less**. According to chemist, Michael Braungart, “To destroy a little less doesn’t protect anything [1].” In other words, creating helpful “green” means, that will only help at its minimum capacity, does not keep the waste, discarded by consumers, from harming the planet. This is where the concept of sustainability should come in. A sustainable condition allows people to meet the needs of the present without compromising the ability of future generations to meet their own needs [6]. Since humans are clearly not living in a sustainable manner, much should be done in order to replenish and clean the Earth’s resources.

It is of paramount significance to note that technology is of no exception. According to Jeff Johnson’s article, “A Tsunami of Electronic Waste,” “The increase of electronics gear and discards is staggering. In 1998, consumers discarded 20 million computers; by 2005, the amount had more than doubled…[5].” Because technology creates so much waste, whether it is through the energy and natural resources used to produce, power, and dispose of new and old technology, affirmative sustainable action should be taken. In order to do so, one must consider Commoner's laws of ecology: everything connects to everything else, everything must go somewhere, nature knows best and bats last, and there is no such thing as a free lunch, the green engineering design principles, as well as the four E’s of sustainability: energy, environment, economics, and social or political equity. As an example of what a somewhat sustainable product embodies, a metal oxide varistor (MOV) will be considered.

MOVs are most commonly used for handling overvoltage events and dealing with transient voltages. These components essentially divert transient currents to ground and away from sensitive circuits by conducting significantly increased current when voltage is excessive. Since they are clamping devices, however, the ac input line is not shorted when activated and recovery occurs automatically once the overvoltage is no longer there. Although MOVs are recognized as effective circuit protectors, a drawback must be considered before implementing them in a system. That is, the slight degradation that occurs with every successive surge activation should be taken into account because while MOVs can handle repeated large surges, they age after each surge and their effectiveness reduces from the breakover voltage increase.

**Energy: **"The conservation of energy and the development of energy-efficient solutions is one of the most critical challenges facing the world today [2].” Therefore, companies, such as EPCOS, strive to reduce their consumption of energy and continuously work on innovating MOVs that qualify as sustainable products. However, the main parameter affecting an MOV’s life expectancy is its energy (Joule) rating. As the energy rating increases, its life expectancy typically increases exponentially, the number of transient pulses that it can accommodate increases, and the "clamping voltage" it provides during each transient decreases [7]. Moreover, for an MOV to operate without failure or degradation, the absorbed energy must be dissipated quickly and the device itself must return to its standby operating temperature. The ability to dissipate energy to the environment will depend on the design of the environment itself—ambient temperature, ventilation, heat sinking, other component population and density, proximity of heat sources, weight of PCB conductor traces, presence of thermal cutoff devices, etc [8]. With the help of secure designs, proper means can be taken in order to provide “sustainability-friendly” devices. Also, creating engineering solutions beyond current or dominant technologies; improve, innovate, and invent (technologies) to achieve sustainability can be accomplished to a great extent with these secure designs.

**Environment: **It is unfortunate to see how much waste is produced from something used on a daily basis. From something thought to have eased our lives. Without doubt, that something is affecting our environment, and growing. According to Howard Learner’s article, “Obsolete Electronics Pose Waste Danger,” “Electronic waste is the fastest growing part of the solid waste stream [4].” It can be observed that one of Commoner's laws of ecology, everything connects to everything else, plays an important role here. That is, our environment is clearly being affected by this growing stream of solid waste. Moreover, it is imperative to note that many of these wastes include toxins harmful to the environment. According to the U.S. Environmental Protection Agency, even the tiniest amount of toxics leaking from a landfill can badly pollute our drinking water supplies [4]. Sadly, so much of what was thought to have bettered our lives is actually affecting it. Therefore, more attention should be paid to nature. After all, nature knows best and bats last. Fortunately, there are industries out there willing to make a difference and willing to minimize depletion of natural resources. EPCOS, for example, defines the following environmental protection principles while maintaining life-cycle thinking in their engineering activities: ■ Above and beyond statutory and administrative requirements, we are continuously working to minimize the burden on the environment and to reduce consumption of energy and natural resources. ■ <span style="color: black; font-family: 'Times New Roman','serif'; font-size: 12pt;">We are taking all precautions necessary to protect our environment against damage.

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 0pt;">The planning and development instructions include regulations and guidelines that aim to identify environmental aspects and to optimize products and processes with respect to material use and environmental compliance, to design them with sparing use of resources and to substitute hazardous substances as far as possible [9]. In other words, EPCOS’ mission statement is to ensure that all material and energy inputs and outputs are as inherently safe and benign as possible. Furthermore, companies such as AVX Corp. now provide MOVs that are lead-free, which is suitable for telecommunications, industrial equipment, consumer electronic and automotive applications [10]. With the use of lead-free MOVs, AVX Corp. is not only developing and applying engineering solutions, but also protecting the environment. That is, when a plethora of electronic devices/components that contain less harmful materials are thrown away, less harmful chemicals, than what most electronic devices/components dispose of, are being discarded. They are, in essence, striving to prevent waste, as well as engineering processes and products holistically, using systems analysis, and integrating environmental impact assessment tools. In addition, because lead can affect the nervous system and cause headaches, dizziness, irritability, memory problems, disturbance in sleep, etc. [3], AVX Corp. is being cognizant of human health and their well-being. In other words, they are conserving and improving natural ecosystems while protecting human health and their well-being.

**<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">Economics: **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">Not only can technology create more waste, it can also increase costs. Companies, however, have been able to decrease such costs. For instance, typical protection devices for overvoltages, such as the MOVs, lead to effective circuit protection, an increase in reliability, and the reduction of cost associated with major system failures or catastrophic fires. W hether the MOVs are used for industrial equipment, consumer electronics, telecommunications, or automotive applications, as long as effective circuit protection is provided, everyone profits from this component. Since reduction of costs associated with major system failure or catastrophic fires occur, costs don’t necessarily accrue. Also, RoHS-compliant MOVs cost about $.04 in quantities of 10,000. Benefits accrue in the sense that more protection is offered for both the system and anyone/anything surrounding that system. Furtermore, the product exists until it reaches its degradation point, which is typically deemed to be fully degraded when its “clamping voltage” has changed by 10%. However, it can also depend on the system it is implemented in. After the MOV serves its purpose or is fully degraded, the device can simply be properly disposed of and replaced by another RoHS-compliant lead-free MOV. **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">Social or Political Equity: **<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">One can denote that we are greatly dependent on technology in order to function in an ordinary manner. However, there isn’t exactly a trade off when producing, using, and disposing of these creations. So there is a great need for communities and stakeholders to actively engage in development of engineering solutions. Howard Learner states in his article, “Obsolete Electronics Pose Waste Danger,” “TVs, computers, monitors, cell phones and other electronic equipment contain lead, mercury, cadmium and other toxic materials. Only about 12 percent of e-waste is recycled nationwide. The rest ends up in landfills [4].” In essence, there is no such thing as a free lunch. That is, so much of these useful electronics are actually producing more harm than helping us in the long run. Moreover, according to Jeff Johnson, in his article, “A Tsunami of Electronic Waste,” “As much as 80% of ‘recycled’ material is in fact not really recycled but is dumped in the poorest parts of the world…[5].” However, there are companies out there willing to make a change. There are companies willing to ensure that all material and energy inputs and outputs are as inherently safe and benign as possible. Such a change is envisioned in companies like Sony, Hewlett-Packard, and Dell. According to Johnson, “Ten states and New York City have created take-back programs, as have Sony, Hewlett-Packard, and Dell [5].” These take-back systems may fall far short of matching the scale of the waste [5], but they are at least attempting to conserve and improve natural ecosystems while protecting human health and well-being. Sony, Hewlett-Packard, and Dell make use of one of Commoner’s laws, everything must go somewhere, by simply finding an adequate place and use for the waste they are producing. In essence, engineering solutions are developed and applied, while being cognizant of local geography, aspirations, and cultures.

**__<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">References __**

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 4.5pt;">[1] McDonough, William and Braungart, Michael, as quoted in “Waste = Food (An inspiring documentary on the Cradle to Cradle design concept)” 2006 [Podcast television program] Directed by R. van Hattum. The Netherlands: VPRO. Available: []. [Accessed: 25 April 2011].

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[2] Global Sources EEtimes Asia, "BJTs with ultrafast switching save on energy", //Global Sources EEtimes Asia//, 14 April 2008 [Online], Available: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[], [Accessed: 25 April 2011].

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 4.5pt;">[3] Occupational Health and Safety, “Health Effects of Lead Exposure,” //Occupational Health and Safety//, 17 February 1997 [Online], Available: [], [Accessed: 26 April 2011].

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[4] Learner, Howard A., "Obsolete Electronics Pose Waste Danger", //Chicago Tribune Online Edition: Environmental Law and Policy Center,// 27 December 2007 [Online], Available: <span style="color: blue; font-family: 'Times New Roman','serif'; font-size: 12pt;">[] <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">, [Accessed: 27 April 2011]. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 0.25in;">[5] Johnson, Jeff, "A Tsunami of Electronic Waste," //Chemical & Engineering News//, vol. 86 no. 21, 2008, pp. 32-33, Available: [], [Accessed: 27 April 2011]. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 0.25in;">[6] The World Commission on Environment and Development, //Our Common Future//, chaired by Norwegian Prime-Minister Gro Harlem Brundtland, 1987. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[7]Pharr, Jim, [|"Surge Suppressor Fires,"] //<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">ESD Journal //<span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">, 24 March 2004 [Online], Available:  <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[], [Accessed: 29 April 2011]. <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[8] Brown, Kenneth, “Metal Oxide Varistor Degradation,” //IAEI Magazine//, 22 March 2004 [Online], Available: [] __ <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">, [Accessed: 29 April 2011]. __

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 4.5pt;">[9] EPCOS, “SIOV Metal Oxide Varistors,” //EPCOS//, December 2007 [Online], Available: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[] <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">__, [Accessed: 29 April 2011]. __

<span style="font-family: 'Times New Roman','serif'; font-size: 12pt; line-height: normal; margin: 0in 0in 4.5pt;">[10] Roos, Gina, “MOVs are RoHS Compliant,” //EE Times//, 3 November 2006 [Online], Available: <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">[] <span style="font-family: 'Times New Roman','serif'; font-size: 12pt;">__, [Accessed: 29 April 2011]. __