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//A Sustainability Analysis of the Design Idea Presented in the// //Article, “Bruton Charisma:////Make those inductors vanish using to savvy scaling”// by Ryan Thiebaud

Consumer electronics continue to increase in usefulness and abundance. The users of these goods enjoy the utility of these products and the increased standard of living that accompany them, but rarely do individuals who aren't intimately affiliated with the industry reflect on the effect that these electronics have on our world. When thinking about what ramifications electronics have on our world and our society, B. Commoner's laws of ecology provide some useul maxims to consider,
 * ==Everything connects to everything else ==
 * ==Everything must go somewhere ==
 * ==Nature knows best and bats last ==
 * ==There is no such thing as a free lunch [1] ==

As this sustainability analysis progresses, keep these laws in the back of your mind. If something sounds too good to be true, it probably is.

Bruton Charisma, coined and authored by “The Filter Wizard,” Kendall Castor-Perry, presents a fascinating filter design technique to eliminate ‘pesky’ inductors from his filters. The Bruton Transform allows scaling of the impedances in a circuit. This scaling transforms each element into a different element, and eliminates the need for inductors all together. [2] Eliminating inductors is convenient for several reasons which will be discussed in the analysis, but does this technique embrace the principles of sustainable design?

The 4E’s of Sustainability offer useful insight into how this design idea influences and affects the world.

__Environment__- The electronics industry has a very real effect on the global environment. Electronics companies typically concern themselves more with profit margins and keeping investors happy than the impact of their products and processes on the ecology of the world. Castor-Perry’s design idea presents an interesting ecological tradeoff, and, depending on how each individual component is made, may or may not foster sustainability. The real question to be answered is “Is an inductor or a D-element more harmful to the environment?”

The answer? It depends. Inductors made during the middle of the 20th century contained lead, a harmful metal that is poisonous to many species. Lead that is disposed of improperly may leach into the soil and contaminate groundwater. In recent years, however, international regulations and the demand for green technology and sustainable practices has caused the industry to move towards leadless inductors. Kastor-Perry’s move to eliminate inductors via the Bruton Transform removes the need for inductors, but demands a new device to fill the void.

The D-element is an active device realized in an Operational Amplifier circuit. This circuit contains two op-amps, each of which likely contains around 20-25 transistors. The facilities that produce transistors are state of the art, and serve to process, purify, and shape silicon into the wafers that form the building blocks of modern electronics. Unfortunately, the silicon production life cycle harms the environment in more ways than one and the manufacture of transistors poses many ecological risks. Silicon must be prepared from silicon dioxide, a naturally occurring compound mined from the earth. The byproduct of the conversion of silicon dioxide to silicon is carbon monoxide, a poisonous gas contributing to the atmospheric carbon problems we face today. Additionally, semiconductor facilities use a myriad of hazardous chemicals and compounds to process and purify the silicon. In 1981, drinking water in San Jose, CA was contaminated by trichloroethane and Freon, toxic chemicals used in the semiconductor industry. The cause of this contamination was the leakage of these toxins from underground storage tanks at facilities operated by Fairchild Semiconductor and IBM. [3]

So the verdict is still out on whether the Bruton Transformed circuit is more ecologically sustainable than its inductor-employing counterpart. It really depends on how the individual elements in the circuit are manufactured. Modern inductors seem to be less harmful to the environment than the practices that produce silicon transistors, but as manufacturing improves and pressure from environmental activism mounts, semiconductor fabrication will become more sustainable.

__Energy__- As scarcity of fossil fuels drives up the cost of energy and an exponentially growing population demands more and more of it, the need for energy efficient electronic designs will continue to increase. Kastor-Perry's idea is certainly more focused on the convenience of the D-element, not its power efficiency. An ideal inductor consumes no real power. Energy is conserved by converting from a time-varying current to a time-varying magnetic field and back again. Now, obviously ideal inductors do not exist and in the real world, there will be resistive losses and paracitic capacitance that will dissipate some power. However, these power losses are minimal compared to the powering of two op-amps and the resistive losses in the D-element from actual resistors. As such, this design idea is not sustainable with regards to energy.

__Economics__- One of the motivations for eliminating inductors from the filter is that large inductors are costly. They require a lots of metals, both for the windings and the core. A D-Element on the other hand is composed of op-amps, resistors, and capacitors - all relatively inexpensive, light-weight components. Money-wise, the Bruton transformed filter is much more sustainable that its purely passive counterpart.

__Equity__- The social equity of the Bruton transformed filter is also a complex issue. Many metals used in semiconductors and capacitors come from regions of the world, such as the Democratic Republic of Congo, where the means by which the metals are obtained infringe on the social equity of many. These "Conflict Metals" provide much of the funding for the rebel armies who wage war in this territory. Millions of innocent civilians have been maimed, raped, or killed at the hands of these militant groups. Tin, which is used to make the solder that forms the electrical interconnects between circuit elements, and tantalum, a metal used in many capacitors, are used extensively in the electronics industry. Whether a typical passive filter or a brutonized counterpart is more equitably sustainable is up in the air. It depends more on the ethics of the manufacturer and whether or not they make a point of boycotting goods that fund these human rights attrocities. [4]

Citations: [1] B. Commoner, //The Closing Circle: Nature, Man, and Technology.// New York: Alfred A. Knopf, 1972, pp. 16-24. [2] Kendall Castor-Perry, //Bruton Charisma: Make those inductors vanish using savvy scaling// @http://www.analog-eetimes.com/en/bruton-charisma-make-those-inductors-vanish-using-savvy-scaling.html?cmp_id=71&news_id=222901145&vID=100 [Accessed 5/01/2011] EETimes Europe; October 04, 2010. [3] Holden, Jason, and Christopher Kelty. //The Environmental Impact of the Manufacturing of Semiconductors//. Connexions. 2 June 2009 [] [Accessed 5/01/2011] [4] //Conflict Metals//, //[|http://ConflictMetals.org]// [Accessed 5/01/2011]