1. D ESIGN FOR C ONSTRAINTS Neil E. Cotter ECE Department UNIVERSITY OF UTAH necotter@ece.utah.edu

2. LED Lightbulb Constraints LED bulb design Realistic design constraints Economic Environmental Social Political Ethical Health Safety Manufacturability Sustainability

3. LED Bulb Design Individual LED’s Metal heat fins 110 VAC to 4 VDC power [2] [1]

4. Economics Longterm Cost < CFL and Incandescent Initial cost > CFL and Incandescent [3] Light bulb projec ted lifesp an 50,00 0 hours 10,00 0 hours 1,200 hours Watts per bulb (equiv. 60 watts) 101460KWh of electri city used over 50,000 hours 300 500 7003000Cost of electri city (@ 0.10p er KWh) $50$70$300Bulbs neede d for 50k hours of use 1542

5. Environment [4] Light bulb projec ted lifesp an 50,00 0 hours 10,00 0 hours 1,200 hours Watts per bulb (equiv. 60 watts) 101460KWh of electri city used over 50,000 hours 300 500 7003000Cost of electri city (@ 0.10p er KWh) $50$70$300Bulbs neede d for 50k hours of use 1542 Huge power savings depending on hours of light use per day

6. Society Can the poor afford LED bulbs? Transition cost per room > $50 [5]

7. Politics Incandescent ban postponed [6]

8. Ethics Should CFL and Incandescent be banned? [7]

9. Health Is quality of light adequate? Can use phosphors to create colors [8] Light bulb projec ted lifesp an 50,00 0 hours 10,00 0 hours 1,200 hours Watts per bulb (equiv. 60 watts) 101460KWh of electri city used over 50,000 hours 300 500 7003000

10. Safety Lower temperature? Less heat Lower voltage Light bulb projec ted lifesp an 50,00 0 hours 10,00 0 hours 1,200 hours Watts per bulb (equiv. 60 watts) 101460KWh of electri city used over 50,000 hours 300 500 7003000

11. Manufacturability Energy to manufacture < CFL and Incandescent [9]

12. Sustainability No mercury [10] Some arsenic and lead if manufactured poorly [11] [11]

13. LEDs are the Future Less energy Less toxic Less cost [1]

14. References [1]http://eartheasy.com/live_energyeff_lighting.htmhttp://eartheasy.com/live_energyeff_lighting.htm [2]http://blog.makezine.com/2011/08/09/led-light-bulb-teardown/http://blog.makezine.com/2011/08/09/led-light-bulb-teardown/ [3]http://eartheasy.com/live_led_bulbs_comparison.htmlhttp://eartheasy.com/live_led_bulbs_comparison.html [4]I.L. Azevedo, M.G. Morgan, F. Morgan, “The transition to solid-state lighting,” Proceedings of the IEEE, vol. 97, issue 3, 2009, pp. 481-510. Digital Object Identifier: 10.1109/JPROC.2009.2013058 [5] http://www.sears.com/shc/s/p_10153_12605_SPM6583418602P?sid=IDx20070921x00003a&ci_src=14110944&ci_sku=SPM6583418602 http://www.sears.com/shc/s/p_10153_12605_SPM6583418602P?sid=IDx20070921x00003a&ci_src=14110944&ci_sku=SPM6583418602 [6]http://www.washingtontimes.com/news/2011/dec/16/congress-overturns-incandescent-light-bulb-ban/http://www.washingtontimes.com/news/2011/dec/16/congress-overturns-incandescent-light-bulb-ban/ [7]Stevenson, R. “LEDs for less” IEEE Spectrum, vol 49, issue 1, 2012, pp. 39 - 40. Digital Object Identifier: 10.1109/MSPEC.2012.6117834 [8]I.L. Azevedo, M.G. Morgan, F. Morgan, “The transition to solid-state lighting,” Proceedings of the IEEE, vol. 97, issue 3, 2009, pp. 481-510. Digital Object Identifier: 10.1109/JPROC.2009.2013058 [9]S. Uddin, H. Shareef, A. Mohamed, M. A. Hannan, K. Mohamed, “LEDs as energy efficient lighting systems: A detail review,” Research and Dev (SCOReD), 2011 IEEE Student Conference on, pp. 468-472, 2011. [10] E.F. Schubert “Invited talk: Promises and challenges in light-emitting diodes for lighting applications”, Microelectronics and Electron Devices (WMED), 2011 IEEE Workshop on, 2011, pp. 1. Digital Object Identifier: 10.1109/WMED.2011.5767269 [11]http://today.uci.edu/news/2011/02/nr_LED_110210.phphttp://today.uci.edu/news/2011/02/nr_LED_110210.php Neil E. Cotter necotter@ece.utah.edu