impo s sibl e to exa ctly quantify the expatriate population (Roz e n b e r g 1990). Language While Catalan and Spanish are the official langua g e s of Ibiza, a "diale ctal variation [of Catalan]...called Eiviss e n c or Ibicenc o is mor e readily spok e n by both the resid e nts and thos e of Form e nt era . Additionally, be c a u s e of the influenc e of tourism (se e below) and expatriate s living in or maintaining resid e n c e s on the island other, atypical langua g e s , such as English, Ger m a n and Rus sian are also spok e n. Polylinguality is the norm, not the exc e ption. Tourism Nightlife Ibiza is con sid er e d a popular tourist de stination,
0 to 24.9% increase a to 4.9% Increase U.S. Center of Population 15.0 to 19.9% increase Decrease The center of u.s. populati on IS the cen te r o f "po p ulatio n gr211fy, " or [he po int o n wh ich [he U. S. wo uld bal ance If ir were a rigi d plan e, assu nll ng all mdividuals weigh the same and exert influenc e p rop orti onal to [h eir di stance from a cen tr al P0l!1 L 2000 FL Source: U.S. Census Bureau Source U.S. Census Bureau Per Capita Income
A block diagram of an audio PWM amplifier is shown in Figure B.5. An audio ampli- fier using PWM is referred to as a class D amplifier. The Philips TDA8920 is a typical class D power amplifier IC, with two 50W audio amplifiers operating at up to 90% effi- 252 Appendix B Figure B.5 PWM audio amplifier. ciency. Class D audio amplifiers typically switch at hundreds of kHz to avoid influenc- ing the audio output with the PWM frequency. The advantages of PWM for audio appli- cations are the same as for any other application: better driver efficiency, smaller power supplies, and less heating. Appendix B 253 Appendix C Some useful URLs Semiconductors www.analog.com Analog devices www.atmel.com Atmel www.burr-brown.com Burr-Brown www.clarostat
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