Circuits with Feedback Assignment Example | Topics and Well Written Essays - 1500 words

Circuits with Feedback - Assignment Example Derivation of Feedback Equation for Inverting Amplifier Let we consider an inverting amplifier as shown in fig. 2. Then if ‘A, is the gain then, as vi+ = 0, there fore vo = A(vin+ – vin ¯) vo = - A vin ¯ Also from Ohm’s Law the current is simply the difference in the voltage across R1 divided R1, i1 = (vin+ – vin ¯)/R1 †¦Ã¢â‚¬ ¦(5) Similarly, if = ( vi ¯ – vo)/Rf †¦Ã¢â‚¬ ¦(6) By Kerchief’s current Law at the inverting input, i1 = if + i ¯ where i ¯ is the current entering the amplifier at it’s inverting point, yet for an idea amplifier it reaches to zero hence, i1 = if †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ (7) Substituting the values from equations (5) and (6) we have, (vin+ – vin ¯)/R1= (vi ¯ – vo)/Rf †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ (8) Or vin+/R1 – vin ¯/R1= vi ¯/Rf – vo/Rf Solving for , = †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ (9) This is the required voltage gain expression for inverting amplifier with feedback in terms of open loop gain. Problem 2: Each of the amplifiers shown below incorporate series feedback. The gains, input resistances and output resistances are quoted without feedback. For each amplifier determine: - a) The feedback fraction. b) The gain with feedback. c) The input impedance with feedback. d) The output impedance with feedback. Solution: (i) a) If we consider the given cct. then for feedback fraction ‘Î ², for given cct. is defined as, ... terms of open-loop gain A. Derivation of Feedback Equation for Inverting Amplifier Let we consider an inverting amplifier as shown in fig. 2 (Bogart, 1997, p. 670). Then if 'A, is the gain then, as vi+ = 0, there fore vo = A(vin+ - vin) vo = - A vin Fig. 2(a) Also from Ohm's Law the current is simply the difference in the voltage across R1 divided R1, i1 = (vin+ - vin)/R1 (5) Similarly, if = ( vi - vo)/Rf (6) By Kerchief's current Law at the inverting input, i1 = if + i where i is the current entering the amplifier at it's inverting point, yet for an idea amplifier it reaches to zero hence, i1 = if (7) Substituting the values from equations (5) and (6) we have, (vin+ - vin)/R1= (vi - vo)/Rf (8) Or vin+/R1 - vin/R1= vi/Rf - vo/Rf Solving for , = (9) This is the required voltage gain expression for inverting amplifier with feedback in terms of open loop gain. Problem 2: Each of the amplifiers shown below incorporate series feedback. The gains, input resistances and output resistances are quoted without feedback. For each amplifier determine: - a) The feedback fraction. b) The gain with feedback. c) The input impedance with feedback. d) The output impedance with feedback. Solution: (i) a) If we consider the given cct. then for feedback fraction ', for given cct. is defined as, = (2ia) Substituting the values in equation (2ia) from given cct. we have, == 0.175 2ia Fig. (2i) (2ib) If 'Avf, be the gain

International Marketing Strategy of Starbuck in China and In the UK Essay

International Marketing Strategy of Starbuck in China and In the UK - Essay Example This paper will discuss the way Starbuck Corporation in China and UK was created and how it changed over time especially with increased competition in a marketing environment based on cultural differences. More significantly, this study wants to emphasize the strategic thinking about all the factors involved in applying and analyzing the increasingly enthusiastically satisfied customers served by Starbuck’s management unlike its competitors in the international market. More considerably, the main debate on this subject is on the impact faced by Starbuck Corporation in its expansion globally into China and UK based on regulations, international marketing strategy to increase profitability and increased competition. As a remarkable company, Starbucks Coffee Company has grown into a global brand since it was founded in Seattle, the United States, in 1970 and is focused on building increased customer satisfaction as it treats every customer with respect and dignity. As a company, focused on building its market share, profitability and productivity, Starbucks Coffee outlet began in the 1970’s as a single shop offering high-quality coffee and brewing products. More so, Starbucks Coffee outlet has grown to be the largest roaster internationally with over nineteen thousand stores as it offers the high standard of excellence in all aspects of purchasing, fresh delivery of coffee and roasting as it provides increased customer satisfaction. Over the years, Starbucks has enriched its service in offering roasted coffee sold out to customers its enriched Italian style espresso coffee beverages in all Starbuck stores and branches along with pastries and other coffee-related products. More remarkably, the chain of outlets seeks to give its consumers increased service reliability, high product quality, and management of operations as it seeks to increase its business growth and sustainability. As a result, Starbucks embrace cultural diversity in different regions through its employees who seek to blend with different cultures thus, developing increasingly enthusiastically satisfied customers.