Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.chapter 4electronics fundamentalscircuits, devices, and applicationsTHOMAS L. FLOYDDAVID M. BUCHLAChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.All circuits have three common attributes. These are:Series circuits1. A source of voltage.2. A load.3. A complete path.R1VSR2R3+Chapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Series circuitsA series circuit is one that has only one current path.VSVSVSR1R1R1R2R2R2R3R3R3Chapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Series circuit rule for current:Because there is only one path, the current everywhere isthe same.R2R1VS+_+_++__2.0 mAFor example, the reading on the first ammeter is 2.0 mA, What do the other meters read?2.0 mA2.0 mA2.0 mAChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Series circuitsThe total resistance of resistors in series isthe sum of the individual resistors.4.38 kFor example, the resistors in a series circuit are 680 , 1.5 k, and 2.2 k. What is the total resistance?RR23R1VS6 8 0 2 . 2 k1 . 5 k1 2 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Series circuitTabulating current, resistance, voltage and power is a useful way to summarize parameters in a series circuit. Continuing with the previous example, complete the parameters listed in the Table.I1= R1= 0.68 k V1= P1= I2= R2= 1.50 k V2= P2= I3= R3= 2.20 k V3= P3= IT= RT= 4.38 k VS= 12 V PT= 2.74 mA2.74 mA2.74 mA2.74 mA 1.86 V4.11 V6.03 V5.1 mW11.3 mW16.5 mW32.9 mWRR23R1VS6 8 0 2 . 2 k1 . 5 k1 2 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Voltage sources in seriesVoltage sources in series add algebraically. For example, the total voltage of the sources shown is+++9 V9 V9 V27 V9 VWhat is the total voltage if one battery is accidentally reversed? +++9 V9 V9 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Kirchhoff’s voltage law The sum of all the voltage drops around a single closed path in a circuit is equal to the total source voltage in that closed path. KVL applies to all circuits, but you must apply it to only one closed path. In a series circuit, this is (of course) the entire circuit.Kirchhoff’s voltage law (KVL) is generally stated as:A mathematical shorthand way of writing KVL is10niiV==�Chapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Kirchhoff’s voltage law Notice in the series example given earlier that the sum of the resistor voltages is equal to the source voltage. I1= R1= 0.68 k V1= P1= I2= R2= 1.50 k V2= P2= I3= R3= 2.20 k V3= P3= IT= RT= 4.38 k VS= 12 V PT= 2.74 mA2.74 mA2.74 mA2.74 mA 1.86 V4.11 V6.03 V5.1 mW11.3 mW16.5 mW32.9 mWRR23R1VS6 8 0 2 . 2 k1 . 5 k1 2 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Voltage divider rule The voltage drop across any given resistor in a series circuit is equal to the ratio of that resistor to the total resistance, multiplied by source voltage.8 VAssume R1 is twice the size of R2. What is the voltage across R1?R1R2R21VSVS1 2 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.What is the voltage across R2?The total resistance is 25 kApplying the voltage divider formula:22 ST10 k20 V25 kRV VR� �W� �= = =� �� �W� �� �R1VSR2+10 k15 k20 VVoltage dividerNotice that 40% of the source voltage is across R2, which represents 40% of the total resistance.8.0 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Voltage dividerVoltage dividers can be set up for a variable output using a potentiometer. In the circuit shown, the output voltage is variable. What is the largest output voltage available?VSVOUTR2R1+10 k20 k15 V5.0 VChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Power in Series CircuitsApplying the voltage divider rule:1470 20 V 800 VW� �= =� �W� �The power dissipated by each resistor is:( )2111.75 V470 P = =WUse the voltage divider rule to find V1 and V2. Then find the power in R1 and R2 and PT.R1VSR2+330 470 20 V2330 20 V800 VW� �= =� �W� �( )228.25 V330 P = =WPT = 0.5 W}11.75 V8.25 V0.29 W0.21 WChapter 1Chapter 1Chapter 4Chapter 4Electronics Fundamentals 8th edition Floyd/Buchla© 2010 Pearson Education, Upper Saddle River, NJ 07458. All Rights Reserved.Voltage measurementsVoltage is relative and is measured with respect to another point in the circuit.Voltages that are given with respect to ground are shown with a single subscript. For example, VA means the voltage at point A with respect to ground (called reference ground). VB means the voltage at point B with respect to ground. VAB means the voltage between points A and B.