Slide 1What does this symbol represent?OutlineLearning objectivesContext for this moduleDiode Types and Circuit SymbolsP-N Junction – Forward BiasP-N Junction – Reverse BiasI-V Characteristic for a Diode (non-linear)I-V Characteristic for a Zener DiodeDiode Example 1Diode Example 2Diode ApplicationsBipolar Junction Transistor (BJT)BJT Operation (conceptual)BJT low-side driveReview from last lectureBJT low-side drive exampleReview – Interfacing to Control PowerExample – Arduino to AC motorDesign the interface to the relay coilConfigure the componentsCalculations – Follow the procedureConfigure the componentsPossible choice of transistorThe Darlington pairSwitching loads with having appreciable inductanceChoosing the transient suppression componentsBJT high-side driveThe interface designInterface with ULN2803The MOSFETThe MOSFET (hydraulic analogy)MOSFET high and low-side drive examplesLogic Level vs. ‘regular’ Power MOSFETBJT vs. MOSFET – which to use?Intrinsically Safe CircuitsFor More InformationBJ Furman02OCT2014Interfacing to Control Powerhttps://www.jameco.com/Jameco/Products/ProdImag/1939589.jpgIntroduction to Mechatronics, Figure 17.16, p. 410.http://arduino.cc/en/uploads/Main/ArduinoDuemilanove.jpgWhat does this symbol represent?01/14/2019BJ Furman SJSU Mechanical Engineering ME 1062http://upload.wikimedia.org/wikipedia/commons/thumb/a/a1/Check_Valve.svg/500px-Check_Valve.svg.pnghttp://www.clippard.com/downloads/PDF_Documents/Application_and_Training/Clippard%20Schematic%20symbols.pdfOrCheck valveOutline01/14/2019BJ Furman SJSU Mechanical Engineering ME 1063Learning objectivesContext for this moduleDiodesBipolar junction transistors (BJT)MOSFETsUsing transistors to control powerLearning objectives01/14/2019BJ Furman SJSU Mechanical Engineering ME 1064Explain the theory, construction, and behavior of a diodeExplain the theory, construction, and behavior of a bipolar junction transistor (BJT)Explain the theory, construction, and behavior of a MOSFETDesign an interface between a microcontroller and device that needs significant powerContext for this moduleSystem toControlSensorSignalConditioningController(Hardware & Software)PowerInterfaceActuatorUserInterfacePowerSourceBJ Furman 22JAN2011ME 106ME 154ME 157ME 195ME 120ME 284ME 106ME 120ME 30ME 106ME 190ME 187ME 110ME 136ME 154ME 157ME 182ME 189ME 195ME 106ME 120ME 106INTEGRATIONMechatronics Concept Map‘Muscle’01/14/2019BJ Furman SJSU Mechanical Engineering ME 1065Diode Types and Circuit SymbolsDiode TypesSignal DiodesRectifier DiodesTransient Voltage Suppress (TVS) DiodesLight Emitting Diodes Zener DiodesAnode(P)Cathode(N)Symbol:Actual Device:Anode(P)Cathode(N)01/14/2019BJ Furman SJSU Mechanical Engineering ME 1066Surface mounthttp://www.ebay.com/itm/Dual-H-Bridge-DC-Stepper-Motor-Drive-Controller-Board-Module-L298N-for-arduino-/251080674810P-N Junction – Forward BiasP TypeDoped with Boron or Gallium(1 Less e-)N TypeDoped with Arsenic or Phosphorous(1 Extra e-) Anode(P)Cathode(N)+ -Holese-Net currentA Diodeis formed byA junction between positively and negatively doped semiconductor materialP N01/14/2019BJ Furman SJSU Mechanical Engineering ME 1067P-N Junction – Reverse BiasP TypeDoped with Boron or Gallium(1 Less e-)N TypeDoped with Arsenic or Phosphorous(1 Extra e-) Anode(P)Cathode(N)- +P NHolese-No net current01/14/2019BJ Furman SJSU Mechanical Engineering ME 1068I-V Characteristic for a Diode (non-linear)VIForward BiasAnode voltage higher than cathode voltageReverse Bias Cathode voltage higher than anode voltageIV Characteristic for a ResistorBreakdown Voltage50-1000V0.6 to 0.7 V for silicon diode,For LED ~ 1.5 V (IR) – 3.8 V (Blue)= 1/RWhy do you need a resistor in series with a diode?Anode(P)Cathode(N)01/14/2019BJ Furman SJSU Mechanical Engineering ME 1069I-V Characteristic for a Zener DiodeAnode(P)Cathode(N)Introduction to Mechatronics, Figure 10.8, p. 203.01/14/2019BJ Furman SJSU Mechanical Engineering ME 10610Find VD, IR, VR, R = 1Ω (assume Vf = 0.7 V, and look closely at the diagram) Diode Example 1+ VD -+ VR -IR- 10V+VD = -10V, VR = 0, IR = 001/14/2019BJ Furman SJSU Mechanical Engineering ME 10611Find VD, IR, VR , R = 1Ω (assume Vf = 0.7 V) Diode Example 2+ VD -+ VR -IR+ 10V-VD = 0.7VVR = 10 – 0.7 = 9.3VIR = 9.3 / 1 =9.3A01/14/2019BJ Furman SJSU Mechanical Engineering ME 10612Diode Applications01/14/2019BJ Furman SJSU Mechanical Engineering ME 10613AC Rectification Half wave+ VD -+ VR -IR+ 10V-~Full wavehttp://newton.ex.ac.uk/teaching/CDHW/Electronics2/PHY2028-C14.2.gifhttp://www.bowdenshobbycircuits.info/page12.htm#317.gifBipolar Junction Transistor (BJT)01/14/2019BJ Furman SJSU Mechanical Engineering ME 10614Construction and schematicSo, B-C and B-E junctions look like…?Remember this!Introduction to Mechatronics, Figure 10.15, p. 206.BJT Operation (conceptual)01/14/2019BJ Furman SJSU Mechanical Engineering ME 10615Like a current-controlled valve where base-emitter current controls collector-emitter currentHydraulic analogy for NPNHow much ‘pressure’ (i.e., voltage, VBE) is needed to cause iBE?Introduction to Mechatronics, Figure 10.16 p. 206.Introduction to Mechatronics, Figure 10.17 p. 207.Key conceptsMust turn on B-E diode to get C-E currentIc = hfeIB (up to saturation)Introduction to Mechatronics, Figure 10.18 p. 207.BJT low-side drive01/14/2019BJ Furman SJSU Mechanical Engineering ME 10616For mechatronics, transistors are mostly used as electronically controlled switchesEither fully off (cut off) or fully on (saturated)Want to avoid the in-between condition (linear region). Why…?Minimize power dissipation in the transistor-4 -3 -2 -1 0 1 2 3 4 5 6051015Vce vs. VinVin, voltsVce , volts-4 -3 -2 -1 0 1 2 3 4 5 60510152025Ic vs. VinVin, voltsIc, m A-4 -3 -2 -1 0 1 2 3 4 5 600.020.040.060.08Pt vs. VinVin, voltsPt, W-4 -3 -2 -1 0 1 2 3 4 5 600.050.10.150.20.250.3Pload vs. VinVin, voltsPload , WConsiderhfe= 100 (current gain)V+= 12 VVce(sat)= 0.3 VRB= 10 kohmsRload=500 ohmsPlot Vce, Ic, Pt, and Pload vs. VinReview from last lecture01/14/2019BJ Furman SJSU Mechanical Engineering ME 10617BJT used as an ‘electronic switch’ to control powerTwo ‘flavors’ of BJTNPNTurn on with Vbe > 0.6 VIce is controlled by ibe up to saturationUp to saturation, ic = hfe*ibMake sure that transistor IS driven into