CONCEPTUAL TOOLS Introduction to Electronics Neil E Cotter

CONCEPTUAL TOOLS Introduction to Electronics Neil E. Cotter Associate Professor (Lecturer) ECE Department University of Utah

CONCEPTUAL TOOLS Outline Quantities: Voltage Current Power Devices: Resistor Capacitor Inductor LED Transistor Op-Amp Laws: Ohm’s Law Kirchhoff’s Laws

CONCEPTUAL TOOLS Filter

CONCEPTUAL TOOLS Voltage = pressure that pushes electrons through circuit Water analogy: voltage = altitude of water

CONCEPTUAL TOOLS Current

CONCEPTUAL TOOLS Current = flow of electrons through circuit Water analogy: current = flow of water

CONCEPTUAL TOOLS http: //www. usbr. gov/power/data/sites/gle ncany/glencany. html Power http: //en. wikipedia. org/wiki/H ydroelectric http: //www. wapa. gov/newsroom/cct/20 05/july 15/27 no 141 a. htm

CONCEPTUAL TOOLS Power http: //www. usbr. gov/power/data/sites/gle ncany/glencany. html http: //en. wikipedia. org/wiki/H ydroelectric http: //www. wapa. gov/newsroom/cct/20 05/july 15/27 no 141 a. htm Power = voltage x current Water analogy: power = altitude drop x flow

CONCEPTUAL TOOLS Resistor

CONCEPTUAL TOOLS Resistor reduces current flow Water analogy: flow less for winding river

CONCEPTUAL TOOLS Capacitor

CONCEPTUAL TOOLS Capacitor stores charge Water analogy: tank stores water

CONCEPTUAL TOOLS Inductor http: //www. magnariders. com/html/Ride s/rally/2005_Rally. html

CONCEPTUAL TOOLS Inductor http: //www. magnariders. com/html/Ride s/rally/2005_Rally. html Inductor creates magnetic field opposing current change Water analogy: mill wheel with inertia opposes flow change

CONCEPTUAL TOOLS http: //www. furuier. com/english/product/index 0. htm LED http: //www. xmission. com/~m 3 lody/jun k/xmas 2002/lit_waterfall 1. jpg

CONCEPTUAL TOOLS LED http: //www. furuier. com/english/product/index 0. htm http: //www. xmission. com/~m 3 lody/jun k/xmas 2002/lit_waterfall 1. jpg LED lights up and acts like voltage drop Water analogy: lit waterfall

CONCEPTUAL TOOLS Transistor

CONCEPTUAL TOOLS Transistor current flow controlled by second small current flow Water analogy: spillway for dam controlled by hydraulic line

CONCEPTUAL TOOLS Op-Amp

CONCEPTUAL TOOLS Op-Amp Op-amp magnifies voltage across inputs Water analogy: Lever translates small pressure into high pressure

CONCEPTUAL TOOLS Ohm’s Law

CONCEPTUAL TOOLS Ohm’s Law Current in resistor = voltage / resistance Water analogy: flow = altitude drop / length of river

CONCEPTUAL TOOLS Kirchhoff’s Voltage Law

CONCEPTUAL TOOLS Kirchhoff’s Voltage Law Sum of voltage drops around loop = 0 Water analogy: total altitude change for loop = 0

CONCEPTUAL TOOLS Kirchhoff’s Current Law

CONCEPTUAL TOOLS Kirchhoff’s Current Law Sum of current flowing out of node = 0 Water analogy: what flows in must flow out