Introduction to Electrical Computer Engineering Circuit Representation Dr

Introduction to Electrical & Computer Engineering Circuit Representation Dr. Cynthia Furse University of Utah 1

Introduction to Electrical Engineering Circuit Representation • • • Voltage, Current, Resistance Ground / Reference / Neutral Variable Resistors / Resistive Sensors Measuring V, I, R Series & Parallel elements Node, Path, Loop 2

Voltage (DC) I DC + - VDC I DC + I DC -V VDC -

Ground / Reference / Neutral Vref(erence) = 0 V = ground

Voltage (AC) VAC + V + VAC -

Resistor R (Ω)

Variable Resistor / Resistive Sensor R (Ω)

Resistance • Standard Resistor Values • Variable resistor a)Potentiometer: 3 -terminal variable resistor. Rheostat: 2 -terminal variable resistor • Resistive Sensor – Temperature – Thermister – Pressure – Piezoresistor – Light intensity – Light-dependent R (LDR) 8

Measuring Voltage (Voltmeter) DVM = Digital Volt. Meter + DC voltmeter + VΩ com A DVM - VDC - AC (RMS) voltmeter + VAC RMS

Measuring Resistance (Ohmeter) Ohm meter VΩ com A Ω

Measuring Current (Ammeter) + DC ammeter + VΩ com A - I DC - AC RMS ammeter + I AC RMS

Circuit Diagram Picture From: Wikipedia 12

Series & Parallel 13

Series: CURRENT is the same 14

Parallel: VOLTAGE is the same 15

16

Wheatstone Bridge • Tune Rv until V= 0 • Ru = (R 2/R 1) Rv V 17