Teaching STEMTeaching STEM

• Science Technology Engineering Science Technology Engineering and Math can be taught hands-on and Math can be taught hands-on in lieu of in lieu of ““painfulpainful”” science / math science / math classesclasses

• Demo today will utilize the Demo today will utilize the assembly and operation of an audio assembly and operation of an audio oscillatoroscillator

The ProblemThe Problem

• Students see little if any Students see little if any connection between science and connection between science and real lifereal life

• Students are subsequently bored Students are subsequently bored and learn to hate math and scienceand learn to hate math and science

• Most curriculum separates STEM Most curriculum separates STEM subjectssubjects

The SolutionThe Solution

• Combine STEM subjects with Combine STEM subjects with hands-on projectshands-on projects

• Students learn math and science Students learn math and science WITH technology and engineeringWITH technology and engineering

• We call this applied scienceWe call this applied science

The Solution AppliedThe Solution Applied

• The box: math & science must be The box: math & science must be taught without applicationtaught without application

• Teach outside the boxTeach outside the box• Applied science (e.g., auto mech, Applied science (e.g., auto mech,

elec, rocketry, hiking) can be elec, rocketry, hiking) can be science & math science & math ““creditcredit””

• Most do not have time for both Most do not have time for both ““core sciencecore science”” and and ““applicationapplication””

Audio OscillatorAudio Oscillator

• Audio frequencies 20HzAudio frequencies 20Hz––20KHz20KHz• OS'CILLATE, v.i. [L. oscillo, from OS'CILLATE, v.i. [L. oscillo, from

ant. cillo, Gr. to move.]ant. cillo, Gr. to move.]• Oscillator: creating some type of Oscillator: creating some type of

frequency (oscillation)frequency (oscillation)• Frequencies have a waveform (e.g., Frequencies have a waveform (e.g.,

sine, square, triangle)sine, square, triangle)

The MathThe Math

• Powers of 10 Powers of 10 –– electronic electronic components use exponentscomponents use exponents

• Calculators Calculators –– $10 scientific $10 scientific calculator takes the calculator takes the ““painpain”” out of out of calculationscalculations

• E = IR, P = IEE = IR, P = IE•

Principles of OscillationPrinciples of Oscillation

• An oscillator circuit converts DC An oscillator circuit converts DC current to AC currentcurrent to AC current

• Amplifier with feedbackAmplifier with feedback• A capacitor stores energy and A capacitor stores energy and

releases energy releases energy • 555 timers or transistors trigger 555 timers or transistors trigger

the alternating storage and release the alternating storage and release of energyof energy

The BreadboardThe Breadboard

• Holes in rows and some columns Holes in rows and some columns are connectedare connected

• ““GroundGround”” is used to connect is used to connect battery (-) to a common pointbattery (-) to a common point

The ComponentsThe Components

• battery battery –– 9V 9V• resistor resistor –– ohms ohms • capacitor capacitor –– microfarads microfarads• 555 timer 555 timer –– 8 leg IC 8 leg IC

– pin numberspin numbers

• speakerspeaker• wireswires

555 Timer Pins555 Timer Pins

The CircuitThe Circuit

• Assemble the components on the Assemble the components on the breadboardbreadboard

ApplicationsApplications

• Electronic pianosElectronic pianos• Police sirensPolice sirens• Radio frequencies (RF)Radio frequencies (RF)• Microwave Microwave –– cooking, comm cooking, comm• Computer clock signalsComputer clock signals• Tuning deviceTuning device

Electronic CareersElectronic Careers

• MilitaryMilitary• EngineeringEngineering• MissionariesMissionaries• Certified TechniciansCertified Technicians• Space IndustrySpace Industry• Automotive IndustryAutomotive Industry• BioTech / MEMSBioTech / MEMS

Teach a Man to Fish Teach a Man to Fish ……

• "If you give a man a fish you feed "If you give a man a fish you feed him for a day. If you teach a man to him for a day. If you teach a man to fish you feed him for a lifetime." fish you feed him for a lifetime."

• Teach principles of observation and Teach principles of observation and inquiry for lifetime learninginquiry for lifetime learning

• Allow failure Allow failure –– Teach responsibilityTeach responsibility