P10041: TEAK - Sound and Music Sheryl Gillow Heather Godlewski Bryan Lozano Jeremy Schuh Mechanical Engineering Electrical Engineering Sponsors: The National Science Foundation

Project Description TEAK – Traveling Engineering Activity Kits The TEAK project involves the design and fabrication of 4 hands-on engineering activity kits that relate sound and music to engineering and engineering design Kits are focused on teaching students in the surrounding Rochester community

Customer Needs Kits must operate safely in a classroom environment Kits must relate music and sound to engineering concepts and design Kits must be portable and durable Kits must be usable by groups of up to 30 students Quick set up and storage Kits must be well documented

Design Concepts Xylophone Kit Electronic Keyboard Kit Communications Kit Electric Guitar Kit

Xylophone Kit

Xylophone Kit Kit Description This kit will allow students to explore the relationship between material properties and the sound produced. By designing a xylophone utilizing a variety of key materials, key lengths and different mallets, students will hear how the various properties affect the tone and pitch.

Xylophone Kit Design Variables Key Material Mallets Key Length Key Geometry

Xylophone Kit Design Sketches Key GeometriesBase Concepts

Xylophone Kit Testing Methods Human hearing (how do the sounds differ) Use an electric tuner

At the end of this activity, students will be able to… Explain what sound is and how sound waves travel Explain the difference between tone and pitch Observe how material properties effect the tone produced Observe how material geometry can effect the sound produced

Xylophone Kit Associated Risks Size/weight Cost Activity Time Creating keys that have distinct pitches Parts breaking Parts easily lost Difficult to change out keys Creating a base that can support multiple geometries

Questions, Concerns, Ideas

Electronic Keyboard Kit

Electronic Keyboard Kit Kit Description This kit will offer students the opportunity to build and modify the design of an electronic keyboard, modifying the gain of an inverting amplifier, and the filter type used to modify the tone. Also, they will be able to test the effects of their design decisions

Electronic Keyboard Kit Design Variables Gain of Amplifier Frequency Response of Filter  High Pass  Low Pass

Electronic Keyboard Kit Design Sketches

Wein Bridge Oscillator

Electronic Keyboard Kit Design Sketches

Vo = [-(Rf)/(R1=R2=R3)] x [V1+V2+V3] Summing Amplifier Used to Summate Signals

Electronic Keyboard Kit Design Sketches Inverting Amplifier Vo= - Vi x [Rf/Ri] Student will manipulate ratio of R2 to R1 to control signal level

Electronic Keyboard Kit Design Sketches High Pass Low Pass Student can manipulate filter type and cut-off frequency

Electronic Keyboard Kit Testing Methods Human hearing (Is it loud enough?) dB Meter Digital Multi Meter Test Performance

At the end of this activity, students will be able to… Visualize and understand the propagation of sound waves Understand the goal and necessity of Amplification Understand how filtering and frequency content affects tone

Electronic Keyboard Kit Associated Risks Notes are atonal due to component tolerances Activity time too short Circuitry not durable enough PCB boarding too expensive or improperly laid out

Questions, Concerns, Ideas

Communications Kit

Communications Kit Kit Description By comparing a mechanical communication device to an electrical one, students will see how there are multiple solutions to the same problem. They will also get a basic understanding of electromagnetics by building and testing their own speaker and microphone.

Communications Kit Design Variables Amplifier gain Number of turns in the speaker coil Shape and/or mass of the speaker

At the end of this activity, students will be able to… Explain what sound is and how sound waves travel See how a mechanical speaker/microphone system differs from an electrical one Explain what an electromagnet is and how it can be used to make a speaker Understand what an amplifier is and why it is used in an electrical system Understand why a change in resistance creates a change in sound

Communications Kit Concept Drawings/Schematics INPUToutput Amplifier Image Sources: Clip Art

Communications Kit Testing Methods Human hearing (i.e. is it “loud” enough) Use a DB meter to measure the difference in volume Use oscilloscope to view output waveforms

Communications Kit Risks Not enough activity time Speaker output not high enough A homemade speaker may be insufficient as a microphone The students place the electronic components in the wrong breadboard locations Loose wires that cannot be detected

Questions, Concerns, Ideas

Electric Guitar Kit

Electric Guitar Kit Kit Description This kit offers the opportunity to design and build one of the most popular instruments in American society. The Electric Guitar is a complex device that integrates several systems demonstrating a great deal of team work. Each kit will focus on the tone contribution of a single string.

Electric Guitar Kit Design Variables String Diameter and Tension Volume Control  Amplifier Gain  Number of windings in pick-up Tone Control  Low Pass Filter “Tone Knob”  “Pick Up” placement Optional inclusion of effects

Basic Electric Guitar E-Guitar PickupEffectsAmplifier Speaker Under the strings mounted on the body of the guitar converts mechanical vibration into electric signal Changes the signal that is coming from the guitar Signal needs to be amplified to audible volume Reproduces the signal

Simple Guitar Amplifier BB Amp IN Speaker Box that has an input for the guitar (clear top panel to see the amplifier) Contains the preamp/amplifier, mounted on it are the speaker, a breadboard, ON-OFF switch, various knobs for adjusting volume, gain, high and low frequencies. Must be battery powered for classroom use. Push-Pull amplifier to reduce power consumption. (use Class AB output stage)

Electric Guitar Kit Testing Methods Human hearing dB Meter Digital Multi Meter Oscilloscope Electronic Tuner

At the end of this activity, students will be able to… Visualize and understand the propagation of sound waves and their properties Understand the goal and necessity of Amplification Understand how filtering and frequency content affects tone

Electric Guitar Kit Associated Risks Guitar string fails under tension Activity time too long Output volume too loud Power requirements are too large Mechanical failure of “guitar body”

Questions, Concerns, Ideas

Concept Selection

Project Risks Scheduling Allocation of budget Ensuring all kits are engineering oriented rather than just music oriented Provide adequate engineering analysis to support proof of concept Ensure selected kit activity is not too complicated Ensure kits are portable

Work Breakdown Structure

Plan Forward Product Feasibility Assessment Finalize Engineering Analysis Finalize Technical Drawings and Schematics Finalize BOM Risk Assessment Prototyping

Questions, Concerns, Ideas