Team Theremin1 Analog Theremin Using Vacuum Tubes and Frequency Detection via Band-pass Filters Ryan Adams, Matt Britt, Yuri Yelizarov, William Findley Jr., James Lewis Georgia Institute of Technology School of Electrical and Computer Engineering April 10, 2008

Team Theremin2 Presentation Outline Project description Theremin diagram Theremin specifications and design Frequency detector specifications and design Demonstration plan Problems Project schedule Cost analysis Current status

Team Theremin3 Analog Theremin and Frequency Detector The Theremin is an electronic musical instrument controlled by interaction with volume and pitch antennae The frequency detector is designed to assist new players in playing on the musical scale The target customers are musicians The projected cost of the Theremin is $550 The projected cost of the frequency detector is $145

Team Theremin4 Theremin: Block Diagram

Team Theremin5 Theremin: Technical Specifications SpecificationSpecifiedResult Pitch range30 Hz to 1 kHz80 Hz to 1.2 kHz Volume control rangeUnspecified 34 dB dynamic range (simulated) Sensing rangeUnspecified~ 0–20 inches Heater supply6.3 VAC, 2.5 A6.3 VAC, 4 A High voltage supply75 VDC,10 mA75 VDC, 25 mA Output Audio line level (1.4 V RMS max) ~ 300–500 mV pp or greater

Team Theremin6 Theremin: Case Design

Team Theremin7 Frequency Detector: Overview Objective –Make the Theremin easier to play Problems –The Theremin produces a continuous pitch range –Most instruments produce discrete notes –Playing the Theremin requires good tone perception and muscle memory Solution –Mute notes that are not in the musical scale

Team Theremin8 Frequency Detector: Building Block

Team Theremin9 Frequency Detector: Simulation

Team Theremin10 Demonstration Plan Measure DC potential on the antennae Demonstrate pitch range –Keep volume hand steady and change position of pitch hand Demonstrate volume range –Keep pitch hand steady and change position of volume hand Demonstrate discrete musical scale with frequency detector

Team Theremin11 RF Propagation Problem Symptom –5 V pp signal from the oscillators easily couples and propagates throughout the circuit Solution –Careful isolation of functional components –Metal enclosure and ground planes –Power supply decoupling –Minimize wire length

Team Theremin12 Project Schedule TaskOwnerStatus Evaluation and ordering tubesMatt BrittCompleted Prototype board constructionRyan AdamsCompleted Oscillator designMatt BrittCompleted Antenna designWill FindleyCompleted Mixer designMatt BrittCompleted Power supply designJames LewisCompleted Case designJames LewisIn progress Frequency detector designYuri YelizarovIn progress Voltage controlled amplifier designMatt BrittIn progress PCB board layoutWill FindleyIn progress Final constructionRyan AdamsIn progress

Team Theremin13 Theremin: Cost Analysis Projected sales volume of 10,000 over a four year period Three group members working on Theremin portion of project The cost of each Theremin unit is $550 DescriptionUnit CostOverall CostType Development personnel$36,000Non-recurring Development capital equipment $10,000Non-recurring Development overhead 200 % $92,000Non-recurring Total development cost$138,000 Parts$200$2,000,000Recurring Production$50$100,000Recurring Market and sales$100,000Recurring Total recurring cost$2,200,000 Recurring cost overhead, 150%$3,300,000 Adjusted recurring cost$5,500,000

Team Theremin14 Frequency Detector: Cost Analysis Projected sales volume of 20,000 over a four year period Two group members working on frequency detector portion of project The cost of each frequency detector unit is $145 DescriptionUnit CostOverall CostType Development personnel$24,000Non-recurring Development capital equipment $10,000Non-recurring Development overhead 200 % $68,000Non-recurring Total development cost$102,000 Parts$50$1,000,000Recurring Production$30$60,000Recurring Market and sales$100,000Recurring Total recurring cost$1,160,000 Recurring cost overhead, 150%$1,740,000 Adjusted recurring cost$2,900,000

Team Theremin15 Current Status Theremin circuitry finished except for voltage-controlled amplifier Theremin case is designed and under construction Frequency detector topology chosen

Team Theremin16 Questions?