1. Precision Variable Frequency Drive Group May07-13 Jason Kilzer Nick Nation Dave Reinhardt Matt Shriver Client: Jim Walker Faculty Advisor: Professor Ajjarapu

2. Precision Variable Frequency Drive Nick – Uses and Constraints Jason – Technology and Overall Design Matt – Detailed Design Dave – Requirements, Schedules, Conclusions

3. Problem Statement The problem is the ability of a record player to keep a specific speed. The synchronous motor used on a record player is supposed to play the record at a specific speed. However, the motor does not always run at the specified speed which causes the record to sound out of pitch. A precision variable frequency drive will provide a constant frequency to the synchronous motor which in turn will maintain a constant speed of the record table.

4. Executive Summary Synchronous motors are motors that run at a specific speed. A customer may want to run the motor at different speeds, like for a record player that needs to operate at 45 and 33 1/3 rpm. A precision variable frequency drive is a way to speed up or slow down the motor by changing the frequency of the input voltage. This product will be designed to adjust the frequency between 58 to 62 hertz by the turning of a dial. The digital display will be accurate up to the thousandth of a hertz. In addition, a strobe light will allow the user to observe the rpm of the motor. The precision variable frequency drive will have a long term drift that requires a gradual decrease/increase of speed that allows for more accurate tuning.

5. Operating Environment Indoors No extreme dust No extreme temperatures

6. Intended Users and Uses Users –Avid music listener –Lay person Uses –Adjust the frequency of the turn-table –With other synchronous motors

7. Assumptions Constant linkage – the belt connecting the motor to the turntable is constant over a short time period. Basically, an increase in motor speed by a certain factor will result in an increase in the speed of the turntable by the same factor. Plug – the plug from the record player can plug into a standard three pronged outlet.

8. Limitations Precision – the precision variable frequency drive will be accurate to.1 Hertz. Price – the total end product cost must be less than $1,000. Frequency Range – 58 to 62 Hertz with step of 0.1 Hertz. Nominal Voltage – 120 VAC. Stability – the precision variable frequency drive must be stable. Short term stability of less that +/- 0.01%. It shall not be affected by fluctuations in incoming voltage or frequency. Power Output – 75 W minimum. Input Voltage – the input voltage will be a standard household outlet of 120 V at 60 Hz. single phase

9. Design Considerations Maximum weight and size Minimum power output Minimum operating frequency

10. Functional Requirements Synchronous motor frequency controller Knob controller to adjust frequency Digital read-out of frequency Portable strobe system

11. Technology Considerations Pulse Width Modulation Crystal Oscillator

12. Technology Approach Considerations 1. An AC/DC converter was needed to change the input of AC voltage to DC voltage. 2. The pulse width modulator will allow the user to change the frequency of the voltage. 3. A low pass filter would change the DC signal back into an AC signal at the desired frequency. 4. A amplifier would be needed to step the voltage up to an appropriate level to feed the turn-table. 5.A frequency counter would be used to display the frequency output of the low pass filter. 6. A strobe light system would be used to measure the RPM of the motor.

13. Testing Considerations Pulse-width modulator Strobe system Complete system

14. Product Design

15. Power Source 110-120 VAC 60 Hz nominal frequency Standard wall outlet

16. AC to DC Converter The AC to DC converter will take in 120 VAC and produce 25 Volt DC. The project team will purchase this component. The group is going to purchase a converter of the same type that a cell phone charger would use. The converter is around $20 to purchase. After the power has been changed into DC pulse width modulation can take place.

17. Circuit Simulation via Simulink

18. Pulse Width Modulator (PWM)

19. Circuit Design of PWM

20. Triangle Waveform Generator Circuit

21. Triangle Waveform

22. Comparator Circuit

23. Waveform after PWM

24. Low Pass Filter

25. Waveform After Low-Pass Filter

26. Transformer

27. Waveform After Transformer

28. Frequency Counter A frequency counter will connect to the circuit after the low pass filter and measure the frequency of the AC signal being outputted to the voltage amplifier. This device will display the frequency of the power it is sampling on a LCD screen. Figure 8 shows a picture of the frequency counter that will be purchased.

29. Product Design

30. Strobe Light System Figure 10: Strobe Light Schematic (Vinyl Engine) Figure 11: The strobe light shinning on the special disc. (Vinyl Engine) The strobe system will be used to measure the the RPM of the turn-table. As the picture shows, there are three different circles for the three rates, 33 1/3, 45, and 78.

31. Personal Requirements NameTask 1Task 2Task 3Task 4Task 5Task 6Task 7Task 8Totals Reinhardt, Dave174065452492 Kilzer, Jason1104235251886 Nation, Nick174035651885 Shriver, Matt1.564035652086.5 Total (hours)4.5301621520182080349.5

32. Other Resource Requirements ItemTeam HoursOther HoursCost Miscellaneous Parts & Materials 0 0$20.00 Device Components20$65.94 Project/Poster Printing50$0.00 Total70$85.94

33. Financial Requirements Item W/O LaborWith Labor Miscellaneous Parts & Materials $20.00 Device Components $65.94 Project/Poster Printing $0.00$40.00 Subtotal$85.94$125.94 Labor at $15.00 per hour: Reinhardt, Dave $1,380.00 Kilzer, Jason $1,290.00 Nation, Nick $1,275.00 Shriver, Matt $1,297.50 Subtotal $5,242.50 Total$85.94$5,368.44

34. Schedule

35. Deadline Chart

36. Design Evaluation

37. Summary Upon review of the detailed project design, it has been decided to continue the project as planned. It will be continued as scheduled because the detailed design has meet the functional requirements of the precision variable frequency drive.

38. Questions?