LED Atomic Clock

1. LED Atomic Clock Group 20 Ryan Kagin, Piotr Wiczkowski, Tomasz Wojtaszek ECE 445 December 2nd, 2006

2. Introduction – Description • Clock uses aesthetic LED array to minimize number of LEDs lit. • Syncs with the atomic clock signal sent from Boulder, CO. • Created as a desk clock to sit compactly at the corner of a desk or shelf.

3. Introduction - Features • Aesthetic LED design • Manual set of accurate time • Atomic clock sync to maintain accurate time • Manual dimming of LEDs

4. Introduction - Components • LED array • Power circuit • Timing circuit • Atomic clock receiver

5. Product Overview

6. Product Overview – Block Diagram

7. Product Overview – Components • Hardware • LED array • Power circuit • Atomic clock receiver • Software – PIC programming • Timing circuit • Atomic clock analysis and sync

8. Product Overview – Components • Phased out components • Alarm and alarm set • Solar panel recharge • Time zone customization

9. Product Overview – LED Array • 3 rows of LED’s display 12 hours, 12 5-minute and 4 1-minute increments

10. Product Overview – LED Array

11. Product Overview – Power Circuit • Comprises wall unit, diodes for polarity checks, capacitors to smooth output, and a voltage regulator • Adequately steps down voltage from 120V AC to 5V DC • Mains were better than batteries because of W-h consumption

12. Product Overview – Power Circuit

13. Product Overview – Timing circuit • Quartz oscillator used as clock at 1MHz • PIC keeps track of time accurate to 1/10th of a second • Accurate time displayed based on increments of 1/10th of a second

14. Product Overview – Timing circuit

15. Product Overview – Timing circuit

16. Product Overview – Atomic Clock Receiver • Signal from Boulder, CO. is 60kHz modulated signal • Antenna tuned to signal to pick it up • Receiver demodulates signal and converts power drops to DC voltage values • PIC analyzes signal and stores data for sync

17. Product Overview – Atomic Clock Sync • Signal is modulated sine wave, operating at 60kHz at 50kW power. • Bits sent every second: decrease in power by 17dB for certain periods of time denote bits

18. Product Overview – Atomic Clock Sync • Receiver DC output is input for PIC • Reads the voltage over one second to determine bit value • At the end of a minute, saves the value for potential sync

19. Product Overview – Design Alterations • Manual atomic clock sync – to demonstrate functionality of atomic clock sync feature • Use of ECE445 breadboard • ensure a clean-cut internal design and allow for quick replacements of oscillators • simulate output of the atomic clock receiver

20. Product Tests – Power • Test power draw for individual parts of circuit to determine power sources

21. Product Tests – Atomic Clock Receiver • Measure antenna and receiver unit to determine functionality and sample output • Output was simulated on a separate PIC on the breadboard.

22. Product Tests – Timing Accuracy • Determine the accuracy of clock over a long period of time.

23. Recommended Optimal Use • Keep near a window for best reception of atomic signal • If necessary, rotate the clock so that the antenna faces west towards the transmitter • A clock is a clock is a clock

24. Future Developments • Alarm capabilities • Battery and solar panel recharge unit • Faster oscillator • PCB optimization

25. Future Developments - PCB

26. Ethical Considerations • Diodes in power circuit prevent power surge or accidental reverse polarity • Encasement prevents possible shocks through charge build-up and hides potentially loose wires from front user • Minimal user input prevents potential for damage

27. SWOT Analysis for Marketability

28. Credits • Mr. Jim Skaggs • Prof. Makela • Mr. Austin Kirchhoff