LED Atomic Clock

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LED Atomic Clock

• Group 20
• Ryan Kagin, Piotr Wiczkowski, Tomasz Wojtaszek
• ECE 445
• December 2nd, 2006

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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.

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Introduction - Features

• Aesthetic LED design
• Manual set of accurate time
• Atomic clock sync to maintain accurate time
• Manual dimming of LEDs

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Introduction - Components

• LED array
• Power circuit
• Timing circuit
• Atomic clock receiver

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Product Overview
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Product Overview Block Diagram
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Product Overview Components

• Hardware
• LED array
• Power circuit
• Atomic clock receiver
• Software PIC programming
• Timing circuit
• Atomic clock analysis and sync

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Product Overview Components

• Phased out components
• Alarm and alarm set
• Solar panel recharge
• Time zone customization

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Product Overview LED Array

• 3 rows of LEDs display 12 hours, 12 5-minute and
  4 1-minute increments

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Product Overview LED Array
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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

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Product Overview Power Circuit
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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

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Product Overview Timing circuit
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Product Overview Timing circuit
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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

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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

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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

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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

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Product Tests Power

• Test power draw for individual parts of circuit
  to determine power sources

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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.

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Product Tests Timing Accuracy

• Determine the accuracy of clock over a long
  period of time.

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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

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Future Developments

• Alarm capabilities
• Battery and solar panel recharge unit
• Faster oscillator
• PCB optimization

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Future Developments - PCB
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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

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SWOT Analysis for Marketability
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Credits

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