Transcript Emergency Response Radio

Emergency Response Radio
Ashok Basawapatna
Joe Friedrichsen
Chris Lasek
Jeff Ritter
Purpose

A radio that alerts users to emergency
broadcasts
– Constantly monitors specified frequency
– Broadcasts emergency message when the
Emergency Alert System is activated
– Otherwise behaves as normal radio
Design Objectives

Radio Block
– Receiver antenna
– Isolation & Demodulator circuits

Control Block
– Signal detection
– Combinational logic
– Voltage and Power regulation

Amplifier Block
Functionality - Appearance
1
2 3
10
98
1. Emergency Radio Tuner Indicator
2. Emergency Radio Band Selector
3. Emergency Radio Tuner Knob
4. Emergency Radio Manual Override Button
5. Manual Override Light
4
5
6
7
6. Power Button
7. Volume Knob
8. Standard Radio Tuner Knob
9. Standard Radio Band Selector
10. Standard Radio Tuner Indicator
Functionality – Components
Radio
Power Conditioning
Control
Amplifier
Radio Block
Power
Radio
Antenna
Radio
Signal
Demodulator
Tuner
Radio
Signal
Power
Radio Block

Receiver Antenna
– Receive radio signals

Isolation Circuit
– Sets radio to desired
frequency
– Tunable band-pass
filter
– Tank circuit & other
peripheral circuitry

Demodulator Circuit
– Separate voice from
carrier signal
– Scheme?
» Synchronous vs.
Asynchronous
» Digital vs. Analog
Control Block
Power
Power to ERR
Power to Standard
ERR Radio Signal
Control
Power to Amplifier
Standard Radio Signal
Chosen Radio Signal
User Input
Power
Tone
Recognition
ERR Radio Signal
EAS Tone Matched?
Power
Logic
User Input
On/Off/
Override
Emergency!
Power to ERR
Power
Standard Radio Signal
ERR Radio Signal
Digital
Switches
Power to Standard Radio
Power to Amplifier
Chosen Radio Signal
Control Block

Detect emergency broadcast
– DSP vs. ASICs vs. Analog Notch filters

Combinational logic
– Determine which tuner becomes amplified
– Override button
– Power allocation

Voltage Regulation
– DC-DC Converters
» Buck & Boost converters
» Voltage regulator chips
Amplifier Block

Amplify signal going to the speakers
– Op-Amps vs. Transistors
– Volume control
Division of Labor

Isolation Circuit & Demodulator
– Chris and Jeff

Control block
– Ashok and Joe

Voltage regulation & Amplifier
– Entire group

Documentation
– Entire group
Schedule
Risks & Contingency Plans

Learning to use DSP and ASIC chips
– Use analog notch filters

Control block responding to incorrect signal
– Build higher order filter / Use additional filters
– Use different chip

Use of OP-AMP amplifier questionable
– Use BJT or MOSFET transistors
– Other amplifier ASICs
Marketability

Could benefit a broad audience
– Many listen to the radio
Affordable to all levels of income
 Applicable to many areas

– Could be adapted to car and portable radios
Cost Analysis
Return on Investment
 Estimated Cost:
– Prototype: $250
– Components: $15
– Time: 800 man-hours ($25/hr = $20,000)

Sale Price
– $25

Payback
– Sell 810 units before making profit.
Additions & Extensions
Adapt to car and home stereos
 Design portable version
 Extend to control TV
 Peripheral device compatible with old
radios
