Electroluminescent Cap Project

Team Members:Monica PereiraMonique PeregrinaLiang LiufuIfedayo Ogundana

Faculty Advisor/Reviewers:Dr. Michael FrankDr. Bing KwanDr. Rajendra Arora

Sponsored by:Albert Daci

Milestone # 2-Project Proposal

PROJECT MANAGEMENT

The Team & their Qualifications

Monica PereiraProject ManagerArea of expertise: advanced circuit design, electronics, power analysis.

Monique Peregrina Assistant Project Manager/Documentation CoordinatorArea of expertise: advanced circuit design, electronics, power analysis.

Liang LiufuTreasurerArea of expertise: advanced circuit design, electronics, computer architecture

Ifedayo OgundanaHead of ResearchArea of expertise: Microprocessors, Computer System Architecture, Digital Logics, and Digital Communications

Monica Pereira

Introduction/Overview of the Project

• The purpose of this project is to design an original cap that implements electroluminescent technology. This cap will consist of a panel with flashing capabilities and with a hidden internal circuit.

• Currently, there are a few similar designs in the market that implement electroluminescent wires, panels and tapes. However, the current designs have a bulky circuit while others have their wires and/or switches exposed in the back.

• The design proposed by this team, would implement small rechargeable batteries in order to reduce the size of the overall circuit and use small components in order to make the cap comfortable while providing a slim design.

• Each cap will implement a switch with three states (turn on, flash, turn off) and be provided with an internal circuit with water resistant capabilities. In addition, the cap will come with a mini-USB charger hidden underneath the bill of the cap.

Monica Pereira

Intended Use, Users & Operating Environment

USE: The cap is designed to be used for everyday activities. It will be required to resist exposure to dusty conditions as well as water, sweat and any other agents that may cause excessive dampness within the hat so that it can be worn while being outdoors or performing extraneous activities.

USERS: Any individual from almost any age range can use this product as long as he/she follows the guidelines stated in the user’s manual for handle and care.

OPERATING ENVIRONMENT: The prototype is required to operate under normal conditions since it is intended for regular use. The cap must resist light rain, sunlight exposure, plus any other factors that might follow during daily activities.

Monica Pereira

CONCEPT GENERATION & SELECTION

COMPONENT SELECTION

Approach

• The approach followed for selection is based mostly on the size, weight, and ease of implementation of each part, since all of our components must fit within the cap.

Design Components• Fitted baseball cap• LiPo rechargeable battery • Battery charger• 10cm x 10cm EL panel• 3V DC battery inverter• IC chip• Liquid Encapsulating epoxy resin

Cap Selection Approach• The selection of a cap was carefully done

based on its design since this determines how much room (within the inside of this hat) can be used for storing components.

• As requested by our sponsor, only fitted caps can be used.

Monica Pereira

Option 1: Fitted baseball Cap Benefits :• More comfortable for the consumer to wear • Has an easy and relaxed fittingDrawbacks:• Its lower crown may reduce allowed space to

conceal circuitry and • Its Curved bill makes it more difficult to attach

the switch and the battery charger in the bottom of the bill.

Monica Pereira

Option 2: Fitted Flat-bill Cap Benefits • Has a high crown which allows more

room to conceal the circuit without causing discomfort to the user.

• Its flat bill allows better integration of a switch and mini-USB charger on the front of the hat.

Drawbacks:• Style may not attract certain users

Monica Pereira

Battery Selection Objectives • Battery must power the circuit while remaining small and lightweight

enough to not hinder the cap.

Approach• Several factors must be taken into consideration when choosing this

component: weight, size, voltage output, capacity, chemical composition, and availability.

Liang Liufu

PRT-00339 Lithium Polymer Battery

Specifications • Dimensions: 0.23” x 1.32” x 1.86”

(5.84x34x47mm)• Weight: 0.77oz (22g)• Nominal Capacity: 1000mAh• Nominal Voltage: 3.7V• Charge cut-off voltage: 4.20V• Standard discharge current 0.2 C

• Max discharge Current: 2C• Discharge cut-off voltage: 2.75V• Cell Voltage: 3.7-3.9V• Impedance: <300 Ohms

Liang Liufu

PRT-00339 BatteryBenefits• Small and lightweight allows for good implementation into cap

• Rectangular size allows for easy mounting onto cap without need for battery housing

• Rechargeable: eliminates the need to buy more batteries, saving money for the consumer

• Higher capacity allows for longer use per charge

• Low discharge rate allows for longer storage times before depletion (0.1% per month)

• Very Stable: No explosion or fire when over charged, over discharged, short circuited, extrusion, and thermal shock.

• Durable: vibration, collision, and dropping it does not affect performance.

Drawbacks • Requires a charger and not easily replaced.

• Slightly larger size might present slight problem in order to fit inside the cap.

• Extra charger creates an additional component that needs to be added onto the hatLiang Liufu

Li-Poly Charger Specifications • Regulated output voltage: 4.20V

• Precondition current ratio: 10

• Precondition voltage threshold ratio: 66.5

• Charge termination current ratio: 7.5

• Recharge voltage threshold ratio: 96.5

• Temperature range: -40C to +85C

• Dimensions: 29.4mm x 10.8mm

•Four voltage regulation options: 4.2v, 4.35v, 4.4v, 4.5v

•Programmable charge current: 15mA to 500mA

•Selectable Preconditioning: 10%, 20%, 40%, or disable

•Automatic Power Down

Liang Liufu

CR2032 AAA Lithium LR44 Alkaline PRT-00339

Size Diameter: 19.9mmHeight: 3mm

Diameter: 10.5mmHeight: 44mm

Diameter: 11.4mmHeight: 5.2mm

0.23” x 1.32” x 1.86” (5.84x34x47mm)

Weight 3 grams (0.1oz) 7.6g (0.3 oz) 1.75g 0.77oz (22g)

Capacity 240mAh 1250mAh 105mAh Nominal Capacity: 1000mAh

Nominal Voltage 3V 1.5V 1.5V 3.7V

Discharge Current 0.19mA 600mA 0.2mA 0.2C

Other Possible Battery Choices

Liang Liufu

Benefits • Much smaller board allows for easier integration into cap• Micro USB port is fairly common and can be easily recharged• Automatic power down prevents over charging

Drawbacks • Exposed chip: requires an extra step to encase the chip• Extra component that must be concealed within the cap

Li-Poly Charger

Liang Liufu

Other Possible Chargers

Li-Poly charger, 3.7v mini-USB JSTSpecifications:•5V input via mini-B USB connector•0.1” breakouts for battery, DC IN, and status LED•3.7V output to battery•Supports 10k NTC Thermistor which has been filled by a 10k resistor•0.2oz (5.7g)•Adjustable current by soldering a resistor•Dimensions: 1.3” x 1.4” x 0.3” (33 x 35 x 7mm)

Li-Poly charger for 3.7v cells, JST 2.0mm model USB-uLIPOSpecifications:•Regulated output voltage: 4.20V Precondition current ratio: 10•Precondition voltage threshold ratio: 66.5•Charge termination current ratio: 7.5•Recharge voltage threshold ratio: 96.5•Temperature range: -40 – 85C•Dimensions: 29.4mm x 10.8mm

Liang Liufu

EL Panel Specifications• Glow size: 10cm X 10cm (3.95" x 3.95")• Plastic Size: 10.4 cm x 10.4 cm (4.1" x 4.1"), about

0.5mm thick • Panel lifetime: >25000 hours • Operating voltage: 60-250VAC • Operating Frequency: 50-5000HZ • Current Draw: 0.14mA/cm2 (max) @ 110V / 400Hz • Initial Brightness: 75 cd/m2 • Operating Temperature: -50ᵒ C / 65ᵒ C • 45 nF per panel

Liang Liufu

Benefits• Ultra-thin material allows easy concealment within the cap• Flexibility allows panels to be stitched to the shape of the cap• High efficiency allows for maximum life of batteries• Low temperature makes it cool to the touch• Can be easily cut to the desired shape• Vibration and shock resistant allows it to withstand common wear• Can continue to operate even if puncturedDrawbacks • Cannot be folded: it cannot withstand being folded like a sheet of

paper• Uses more power than EL wires• The connection is not waterproof (it is only heat shrink)

EL Panels

Liang Liufu

Other EL material choicesEL Wire•Input voltage: 40-110VAC•Input frequency: 400-3000Hz•Electrical Current: <150mA•Twisting Angle: 30 degrees per meter•Bending Diameter: >10mm•Stretching Force: <1.5kg•Operating temperature: -10C – 60C•Operating humidity: <60%•Lifetime: 3000-6000 hours•Storage temperature: 5C – 35C•Storage humidity: <30%

EL Tape•Size: 100 cm x 1.5 cm about 1mm thick. The glowing part is 1cm wide. •Panel lifetime: >25000 hours•Operating voltage: 60-250VAC•Operating Frequency: 50-5000HZ•Current Draw: 0.14mA/cm2 (max) @ 110V / 400Hz•Initial Brightness: 85 cd/m2•Operating Temperature: -50 C / 65 C•~10 nF per meter

Liang Liufu

Battery Inverter Selection

Objectives• Select a battery inverter that can provide the necessary amount of AC

voltage and current to the EL panelApproach• The first goal is to find an inverter that is small in size. The inverter, as

with everything else, must fit easily within the confines of the cap.• The second goal is to find an inverter that can convert the voltage

from the battery to 110V AC voltage to power the EL panel.

Ifedayo Ogundana

Battery Inverter specificationsCR2032 ELI-IMC AA F10L20 CI-L3F25

Size 47mm X 23mm X 9mm

13 mm diameter x 10 mm height

87mm x 33mm x 19mm

105mm x 74mm x 41 mm

29mm x 29mm x 27 mm

Weight 11g 2.2g 21g 24.5g 28.35g

Frequency 1000Hz 2500Hz 1000Hz 2000Hz 2000/3000Hz

Power Supply Required

3V DC 3V or 1.5V DC 3V DC 9V DC 12V DC

Modes Off/on/blink None Off/on/blink Off/on/blink Off/on/blink

Ifedayo Ogundana

3 V ELI-IMC Battery Inverter Specifications • External 3V or 1,5V (+/- 20%) power supply (or

battery) needed• Total EL fiber length 0m-0.5m (0"-20")• Frequency: 2500 Hz• Size: 13 mm diameter x 10 mm height (0.5"

diameter x 0.4" height)• Weight: 2.2 g

Ifedayo Ogundana

3 V ELI-IMC Battery Inverter Benefits• Very small size and light weight• Can be used with battery and external power supply• Suitable for use with both EL wires and panels

Drawbacks• Low hum noise is produced during operation• No on/blink /off switch incorporated• Capable of lighting only a small length/area.

Ifedayo Ogundana

Objectives• Select a 555 Timer IC to control the

blinking of the logo.• The IC is required to set a frequency which

will allow the EL panel to blink.Approach• Size will be taken into consideration. • Minimal cost if also preferred

Timing IC Selection

Monique Peregrina

Timing IC SelectionModel 75555 (Advanced Linear Devices, Inc)

TLC555 LinCMOS Timer (TI)

Model NA555 (TI) Model LM555 timer IC (Intersil)

Supply Voltage 2 V ~ 10V 2 V ~ 15V 4.5V ~ 16V 2V ~ 18V

Package/Case 8-SOIC (0.154”, 3.90 mm width)

8-SOIC (0.154”, 3.90 mm width)

8-SOIC (0.154”, 3.90 mm width)

8-SOIC (0.154”, 3.90 mm width)

Frequency 2.5 MHz 2.1 MHz 100 kHz 1 MHz

Price $1.83 $0.30 /2,500 parts $0.11 / 2, 500 parts $0.78

Monique Peregrina

Model LM555 timer IC (Intersil)

Specifications• Type: 555 type, Timer/Oscillator (Single)

• Supply Voltage: 2 V ~ 18 V

• Current: 60µA

• Operating Temperature: 0ºC to 70ºC

• Package/Case: 8-SOIC (0.154”, 3.90mm width)

• Frequency: 1 MHz

Monique Peregrina

Model LM555 timer IC (Intersil)Benefits• Does not present a minimum unit order to

be purchased

Drawbacks • Unit price is higher than other brands

presented (for a single unit price is $0.78, for orders greater than 100 units the price drops to $0.38)

Monique Peregrina

Waterproofing/Insulating component Selection

Objectives• Select the best waterproofing and insulating material to encase the circuit within the

hat.

Approach• The first goal is that the material must be able to cover the entire circuit and remain

water resistant even under normal wear and tear.• The second goal is that it must be dielectric because it will prevent any electric

current from escaping the circuit which could ultimately cause harm to the consumer.

Monique Peregrina

Waterproofing/Insulating component Selection

Sugru Silicone Rubber

Turbo-Coat Acrylic Conformal Coating Spray

Liquid Encapsulating Epoxy Resin

Color Black or White Clear BlackCure Cycle 24 h 10 minutes 24 hDielectric Strength 398 V/mL 1000 V/mL 19.36 kV/mLPot Life 30 minutes none 60 minutes

Monique Peregrina

Liquid Encapsulating Epoxy Resin

Specifications • Color: black

• Pot life: 60 minutes

• Cure cycle: 24 hours at room temperature

• Viscosity: 11500 cps @ 20ºC

• Dielectric strength: 19.36 kV/mm

• Operating temperature range: -60ºC to 140ºC

Monique Peregrina

Benefits • Excellent electrical insulation properties

• Good storage stability

• Supports high temperatures

• Mechanical and impact resistance properties

Drawbacks• If exposed to great stress, the plastic may break

• It may shrink when it dries, stressing components in the circuitry

Liquid Encapsulating Epoxy Resin

Monique Peregrina

Proposed Design

Overall Circuit Design & Preliminary System Level

Design

Internal Circuit • To design the circuit itself, the battery will be

connected to both the charger as well as the switch.

• Switch will be connected to the inverter for ON state and also to the control circuit for BLINK state

• The inverter will then be connected to the panel.

• The entire circuit will be waterproofed and insulated

Monique Peregrina

Front View of Cap

• The logo will not exceed the dimensions of 3 inches by 3 inches.

• The logo will be cut out of the EL panel and stitched into the fabric.

Monique Peregrina

Internal View of Cap

• The switch will be located on the bill of the cap. It will be connected to the inverter and the timing IC.

• The timing IC and inverter will be on the same PCB. The front of the cap will provide the most space to conceal the two components.

• The battery charger will be placed on the front underside of the bill. It allows ease of access for the user to plug in the micro-USB connector.

• The battery component will be placed within the sweat band of the cap and concealed within the layer of fabric.

Monique Peregrina

Benefits of the Proposed Design • Comfort: circuit is small and unobtrusive to the user.

• Ease of use: only one button and a recharger at the bill of the cap will be visible allowing for simple use by consumer.

• Compact: by including as many components as possible into one small circuit design, space is saved.

• Unit cost: the individual cap will be relatively cheap to manufacture

• Waterproofness: with full coverage of the circuit in waterproof material, the risk of water damage will be minimal.

• Insulation: the waterproofing material is also a dielectric, which will insulate the user from the circuit.

Monique Peregrina

Drawbacks

• Durability: even though the circuit is designed to withstand light wear and tear due to common use, it is not designed to withstand rough use or extreme weather condition.

• Not machine washable

Monique Peregrina

Risk Assessment

• Uncertainties at Project Milestones• Required tool kit, components and materials to be used• Features and required capabilities to be incorporated• Incomplete knowledge and technical know-how of the

technology• Costs at project milestones

• Method and formulation challenges• Construction and Fabrication• Design Specifications• Imagination and Rationality• Technical feasibility

Ifedayo Ogundana

Risk Assessment (Cont.)

• Human Managerial factor• Physical loss and damage• Circuitry components malfunctioning

Ifedayo Ogundana

Schedule

Gantt Chart

Monica Pereira

Gantt Chart(Cont.)

Monica Pereira

Budget Estimate

Liang Liufu

Budget JustificationThe budget is made such that the following is assumed:• $30/hr base salary considering 12hours of work per week (both semesters)• Equal base salary for individuals working on this project• Addition of 29% of the personnel subtotal for fringe benefits• 45% of the total direct costs was added to account for the overhead costs• Expenses for the assembly of the internal circuit is included in extra costs

Liang Liufu

THANKS!

Questions?