1. Inductive Charging System Technical Approach for University of Washington APL’s ALOHA Project 1/7/2004 Karl Conroy President S&K Engineering, Inc Confidential

2. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Electronics System Components Float Side –Microcontroller PC/104 based hardware to minimize Development Local Battery Management through Shunt Regulator On/Off Control of SRC Data Link Communication path Communication to other systems –Series Resonant Converter High Frequency AC Current Source Drive Inductive Coupler Constant Frequency (Open Loop) Operation –Shunt Regulator Active Resistance to Provide constant power –RF/IR Transceiver Short Range Link Explore Off the Shelf Options RF in 100s of MHz or IR in 800nm Same Device on Both Sides System Components Vehicle Side –Microcontroller Battery Management on Crawler Side Charge Algorithm Implementation Voltage and Current Sense State of Charge Tracking Communication to other systems on Crawler Data Link Communication path Low Power Consumption uP –Active Rectifier Pass or Shunt HFAC Current High Electrical Efficiency Convert HFAC to DC Power Interface to Battery HF Filtering –RF Transceiver Same Device on Primary Side –Charging Algorithm Stop charge if T bat 45°C Charge at constant current until V bat > 4.1V Then charge at constant voltage until I bat < 10% of initial current Terminate charging on low current to maximize charge Stop charge if V bat > 4.3V Stop discharge when V bat < 2.3V

3. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Mechanical System Components Float Side –Core “C” core design Angled interface to secondary core reduces gap –Flexure Provides necessary degrees of freedom for core alignment Enidine Wire Rope isolators (possible off the shelf device) Absorb impact of vehicle –Guide Structural support of Primary core Attachment to floater Houses communications interface –Primary Winding Litz wire (Size, Turns: TBD) –Floater Electronics Enclosure Vehicle-Float Battery Charger Shunt Load Float Battery Bank 6-8” ID cylindrical pressure housing –HFAC Cable Litz wire Interface from Charger to Coupler Communications wire System Components Vehicle Side –Core 3/4 “C” core design Angled interface to secondary core reduces gap –Guide Provides initial alignment of cores Reduces drag by secondary core Houses communications interface –Structure to Crawler Provide attachment of secondary to crawler –Secondary Winding Litz wire (Size, Turns: TBD) –Vehicle Electronics Enclosure Provided by vehicle Vehicle charger integrated into enclosure –HFAC Cable Litz wire Interface from coupler to Crawler Electronics Communications wire

4. 1/7/04S&K Engineering, Inc. Confidential RF/IR TRANSCEIVER DATA Link RF/IR TRANSCEIVER DATA Link PRIMARY SIDE POWER SYSTEM MICROCONTROLLER Short Range RF/IR Link DC-HFAC CONVERTER Series-Resonant 100kHz HFAC-DC ACTIVE RECTIFIER REGULAOR SHUNT REGULATOR PRIMARY SIDE BATTERY CHARGER CRAWLER SIDE POWER SYSTEM MICROCONTROLLER CHARGE CONTROLLER Input Power From Mooring Cable External Communication FLOAT CRAWLER Inductive Power Coupler On-Board Communication High Frequency AC Power FLOAT BATTERY VEHICLE BATTERY

5. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Mechanical Guide (attached to Floater) Primary Core Flexure (3-6) Secondary Core Secondary Guide Charger Cable

6. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Mechanical Guide (attached to Floater) Primary Core Flexure (3-6) Secondary Core Secondary Guide Crawler Cable

7. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Mechanical Guide (attached to Floater) Primary Core Secondary Core Guide Location of Communication Link: Primary Secondary

8. 1/7/04S&K Engineering, Inc. Confidential Inductively Coupled Charging System Mechanical Guide (attached to Floater) Primary Core Secondary Core Guide Crawler cable Secondary Core Angled core interface

9. 1/7/04S&K Engineering, Inc. Confidential Charging System Requirements –Operating Depth:5000m (16,400 ft) –AO J-Box Supply Power< 100W –Mooring Cable Voltage250-400VDC –Float Supply Powerarbitrary –Charge Time< 6 hrs (minimize) –Interval between chargers~ 4 days –Data TransmissionBi-directional –Data Rate >100kbps –Vehicle CommRS422 protocol –Battery Voltage12 VDC 10.8VDC nominal –Battery ChemistryTBD (Lithium-Ion?) –Peak Charging Current< 20 amps –Supply Voltage48 VDC –Charging Power250W –Charger Efficiency> 90% –Charge AlgorithmRemotely Programmable (constant current then constant voltage) –On Board Size6-8” ID cylindrical pressure housing –On Board WeightTBD (minimize)

10. 1/7/04S&K Engineering, Inc. Confidential Charging System Requirements –ConnectorsTBD –Operating time>5 years –OtherRemovable from cable Constant power draw from AO JBox Resistant to marine bio-fouling –Off Board Size 6-8” ID cylindrical pressure housing –Off Board WeightTBD (minimize) –Reliability Hi-rel components where appropriate consider redundant components/circuits minimize stress on components – thermal, electrical, etc.