Power · control · packaging

System and subsystems

Supported architecture

The intended power path is battery → protection/disconnect hardware → electronic speed controller (ESC) → brushless thruster. A regulated low-voltage branch supplies the Raspberry Pi Pico controller and sensing. The intended command path is wrist input → controller → ESC pulse-width-modulation command. Emergency switching and pressure, temperature, current and moisture monitoring are intended protective interfaces. Their integration and fault response have not been demonstrated in the supplied record. Electrical design sources, T04

For the product concept, the propulsion/mounting subsystem carries two thigh thrusters and straps/buckles; the separate battery enclosure is intended at the side of the tank; the wrist interface provides on-demand control. The functional prototype scope and stand-ins are governed by D04. Cable estimates describe proposed routes, not an as-built harness. A07

Component and interface record

Component and interface record — table 1
SubsystemLatest supported descriptionEvidence boundary
PropulsionAPISQUEEN + ESC appears in SD2 procurement; GA3 bench photo shows a blue/red thruster and an APISQUEEN ESC labeled 100 AExact thruster and ESC variants/settings unconfirmed; the ESC label is not measured system current or continuous capability
BatteryGA3 photographed label states 24 V lithium-ion, 6000 mAh, charge current 1–3 A and charging voltage 29.4 VDCLabel specifications only; brand/model, protection and measured capacity unconfirmed. These are not charging instructions
Power regulation/controlPico RP2040, a buck converter, relay/switching and throttle interfaces appear in the design/order recordsAs-built populated circuit and authoritative PCB revision not established
Wrist interfaceMagnetic encoder/input and switch mechanism in a threaded printed housingPrinted fit problems documented in T02; complete underwater throttle/stop use unverified
SensingAS5600 magnetic encoder and TMP117 temperature sensing proposed; current, pressure and moisture monitoring also plannedOrders change current sensor from a TLE4971-related 75 A selection to ACS725LLCTR-50AB-T; pressure replacement listed as 114991178. Ordering does not establish integration or calibration
PCBGA3 presents a space-optimized PCB layout; narrative holds manufacturing pending physical circuit testing“Completed prototype” wording refers to design progress, not proof of a manufactured, populated and tested board
Propulsion mountingThigh-mount CAD and printed mount iterations; straps, fasteners, washers and buckles planned for assemblyPrinted thruster forms include stand-ins; complete operational wearable assembly and retention loads unverified
Battery enclosureThreaded cap/sleeve, tube, O-ring and cable-entry conceptsFinal assembled revision and pressure qualification absent

V1 circuit descriptions use a 22.2 V battery, a 40 A fuse, disconnect/emergency switches, a Pico, a W30 ESC and preliminary potentiometer/go/stop/arming inputs. The report says 4400 mAh while the historical BOM says OVONIC 6S 4000 mAh; some assembly filenames reference 5200 mAh. Those are historical alternatives, not the identity of the V4 photographed pack. Report, electrical sources

PCB design screenshot with Pico footprint, connectors and routed traces.
Space-optimized PCB layout shown in the third SD2 check-in. Fabrication and populated-board validation are not established by this design image.

Enclosure geometry and material status

GA3 labels the cap and sleeve PLA, with 2 in thread depth, a “3.2500-4” designation and 0.25 in pitch override. It lists cap diameter 3.15 in and sleeve diameter 3.154 in. These are source CAD annotations, not inspected native dimensions, production tolerances or proof of a seal. The same presentation identifies an EPDM AS568-233 O-ring, 2.859 in inside diameter, 3.137 in outside diameter and 0.139 in width. Later/repeated order entries specify AS568-232 and link Buna-N, so the actual fitted seal cannot be selected from the presentation alone. GA3, procurement

Tube descriptions also conflict: the September 29 enclosure narrative says polyvinyl chloride (PVC); an order says clear acrylic while linked item text says polycarbonate. PETG coupon notes do not establish the cap/sleeve material or coating. The architecture is therefore a supported concept with uncertain as-built material/seal identity. Enclosure check-in, coupon notes

Intended system interfaces and bench componentsBattery through intended protection and disconnect to ESC and thruster; a regulated branch to Pico; wrist input and sensors command Pico; Pico commands ESC. Battery, ESC and one thruster are photographed bench components. All dashed connections await integration or protection verification. Two thigh thrusters are full-product intent.INTENDED POWER PATHBatteryPhotographed labelProtection / stopAwaiting verificationESCBench componentOne thrusterBench componentPowerPowerPowerRegulationLow-voltage branchPico controllerDesign / startup workWrist inputMagnetic input / switchMonitoringPressure · temperatureCurrent · moisture (intended)Regulated supplyPowerInputPWM commandSensor signalsEmergency switching (intended)FULL PRODUCT INTENTTwo thigh-mounted thrustersSeparate from bench prototypeBlue fill: photographed bench components Dashed line: intended, unverified interface
Supported Sea Gliders architecture: intended power, command and monitoring interfaces. Highlighted bench components belong to the one-thruster prototype; dashed interfaces denote integration or protection features awaiting verification. Electrical sources · T04