UnderBot

r09 converter carrier — review draft

What changed

The power assembly now reserves physical locations for the Pi, Kinect and auxiliary converter modules on a200x180mm carrier. This larger outline is provisional and reflects real module sizes rather than the old100x90mm fuse-only board. The T12 battery stays separate. One Adeept arm still uses its onboard regulator after controller revision/USB-backfeed verification.

Electrical: Pi fuse -> J3 -> EP-0225 DC input -> supplied USB-C cable to Pi. Kinect fuse -> J4 -> DDR terminal5+ and6-; DDR terminals3+ and1- -> J5 -> J6 -> Kinect v2 adapter. Terminal2(-) and4(+) unused duplicates. U3 auxiliary module mounts directly via soldered pins -> J8 regulated5V. Arm J7 remains switched nominal12V. J2 remains the external manual-reset stop contact interface; both pins positive, no ground. Aux/audio/pan-tilt stop with arm. System GND deliberately bonds DDR negative output and input: isolation is not claimed.

Module decisions and mechanical evidence

1. 52Pi EP-0225 is87x57mm per official labelled photograph. Accepts9-24V and supplies5.15V/5A USB-C PD. It will sit above the carrier on standoffs with short DC cable. Exact mounting-hole centre coordinates are NOT published in reviewed material: an outline and access allowance are drawn, but holes are NOT invented/drilled. Obtain physical measurements or vendor CAD. Preserve button/switch and USB cable access. Barrel-size conflict in vendor pages remains unresolved.
2. Mean Well DDR-60G-12 is9-36V input,12V output. The headline60W/5A requires appropriate conditions: at input9-18V its curve allows85%, i.e.51W/4.25A up to50C in specified vertical mounting. Higher temperature requires further derating. This has more provision than the provisional36W Kinect supply budget, but exact adapter/startup demand still needs verifying. Body52.5x90x54.5mm with58.4mm maximum projection;216g. This is a bulky DIN-rail part, selected for documented input range/rating rather than compactness. A short TS35 rail and backing support are required; no solder-in footprint is claimed. The diagram reserves its space; rail fastener holes await actual rail/end-stop selection. Support load through enclosure standoffs/backing, not unsupported FR4. Observe installation spacing and vertical orientation; flat mounting requires separate thermal qualification.
3. Pololu D24V50F5 #2851:6-38V input,5V fixed output (4% accuracy), typical up to5A subject to heat.17.8x20.3x8.8mm. New carrier footprint from official drawing, with top-view left-to-right pins EN,VIN,GND,GND,VOUT. NC EN permits normal enable. Two ground pins connect. Use directly soldered adequately rated pins, not an unqualified removable header at5A. Underside component clearance and module elevation require checking. The footprint remains a candidate until1:1 physical overlay verification.

Budget impact — not hidden

Updated hardware allocations: EUR609.69, before a delivery reserve. That is EUR9.69 above the EUR600 cap. Changes: auxiliary converter allowance15->45; carrier/mechanics30->45; Kinect module allowance remains35. Earlier35.31 reserve absorbs most but not all increase. These are allowances, not final landed quotations. Options to recover budget: defer microphone allowance20, or defer one/two ToF boards at20 each. No items are silently removed; no purchase or fabrication has occurred. Prefer recovery through actual quotes first. The oldEUR600 table no longer establishes affordability of this revision.

Still unresolved before routing/fabrication

Physical Pi/rail mount geometry, enclosure cooling/clearance, stop power-contact/reset hardware and independent T12 stop, input polarity/transient protection, fuse amperages/wire fault coordination, NOCO operating output range, arm revision/USB VBUS blocking, Kinect adapter polarity/current. Modules are selected candidates, not hardware-qualified. Copper is UNROUTED; no trace ampacity, DRC pass or fabrication readiness claimed. No Gerbers generated.

Sources and local downloaded diagrams are in module-selection.csv and vendor/. Board preview silhouettes are placement envelopes, not detailed manufacturer3D models. r09 supersedes the physical r08 placement; r07 remains the whole-system context with its old power-module choices superseded here.

EUR600 staged option

See budget-r09.xlsx: proposed two ToF sensors initially, with the other two deferred. This yields EUR569.69 hardware plus EUR30.31 delivery/contingency = EUR600. Full four-ToF scope remains shown separately at EUR609.69 before delivery. No hardware or orders were changed.