Network cabinet fan controller
Public Unreviewedby matt
Two independently controlled 12 V fans, Ethernet and Wi-Fi, and an RGB speed display in a custom printed puck. Routed development preview, not approved for manufacture.
16485bb
Fan-controller — MTA-156 development revision
J1 now uses the two-pin TE Connectivity 640445-2 MTA-156 vertical header (3.9624 mm pitch, LCSC C86497). Pin 1 is +12 V input; pin 2 is ground. The footprint, schematic, BOM, routing and manufacturer STEP model have been updated. Choose the matching cable-side receptacle for the actual wire gauge; that receptacle and its wire bend have not yet been fitted in the enclosure model.
Open and review
Open fan-controller.kicad_pro in KiCad 10, then its PCB editor; Alt+3 opens the 3D viewer. On this PC a separate review window is named fan-controller-mta156. Its board is an identical review copy, allowing the original project to remain open. The source project, schematic and libraries in this revision folder are authoritative.
Why this size and how it mounts
The PCB is 44.5 × 78.5 × 1.6 mm, with rounded corners. Its width follows the original controller's space between the magnet supports. Its extra 34 mm of length provides copper area for heat spreading; it also occupies space the enclosure drawing reserved for cable bends. This is a provisional development outline, not a claim that this is the minimum necessary size.
A new printed carrier supports the PCB with four M2 screws. The carrier is proposed to attach to the existing floor with removable tape. Printed fit and retention on the vertical cabinet door remain untested. The existing cabinet and enclosure OpenSCAD files have not been changed. The new board does not automatically appear in those drawings.
Enclosure reuse is a goal, not a verified result. The board has only 0.30 mm nominal side clearance to the magnet bosses. The bare MTA header leaves about 3.57 mm below the conservative lid plane; its attached receptacle, wire bends and tolerances are excluded. Four lower cable slots exist, each 7.5 mm wide and about 12.41 mm high. Their original plug measurements have not been checked against the ARCTIC P14 Max plugs. Connector access, wire paths and strain relief need a complete assembly review before release.
Read the detailed mechanical review for the dimensions, assumptions and proposed cable assignments.
Validation and limits
Native KiCad 10 DRC: zero violations and zero unconnected items. ERC: zero violations. All 28 expected electrical nets match the schematic. Native connectivity preserves all 619 assigned pad/track items. The real manufacturer connector model has been checked in KiCad's 3D viewer.
Current and thermal engineering screens pass the existing limits. A finer 0.1 mm solve independently estimates about 42 °C maximum board temperature rise in still air under the stated conservative losses, not a measured prototype temperature or a junction-temperature qualification. Existing electromagnetic compatibility advisories remain, including an input-filter recommendation. This connector revision does not resolve those inherited prototype issues.
Development exports are supplied for review, not an order authorization. Confirm the JLC stackup, through-hole assembly, connector orientation, mated fit and prototype performance before ordering. No purchase has been made. Ethernet and PoE are not included in this revision.
# Fan-controller — MTA-156 development revision
J1 now uses the two-pin TE Connectivity 640445-2 MTA-156 vertical header (3.9624 mm pitch, LCSC C86497). Pin 1 is +12 V input; pin 2 is ground. The footprint, schematic, BOM, routing and manufacturer STEP model have been updated. Choose the matching cable-side receptacle for the actual wire gauge; that receptacle and its wire bend have not yet been fitted in the enclosure model.
## Open and review
Open `fan-controller.kicad_pro` in KiCad 10, then its PCB editor; Alt+3 opens the 3D viewer. On this PC a separate review window is named **fan-controller-mta156**. Its board is an identical review copy, allowing the original project to remain open. The source project, schematic and libraries in this revision folder are authoritative.
## Why this size and how it mounts
The PCB is **44.5 × 78.5 × 1.6 mm**, with rounded corners. Its width follows the original controller's space between the magnet supports. Its extra 34 mm of length provides copper area for heat spreading; it also occupies space the enclosure drawing reserved for cable bends. This is a provisional development outline, not a claim that this is the minimum necessary size.
A new printed carrier supports the PCB with four M2 screws. The carrier is proposed to attach to the existing floor with removable tape. Printed fit and retention on the vertical cabinet door remain untested. The existing cabinet and enclosure OpenSCAD files have not been changed. The new board does not automatically appear in those drawings.
**Enclosure reuse is a goal, not a verified result.** The board has only 0.30 mm nominal side clearance to the magnet bosses. The bare MTA header leaves about 3.57 mm below the conservative lid plane; its attached receptacle, wire bends and tolerances are excluded. Four lower cable slots exist, each 7.5 mm wide and about 12.41 mm high. Their original plug measurements have not been checked against the ARCTIC P14 Max plugs. Connector access, wire paths and strain relief need a complete assembly review before release.
Read [the detailed mechanical review](docs/mechanical-review.md) for the dimensions, assumptions and proposed cable assignments.
## Validation and limits
Native KiCad 10 DRC: zero violations and zero unconnected items. ERC: zero violations. All 28 expected electrical nets match the schematic. Native connectivity preserves all 619 assigned pad/track items. The real manufacturer connector model has been checked in KiCad's 3D viewer.
Current and thermal engineering screens pass the existing limits. A finer 0.1 mm solve independently estimates about 42 °C maximum board temperature rise in still air under the stated conservative losses, not a measured prototype temperature or a junction-temperature qualification. Existing electromagnetic compatibility advisories remain, including an input-filter recommendation. This connector revision does not resolve those inherited prototype issues.
Development exports are supplied for review, not an order authorization. Confirm the JLC stackup, through-hole assembly, connector orientation, mated fit and prototype performance before ordering. No purchase has been made. Ethernet and PoE are not included in this revision.