¶ Specifications
This module is based on the Texas Instruments brake and tail light module reference design which can be found, here.
The 70mm PCB module is designed to replace the traditional filament bulb, holder and reflector in a Triumph Spitfire MK4/1500 rear light cluster. It can be used for both the tail light/brake light in dual brightness mode, or as a replacement for the turn signal bulb using a single input. The brake or tail light input can be used for the indicator, depending on brightness preference.
Features:
- 18 LEDs on a compact 70mm diameter PCB
- Texas Instruments TPS92830 Linear LED controller ICs
- Complete solution including 3D printable mounting hardware and diffuser
- Adjustable LED current/brightness set by resistor
- Polarity protected inputs
¶ PCB Assembly
The schematics and PCB design files are available on OSHWL (Open-Source Hardware Lab), here. Bill of materials, pick & place file and gerbers can be downloaded directly here. I highly recommend conformally coating the PCB once assembled and tested. The Spitfire rear lights are not that well sealed and will let moisture in.
I prefer to use red or amber LEDs depending on the brake/tail light or indicator application as I find it gives a more accurate colour representation. I use two CREE LED part numbers for the LEDs on my modules. Links to Mouser parts at the time of writing.
¶ 3D Printed Parts
3D printed parts are available on GrabCAD as STEP files. A suitable material for printing parts should be selected that has a reasonably high glass-transition temperature. As a minimum, I would recommend using PETG for an FDM printer. The 3D-printed diffuser will need to be printed using a transparent material.
The 3D-printed nut is available with a standard M30 thread and also an M30 thread with a tolerance of 4% specifically for 3D printing. If you are having difficulty getting the nut to engage, you can adjust the standard model size in both the X and Y dimensions in your slicer until the thread engages without binding. Your printer, settings and material choice are all factors that affect the thread engagement.
¶ Assembly
The kit replaces the bulb, bulb holder and plastic reflector (highlighted in the image below) in a standard Spitfire rear light cluster. The reflectors can be removed and replaced at a later time without damaging them.
A good wire choice is 0.75mm2 (17AWG). The modules draw less than 1A.
- Remove the tail light bulbs, holders and reflectors as shown in the image above from the original light cluster units.
- Solder 3 wires to the 3 PCB through holes for brake, tail and ground into the back of the LED module PCB. Alternatively, either ground and one of the other two inputs depending on the required brightness for the indicator.
- Pass the three wires from the back of the PCB through the 3D-printed mount at the flat end. Terminate the 3 wires with the correct spade terminals to connect to the existing harness making note of brake, tail (or indicator) and ground connections.
- Assemble the diffuser, diffuser spacer, PCB and 3D-printed mount with a 70mm socket cap bolt and nyloc nut.
- Insert the assembly into the chrome housing of the light cluster observing the key in the M30 thread on the 3D-printed mount.
- Secure the module assembly with the 3D-printed hand-tightened nut.
- Connect to the harness and test.
¶ Licensing & Open Source
The Triumph Spitfire LED Rear Light Module is open source and has been developed with DIY enthusiasts in mind.
Triumph Spitfire LED Module by Joe Mann is licensed under CC BY-NC-SA 4.0
