30 mm Cage Plate LED Driver

Description:

This board is an entirely self-contained LED and driver circuitry designed to be compatible with the Thorlabs 30 mm cage plate system: https://www.thorlabs.com/navigation.cfm?guide_id=2004

Design:

To view and modify the board, download KiCAD https://www.kicad.org/, and open the project file.

Make sure to modify the LED footprint to match the footprint for your desired LED, and to change the current limit resistor to the desired value (see AL8843Q datasheet, p. 11):

RSET (Ω)  Nominal Average Output Current (mA)
0.033     3,000
0.05      2,000
0.067     1,500
0.1       1,000
0.15      667
0.3       333

Ordering:

The BOM can be found here: https://docs.google.com/spreadsheets/d/1ZUOHqLCISnd-vsBcDY3z2q5rFzEznOQzioUf6a6fGwg/edit?usp=sharing

To order the PCBs, upload the Gerber files to your desired PCB vendor, such as: https://www.pcbway.com/project/shareproject/30_mm_Cage_Plate_LED_Driver_8c990405.html

Assembly:

To start, use thermal epoxy to connect the PCB board to the Thorlabs cage plate. It is helpful to use cage rods as an alignment guide to ensure everything it positioned correctly: Press firmly with a vise or heavy weight and bake at 50°C overnight to cure.

Next, assemble the board similarly to other reflow soldering boards. See the following manual: https://github.com/Llamero/Light_Color_and_Intensity_Datalogger/blob/master/Data%20logger%20assembly%20manual.pdf

Finally, use thermal epoxy to connect the heatsink to the Thorlabs cage plate, press firmly, and bake at 50°C overnight to cure.

Operation:

Connect a 5V to 40V power supply, with the positive terminal connected to the Vin pin and the negative terminal connected to the Gnd pin. To control the LED current, you can send a +0.4V (10% current) to +2.5V (100% current) to the Ctrl pin. The LED can also be dimmed with PWM with a voltage up to 5V.