Modular Mini Photo or Video Studio Light With High CRI COB LED and Raspeberry Pi Pico

This mini Photo studio light was created out of a need to have reliable high-quality lighting in the 10-30W range (ca 1000-4000 lumens).

The design is based around VGA heatsink/fan assembly that is cheaply and readily available on Aliexpress. For the LED, an F17 package (19x19mm) works well this must then be glued to the heatsink with thermal glue. I recommend using a LED with a CRI above 90. 

The forward housing will accommodate a reflector with a 50mm diameter, two lengths are included depending on the reflector/LED combination.

The body of the light is designed to fit a custom PCB with a Rasberry Pi pico used to control the LED through a Meanwell LDH driver. In this configuration, brightness can be controlled and the fan operation is temperature based with an OLED displaying temperature and brightness. 

A simpler design can however be built without the Pi, with the housing having adequate space for a variety of LED drivers. 

The rear plate should be selected based on the use case, with a variety of power supply options included.

Important: This is a slightly more advanced project and assumes familiarity with basic electronics and microcontrollers as well as the ability to solder.

The firmware is still in its early stages and does contain bugs.

PCBs were sponsored by PCBWay, they offer high quality PCBs and more at affordable prices, please consider using them for your next project!

Core components:

Custom PCBs, Gerber files are available here.

3D printed parts set download from Printables

LED Reflector 50mm

Rasberry Pi Pico

10-30Watt COB LED, max 19x19mm, CRI90+ recommended, note the current and voltage requirement

Meanwell LDH-25-700 DC-DC Constant Current Step-Up LED driver, pick one to match the selected LED (datasheet)

Heatsink with 12v Fan, there are various sellers on Aliexpress, the usual cost is about 2 USD

Thermal Glue* to fasten LED to Heatsink

Electrical components:

1x TMP36* analog temperature sensor

2x IRF5210* MOSFET

1x LM7805* Voltage regulator with Heatsink*

1x 0.96" OLED* display

1x 10K Potentiometer

1x 10uF and 1x100uF capacitors, Capacitor set*

2x1k Resistors, Resistor set*

Connectors and Fasteners:

JST-XH connector set* (optional but makes life easier)

5.5mm power jack

3.5mm switch jack (optional, alternatively use a SPST switch or jumper)

4x30mm + 8x16mm + 4x14mm M3 Hex screws M3 Hex Screw set*

2x2mmx5mm self tapping screws Small screw set*

Consumables

Solder

Electrical Wire*, 24AWG recommended

Super Glue (optional)

Heatshrink or Electrical tape

Tools

Soldering iron*

Hex wrench (Allen key)

Small side-cutters

Small long-nose pliers

Heat gun (if heatshrink is used)

Small round file (ca 5mm Diameter)

Hacksaw

If you're interested in the other lights pictured, here is the component list for them too:

UV Lamp:

(not fully tested)

Meanwell-LDD 1000L DC-DC Constant Current Step-Down LED driver

USB PD module

10 Watt UV 365nm LED

40mm ZWB2 UV Bandpass filter

RGB lamp:

10W RGB LED 30mil

RGB Driver with Remote

240-12v Fan power supply

*Note: Links have been placed as a convenience, I am based in Germany so some may not be valid in your region. those with an asterisk are Amazon affiliate links where I may earn a small commission at no extra cost to you. If you have trouble sourcing components feel free to get in touch with me.

Order the PCBs and Printed parts or print yourself.

The PCBs were kindly sponsored by PCB way, consider using them for your PCB needs, simply click here and enter the dimensions of 69.3x49.7mm for an instant quote. Gerber files are available here.

3D printed parts set download and self-print from Printables.com or PCBWay printing service (note, I have not tried this service yet however I have no reason to doubt that the results would be excellent)

Solder all the electrical components to the PCB as per the silkscreen and circuit diagram.

Start with the JST connectors then the other electrical components then the Rasberry Pi header and finally the LDH module.

The Pi can then either be inserted or soldered in place.

Note: the fan comes fitted with a different connector, use a male header as pictured not a JST connector.

PCB, circuit, and code design by:

Aman Ullah Aman

LinkedIn

Email: au.aman(at)hotmail.com

Mark the heatsink from corner to corner with a sharp object (ie small screwdriver) then clean with Isopropanol Alchohol

Apply a small amount of Heatsink glue to the rear of LED COB and carefully place in the center of the heatsink using marks to help alignment.

Use a medium amount of force on the edges of the LED to push in place so that the glue is evenly spread ensuring you don't touch the light-emitting surface.

Glue the TMP36 next to the LED as pictured.

Solder the wires to the LED and TMP, use heatsink or electrical tape around the TMP legs to ensure they are insulated.

Route the wires as pictures, pinching the fins with pliers to hold them in place.

Note: Pictured is both a standard white led as well as an RGB led, the RGB LED is slightly thicker and will require the use of the 27.5mm reflector mounting to ensure clearance.

Clean up printed files if necessary and pre-thread the M3 screws as pictured.

Use the 4x16mm screws on the rear housing.

File a small area of the reflector as pictured to enable clearance for the TMP sensor.

Insert the reflector into the forward housing, using a blob of glue if required.

Prepare the power and switch cables and add JST connectors.

Note: install the 5.5mm barrel connector into the housing before adding JST connector.

Add connectors as required to LED, TMP, OLED and Pot wiring.

Attach the OLED to the display as pictured using the 2 small 2x5mm screws.

Insert the Potentiometer with wires attached, using a small amount of glue if required.

Attach the knob onto the Potentiometer (you may need to saw a few mm off to ensure a good fit)

Code is available free of charge at Github, use the Arduino IDE bootloader to upload to your Rasberry PI, and ensure the required libraries are downloaded.

Before uploading the code, you will have to add this file to your Arduino library, located at:

C:\Users\*username*\Documents\Arduino\libraries\Adafruit_SSD1306

Note the orientation of the Fan grid now place over fan with the detented area towards fan. If you printed in PLA the standard grid should work fine however if you're having clearance problems use the increased clearance version.

Slide the PCB into the housing and attach all connectors. This can be a bit fiddly, use the pliers to make your life a bit easier.

Test the light to ensure it functions then fasten the front and rear assemblies to the main housing with the 8 screws.

Attach the barn doors if desired.