PCB Exposure Unit




Introduction: PCB Exposure Unit

About: Passion for making.

I made this to replace my old exposure unit. This one got internal timer and real UV leds. Main material is 20mm MDF. Electronics are controlled with arduino nano. Even if you are not interested making own PCB's or stuff like that, you may find usefulI tips when working with MDF. Entire making of process is documented in video below.

Step 1: Making of Exposure Unit

Any comments and questions are welcome :)

Step 2: Technical Info

Schematic is a mess but basically I made simply expansion shield for arduino nano where you plug all the wires, pullup/down resistors, buzzer, terminals, FET etc... That external 5v regulator is not needed if you use arduino's build in regulator.

Glass panel inside unit is from old scanner. That determines my box size.

R1 and R7 are 10k pulldown resistors.
R4 and R6 are ~ 200ohm current limiting resistors for led and lcd backlight.

Both trimmers are ~5k. I think you can use any other values too. LCD brightness and voltage to FET gate are controlled with them.

Caps are for smoothing purpose for regulator LM7805.

C2 1uf-10uf
C1 0.1uf

FET IRLZ44N or similar logic level fet. This one is bit over kill but i had it laying a round.

To potpin I attached multiturn 5k pot. If you are using my code I recommend using multiturn pot because accuracy is much better compared to normal pot.

PAD1 and PAD4 are meant to be connected via jumper wire.

PAD2 and PAD3 are meant to be connected via jumper wire.

Piezo is 5V Continuous Sound Piezo Buzzer. I Dont know exact part number. Bought from ebay.

Step 3: Files

Eagle files, google sketchup file and arduino code.



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    31 Discussions


    1 year ago

    Thanks for sharing. What did you use for your LCD?

    1 reply

    Question 8 weeks ago

    I want to do this project but I can't find a uv LED panel for a reasonable price. If you could please post where you got yours that would be great

    1 more answer

    My suggestion would be to go to Ebay and buy a UV LED strip and cut it up into appropriate lengths (on the CUT spots) and then wire it together. I did this and it works well.

    For example: www.ebay.com/itm/322710778646 I got 3M of the non-waterproof and I actually used this manually to make the PCB to make it automatic.

    hi, tried to upload code to arduino nano, i got sketch uses 4398 bytes of the program storage space, maximum is 30720 bytes, how to upload please?

    Hi that´s and amazing work. What LCD screen do you use it??


    Excellent workmanship


    7 months ago

    Excellent workmanship.

    This looks very well made! Would it work for exposing photopolymer plates? the ones used for letterpress print.

    Very professional project.

    Can you shortly describe a method to produce PCB by exposer unit. I know, it should be a photo, but which type of material do you use?

    Superb make.


    1 year ago

    That flush panel mount status LED is way cool. Is that something custom you did? Any details?

    2 replies

    It's a reflecting cover for 5mm leds.


    How to weld that 5mm leds? Do you know any shop store that ship it to Brazil?

    Hello, nice project. Do you create the schematic circuit? If no, can you send me the original schematic circuit from where do you based on to create its layout using EAGLE CAD, please? I want more information about that circuit. Thanks

    Yes it is a regular 4pin RGB led. If you take a look at the schematic you will see how its connected to the arduino.

    yay! made the breadboard, time to print the PCB. nice work, Thnx for information