Introduction: UV "LightSaber" Nightlight
This UV (ultra-violet) nightlight circuit has a touch sensitive 4-bit d/a dimmer with 16 brightness levels and a transformerless AC mains power supply. Power consumption is under 0.25W . It gives off a very spooky deep violet light. You will also see many objects in your room glowing faintly in the dark. Light diffuser is made of Endlighten Plexiglass, a transparent acrylic material which contains microscopic particles that reflect light in random directions.
I have included a PCBoard PDF for download.
Step 1: Endlighten Plexiglass
Endlighten Plexiglass contains microscopic particles which reflect light in random directions. You can find it as square/round section rods and also as sheets.
Step 2: Device Overview
If you have a 3-D printer you can make a custom enclosure. I used a 10cm long diffuser, but you can use a longer one with even better results.
Step 3: Circuit Built on Single-sided Board
Step 4: PCB Download
Step 5: Circuit Operation (1)
Step 6: Circuit Operation (2)
Step 7: X and Y Rated Capacitors
x and y rated capacitors are specifically designed to be connected to the AC mains. These are metalized polyester film capacitors and should never be replaced by ceramic or any other kind. Use 0.33uF for 220v operation (minimum 400v voltage rating) or 0.68uF for 110v operation (minimum 250v voltage rating).