Painting with Light: Build a Light PainterDifficulty: Beginner
Assembly Time: 2 hours
Light painting is a photographic technique that captures light in motion at slow shutter speeds. The light painter has 5 different colors all controlled by a MOSFET-based momentary touch switch and is powered by a 9V battery.
Required tools and components:
Soldering iron and lead-free solder
Hot glue gun and glue sticks
Heat shrink tubing and heat gun
|Description||Mfr. Part No.|
|9V Battery||ALK 9V 522|
Step 1 – Positioning and drilling into the caseFirst you need to decide on the location of the touch switches and LEDs. Use four red, four yellow, two green, two blue, and two white LEDs. Using one LED per color will allow you to use a smaller case and create more solid lines when you paint. If you use RGB LEDs, you can produce a wide range of colors by varying the resistor values.
Step 2 – Installing the touch switchThe touch switch is a momentary switch with N-channel MOSFETs. When you touch the anode (+ terminal) and gate, it will turn ON. Touch sensitive switches respond instantaneously and allow you to use multiple colors at the same time.
In this circuit, there are six wires which are the electrodes. Since MOSFETs rely on charging their internal capacitors to turn ON, they need to be discharged before it will turn OFF. The 10M resistors will discharge them. A smaller enclosure (and circuit board) is preferred.
Solder the MOSFETs, wires and 10M resistors to the board. For metal cases, make sure to insulate underneath the PCB with a sheet of plastic. If you need to grind the PCB, wear a safety mask and protective eyewear.
1. Common anode (solder wire here)
2. red (on) electrode
3. blue (on) electrode
4. green (on) electrode
5. yellow (on) electrode
6. white (on) electrode
8. 10M discharge resistor
9. Touch switch circuit
10. Current limiting resistor