3,
Night Brights
It's a small light that turns on when it's dark. And it's rubbery soft. And you can decorate it any way you like.
2. Materials
Electrical Circuit components
(Details are for three small lights inside the casting).
(Digikey part numer coming).
- 3 Surface Mount Leds
- 2 Surface Mount 1K Ohms resistance
- 1 Surface Mount 10K Ohms resistance
- 1 TIP120 Transistor
- 1 PhotoCell
options:
- 1 3V Lithium cell battery
- 1 Cell battery holder (optional/ get the right size for your battery if you do)
or
- 1 1F, 5V super-capacitor
- 1 solar cell (4.5V)
3. Skills required
- Basic mold making experience.
Use pre-existing container to avoid having to make a mold if you are just learning. - Beading electronics
- Casting electronics
4. Instructions (in progress)
A--Understanding the electric circuit
The key is to transform a simple and standard circuit into a soft circuit made with conductive thread and beaded components.
Schematic of circuit
Soft circuit translation
The behavior is simple: when the photocell recieves enough light, it turns the light off and inversly, it allows the leds to glow when it's dark. The resistance of your photocell will determine the sensitivity of your nightlight. The higher the resistance, the less sensitive the light will be (the darker it will need to be for the lights to go on).
Prototyped on breadboard
Light on
Light off
B--Prepare all your parts
You will connect each components of the circuit using the conductive thread.
Prepare each part by using conductive crimping beads soldered on the ends when they are needed.
Bead everything that needs to
TIP120 transistor modified
Leds and Resistors will look like that
test your leds
The green line is Ground
C--Making the circuit
One compnoent at the time, attach and thread each part following your initial sketch. Make sure to secure every knot properly and to leave enough lenght for power and ground or any other parts that will need to stick out of the cast to reach for external components.
Start with the 3 Leds in paralelle
Attach the resistors
Work on solid knots
Test small sections to find problems
Prepare your transistor
Secure with fray check before each cut
Connect the parts together
until you finish the entire circuit
Test the entire circuit as well
D--Pour the rubber on the circuit
Delicatly place your soft circuit at the bottom of your mold. Test the circuit after you have placed it at the bottom and try to space each component as well as possible. Bring your ground and power threads to the edge where your battery will be and tape them there. I've added this little plastic cap to create a slot for the cell battery to fit in.
Stand photocell face down
Put your circuit in the bottom
Power and Ground threads
Prepare your rubber
Pour the rubber slowly
Let it sit
D--Test the finished piece
Apply current and see the magic. If there's a problem, you can try reaching in with a needle and pull parts of the thread back out or breaking it. Add your battery outside.
Your finished piece
Keep testing
5. Estimated Price
6. Estimated Time
2 hours preparation
2 hours for the circuit
2 hours to pour rubber
Let it sit overnight
Half an hour afterwards you're done.
8. Credits
Concept and design by mouna andraos. Produced with the support of Eyebeam
9. Variations
This light might use an external switch as well.
Newest design includes a solar cell and a supercapacitor. See that part of the circuit here