1. Concept:
My final project will be focused on the design of a home office solution in the form of a desk that will reduce the amount of power wires for desk and other personal portable devices. This will be achieved mainly through the use of a microcontroller that can operate a charging induction coil by means of a sensor which will detect the presence of the device to be charged. (This means that these devices will have their own rechargeable battery.)
2. Existing projects and products:
Some similar projects exist, (and also commercial products, since the appeareance of IKEA launched its first product line of furniture with wireless recharging stations last april.) But most existing solutions doesn´t have the possibility to switch off / on the power source other than unplugging them. In this particular is where I want to make an small improvement by adding a photosensor and a microcontroller unit to disconnect the charging coil when there´s not a device placed over it.
Electrify table. Esther Haering Design Studio. IKEA Wireless furniture collection.
3. Materials & costs (*):
The project will be developed in 3 main areas. In terms of materials (the costs are roughly translated from Mexican pesos.):
A. Design exploration and development of a basic structure to be made in commercially available wood presentations, such as plywood and solid structural poles in different sections.
1. 1,20 x2,44mts, 18mm thick plywood, C grade quality: 30 U$
2. 3 x 2mt long 1 1/2″ diameter, round section wood poles: 12 U$
3. Sandpaper and other finishing products: 5 U$
B. A system of 3D printed joints. These joints will be designed taking advantage of FFF / FDM technology because of its availability and replicability.
1. Set of 2 x 90 deg joints, top and bottom enclosure for the MCU and other electronics, lamp base, all FDM printed in ABS at medium resolution: 80 U$.
2. 11 x 17″ , 0.6mm thick white translucent polipropylene, plus laser cutting and engraving to make the lampshade: 2U$
C. A group of integrated electronic devices that can be made at FabLabs, consisting (at least.) of a purposely made microcontroller unit, sensors, switching devices and a basic emmiting and receiving inductive unit wit its charging and receiving coils.
1. Microcontroller; FR1 board, SMD components, microprocessor, connectors and wires: 15 U$
2. Phototransistor sensor board: 8 U$
3. Optocoupler / MOC-Triac. board and components 3 U$
4. Adafruit Inductive charging set, 5V): 9.95 U$ here
5. 1 watt cool white LED, heathsink mounted: 4U$
6. 9V DC, 1000mA power adapter: 7U$
7. 1/64″ diameter, flat end mill: 22 U$ (in México.)
Final approximate cost for a working desk plus inductive rechargeable lamp: 158 U$*
*: These are retail costs, not wholesale or industrial costs.
4. Parts to be made by me / FabLab:
4.1. CNC routing and cutting of wood parts.
4.2. 3D printing of joints, enclosure and lamp base.
4.3. Construction of MCU, photosensor MCU, Opto board.
4.4. Rechargreable inductive lamp.
5. Processess involved:
5.1. CNC routing (desktop.) CNC milling & engraving (PCB boards.)
5.2. Laser cutting & engraving.
5.3. FDM 3D printing.
6. Tasks completed:
6.1 General design exploration of concept, design of possible desk parts and electronic components.
6.2 Development of 3D, 2D CAD, CNC, 3D printing, Circuit design (Eagle.) files.
6.3 Physical adjustment and assembly of desk and lamp parts.
6.4 Physical assembly / welding of components on several boards.
6.5 Programing of Microcontroller unit and sensor board.