User:Medelen8/ENES100/LEGO Circuits Conceive

Idea
Use lego blocks to create basic direct current circuits such as parallel circuit,series circuit, led circuit or a simple dc motor circuit powered by batteries.

Problem Statement
To find ways to modify Lego bricks and create a set of DC circuits elements ( Resistors, Batteries, Led's, motors...) that can be used as Electronics tutorial for kids. There are some pretty good products similar to the lego circuits on the market.Unfortunately, they can be quite expensive and are beyond reach to many families. Our focus here is to modify those Lego bricks and create affordable DC circuits that can be used to teach electronics or basic electricity to kids.

Market/Customer needs
Below are the major customer needs for this Lego Circuits project; by satisfying those needs, we can be certain that a broad portion of the market could be reached.

1. The required dc voltage to run the circuits should be around 9V.

2. The product should be tested  many times before it is sold to ensure customer satisfaction.

3. The product should be safe for 6 years old kids and up.

4. The product should be easy to understand for 6 years old kids and up.

5. The  pieces  of the product should be tested and make sure that they are all functional.

6. Each kit should come as a complete assembly for different activities.

7. The product should be used as tutorial for basic electric  circuits or electronics.

8. The product needs to be simple for different ages to work with from ages of 6 years up.

9. The product needs to be easy for 6 years old kids to assemble and to disassemble.

10. Replacement pieces for the product should be included.

Enterprise goals and capabilities
This Lego Circuits project is part of ENES100 at Howard Community College; the Engineering Lab is at the disposition of students working on their projects and a small budget can be allocated to purchase some material needed. This Lego Circuits projects is less expensive than similar products on the market and a success in this project will be a very good tutorial for kids desiring to immerse  into basic electricity or electronics, it will enable them to quickly learn the basic concepts of direct current circuits in a very practical way.; this project will certainly attract curious kids at various Engineering Fairs and the Image of HCC will be enhanced.

Competitors and benchmarking information
Three Major products are quite popular among kids and high school students willing to learn the basic of DC circuits, basic Electronics and even some robotics. The first one is called " Little Bits": pre-enginered electronics modules that connect with magnets and based on an open source concept. The prices were ranging from $100 to $200. The following link is a short youtube video explaining the "Little Bits" concepts. https://www.youtube.com/watch?v=QixV_Hlh2CM The next product is the "Snap Circuits: quite intuitive  and was also built on pre-engineered  components that connect by snapping one component to the other.They were ranging from $45 to $200 depending on the version: SC100, SC300 or SC750. This is a short video  on the " Snap Circuits" . https://www.youtube.com/watch?v=kgQvwX3JKCs The third one is the top of the line and is even more into robotics than basic DC circuits or Electronics: "Lego Mindstorms". The down side is the hefty price ( around $350 for the kit). Here is a very interesting short video on " Lego  Mindstorms"; https://www.youtube.com/watch?v=JWqFH0roIUI As we all see, price is a deterrent factor for all those products and not all the families can afford those expensive products.

Ethical, social, environmental, legal and regulatory influences
There are no any ethical, social , environmental, legal or regulatory influences associated with the lego circuits.

Initial target goals (based on needs, opportunities and other influences)
1. To be safe (No sticking wires out of the Legos)

2. To be for ages from 6 years old and older

3. To run at least 5 different activities with the lego kit: led circuit, motor circuit, parallel circuit,series circuits, resistor circuit...

4. To run most of the circuits designed using batteries

5. To be easy to put pieces together and to take them off easily

6. To have low electricity which would be around 30mA to avoid any electrical shock or any serious injury.

7. To have instructions for building some circuits

8. Must be flexible or modular.

9. Must have extra pieces for replacements

10. To have a price range from $35-$60.

11. No tools should be needed.

12. Up to 3 kids can play with the circuits at the same time.

13. Circuits must fit on a table top and must be less than 10"x15".

System performance metrics
A Digital multimeter set to continuity test with beeper can be used to test wether or not the conductive lego bricks are in fact conductive; the digital meter should buzz and read a resistance of about 0.5 ohm across the conductive sides of the blocks when the block is perfectly conductive; a higher value is a sign that the copper tape was not properly applied or there may be a break in the tape. Likewise, a led lego block should be tested the same way as simple diode or a resistor lego block as a simple resistor. It should be the same process for the rest of the circuit components.

Necessary system functions
The role of the lego conductive block is to carry the current to the different components of the circuits and a junction lego block will serve to make derivations in the circuits.

System concepts
 Copper Foil.jpg|Copper Foil using copper sheet and vinyl cutter Drilled Block.jpg|Drilled Block Copper Tape(conductive tape).jpg|Copper Tape(conductive tape) Midget Lamp.jpg|Midget Lamp Led lego.jpg|Led lego Lego -e-led.JPG|Lego -e-led  The goal for this project is to modify the lego bricks so that some circuits elements (resistors, motor,bulbs,batteries..) can be embedded into the bricks and then conceive circuits with these blocks. We have 3 major concepts here; the first idea is to use some copper or conductive tape to render the block or brick conductive. The next idea is to drill the brick and insert a conductor or component into it; resistors, led's or some other tiny components can be inserted into the block or brick the same way. The last idea is to use copper foil and with the help of vinyl cutter, make so holes into the copper sheet and then cut it into small pieces the same area as the top of the lego piece we would like to render conductive. With conductive blocks and lego components ready, the next task is to conceive different circuits for the kids activities using those components. The activities will be:

- Led circuit: Teaching kids how polarity is important for diodes or led's.

-Simple motor circuit: Teaching kids how to wire a simple dc motor and change his rotation by inverting its polarity.

-Resistor circuit: Teaching kids the effect of resistor in a circuit; it will protect the led and also dim the brightness of the bulb.

-Parallel circuit: Teaching kit the concept of parallel circuit using two midget bulbs.

-Series circuits using the midget bulbs: Teaching kids the concept of series circuits using two midget bulbs.

Trade-offs among concepts
As far as trade-offs among concepts are concerned, there are quite a few that should be exposed; the main goal of this project is to find ways to modify lego blocks as to embed components in them and conceive circuits with these blocks. The most aesthetic and accurate way to render a lego block conductive is to use some copper sheet and cut it with a vinyl cutter in small pieces the same sizes of the lego blocks and snap them on top of the lego block: the finish product is a nice and solid conductive lego block but the down side is that a vinyl cutter is expensive(around $900) and HCC does not have a vinyl cutter available so this concept was out question.The next concept is to drill holes on top and sides of the lego blocks to insert components like led's and bulbs and fish the conductor wires through the side holes; with this approach, price is a real advantage since no special tools are needed but the trade-off is that the integrity of a lego block with many holes is not maintained, the modified brick does not snap on the lego platform as firm as it should ,the protruding holes on the side are not quite aesthetic and the wires must be trimmed and soldered on the side. Another concept is to use copper tape to render the blocks conductive: this approach is quite simple and very affordable( a copper tape roll is about $15 and can be used for more than 50 lego circuits) but the only down side is that over time and with repetitive frictions on the block, the conductive tape tends to peel off and another stripe of tape has to be reapplied.The last concept is how to embed batteries into lego blocks; the simpler approach is to use a 9v battery with a snap on terminal block and a switch or a batteries pack to power the circuit; this approach is simple and affordable but the trade-off is that the pack is somewhat cumbersome and the wiring connecting it to the circuit tends to break off and has to be re-soldered. An alternative concept for this is to use button cell batteries as Pr. Mark suggested; the trade-off with this option is that the integrity of the lego will not be preserved since the lego block has to be cut or drilled to insert the cell batteries in series. A pre-engineered lego block is the best solution for this but we have to rely 3D printed block for this. For the trade-offs overall, we do not have to use any form of decision matrix because we have to use all the concepts interchangeably even though the copper tape concept is the major one that will be used for this project. .

The decomposition of form into subsystems, assignment of functions to subsystems, and definition of interfaces
The lego components will be laid on a lego platform of about 10"x15" and the circuits will be built around the conductive blocks, the junction blocks and the various lego circuit components:led, motor, bulbs...

Modeling of System and Ensuring Goals Can Be Met
This step of the CDIO does not apply to the Lego Circuits: this project is not based on any existing project.

Project cost and schedule
Our projections estimate that the total cost to conceive,design and implement a set of 5 basic lego circuits will be around $40-60 ; the major material needed will be a set of lego blocks with a base platform of 6"x8" ,two led's,1 dc micro motor, 2 midget lamps, 2 22ohm resistors,a single switch, a 9V battery pack, 1 roll of adhesive copper tape and some wires(18 gauge).Less than 5 weeks are necessary to have the first fully functional prototype of the 5 basic circuits.

Estimation and allocation of resources
The amount of money needed to finalize this lego circuits project will be far below the maximum amount the College can allocate for a project ($500-600). Since this project  does not involve a lot of expensive material,no financial assistance is needed at this point.

Risks and alternatives
As far as the Lego Circuits are concerned, there are no risks or alternatives associated with this project; lego circuits are safe, reliable and very affordable.

Next Steps
With the success we had in building a prototype of a led- lego circuit, a design and implement phases are necessary to further this project with complete success; some improvement, modifications will be effected during the next phases. The Lego Circuits will be a very reliable and affordable alternative to the similar products currently on the market. We therefore strongly recommend a design and implement phase for this third project.