Copper Foil Connected Lego Block Circuit
Introduction: Copper Foil Connected Lego Block Circuit
In the past I used to have one of the solder free plug and play electronics kits that now can be found in a number of forms.
Whilst in the process of reminiscing the thought of making my own came to mind.
What form will it take, base plate with socket, pins or nuts and bolts, what about the components, on stripboard, PCB or air wired on Perspex or a 3D printed carrier, all would have been possible but then the Tin foil competition was launched and it became clear.
The interconnections would be made with Copper foil tape, its conductive can be easily formed, cut and soldered, whilst at the same time it needs to be reconfigurable.
But where would the tape be used on the base plate on the components or both.
In the end I decided that the tape would be used solely on the component carrier with the component soldered to the tape.
This would mean that the base plate would simply be a support with no electrical connections.
The connections being made by the intermate contact between the carrier faces.
Using a square carrier meant that there were 4 sides with which to make contact, the base of the carrier would simply lock to the base and the top surface would be used to mount the component.
So now I needed a square carrier that will allow tape to be mounted on four sides that will support a component and enable reconfigurable attachment without the need for tools.
After thinking about various methods an opportunity presented itself in the form of LEGO, the 2 * 2 blocks fitted the bill for the carrier, being easy to handle and uniform making layout easy additionally base plates existed in a variety of sizes to suit a range of circuit sizes.
A bonus was in the variety of colours which allowed component types to be easily identified by colour coding.
The colour coding adopted:
White - wire links
Yellow - Indicators
Blue - Capacitors
Green - Transistors
Red - Resistors
Colour codes were chosen based on what I had available.
If more colours are available differentiation could be applied to the wire links and in addition the part type reference could be added for another means of identification.
I just needed to put the idea together in physical form.
Supplies
Copper foil adhesive tape 250 cm long * 12 mm wide
45 (2 * 2), blocks
7 * 8 (2 * 2 block) area, 120 mm * 128 mm
Component block.
2 * LED (yellow blocks) - red LED's
4 * Resistors (red blocks) - 2 * 470R, 2 * 47K
2 * Capacitors (blue blocks) - 2 * 10uF/16V
2 * Transistors (green blocks) - 2 * BC109C or equivalent NPN transistors
Interconnect link Types (white blocks)
2 * P4 (4 connection link common head pin)
17 * L2 (2 connection link)
13 * L3 (3 connection link - T shape)
3 * XU (cross under, 2 isolated links)
1 mm drill bit and drill.
Scissors.
Wire cutters.
Pointed nose pliers.
Pencil or other visible marker.
Fine (0.4mm), tip long soldering iron bit or similar.
Solder.
Soldering Iron.
Flat ruler or tape.
22 AWG tinned copper wire.
22 AWG enamelled copper wire.
Step 1: Circuit
I would need a circuit with which to determine the required elements rather than randomly creating a stack of elements then look for something to build.
This meant I would only build the required elements for the chosen circuit, but which circuit?
For this first incarnation I would use discrete components with no more than four pins, fitting for the following resistors, capacitors and transistors essentially the basic electronics building blocks.
It is not to say that more complex devices could not be supported it would just require a departure from the 2*2 block. (The 2 * 4 block would enable an eight pin IC to be accommodated for example), but that's for another project.
The circuit chosen was a previous Instructable Disctrete_Chain_Link_Oscillator with full details of operation.
Step 2: Layout
Now that I had decided on the circuit I would need to lay it out using blocks.
The components would simply have one connection per side.
However, suitable links would need to be provided to keep the layout to a small size, resulting in a range of links for different purposes.
1: A block where all 4 sides are interconnected having a common top side connection. Named P4 to indicate it has an external pin connection for applying power or measuring a node whilst also connected on all 4 sides. 982