3D Christmas Tree Soldering Kit - 2019

By Jamal Bouajjaj

Introduction:

This project is a PCB soldering kit in the shape of a christmas tree. The 3D parts of the projects comes from connection the main PCB and 2 "auxilary" PCB thru a right angle connector. The kit has been designed with some SMD and THT parts. If you plan to use this design as a kit for people who have no/minimal soldering experience, it is recommended to pre-solder the SMD parts before giving the board to them for them to solder.

Warnings/Issues:

Due to the original intent of this kit, it will have many reference to the University of New Haven and it's makerspace.
If you plan to use this kit for your own purpose, it is recommeded to update the PCB in Kicad to remove such marks. The same applies for all CAD drawings made in Autodesk Inventor 2018.

Note:

The main PCB can run standalone without the 2 auxilary boards shown in the drawings/pictures

Project's folder:

Click the GitHub folder below to access the project's files, which include the KiCad PCB files, the Gerber files, and the Autodesk Inventor CAD files.

Theory of Operation:

The circuit is based on a 555 timer and a 4017 decade counter. The 555 timer is set to operate as a astable multivibrator. The clock output of the 555 is connected to the 4017 decade counter. This counter then incremently turns on a "channel" at a time. Each "channel" signal is connected to a Darlington array in order to drive the potential 4 LEDs connected per channel. Each "channel" output has 2 LEDs connected to it in the main board, and 1 in each auxilary board. The auxilary boards are not required for the operation of the main board, but is recommeded to solder them on, mainly because they look cool.

Pictures:

PCB Parts:

This kit has some THT and SMD parts to be soldered (THT means through-hole, and SMD means surface-mount).

Main Tree
PCB Reference	Part Description	Package Size	Quantity per Board
U1	555-Timer	8-DIP	1
U2	ULN2003 Darlington Transistor Array	SOIC-16	1
U3	4017 Decade Counter	SOIC-16	1
F1	250mA Polyfuse	THT	1
J3	Micro USB Right Angle	Würth Elektronik 614105150721	1
J4	5-9V Battery Connector	2-pin 0.1" header	1
C2	0.1uF Decoupling Capacitor	SMD-0805	1
R1	4.7KΩ Resistor	THT	1
C1	100uF Capacitor	THT	1
D1-D15	5mm LED	THT	15
R2-R16	330Ω Resistor	SMD-0805	15
Auxiliary Tree
PCB Reference	Part Description	Package Size	Quantity per Board
R1-R7	330Ω Resistor	SMD-0805	7
D1-D7	5mm LED	THT	7
J1	8-pin Right Angle 2.54mm Header	THT	1

Schematic:

Here is the PCB's schematic (The first one is for the main tree, the second is for the auxilary tree):

Technical Diagrams:

Here is some diagrams relating to the project:

Case:

The PCB is designed to be screwed or tight-fitted into a case at the buttom of the board. I have designed such case, which you can find in the project's GitHub folder.