Winter is here, and the most interesting thing in winter is Christmas. As a PCB designer, I decided to build something useful for Christmas and so I made a blinking PCB snowflake for Christmas tree decoration. we can use this to decorate our Christmas trees, walls etc. The flashing of LEDs will attract everyone. So let’s see how I made this.
CIRCUIT DIAGRAM
So everything starts from this basic ic 555-based astable multivibrator circuit. the output current of the ic 555 is not enough for driving 16 LEDs, so I just added a transistor to the output of the IC 555 to drive 16 LEDs. I designed the circuit in easyeda.com and used all SMD component layouts to make the circuit. we can change the on/off (blinking) frequency by changing the values of the resistor and capacitor.
PCB DESIGNING
Next, I converted the circuit diagram into a PCB. As I said earlier here I used all SMD components so my plan is to place all components except the LEDs on the bottom of the PCB and LEDs on the top side of the PCB. Here I designed the PCB just like a snowflake shape. for that, I used the insert image tool of easyeda. after inserting a snowflake shape I drew the outline just above the image. After making a snowflake-shaped PCB I placed all components on the bottom side of the PCB. On the other side, I placed the LEDs. Here is the PCB after the design. Now I downloaded the Gerber files for PCB fabrication.
PCB FABRICATION
To fabricate PCBs I went to JLCPCB.com. JLCPCB provides PCB fabrication and PCB assembly for a low price. You will get 5 PCBs just for 2$ and PCB assembly starts from zero dollars. To place an order click on order now and upload the Gerber file. After uploading the Gerber file select the quantity, thickness, colour etc. Here I choose white colour. Then I selected the shipping method and finally placed the order.
PCB ASSEMBLY
After two weeks l received the PCBs from jlcpcb. You can see that the PCB looks very nice and the quality is superb.
components
following are the things required in this built-
- 1*555 timer IC
- Custom PCB from jlcpcb
- 1*10K Resistor -0805
- 3*1kiloOhms Resistors-0805
- 1*10uf Capacitor-0805
- 1*10nf Capacitor-0805
- 12*LEDs – 0805
- 6*LEDs -1206
- 1*SOT-23 2n2222 transistor
This circuit only has a few components so we can either solder it by hand or we can use the reflow method here I used both methods. After soldering the components, on the opposite side, I solder the LEDs. We can use any colour LEDs here. I used two types of SMD LEDs here that are 1206 and 0805. Here are the PCBs after soldering the components to PCB
TESTING
On the back side of the PCB, there are two points for connecting the power wire. There I connected the single-stranded copper wires which will also act as the hanging support while using it on trees. That’s it. now you can see the result of our snowflake.
You can buy kits from here. So that’s all about today hope you enjoyed and learned something new from my tutorial if so please like share and subscribe. Thanks for watching. Will see you with another tutorial.
Leave a comment