I answered your other post

Ahmet, Do not rely on the Autorouter for designs like this. It will (and indeed already has) mees up the PCB. Please study the Layout information 11 in: [http://www.ti.com/lit/ds/symlink/mc33063a.pdf](http://www.ti.com/lit/ds/symlink/mc33063a.pdf) and Figures 15 and 16 in: [https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF](https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF) Also, you would do well to read this: [https://www.onsemi.com/pub/Collateral/SMPSRM-D.PDF](https://www.onsemi.com/pub/Collateral/SMPSRM-D.PDF) especially the section on **Laying Out The Printed Circuit Board** starting on page 21. You might also want to watch: [https://training.ti.com/pcb-layout-smps-part-1](https://training.ti.com/pcb-layout-smps-part-1) [https://training.ti.com/pcb-layout-smps-part-2](https://training.ti.com/pcb-layout-smps-part-2) [https://training.ti.com/pcb-layout-smps-part-3](https://training.ti.com/pcb-layout-smps-part-3) Oh, and: [http://tech.mattmillman.com/mc34063-a-tough-lesson/](http://tech.mattmillman.com/mc34063-a-tough-lesson/) :)

@andyfierman  You are very useful and thanks for sharing such important links with me. I checked some of them and do you know if i need to use parasitic components other than components included in the first, original project circuit photo?  Do i need to use any other component than seen on that project? And why did you say "Autorouter already messes up your PCB"? What is the problem here on my easyEDA PCB layout? Please tell me any problems you can see, so that i will try to correct them. And, if i blow my MC34063 just like that link you gave me, can i burn my hand or can i get injured? Or can i fire get started in my house?

If you compare your layout with the layouts in the examples in the datasheets that I listed you will see that the components are not well placed and the traces are poorly laid out and are way too thin. "...if i blow my MC34063 just like that link you gave me, can i burn my hand or can i get injured? Or can i fire get started in my house?" All of the above is possible. This is why it is important to understand what you are doing and how to verify your component choices by using the design procedures given in the device datasheet. Do not assume that just because someone else has published a circuit that it works and is safe.

Thanks for the warning and i am happy you warned me about the explosion. At least now i will be on my guard. I never thought about it, because our teacher gave such projects to us and i thought it was safe. We haven't been taught about what to do... And this project could have cost me my hand or my eyes, i can't believe it. Thanks a lot for getting me on my guard. And what about parasitic components? Are my components already enough, or do i need some more components in my PCB Layout?

The perfect, ideal electronic components only exist in textbooks and electronic circuit simulators. Real electronic components are not ideal. Parasitic components are the unavoidable extra elements of any real electronic component. They are not additional components that you need to add to existing components. For example, a real resistor has a parasitic series inductance and a parasitic capacitance in parallel with it.

Don't get too worried about the risks of things catching fire or blowing up but do be aware of them. Anything to do with power supplies and especially mains and switch mode supplies must be treated seriously. If your teacher has set this as a project then they should be sure to warn everyone about the results of what could go wrong if there circuit is wired up wrongly for example.

Oh, i think i understood what is a parasitic component now, thanks to your great explanations. If i can ever succeed of creating a pcb related to my schematic, after i order my pcb, i will need to solder little SMDs on it, so much probably i was gonna lower my eyes to see better and BOOM. Then i would be blind, if i wasnt on guard. Thanks a lot for informing me so well. Ordering a PCB is not a cheap thing for me, nor do i have much time to order again. So, i really am afraid of doing something wrong and ordering a wrong PCB. If i order a wrong one, i will run out of time and i will not be able to graduate, so i am incredibly stressed at this last university semester of mine. I think my schematic is okay but if you have free time and can help me with converting into PCB stuff, i would be more than happy. Regardless, thanks for so much useful info.

As I said before: Compare your layout with the layouts in the examples in the datasheets that I listed you will see that the components are not well placed and the traces are poorly laid out and are way too thin. Use the datasheet examples as a guide for what your layout should look like. Your circuit is not that different from the example figures that I pointed you to: Study the Layout information 11 in: [http://www.ti.com/lit/ds/symlink/mc33063a.pdf](http://www.ti.com/lit/ds/symlink/mc33063a.pdf) and Figures 15 and 16 in: [https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF](https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF) Also, you would do well to read this: [https://www.onsemi.com/pub/Collateral/SMPSRM-D.PDF](https://www.onsemi.com/pub/Collateral/SMPSRM-D.PDF) especially the section on **Laying Out The Printed Circuit Board** starting on page 21. If you are studying for a degree in electronic engineering then you need to learn about and understand these issues anyway. Suggest you read (2.2), (2.3) (4) & (6) in: [https://easyeda\.com/andyfierman/Welcome\_to\_EasyEDA\-31e1288f882e49e582699b8eb7fe9b1f](https://easyeda.com/andyfierman/Welcome_to_EasyEDA-31e1288f882e49e582699b8eb7fe9b1f)

Figures 15 and 16 in: [https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF](https://www.onsemi.com/pub/Collateral/MC34063A-D.PDF) They are through hole components not SMD. First, I need answer to much simpler things like why my GND traces have dissappeared after copper area. Or like should i destroy my female header and use pad/via instead of it? Can i give 12V dc from one pad/via and GND to other pad/via? Such simple questions for you are not simple for me, which limits me to understand some further details in some of the links you gave me.

The pin out of the through hole and and parts are the same so the basic layout is the same. I have answered your question about the ground tracks.