struggling to place components on the correct position of PCB layout

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Hi, 

 

I am trying to learn PCB design with Eagle software. I have drawn one schematic and I want to convert it in to PCB layout 

 

I am getting really trouble when its time to place all parts on layout. Can somebody give me any idea how do you  place components on the correct position of PCB layout ?

 

   

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gandhi1 wrote:
Can somebody give me any idea how do you  place components on the correct position of PCB layout ?

One generally clicks & drags.

 

BTW:

  • It is conventional to add values to components on the schematic.
  • Your footprints for polarised capacitors are lacking identification of which way around to fit them.

 

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The first thing you should do is correct the connection of C3 to ground on your schematic.

 

You will find the process easier if you place (by clicking/dragging and dropping) the components in the same relative positions from left to right. The yellow lines in your layout show how each component connects to other parts. Your task is to place and orient the components so that the yellow lines do not cross over other yellow lines. You do this by moving the components around. This simple schematic/pcb design should be able to be done as a single sided pcb.

 

 

Ross McKenzie ValuSoft Melbourne Australia

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Hi 

 

I am trying to make power supply circuit that take 12 V DC and supplies 5V DC to AVR microcontroller 

C1- 1000uF

C2 - 33 uF

R1 - 660 ohms 

 

Does it make sense ?

 

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A few suggestions.

 

You don't have any mounting holes. Even if you are not putting it in an enclosure you should keep the bottom of the assembly above the table... especially if it is conductive.

 

C2 should be 0.33uF

 

C3 should be 0.1 uF.

 

C2 and C3 should be close to the 7805 regulator

 

You do not have any terminals for connecting  the % 5 volts to your microcontroller.

 

You have not marked pin 1 on the regulator pins. You could  easily mount it backwards. Likewise for the LED and the other polarity sensitive parts.

 

I think your traces are too narrow for carrying any reasonable level of current.

 

Just some quick suggestions before I go to bed.

 

edit typo

 

Ross McKenzie ValuSoft Melbourne Australia

Last Edited: Mon. Apr 5, 2021 - 01:10 AM
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You are off to a great start!

 

If your question is how does one use the Eagle software, then I can't help.

 

If your question is more about laying out PCBs than I can give you a few suggestions.

 

I am certainly not an expert, but I'll show you one PCB to use as an example for the comments that follow.

 

There are different approaches to laying out a PCB.

For most "simple" PCBs, one easy approach is to have most of the top PCB traces run left-right, and most of the bottom traces run Up-Down.

On this board you can see that most of the traces on the top are all running Left-Right.

 

You can use a "via" to connect the top and the bottome traces together.

 

(As Ross mentioned, your power supply can be laid out on one layer.)

 

You have lots of room on a PCB, so make the traces larger, (wider).

Wide traces carry more current, and have less resistance.

 

You can use the small traces when routing signals around a multi-pin micro, otherwise make them wide.

 

I then to put mounting holes on most boards.

I usually start by adding the holes and marking off the corners so that I don't put a part or a trace where a bolt or nut is going to go.

This board has four mounting holes in the corners with a "boundary marker".

 

You will probably want to add an On/Off switch to your power supply!

 

Small, SPDT, (Single Pole, Double Throw), slide switches take up very little PCB space.

Just use 1/2 of the switch for your On/Off switch.

This PCB has one in the lower left corner, and the board is labeled On/Off.

 

If you are going to etch the board yourself, then keep-it-simple.

 

If you are going to send the gerber files to a company to make your board for you, then put lables on the board.

Some boards you can label the parts.

Be sure to label the connectors, (Vin, Vout, +5V, Gnd, Pwr (Power), etc.).

 

It is nice to put a little + sign on polarized parts, it helps when it comes time to install the parts and when testing the board.

The Circle in the top left is for a piezo, (but it could be for a cap).  One of the pins is marked with the + sign.

(In this case the + sign will be hidden from view once the part is installed, but so be it.)

 

There are three small LEDs on the right side,if you look closely there is a small + sign for the LEDs.

 

Be sure to put your initials, a date, a V1 (For version #1 of the PCB), and a PCB name, (e.g.  PS5V, Power Supply 5 V), on the board.

Over the years you will likely make many boards, and you will want to easily identify them as the pile grows.

 

Finally, I would add an "extra" pair of pads on the PCB for the  +5V and the Ground.

You can then connect a voltmeter, (DMM, O'scope, etc.), easily to see the output voltage.

Your voltmeter will need a Ground connection, and having a separate, good, ground pin / pad makes troubleshooting your boards much easier.

 

On this PCB there is a dedicated Ground pad / pin in the upper left corner, just below the big circle.

 

One more...

In the lower left of the PCB, above the ON/Off switch, is a rectangle with a line across it.

That is the pad for the Reverse Polarity Protection diode, just like the one you have in your schematic.

The line (bar) on the rectangle matches the cathode band on the diode, to make sure you insert it the correct way on the PCB.

 

One more...

As your boards get more complex, make sure you also lable your connector's and chip's Pin #1.

To the right of the diode there is a >>#1  marker for that string of 8 pads.

 

On your board it would be wise to mark the + for the polarized caps.

It would be good to put Vin, G, and +5 labels on the 7805's pads.

 

Good luck with your projects!

 

JC

 

 

Edit: Typo

 

 

 

Last Edited: Sun. Apr 4, 2021 - 04:58 PM
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Hi

Thank you for good advice I hope all the connections looks correct. I am new in eagle I am having a bit of trouble, marking on PCB. I don't know how to mark pins of 7805 

 

There is slight change in design. I am using bridge rectifier IC instead of diode 

 

What do you  think, are all my connection correct ?    

 

 

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I like your advice I am having trouble marking in eagle software. The board you showed is a nice and clean design. 

 

Which software do you use for PCB design ? 

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There's a lot to be said for using a polarised connector for the power output... but it's not critical if you're careful when you connect. And as mentioned earlier, you might want to increase the thickness of the traces.

 

Neil

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Electrically, your layout looks fine.

 

You still might want to add a power on/off switch, and add holes for mounting, as well as make the traces wider!

 

I use RIMU, which works well on a PC, but it hasn't been updated in a long time.

There are also many other programs that are perhaps easier than Eagle.

 

JC

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"Dare to be naïve." - Buckminster Fuller