Hey,
So i’ve always wanted to have a PCB made i’ve designed a very simple clock in eagle with lots of help from Sparkfun’s tutorials and library’s :D. I’m about to send it to Batch PCB but i dont want to end up with a $30 coaster so if someone could look over the schematic and board that i attached to find some of though beginner mistakes or maybe a better way to do things i would really appreciate it. Though i feel confidant in the design i dont fell $30 confidant 
Thanks
Sean
If you upload PDFs or JPGs those of us that don’t use Eagle might be able to help…
Good point, thanks. Here are the .jpg images of the board and schematic.
You need decoupling capacitors on all devices, and good supply and ground distribution with wide tracks.
I agree with the points raised by Leon, and would also add:
It’s good if you can dedicate as much as possible of one layer (normally the bottom layer) to a ground plane.
I always like to see some protection on external power inputs (eg diode to protect against reverse polarity, and spike / surge protection depending on what sort of supply you’re using).
Not sure if this is just an issue with export from Eagle, but the schematic is hard to read with all the text overlapping other text.
Minor point - on schematics, normally “GND” is indicated with a ground symbol rather than a bunch of net labels.
Hi,
I have added decoupling capacitors on all devices, i’ve also added input protection to the power supply which will be a 9v battery. I’ve also moved some text around to it will be easier to read when eagle exports a image. I’ve also change the GND nets to the ground symbol. Though i have a few questions, when i make the tracks wider do i click info then just change the width in that properties box? Lastly how do i go about creating a ground plane i can’t seem to find it in the menu?
Thanks again for the help!
-Sean
I guess you changed the Eagle files only, as the images look the same…
Sorry, I can’t help with Eagle specific questions, but there are a bunch of people on these boards that should be able to.
You use a polygon fill for copper pour, IIRC.
Sorry i did not update the pics above, but i got the polygons to work and i now have a GND layer with the input protection and decoupling cap’s. 
I attached the eagle files and i will upload the pictures soon but i’m on dial-up now and it would take hours but they will be up soon. Did anyone notice any problems in the circuit the only changes were two diodes and some capacitor so not much have changed in the schematic image.
If IC10 ground lead is pin 2, then there is not a need to isolate the mounting hole from ground. In fact, having the screw and that area having copper pour connected would increase the heat-sinking. It may not be needed, but it wouldn’t hurt. It could help.
On IC 10 pin 2 is ground. I’m not sure how to connect the mounting hole to ground it is in Sparkfun’s library like that. Though it should not get that hot that its needed i will only have a 9V power source.
Agreed. That's one reason I like SMD regulators in a "D-Pack" style (or similar) package - they have a thermal tab that can be soldered directly to a large copper plane to really help with heat dissipation. To solder them you really need to use reflow techniquest (skillet / oven) rather than soldering by hand...analogon:
If IC10 ground lead is pin 2, then there is not a need to isolate the mounting hole from ground. In fact, having the screw and that area having copper pour connected would increase the heat-sinking. It may not be needed, but it wouldn’t hurt. It could help.
MichaelN:
That’s one reason I like SMD regulators in a “D-Pack” style (or similar) package - they have a thermal tab that can be soldered directly to a large copper plane to really help with heat dissipation.
Could’nt agree more! I use them whenever I can:
http://www.rpc-electronics.com/img/rtra … ite008.jpgHmm, that does not look to hard to solder maybe ill give it a try Thanks!
