PCB short in eagle? - Page 1
Forum section: electronics / beginners

author: GoatZero
author_rank: Regular Contributor
timestamp: January 08, 2014, 06:17:37 am
content: Please bear with me for a second im learning to use eagle, while i modify this 2 side PCB design, i look at the diagram and i feel ok, but when i look at the board i cant understand why is eagle trying so hard to force me to join pins 3 and 5Could anyone explain to me whats going on here?i added the schemmatic in case anyone wants to take a look at it

author: Unknown
author_rank: Unknown
timestamp: January 08, 2014, 06:27:00 am
content: Have you got the 2 nets called the same thing and/or were they once connected together?

author: homebrew
author_rank: Frequent Contributor
timestamp: January 08, 2014, 07:00:17 am
content: Yeah, most probably a problem with the net list. Just erase those segments in the schematic and redraw them.Three other little things with your board:First, you accidentally connected pin 5 and 9. It is always a good idea to run DRC. You would have gotten a clearance error there.Second, if you use a fuse, use it to protect the whole circuit. I would also give more clearance between pos and neg supply around the fuse.Third, your regulator NEEDS some 100nF capacitors to produce a stable output. And, even if not mentioned in the data sheet, give the LM3914 a 100nF capacitor close to its supply pins.What battery should it be able to monitor? 24V?

author: GoatZero
author_rank: Regular Contributor
timestamp: January 08, 2014, 07:43:59 am
content: Thanks for all the feedback, since im learning i somehow found a way to forget about the right configuration of a voltage regulatorI will redo the design with all that feedback and check the net listsYea this circuit will be used to monitor 2, 12v batteries in series since the LM3914 Its rated for 18V maximum. i added a 7815 to adapt the circuit.An easy way to picture it is to place the 7815 on the same place of the fuse, while disconnecting the wire coming from R1.there shouldn't be any issues as long as i feed 15V (where you can see +12v in circuit should be +15v) to the LM3914 since it cannot handle anything above 18V.but yeah im trying to learn to use eagle while doing this, it works with a single 12v Battery, in the breadboard so i redesigned it and these new resistors were calculated for a full battery at 27V (twice the voltage 13.5V) and empty at 20V (also twice the voltage 10V). either way they are pots so i can adjust themBut now i have to find the net lists thing in order to fix this, or as you said delet the tracks and re do them and see how it goes, i find using eagle this quite entretaining, however i think this proyect might fail because im new to it

author: GoatZero
author_rank: Regular Contributor
timestamp: January 08, 2014, 07:50:39 am
content: Quote from: Lurch on January 08, 2014, 06:27:00 amthey were connected together once i guess, i had the 10k resistor to the top left 12v rail but then i modified the circuit a bit, i also renamed the +12v that you see in the schematic to 15v however even if i could see 15 volts number in the 3 rails, if i went to properties the field Device was still "12v" im a bit confused now

author: GoatZero
author_rank: Regular Contributor
timestamp: January 08, 2014, 08:09:02 am
content: ok since this is more like a learnign session i just rewired the circuit and i got asked if i wanted to merge +15v net with +12v i just clicked yes but i really dont know what going on heres a picture with some corrections thanks to this thread, i have yet to rearrange the board, if anyone notices something terrible worng please let me now

author: Skimask
author_rank: Super Contributor
timestamp: January 08, 2014, 08:13:31 am
content: Right click on ....whatever...., and the net name will show up in the lower left corner of the window. Check the drop down menu when you right click ....whatever..., and you'll see an option for naming (or renaming) that particular connection/wire/junction/net/etc.