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Quick schem/board verification if you please?

Started by Sibob, February 04, 2014, 12:51:19 AM

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Sibob

*Sorry if this is in the wrong forum, please move as you think is best**

Hi guys,

Sorry, could I trouble you to take a quick look over the 3PDT daughter board I've put together for my builds?
It's real late here, and whilst I'll take another look tomorrow, might as well let some USA pedal dudes take a look while I'm sleeping ;)

Cheers





All input is helpful
Thanks very much

Si

jubal81

Looks good to me. The top pads are just about under the switch. You could scoot them out a bit - maybe space them so a header could be used ...
"If you put all the knobs on your amplifier on 10 you can get a much higher reaction-to-effort ratio with an electric guitar than you can with an acoustic."
- David Fair

catfud

I'd probably try to move the led a little further away from the footswitch.

Sibob

Quote from: jubal81 on February 04, 2014, 01:36:02 AM
Looks good to me. The top pads are just about under the switch. You could scoot them out a bit - maybe space them so a header could be used ...

Didn't think of using headers! What would be the benefit of them? I use solid-core cable, so perhaps even a row of sockets?
Any idea as to pad spacing?

I'll be moving the pads out from the switch and the LED a little further right today at lunch.

Thanks guys :)
Si

rullywowr

Looks good, keep it up!.  Using standard .100" (2.54mm) spacing would open up a lot of possibilities for using .100" headers or even .100" spaced ribbon wire.  I like the ribbon wire in this spacing like 3M 8124.  I agree with many of the previous comments, such as moving the LED away from the switch. 

Also, I see you have put a capacitor on there.  What purpose are you using it for (power filtering?  LED noise?).  Can't hurt, but I wonder how important it is to have?  If you must have this, I think you will want to mount it on the bottom of the board as it will likely not fit on the top with the cover on your enclosure.  You will want to change the silk and part position to have the cap on the bottom. :)

Additionally, its a personal preference however it is my personal opinion (along with others) to not use a power plane on one side and ground on the other plane.  Yes it is more convenient using both planes for PWR/GND, but it does have the potential to form a mild capacitor which may affect your connected circuit.  Running planes like this are more likely for a direct short as the power and GND are now just a component lead away from each other.  My suggestion would be to run two GND planes or just one GND plane.

For extra reliability, you may also want to increase the "isolation" of the ground pour to the traces.  The PCB looks OK as it is but it never hurts to have a little more wiggle room in case the fab screws up, something doesn't etch completely away, or you get an errant solder blob shorting them out.

Lastly, as a pure aesthetic thing, you may want to round the corners of the board with the miter tool...makes them easier to handle without sharp edges.  You won't want to do this if you plan on panelizing them or setting them up on a panel for v-scoring (for easy snapping subboards apart).

Keep up the good work!



  DIY Guitar Pedal PCB projects!

Clayford

Looks like he's using Jack Orman's LED Pop reducer schematic. I don't know why a 22k resistor is being used That's a 2k2 resistor I missed the decimal.
looks like your lugs will be going |  |  | not — — — right? Overall a nice idea, but yeah try and get your solder pads on a 2.54mm (0.1") pitch for ease of use and possible header usage. Take a look at aballen's 3PDT board for an idea of what is meant. Love the extra grounds and +9v's idea. With all the extra space in the bottom right corner, maybe you can get those resistors laying flat rather than standing? Not putting anything down by any stretch, I couldn't do any better.
head solder jockey, part time cook: cranky&jaded

Sibob

Hi guys,

Thanks so much for the input.
You're correct in that the extra resistor and cap on the board is the AMZ pop circuit, I genuinely find it helps my builds, i'm pretty bored cutting the vero each time I build something and that can look messy (see m 'Builds' thread).
I'm interested in what you're saying about not using a 9v plane and a gnd plane.  When I first started looking into Eagle, I (very naively) understood that you needed to assign a use to the plane in order to lay tracks on both sides......now I think about it, that's probably not the case?! You can simply have a layer that isn't performing a function other than having tracks on it?!

Also, yes, fully understand that the cap will need to be mounted on the underside due to cleareance, although you mention changing posistion? Could you explain what you mean? I'm not fussed about where the silk lies although easy enough to move it to the back.

Here's the latest incarnation, still some changes to make, but only got five minutes earlier.



Thanks guys
Si

gjcamann

Have you seen the 1776 effects 3PDP board? I really like how this guy put the IN and OUT jacks on the right/left side of the board to keep the wiring cleaner - I wish I did this on my 3PDP board. If he had the filter caps on-board it would be perfect. 
http://1776effects.com/store/

On your board I would suggest grouping PI,PO,G,9V (no particular order here) so you would have  a nice clean run of 4 parallel wires to you circuit board. 

And finally, double check the orientation of the switch to make sure it isn't rotated 90 degrees and that it is switching in the direction you think it is - this almost bit me.

Also, for my own curiosity, what diameter holes did you use? What switch is this for?

Good Luck!

Sibob

The diamter of the holes are:

Diameter: 0.12598425
Drill: 0.1023622

It's just the standard 3PDT part from the MB library.

Here's the latest incarnation:



I haven't tried routing it without the +9v plane yet
I messed about with the 2.54m spacing for headers etc, but I didn't like the look of it and it was starting to look a tiny bit messy.  Will experiment further.

Any further comments more than welcome, learning plenty here :)

Thanks guys
Si

gjcamann

Looking better. I usually have my input jack on the right side of the pedal, and my output on the left. But maybe I'm just not reading the orientation of the board correctly.

Clayford

Yeah - It would be great to know which side of the board we're looking at. Input on the left side Output on the right would save you from crossing wires.
head solder jockey, part time cook: cranky&jaded

Sibob

So currently this is as if you had opened the enclosure and were looking down into the pedal.
As such, the ins & outs are on the correct sides?!

Thanks
Si

Clayford

If you have the input (JI?) on the left and the output on the right(JO) you are correct. I will second the idea of getting the Effect in/out and power/ground setup so it's one run up, without a bunch of crossed wires.
Effect In - Ground - Effect Out - +9V Most boards have worked with all have the schema for In/Ground/Out and it's hit or miss as to +9 being to the left, right, or above.
head solder jockey, part time cook: cranky&jaded

Sibob

Hi guys,

Cheers for all the advice so far.
I did think I had the Jack Ins the right way round, but am still in that "oh have I done something done" stage when someone questions me on it haha.
I completely agree about having a clean run to the board, so will get a GND in between PCB In/Out.

Certainly not that I didn't believe you guys about having a 9v plane as well as a gnd, but being a cusrious soul, I asked a few more opinions and it seems to be fairly unanimous, so will redesign with no 9v plane.  Any tips on this? Or simply about being clever with your track laying between components that require power?

Cheers
Si


Sibob

Latest:



No 9v plane, moved the 9v pads to make routing easier.
Re-arranged PI/G/PO

Feeling like it's getting there?!

Cheers all
Si