Help understanding a schematic and transistor question

[11-90-an]

Or maybe box that psu up in another container and give your compressor its own box...

[jfrabat]

Rob, you think something like this may work?  I could even put a fiberglass divider between the power supply and the main board (and I could use some copper tape to shield it somewhat).  That power supply would leave me a 86 X 100mm board, which makes it much more possible to fit all components in...

For that one you might need to add a dummy load as the minimum current is 0.1A.    It still has the same problem as the other switchmode.   That one is 25W so it might be less angry than the 65W.   With any switchmode near an audio circuits there's a risk of noise problems.    Even mains wiring too close to audio circuits can cause noise problems.   Copper shielding would help but it doesn't shield magnetic fields very much at all.  Separation distance helps but if you have to move it 300mm away then that's not practical.

Or maybe box that psu up in another container and give your compressor its own box...

I ran into an even bigger issue; it seems the Eagle I have (ver 7.7) will not let me design a board bigger than 100 X 80 mm.  And in a project like this one, that is simply not enough...  I mean, I can get all the components in that space, but the board is so dense, traces are impossible to run.  At this time, I am honestly just considering using the power source I bought, but placing it in a different enclosure and just running a cable from one to the other, but even then, the board is a mess!  Anyone know how to hack Eagle to allow for a bigger board?

[11-90-an]

Looks like you have to upgrade your license...

KiCad apparently has unlimited space...

Hows your SMD skills...?

[jfrabat]

I am tempted to pay the $40 for 1 month and be able to do a 100 x 160mm board...

[jfrabat]

I am tempted to pay the $40 for 1 month and be able to do a 100 x 160mm board...

Bit the bullet; paid the $60.  Waiting for it to process so that I can make the board twice as big.  That should make fitting everything in the board simpler! 

By the way, I had a small 1444-6415 Hammond enclosure (originally intended for the EQ prior to using the 1590 type enclosure) that may just fit the power supply in.  I intend to use 4 pin DIN connectors to plug to the power supply cable to the compressor (cable will not be removable from the power supply side, only the compressor side).  I will need to rework the art of the rear panel a bit to fit the plug in, but no biggie; I have the physical space (just the graphics need adjusting).

Now it may be a tight fit, and I may need to work the lips of the enclosure a bit; the power supply is (W X H X D) 98 X 38 x 129, and while the enclosure is 152 X 102 X 38, the internal heigth (measured) seems to be only 36.  Also, the lip takes up some space, the hole being 133 X 81.  But since the top screws only on the length wise lips, I figured I can bend one (or both) side lips to get the width I need.  As for the height, I can always use a gasket or something.  I even have some gasket making material at home that should get me the extra 2mm...  And it is heat proof and withstands high temperatures.  I will need to drill some holes in the enclosure for it to cool down, but nothing extraordinary about that!

[jfrabat]

Finished the board.  Made it rather big to have space to lay all components with as much tracing space as possible.  Here is what it should look like (not yet ordered):

Front:


Rear


Here are the traces:
Front:


Rear:


Any advice you may have regarding my board layout?  Also, what would be the best place to have it printed?  I typically use OSHPark, but a board this size (152 X 100 mm) is $125, so I wonder if there is not cheaper alternatives out there...  If difference is not huge, I will go with them, as I know they do a good job.

[11-90-an]

I think you could use one of those china based ones... they generally are a lot cheaper...

https://www.diystompboxes.com/smfforum/index.php?topic=125183.0

[jfrabat]

Went ahead and ordered the boards.  I used OSHPark, as I have read that the Chinese boards sometimes lack definition in small text, and I have A LOT of small text on this board!  So certainly not a cheap compressor, but certainly a fun challenge!  This will be the most complicated electronic project I have tackled so far.  I really hope it works well!

[11-90-an]

Woah, that's very expensive...   (For 3 pcbs... )

Oh well.. Good luck..

[jfrabat]

Woah, that's very expensive...   (For 3 pcbs... )

Oh well.. Good luck..

Well, sort of.  A comparable board in PCBWay was similar (when you add lead free and same type of board).  So since we are talking over $60 plus shipping, I rather go with a known quantity.  Remember I still need to ship is overseas (even more shipping and taxes), so I rather pay a bit more and make sure it works the first time.

[11-90-an]

Ahh ok, makes sense... (I was assuming that our shipping fees were the same, but you live in the western side and i live in the east... sorry... )

[jfrabat]

I ship to Miami and then a freight forwarder brings it to my door.  Mail service in Panama is HORRIBLE, so it is better to do like this.  Ads about $20 to the boards, but I get them less than a week after they reach Miami (not to mention, they deal with all the taxes, which FedEx and DHL and UPS do not do).

[StephenGiles]

Only just read all this - very interesting. Seems strange that I ran my vero build back in 1986 or so from 2 large 9v batteries!!

[jfrabat]

Only just read all this - very interesting. Seems strange that I ran my vero build back in 1986 or so from 2 large 9v batteries!!

So you built it back in the day?  How did you like it?

By the way, I started a build thread if you want to follow.