FS: powered bus board PCB

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EATyourGUITAR
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FS: powered bus board PCB

Post by EATyourGUITAR » Tue Mar 10, 2020 1:13 pm

EDIT: the picture in the first post has been cancelled. the new design is in on page 2

I am building this for myself but wanted to see if I should make it available for all. it is a 18in by 4in powered bus board that has 317T/337T linear regulators on board. keyed 10 pin power connectors are used on the bus board to save space. it is specifically designed to solve a problem when people have a 6U skiff with long spring reverb crammed in to take up half the bus board area. there are places where the bus board has been trimmed back to allow for the RCA connectors of the spring reverb. yes you will need all new power cables. deal with it. I did. they are available online. I could sell the PCB for $20 each but only if I buy 100 units. I would need like 20 people to at least say they want it no deposit just a thumbs up.

this is 2mm thick PCB with 2oz copper M3 standoffs. selling as a bare PCB nothing included. mouser cart provided. 750mA per regulator, there are two of each 317 and 337. this gives 1.5A total +12v for a 96HPx2 6U case. 2.4A if you put a fan inside. you will need two laptop bricks 15.2v each and you will likely need to cut them up and build a box for the bricks or hide them in the case but that defeats the purpose of super compact ninja bus board.

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Last edited by EATyourGUITAR on Sun Apr 26, 2020 7:24 pm, edited 2 times in total.
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Re: interest check small powered bus board

Post by EATyourGUITAR » Tue Mar 10, 2020 2:52 pm

the first design was too complicated with no added benefit. so I made it 3in by 9in. much better. not just for 6U. not just for reverb cases. use it on everything where your input is bipolar DC with > 3v headroom for the regulators. maybe this will appeal to more people now.

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Re: interest check small powered bus board

Post by EATyourGUITAR » Wed Mar 11, 2020 3:10 pm

PCB only $10 each. shipping some time next month. post here to be counted or there may not be enough to go around. almost finished with the design now.
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Re: interest check small powered bus board

Post by Flounderguts » Wed Mar 11, 2020 5:54 pm

I'll take one.
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Re: interest check small powered bus board

Post by mush » Thu Mar 12, 2020 12:50 am

Why 10 pin idc? It limits the users from both 5v rail (legasy) and the CV/gate bus...
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Re: interest check small powered bus board

Post by KSS » Thu Mar 12, 2020 8:03 am

mush wrote:
Thu Mar 12, 2020 12:50 am
Why 10 pin idc? It limits the users from both 5v rail (legasy) and the CV/gate bus...
True. But it also allows the positive and negative rail traces to be as wide as the board allows. At least as wide as the 6 pins used for GND. With a 4oz copper layer you've then got as good a distribution as this less than ideal PCB based power distribution scheme allows. Not singling out EYG's work, the same is true for any IDC cabled--> PCB buss board solution.

When you add the 5V and Gate,CV pins you restrict the width of the traces to .100, which you then try to get width-lower resistsnce by using different layers and other tricks.

Sticking to 10 pins make these efforts less necessary.

Re-edit: Looking at the -new- layout shown, it doesn't does seem to be employing the benefits described. With that being the case there's no reason besides preferential choice to go with 10 pins. Have to wait and see what EYG has in reply to your question. /RE-edit
Last edited by KSS on Thu Mar 12, 2020 8:34 am, edited 1 time in total.

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Re: interest check small powered bus board

Post by EATyourGUITAR » Thu Mar 12, 2020 8:15 am

:hyper: very happy with the results! definitely one of the better powered bus boards available on the market. there is nothing on the market this small and this robust for such low cost and DIY friendly. this is the perfect solution for the 48HP $80 cases. this is the perfect solution for the 96HP $100 cases. the 8.5in by 3in footprint fits everything ever made.
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Re: interest check small powered bus board

Post by KSS » Thu Mar 12, 2020 8:42 am

Thanks for showing the new layout. Personally would trade the thermal concessions seen for the 6 GND pins for the more important electrical resistance imporvement available full fill-pour. I get it's DIY and you want it easy to solder, but those pins and that trace having lowest possible resistance is key to best results overall. Moreso with many digital modules and their lopsided power draw.

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Re: interest check small powered bus board

Post by EATyourGUITAR » Thu Mar 12, 2020 8:54 am

yeah I agree. I was wrestling with how bad this will suck on a shitty iron. it has no benefit to anyone if the build is unsuccessful %100 of the time or if you need to buy special tools. engineering is and always will be about compromise. I have ignored the suggestion for 4oz copper and decided to use 2oz copper. I only needed to make this thing better than existing products. I was not trying to make it into some super high end assembled and tested product. compared to your good suggestions my design is inferior. compared to what is currently available on the market, I believe it is an improvement on existing designs for all the small tweaks added up. low cost has always been my #1 goal becoming a manufacturer. I remember I was looking at modular for many many years before I could buy just the power supply. it is the confluence of poverty and passion. I want to make this available to everyone that might not have access to synths otherwise. I see powered 6U cases for $1000. I think I want to go from the bottom up instead of the top down.
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Re: interest check small powered bus board

Post by EATyourGUITAR » Sun Mar 15, 2020 10:34 am

I want to thank KSS for steering me in the right direction. the more I looked at it, the more I wanted to make it better. so I turned thermals off and I did some rough manual analysis based on copper cross sectional area and resistance per meter. this is easy to obtain since the European standard is MCM.

https://en.wikipedia.org/wiki/Circular_mil

anyway, here is the %100 finished product. this is a large picture with a small file size. feel free to inspect and provide suggestions or criticism.
http://www.eatyourguitar.com/powerpreview4.gif
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Re: interest check small powered bus board

Post by EATyourGUITAR » Tue Mar 17, 2020 1:11 am

made a dummy load with 4 watt resistors 2817 size SMD package from TE (part# 3540). suitable for short periods of time to get the calibration right. then you can remove it easy with handles on the side. 307mA per rail. 3.7 watt per rail @ 12v per rail. it will heat creep. not sure how many I should order or if I should include them with the bus board as a free gift.

the right angle female 10 pin IDC is from Wurth.
mouser #710-613010243121

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Re: interest check small powered bus board

Post by EATyourGUITAR » Thu Apr 02, 2020 9:15 pm

PCB's arrived. they look ok. this is with the 2oz copper option. I wanted to keep the price reasonable. it is better than standard 1oz copper used in modules. standard 1.6mm thickness but they are very stiff. maybe the stiffness is because of the extra copper. now I need to test it with the dummy load before I take any money. only 48 units will be available.
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Re: interest check small powered bus board

Post by tele_player » Thu Apr 02, 2020 10:03 pm

I want two.

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Re: interest check small powered bus board

Post by EATyourGUITAR » Thu Apr 16, 2020 9:06 pm

I didn't want to use the 16v caps I have here. what do you think of this panasonic. mouser part # 667-EEU-TA1E101
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Re: interest check small powered bus board

Post by whyfarer » Thu Apr 16, 2020 10:10 pm

If you still have unclaimed PCBs, I'm interested in one

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Re: interest check small powered bus board

Post by Studioalethea » Thu Apr 16, 2020 10:23 pm

Quick question EYG - did you forego using thick traces and actually just make big planes for each rail and ground? Was trying to follow your convo with KSS and failed.

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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 17, 2020 7:56 am

whyfarer wrote:
Thu Apr 16, 2020 10:10 pm
If you still have unclaimed PCBs, I'm interested in one
I have 46 PCB -2 for you. 44 left over.
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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 17, 2020 8:07 am

Studioalethea wrote:
Thu Apr 16, 2020 10:23 pm
Quick question EYG - did you forego using thick traces and actually just make big planes for each rail and ground? Was trying to follow your convo with KSS and failed.
2oz copper pour for +12/0v/-12v. small traces for the current sense feedback circuit since there is not a lot of current there. KSS was right. I was right. it takes a soldering iron on the max temperature setting. it takes skill to understand how long to keep the heat on the pad. I tried to make it better by following KSS suggestions. the negative side affect is the difficulty of this project. the good news is there is no mains in the case. the bad news is you probably do want to understand mains wiring if you are building the external AC to dual output DC power supply. I included enough screw down terminals to connect mains earth or case ground 0v bus bar if you have a 9U or 12U. on my small case I have dedicated mains earth connected to 0v on the bus boards. the laptop bricks are isolated no ground. everything connects at 0v inside the case. if I get a metal box for the external bricks, I will earth that also.
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Re: interest check small powered bus board

Post by Studioalethea » Fri Apr 17, 2020 11:36 am

EATyourGUITAR wrote:
Fri Apr 17, 2020 8:07 am
Studioalethea wrote:
Thu Apr 16, 2020 10:23 pm
Quick question EYG - did you forego using thick traces and actually just make big planes for each rail and ground? Was trying to follow your convo with KSS and failed.
2oz copper pour for +12/0v/-12v. small traces for the current sense feedback circuit since there is not a lot of current there. KSS was right. I was right. it takes a soldering iron on the max temperature setting. it takes skill to understand how long to keep the heat on the pad.
I guess I’m just learning what a “pour” is, but from context, rather than thin film traces typical in a PCB, the copper is thick and spread out. So then the soldering skill required is based on the heat dissipation of the copper pour acting like a heat sink and making it difficult to get the work up to temperature?

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Re: interest check small powered bus board

Post by KSS » Fri Apr 17, 2020 12:30 pm

Studioalethea wrote:
Fri Apr 17, 2020 11:36 am
I guess I’m just learning what a “pour” is, but from context, rather than thin film traces typical in a PCB, the copper is thick and spread out.
It's still the same thin copper. Called a pour because of the workflow when making the PCB design in software. Define the edges. 'Pour' the copper into the area so defined. One can also exclude items or areas within the pour outline. Pour outline can be the entire board. Think of MSPaint's paint bucket tool. That's a similar 'pour' operation.
So then the soldering skill required is based on the heat dissipation of the copper pour acting like a heat sink and making it difficult to get the work up to temperature?
Correct. Use of a bigger chisel tip on your iron helps, and decent flux/solder too. But it really shouldn't be much of a problem with 2oz. copper.

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Re: interest check small powered bus board

Post by Studioalethea » Fri Apr 17, 2020 1:34 pm

KSS wrote:
Fri Apr 17, 2020 12:30 pm
Studioalethea wrote:
Fri Apr 17, 2020 11:36 am
I guess I’m just learning what a “pour” is, but from context, rather than thin film traces typical in a PCB, the copper is thick and spread out.
It's still the same thin copper. Called a pour because of the workflow when making the PCB design in software. Define the edges. 'Pour' the copper into the area so defined. One can also exclude items or areas within the pour outline. Pour outline can be the entire board. Think of MSPaint's paint bucket tool. That's a similar 'pour' operation.
So then the soldering skill required is based on the heat dissipation of the copper pour acting like a heat sink and making it difficult to get the work up to temperature?
Correct. Use of a bigger chisel tip on your iron helps, and decent flux/solder too. But it really shouldn't be much of a problem with 2oz. copper.
So, when people are talking about a "Ground plane" that is usually meant to be this copper pour? Is that fairly common in PCB design to make a ground plane copper pour? Other than the above application, where else might this be useful?

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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 17, 2020 1:54 pm

DC resistance per meter of copper wire depends on the cross-sectional area of the copper. The same math applies to the area of any pcb trace if you look at it from the cut away. It could be 10mm by 0.01mm in area of copper. Not sure the thickness. That is a made up example. If you lower the resistance you lower the voltage drop. There are other benefits also.
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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 17, 2020 2:20 pm

if you want panasonic 25v 125c temperature rating it will definitely drive the price of the build up a lot. I have the mouser cart here between $12 to $20 depending on your preference.

you will need 8 x 100uF
2 x 10uF

panasonic
EEU-TA1E101
EEU-TA1H100B

mouser cart available
https://www.mouser.com/ProjectManager/P ... f7407717b7
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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 17, 2020 6:23 pm

cheaper capacitors part#
10uF
UST1H100MDD1TE
100uF
ECA-1EHG101B
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Re: interest check small powered bus board

Post by EATyourGUITAR » Fri Apr 24, 2020 10:39 pm

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