Page 1 of 2
Daughter boards
Posted: Mon Dec 04, 2017 12:09 pm
by DRodriguez
I'm building a few different pedals that are all running on bipolar power. So I was figuring that I just build 9v dc to +-12v daughter board. Never done daughter boards besides true bypass switch ones here or there.
What are your favorite methods for multiple boards? Stack them, ribbon cables, jumbled wads of cables, something else I'm ignoring?
Re: Daughter boards
Posted: Mon Dec 04, 2017 12:14 pm
by BetterOffShred
Typically they only have 2 "in" wires 9v and ground, and then 2 or 3 "outs" like 9v+,9v - and ground. I like to keep them as close to the dc plug as possible and I find it helpful to plan the pot and Jack locations around them since typically they have big electrolytic caps on them. That being said down by the stomp switch usually has extra space so sometimes they naturally migrate down there. Stacking isn't usually an option in my builds since I most use 1590 b and BB size boxes. The 7660 charge pump fits nicely on it's side though.
Re: Daughter boards
Posted: Mon Dec 04, 2017 12:19 pm
by DRodriguez
Oh yeah, my application is just a simple 2 wires. But I was just thinking in general. What y'all lean to or any tricks you like to do.
Re: Daughter boards
Posted: Mon Dec 04, 2017 12:41 pm
by BetterOffShred
I put them on their side right behind the dc plug everywhere I can
In my Skyripper I tucked it under the rotary switch, in the Lion the main board sits at an angle, so I have the daughter board at the low area with a piece of florescent pink card stock (dollar store) between the 2 boards.
I also like to use the pink foam that Tayda ships their chips in as insulators or risers when I have to layer or stack
Re: Daughter boards
Posted: Mon Dec 04, 2017 1:55 pm
by crochambeau
For DC stuff I prefer to mount the board on the DC inlet jack.
This is just a 555 in boost configuration switching at around 60 kHz, for bipolar I'd want to go proper DC fed SMPS. As you can imagine, this approach requires a roomy enclosure. I drill out a matrix of 0.5" holes on Lexan and turn them into squares on the bandsaw to serve as an isolating stand-off to scare away short circuits.
Other daughter board application is seen at the stripboard, which is mounted via a 40 pin connector. This will allow additional power supply "processing" depending on how you draft the mother board - but from a simplicity/3rd party troubleshooting stand point, having PSU mounted at the jack makes supply rail assessment a breeze. Modular exists for a reason.
A third method could be a PSU board with separate mounting, but that can get tricky as you need to adhere to whatever mounting system is utilized in the rest of build.
Re: Daughter boards
Posted: Mon Dec 04, 2017 2:03 pm
by BetterOffShred
Nice stuff Crochambeau! I want to get into eagle and start making PCBs..
I'd also like to start using ribbon wiring as well.
Re: Daughter boards
Posted: Mon Dec 04, 2017 3:49 pm
by cherler
The power jack mounted board is awesome, I love that idea!
Re: Daughter boards
Posted: Mon Dec 04, 2017 7:49 pm
by drolo
crochambeau wrote:For DC stuff I prefer to mount the board on the DC inlet jack.
this is so brilliant :-)
Re: Daughter boards
Posted: Mon Dec 04, 2017 9:07 pm
by eatyourguitar
there are a LOT of options. this thread could actually get really long if we talk about all of them. what is your price range and what country would you be buying a kit or PCB? what are your requirements for mA per rail? are you trying to do it DIY on prototype board or do you prefer a nice PCB?
Re: Daughter boards
Posted: Tue Dec 05, 2017 12:29 am
by multi_s
eatyourguitar wrote:there are a LOT of options. this thread could actually get really long if we talk about all of them. what is your price range and what country would you be buying a kit or PCB? what are your requirements for mA per rail? are you trying to do it DIY on prototype board or do you prefer a nice PCB?
the far off region of brooklyn is in the north americas if im not mistaken
i wanted to post "GOD DAMN" after crowmybows pics, that is pretty sleek on the DC jack mounted board. what if it was all smd? would you need a spacer? hmm. has me thinking.
Re: Daughter boards
Posted: Tue Dec 05, 2017 12:41 am
by BetterOffShred
Dat crowmybow..

Re: Daughter boards
Posted: Tue Dec 05, 2017 1:27 am
by eatyourguitar
multi_s wrote:that is pretty sleek on the DC jack mounted board. what if it was all smd?
I was thinking this but I didn't want to show my hand yet.

Re: Daughter boards
Posted: Tue Dec 05, 2017 9:46 am
by crochambeau
I use spacers in my builds because the steel walls of my enclosures are a lot thinner than cast aluminium and I prefer to avoid sticking a ton of thread outside the enclosure.
eatyourguitar wrote:multi_s wrote:that is pretty sleek on the DC jack mounted board. what if it was all smd?
I was thinking this but I didn't want to show my hand yet.

I'll show my hand then. I have every intention of steering (some of) my designs toward modular and or studio use, so eventually I'll get around to producing a 9 volt in bipolar out on my own - unless of course someone has beat me to it.
My criteria will be:
Switching speed of at least 100 kHz, positive and negative rail need to be able to deliver minimum of 24 volts at 100 ma, should have on board trimmers to set output voltage in case +/-24 is too lofty. Mounting as pictured above...
At this point I'm not interested in contracting anyone to design this (my needs are a ways off and I too enjoy PCB design), but should my needs align with those of others perhaps there's a buck in there for somebody, and I'm not above buying something at spec and investing that time saved into something else.
Re: Daughter boards
Posted: Tue Dec 05, 2017 10:44 am
by BetterOffShred
crochambeau wrote:I use spacers in my builds because the steel walls of my enclosures are a lot thinner than cast aluminium and I prefer to avoid sticking a ton of thread outside the enclosure.
eatyourguitar wrote:multi_s wrote:that is pretty sleek on the DC jack mounted board. what if it was all smd?
I was thinking this but I didn't want to show my hand yet.

I'll show my hand then. I have every intention of steering (some of) my designs toward modular and or studio use, so eventually I'll get around to producing a 9 volt in bipolar out on my own - unless of course someone has beat me to it.
My criteria will be:
Switching speed of at least 100 kHz, positive and negative rail need to be able to deliver minimum of 24 volts at 100 ma, should have on board trimmers to set output voltage in case +/-24 is too lofty. Mounting as pictured above...
At this point I'm not interested in contracting anyone to design this (my needs are a ways off and I too enjoy PCB design), but should my needs align with those of others perhaps there's a buck in there for somebody, and I'm not above buying something at spec and investing that time saved into something else.
I was reading up on 7660s and 1044s yesterday, and apparently you can parallel them and also run them with an external oscillator up to 400khz.
I want to get into some +/- 15V myself
Re: Daughter boards
Posted: Tue Dec 05, 2017 2:02 pm
by eatyourguitar
while agree that those are basically the best solution after all these years, I have noticed a lot of new power products on the market that run faster clocks and less ripple. these are usually spec to supply more current than a typical state variable filter guitar pedal. you can get anything from 100mA per rail to 800mA per rail in something that looks like a belton brick. they are usually too big too expensive and too much mA to be appropriate for a guitar pedal builder. there was also the issue of the ripple and clock wine being pretty much the same level of performance. so while it was not the thing then, it might be the thing now. in SMD at a reasonable cost and 50mA per rail I would expect a 7660 or a 1044.
if you want to hand me a circuit then I will hand you a gerber and .BRD for your private use. I sell PCB's on my site so all I would ask is that you not sell blank PCB. obviously you can sell assembled. do we have a deal?