soundguy

Official Forssell Limiter Build thread
« on: November 02, 2004, 04:19:18 PM »
I figured since many of have boards now, instead of sorting through the development thread we could post our build issues here.  To start, I have two questions-

What is the best size to use for pin receptacles for the discrete opamp?

There shouldnt be any issues with using a single power transformer to feed two boards in a single box, right?

If anyone has time, can someone post a link to ALL the docs for this project here, would be helpful.

dave

chips are good with dip...


Kev

Official Forssell Limiter Build thread
« Reply #1 on: November 02, 2004, 04:25:27 PM »
I'm using the knurled sockets from Farnell for the JLM unit and I'm 99% sure they are fine for the pins on the Forssell unit.

RS have a silver socket but min order of 20
RS :- 434-712 $0.49

Farnell :- 149-319  knurled gold $0.66aust (I like this one)
Farnell :- 149-318  plain silver $0.50aust (min 20)
Farnell :- 150-501 plain gold $0.70aust


These are listed as 1.0 mm sockets


The JLM power supply or any other supply that suits Project 2 will also suit this project.
Kev
DIY Factory

tommytones

Official Forssell Limiter Build thread
« Reply #2 on: November 02, 2004, 04:43:20 PM »
Don't forget Dave that you must feed dc voltage to the boards.  There's no problem with using 1 main psu to feed the individual boards.  This is how I'm gonna handle mine.
As for the docs, I'll have to search through the main thread we had going cause I've sorta lost track of who's hosting what.  I'm also gonna add a few things like a block diagram to help make use of the various schems and pdf artwork for those who wish to home brew this board.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

tommytones

Official Forssell Limiter Build thread
« Reply #3 on: November 02, 2004, 04:44:57 PM »
Oh ya, the hole's for the discrete amps are 0.050" minus a couple thou for the through plating.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

[email protected]

Official Forssell Limiter Build thread
« Reply #4 on: November 02, 2004, 05:40:03 PM »
Dave,

Digikey sells these sockets. I use them with the JLM board.
http://www.groupdiy.com/FORUM/viewtopic.php?t=3170&sid=ef7447f064fc85f3c5409be5ee428734

Tamas

tommytones

Official Forssell Limiter Build thread
« Reply #5 on: November 02, 2004, 05:48:35 PM »
So I've done the pdf files and the block but need someone to host.  Ideally this should be the same person who's hosting the other stuff too.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

soundguy

Official Forssell Limiter Build thread
« Reply #6 on: November 02, 2004, 06:45:02 PM »
I can host it if you want, can someone put a pack together and I'll put it up?

dave

chips are good with dip...

rafafredd

Official Forssell Limiter Build thread
« Reply #7 on: November 02, 2004, 09:16:42 PM »
Quote from: "Kev"
RS have a silver socket but min order of 20
RS :- 434-712 $0.49

Farnell :- 149-319  knurled gold $0.66aust (I like this one)
Farnell :- 149-318  plain silver $0.50aust (min 20)
Farnell :- 150-501 plain gold $0.70aust



Do you have RS and Farnell part numbers for pins?

tommytones

Official Forssell Limiter Build thread
« Reply #8 on: November 02, 2004, 09:24:17 PM »
I'm working on the hosting thing with Kev.  I think this will be another addition to the Factory.  I'll post back as soon as I have a url for you guys.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

Kev

Official Forssell Limiter Build thread
« Reply #9 on: November 03, 2004, 01:14:48 AM »
Quote from: "rafafredd"
Do you have RS and Farnell part numbers for pins?


err  ...  :?  ... um ... we did this
I'm sure there is another thread here that did list that.

however the pins are short and if you want to load a PCB upside down so you can pot and poor ....
does that make sense ??
... you will need long pins.
I think Joe told us he used brass or copper rod cut to length.
I used some pins from DB to RJ45 adapters.
DB15 and 25 had enough pins to make it worthwhile.
Kev
DIY Factory


Svart

Official Forssell Limiter Build thread
« Reply #10 on: November 03, 2004, 08:48:42 AM »
did we ever get a total BOM together for this, or an itemized parts list?
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.

rafafredd

Official Forssell Limiter Build thread
« Reply #11 on: November 03, 2004, 09:05:24 AM »
Quote from: "Kev"
I think Joe told us he used brass or copper rod cut to length.
I used some pins from DB to RJ45 adapters.
DB15 and 25 had enough pins to make it worthwhile.


Two nice solutions. :grin:

ChuckD

Official Forssell Limiter Build thread
« Reply #12 on: November 03, 2004, 01:56:48 PM »
Added to the meta...

Yes there is a BOM in the META as well. I am working on a "Mouser" parts list right now.

-ChuckD

soundguy

Official Forssell Limiter Build thread
« Reply #13 on: November 03, 2004, 10:50:42 PM »
can anyone reccomend the appropriate regulators in the power supply for use with +/- 24 V opamps?

Do I need to increase the voltage ratings of the caps used in the circuit with a +/-24 supply?

what DC voltage does the PS want to see?

thanks

dave

chips are good with dip...

DrFrankencopter

Official Forssell Limiter Build thread
« Reply #14 on: November 04, 2004, 10:44:17 AM »
Hi Soundguy Dave,

You can use the LM317, 337 pair with no problems as a +/- regulator pair. Without the boards and spec sheets in front of me I'm not sure if the layout was designed for a 7824/7924 fixed reg, or the 317/337 adjustable type. I hope it was set up for the adjustables as they provide better performance (less ripple when the adjust pin is properly bypassed).

You'll want to feed the regulators with about 3-5V more than their output 24V, so +/- 27-29VDC or so. You'll get a little more than this from a full wave recitfied +/-22VAC power transformer.

Cheers,

Kris

tommytones

Official Forssell Limiter Build thread
« Reply #15 on: November 04, 2004, 11:03:38 AM »
It's in the parts list Dave...LM317 & LM337 or equivalents.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

soundguy

Official Forssell Limiter Build thread
« Reply #16 on: November 04, 2004, 03:28:52 PM »
thanks, I thought the 317 was a fixed reg, nevermind...

Do I need to double the voltage on the caps?  Seems like it was tested with +/-15 supply, dont caps want to be more than twice the voltage swing?  Should I be sourcing 50v caps with a +/- 24v supply?

dave

chips are good with dip...

TomWaterman

Official Forssell Limiter Build thread
« Reply #17 on: November 04, 2004, 03:34:31 PM »
Hi!

I may be wrong but I thought 35V would be fine for a +-24V design when used as PSU bypass caps, as each rail is treated to a bypass cap individually (?)

Cheers Tom

tommytones

Official Forssell Limiter Build thread
« Reply #18 on: November 04, 2004, 03:48:02 PM »
Either way will be fine but I wouldn't go less than 35V.  There's plenty of room for individual experimentation and customization.
ToM

He who asks is a fool for five minutes, but he who does not ask remains a fool forever.
Chinese Proverb

Svart

Official Forssell Limiter Build thread
« Reply #19 on: November 04, 2004, 04:47:15 PM »
reminder for everyone building this compressor.. check the leg orientation on your 5457 FETs..  I found that the brand that i bought has different leg assignments than what's on the board.  I did some research and it seems that there are at least 3 different brands, each with different leg assignments.  My gate leg was where the drain hole was...

cheers!
Welcome to the GroupDIY leper colony! when something falls off, we just replace it with a tube!
occupation: General Electron Mayhem

Alesis X2 information repository:
http://www.theopiumdenproductions.


 

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