Jump to content

i'm on a roll... the kgsshv


kevin gilmore
 Share

Recommended Posts

I do have a question for the group, would you want a cheap PSU that is good and does the job well or balls to the wall T2 type PSU? The difference in cost will be substantial so it is something Kevin and I are discussing.

RN60 will derate to values suitable for this

The CMF70 would work but isn't that way too big?

Edit: which resistors are you worried about getting even close to this limit?

The output resistors (the reason why they aren't normal metal films in the T2, ditto for the Stax amps) but stuff like the feedback line is split up.

If lurkers are eligible, I'd love a boardset and whatever stuff gets offered as a package with it.

If 2SA1968 are sourced and available for anything close to $.70 ea, I will commit to buying couple hundred extra to bump up the volume discount.

Back under my rock now ....

The boards will be open to everyone and nothing has been decided wrt a group buy of parts. Given the huge logistical nightmare of getting things to me it might not even happen.

Link to comment
Share on other sites

Birgir,

I think that a nice well built power supply is a must in such a design and would personally go for the best possible design, however if such a power supply means off board custom heat sinks and what not it might be a turn off for many people, myself included.

I think the price no object one is the way to go, but using easily sourced parts and on board heatsinks.

Link to comment
Share on other sites

There is also an alternative power supply board, cheaper than the T2 style, its pretty

much identical to the BH power supply board, at 450 or 500 volts.

No reference, opamp or 2sc3675 needed, and 2 less heatsinks.

http://gilmore.chem.northwestern.edu/kgsshvps2.jpg

option for 2nd pass fet and heatsink for better heat spreading.

amp schematic updated.

I've tried having someone else order the boards. But if i pay for them even

if they ship out of state, they still charge me tax. For boards i buy for nwu

with the tax exempt number, i still have to go over it with them every single

time. A real pain. But they are the best boards i have ever seen.

Edited by kevin gilmore
Link to comment
Share on other sites

I'm for the compromise route as (unfortunately) my budget doesn't allow for a price no object option. My opinion is that if a 20% increase in build costs brings about a 5% gain in SQ then I'd rather go for the cheaper option but I'm in whatever the decision.:cool:

Birgir,

I think that a nice well built power supply is a must in such a design and would personally go for the best possible design, however if such a power supply means off board custom heat sinks and what not it might be a turn off for many people, myself included.

I think the price no object one is the way to go, but using easily sourced parts and on board heatsinks.

Link to comment
Share on other sites

I'm for the compromise route as (unfortunately) my budget doesn't allow for a price no object option. My opinion is that if a 20% increase in build costs brings about a 5% gain in SQ then I'd rather go for the cheaper option but I'm in whatever the decision.:cool:

It doesn't make much sense to go for such a project with a short budget. And how can you measure 5% increase in SQ? lol

Link to comment
Share on other sites

Original design can run on +/-600 volts and absolutely requires T2 style heatsinking.

Which puts the chassis at about triple the cost of the rest of the parts combined. Maybe more.

I don't think that is what people want. This is supposed to be an everyman kind of thing.

If you want nuts, go and build a T2. Or you have to be someone like luvdunhill or n_maher with

the equipment at home to do the chassis. Or even kerry which manages to do that kind of stuff

on a balcony overlooking central park. Even i don't do chassis like that at home and i have

all the right machine tools. Getting the heatsink interface right pretty much requires a NC machine.

Or a whole bunch of patience.

I'm working on yet a third power supply design. Shunt regulator. Sure, why not. Except my

version does not blow up without a load, it uses the ixys parts as the current source, and i measure

the current thru the shunt, and if its too much, i shut down the amount the current source supplies.

Sort of the best of both worlds.

Edited by kevin gilmore
Link to comment
Share on other sites

Original design can run on +/-600 volts and absolutely requires T2 style heatsinking.

Which puts the chassis at about triple the cost of the rest of the parts combined. Maybe more.

I don't think that is what people want. This is supposed to be an everyman kind of thing.

If you want nuts, go and build a T2. Or you have to be someone like luvdunhill or n_maher with

the equipment at home to do the chassis. Or even kerry which manages to do that kind of stuff

on a balcony overlooking central park. Even i don't do chassis like that at home and i have

all the right machine tools. Getting the heatsink interface right pretty much requires a NC machine.

Or a whole bunch of patience.

I'm working on yet a third power supply design. Shunt regulator. Sure, why not. Except my

version does not blow up without a load, it uses the ixys parts as the current source, and i measure

the current thru the shunt, and if its too much, i shut down the amount the current source supplies.

Sort of the best of both worlds.

Totally understandable. I'm in for the regular board set everyone else will be getting.

Link to comment
Share on other sites

Ok, time to stop lurking and start lining up a project for when I finish my PhD - I'm also interested in a board set. Kevin, looking at the artwork for the power supply options with and without the reference, opamp and 2sc3675, it seems that the two designs could be combined into one PCB without too much difficulty or increase in board space. The final decision is then up to the user.

Link to comment
Share on other sites

So that one would be some sort of compromise between the cheap well built one and the T2 one?

ps: welcome back Kevin!

I think this would be a good spot to aim for. If someone wants to go no holds barred, that would be the T2, IMO. I was expecting the kgsshv to require off-board heatsinks, but having all on-board heatsinks makes the casing a much easier job. I like that.

Link to comment
Share on other sites

if deemed trustworthy enough, i wouldnt mind volunteering the time to split up a big box of parts into individual kits (assuming none of that parts matching stuff is required). my schedule prohibits any of sort extracurricular activity on days besides friday, saturday and sunday but i figured its better than nothing. so if a big shipment of parts were to land on my desk, i could split it up to kits but obviously it might take me a lot longer than someone who had more time to devote to it. i dont have anything to add to the project intellectually, perhaps time could count for something.

i dont know if this is far too tedious a task or far too difficult but who doesn't like a good dragon to slay every now and then. :P

Link to comment
Share on other sites

Crappyjones123:-

quote_icon.png Originally Posted by Sherwood viewpost-right.png

CJ, I nominate you for team "source absolutely dead fucking last".

quote_icon.png Originally Posted by HighLife viewpost-right.png

AND STOP BEING LIKE A ASIAN GOLD FARMER IN WORLD OF WARCRAFT....they dont play, all they do is buy-sell-buy-sell-buy-sell....

Never mind the detractors, there are two principles in life to keep in mind...............

1/ Nothing (nobody) is ever a complete failure - they can always serve as a bad example.

2/ It may well be that your sole purpose in life is to serve as a warning to others.

Link to comment
Share on other sites

Kevin does the layout for the lsk170s allow the use of those nice little to-92 heatsinks that were group ordered sometime ago? I don't have any, but I'm sure some one has some laying around or that another group order would easily be organized!

I don't think that the stax should be part of the kit, since some might want two, some might want just one and that would require a lot more trouble for the distributor of the boards. The heatsinks would be nice though.

Edited by MASantos
add info
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...