Dangerous Prototypes

In development => Project logs => Topic started by: hak8or on August 17, 2011, 02:16:34 am

Title: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on August 17, 2011, 02:16:34 am
Post on my website: http://archive.hak8or.com/ (http://archive.hak8or.com/)

I saw a post about using magnetic fields on the human brain to get certain reactions, and the first thing that popped to my head was trying it out myself.
http://http://hackaday.com/2011/08/15/controlling-muscles-with-high-intensity-magnetic-pulses/

So, I started to get my old capacitor bank up and running again, which is basically 3 X 7 200V capacitors. I forgot the capacitance on each, but I think it was 2200 uF. Then I realized that I needed a high voltage source. I was about to go make a voltage multiplier for getting Mains to a high enough voltage for the bank, but I finally came to the conclusion that I should make a proper voltage source. So I took one my old finds, a video scale thing. It has a large amount of FPGA's but after a while of thinking I found that I would have no use for such a FPGA based unit, so I took out the boards and started working on the power supply. I did off course save the boards in case they would ever come in handy for something else. :P

Here is how the unit looks.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250084.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250084.JPG
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250086.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250086.JPG

Here is what the inside of it looks like. There was another board ontop that also had more FPGA's, but I took it out a long time ago to try to get access to the JTAG pins. It is rather heavy, and I will tell you why later. I will say now though, it was a major surprise!
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250087.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250087.JPG

Here it is without the PCB inside. It has a power supply which gives me -10v, -5v, gnd, +5v, and +10v. I am going to keep that board inside the unit for powering the digital circuitry, since I suppose it should give a nice clean +5v with ample current, for running all those FPGA's. I need to check it on my scope with a dummy load sooner or later. Sorry for the dark picture. For all my pictures I have been using a point and shoot (DMC-TZ3) and trying to not use flash at all. So far, none of my pictures have used flash! That gives me the macro shots of the boards without the horrendous flash blaze. A tripod is essential. :P
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250091.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250091.JPG

While working on the front of the unit, I wanted to see about drilling holes and a slot for another display, a few buttons, and a few more leds. The chassis itself is spot welded together. The front panel itself was rather heavy after I took it off the rest of the unit, and here is why.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250092.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250092.JPG

Wait for it ....
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250093.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250093.JPG

Holy .. !! It is a solid metal slab, an entire 3/4 of an inch of metal! I am guessing they used laser cutters for it, or something like that, because there is no way on earth I will be able to drill through that with a drill. I am now working on what MCU to use, how to set up a front panel with it (Planning on using a VGA monitor), where to get the connectors for different voltages, and what I want from this unit. Things like that. All my attention will be currently dedicated to this for now. Once I get a satisfying result from this, I will continue working with the little robot thing a ma bob, and then on a desk light using a LCD with CCFL tubes I found a long time ago.

Any comments are welcome! Thanks for reading :)
Title: Re: Power supply using a 1U rack chassis
Post by: hak8or on August 18, 2011, 06:10:11 am
I added in quite a bit of stuff, mainly the high voltage section of it. The reason it took so long for so little progress was because I have to work with what I have. I don't have much hardware tools, so it is very difficult and slow. :P

First, as always, pictures!
I started to think about the layout of components in the chassis, what I will want where, things like that. I decided that I will want a high voltage source from this (MOT, only 2 kV or so), which is also capable of reasonable current. Using a MOT with another MOT with a shorted secondary gives me enough impedance (?) to prevent the breakers from blowing. Problem is that it increases weight by a LOT. Each MOT weighs 20 or so pounds as a quick guess. I won't be moving this that often, so it is not a that much of a problem.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250100.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250100.JPG
As you can see in the above picture, there are a few noticeable components. The white cylinder at the top is a 15V cap, I forgot the capacitance but I think it was 68,000 uF. I will use that as a power source while the unit is shut down for the internal logic, such as a pic24F and the propeller. It should last a very long time with the PIC in the lowest power state and the propeller shut down, but I have yet to do the math and find out what the current usage will be in certain scenarios.

The PCB with components on the right is the psu that came with the original unit. It is a switching power supply, so I am hoping that it is efficient, more efficient than a mediocre transformer, as well as supplying a clean 5 volts. I will use that to drive the logic.

On the left, there is a MOT (Microwave Oven Transformer). These guys supply supply about 2,100 volts with a short circuit current of 16.5 amps usually. That is an excellent very high power high voltage power supply, but extremely dangerous. Only use these if you understand high voltage and all of the dangers/safety associated with it. If it does short with you in the circuit, you are most definitely dead. I will use this as a source of high voltage at high current for all my capacitor bank experiments. Charging them for a future TMS project I intend to do is one of the applications.

Under that is a small transformer that accepts 120v or 240v and sends out 20 and 12 volts, if I am not mistaken. I am going to use this transformer to power a few LM317's or other adjustable voltage regulators I find. This way the power sources that I get from this unit will not use up current from the switching power supply, so I can use a lot more current.

In the middle I have a perf board from radioshack. They are horrible, if you try to re solder a hole even twice, the copper layer just falls off, but they are all I have right now, so I will make due with what I have. I will use this board to hold the PIC24 and the propeller, as well as a few Fet's, transistors, and support circuitry.

The random gray ribbon cable is for a VGA connector in the back, that will be attached to the propeller. The VG will be used for a monitor to display voltages and current usage of each voltage output, things like that. Phew, that was a lot of text for only one picture! :P

This is what I will use for high voltage cable in the unit. I am fearful that the tape will not provide enough insulation from the high voltage, so in later pictures cover the wire with plastic tubing. At the end there is heatshrink tubing, which I later will shrink around the connector to the high voltage transformer. The core I got from some TV or something, I don't remember.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250103.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250103.JPG

I was considering using component cables because they seem to have good connectors, but after looking close up at it I realized that I do not think the connector will be able to handle 2 kV.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250105.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250105.JPG

In this picture you can see that I added in a MOT to provide ballast so no breaker will pop when the transformer is being used. It will basically act as a current limiter for high voltage which would allow at most 7 or so amps at 120 volts. This will give me 400 mA at 2100 V (840 watts). The tubing and insulation for the high voltage source is now seen. I used a thick plastic tube used for water as the main insulator to prevent the high voltage wire from touching the metal chassis.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250107.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250107.JPG

Here is the completed high voltage cable and probe. For the connection end I used a multi meter probe. I aim to have the possibility of using a flyback to generate an even higher voltage (40+kV), hence all the worry about insulation. Granted, the multi meter probe is rated for only 1kV, I am going to use proper gloves anyways during this, so not much worry there. I will have a holder for the probe when not in use, which will prevent arcing to something else if I accidentally enable it when I did not intend to.
(http://http://archive.hak8or.com/pictures/Power_supply_BIG/Thumbs_small/P1250109.JPG)
http://http://archive.hak8or.com/pictures/Power_supply_BIG/P1250109.JPG


I still have a LOT to do. I need to start working on the digital work, as well as finish the mains wiring in the unit, specifically finish working on the relays to enable/disable the main transformer and high voltage transformer. I expect to have that done by tomorrow, and start working on the digital parts of it.

I also started working on my website. I aim to have the website nice and simple, but I know absalutly nothing about HTML or flash or javascript. I wanted to make my own little gallery thing that links to the forum thread and full res pictures relevant to the selected picture, but that turned out a bit too complicated for myself. So instead, I found a template gallery and took out things that I did not want and changed stuff around. Here is what I have so far. As you can see I have a long way to go still. :P
http://http://archive.hak8or.com/

Thanks for being able to get through this long forum post, congratulations for making it through this boring post! :P
Title: Re: Power supply using a 1U rack chassis
Post by: ian on August 18, 2011, 08:05:55 am
Nice build log, and great pictures! I'll post this up.
Title: Re: Power supply using a 1U rack chassis
Post by: bearmos on August 18, 2011, 02:01:32 pm
really interesting project, hack80r!  looking forward to seeing the progression.

[quote author="hak8or"]I also started working on my website. I aim to have the website nice and simple, but I know absalutly nothing about HTML or flash or javascript. I wanted to make my own little gallery thing that links to the forum thread and full res pictures relevant to the selected picture, but that turned out a bit too complicated for myself[/quote]

WRT galleries - i'm currently experimenting with a CMS called joomla (php and mySQL required), along with a gallery plugin called sigplus (http://http://hunyadi.info.hu/en/projects/sigplus/).  the cool part about sigplus is that you can make galleries really quickly -and they look really nice, too.  for comments, you simply include a text file properly formatted which places the images in the correct order and simply incldues filenames, titles, and comments - it's really simple and fast.

depending on what host you have, joomla can be offered as a one click install that makes things pretty easy.  i've found that joomla has quite a bit of a learning curve - most people prefer wordpress, but that's the only thing i have experience with.  like you, i have very little html, CSS, php experience (i'm an embedded guy)

. . .didn't mean to hijack your build thread - just wanted to share some information
Title: Re: Power supply using a 1U rack chassis
Post by: bearmos on August 18, 2011, 02:03:23 pm
btw, do you comment on HAD?  the alias looks familiar.
Title: Re: Power supply using a 1U rack chassis
Post by: hak8or on August 18, 2011, 08:13:26 pm
[quote author="ian"]Nice build log, and great pictures! I'll post this up.[/quote]

Thank you Ian. :D And thanks for moving this to project logs as well.



[quote author="bearmos"]really interesting project, hack80r!  looking forward to seeing the progression.

[quote author="hak8or"]I also started working on my website. I aim to have the website nice and simple, but I know absalutly nothing about HTML or flash or javascript. I wanted to make my own little gallery thing that links to the forum thread and full res pictures relevant to the selected picture, but that turned out a bit too complicated for myself[/quote]

WRT galleries - i'm currently experimenting with a CMS called joomla (php and mySQL required), along with a gallery plugin called sigplus (http://http://hunyadi.info.hu/en/projects/sigplus/).  the cool part about sigplus is that you can make galleries really quickly -and they look really nice, too.  for comments, you simply include a text file properly formatted which places the images in the correct order and simply incldues filenames, titles, and comments - it's really simple and fast.

depending on what host you have, joomla can be offered as a one click install that makes things pretty easy.  i've found that joomla has quite a bit of a learning curve - most people prefer wordpress, but that's the only thing i have experience with.  like you, i have very little html, CSS, php experience (i'm an embedded guy)

. . .didn't mean to hijack your build thread - just wanted to share some information[/quote]

Thank you for the links and information to joomla and CMS! I was looking at the demo's and while it is rather cool looking, I have already found one of the galleries on my own old website. I am going to be using http://http://simpleviewer.net/products/ for the photo galleries themselves. I don't really need to write much up, since I am linking to the forum, where I am going to be doing the write ups anyways, and I already have experience with this so I can jump on it without too much problems and head scratching. Thank you very much for the information on joomla and CMS, I will most definitely check it out more in detail later when I will want to change or add some more stuff to the website. Don't worry about "hijacking" it, more information is always a good thing. :)


[quote author="bearmos"]btw, do you comment on HAD?  the alias looks familiar.[/quote]
Yep, on hackaday I am Someonecool and hak8or as well. I have a few build logs there too, but their forum seems dead right now. I originally wanted to post my stuff on there to help get the forum going with some new posts, but it did not work that well so I ended up posting on here. Needless to say, thanks to Ian's generosity with front page space, my projects sometimes get put on the front page, which leads to much more people seeing them. My last post was about the TMS machine from the guy that had a electromagnet on his head which led to twitches and stuff.
http://http://hackaday.com/2011/08/15/controlling-muscles-with-high-intensity-magnetic-pulses/#comment-435584 <-- there am I.
Title: Re: Power supply using a 1U rack chassis
Post by: hak8or on August 20, 2011, 05:05:44 am
So, yesterday I was unable to do too much, but today I had more time.

I continued working on the wiring, specifically the high voltage (mains) wiring. Then I continued think how to do the digital aspect of this. I am going to have voltage sensing on the one or two adjustable voltage regulators, as well as the 3v3, 5v, and 12v line. I am aiming to have an update rate of maybe once or twice for voltage sensing, which will be easily satisfied using the ADC on the PIC. Next comes the current sensing, which is more problematic. I originally wanted to have enough bandwidth for current sensing for a MCU, so I can tell what is going on for each clock cycle, but with most simple MCU's reaching 40+ MHZ that would mean that I need at least 200 MSPS for one voltage line (3v3 or 5v), which is far far out of my capabilities. So instead I ended up with each current measurement at 1 MSPS at least, that gives me 200 KHZ of bandwidth which is enough I guess for my needs.

Each line will have current measurement at least at 1 MSPS, and I plan on having five lines (3v3, 5v, 12v, and two adjustable) which means I need 5 MSPS at the very least. That means that I will have to use an external ADC, problem is that I cannot find any cheap DIP adc's, so I will maybe have to conjure something up myself later. I am working a few other things out, even considering getting another propeller instead of a PIC since the propeller has 8 separate cogs, each capable of 10 MIPS, which should handle any ADC I throw at it within reason.

I also need to purchase some current shunts, since I only have one at home right now. If I am going to buy current shunts online from mouser, I might as well buy a few other things. I am mainly looking at the PIC24HJ12GP202 since it is so cheap and can do 40 MIPS, not to mention it being a DIP package. It does not have much program flash and ram, but for the price it does not seem too bad, if anyone has any other suggestions please do tell!

That is how far I have come so far, I am mostly working out and planning the digital logic behind it, of which there is a lot. I still have to work out the propeller generating a VGA signal to a monitor for displaying the current usage and voltages, things like that. I will want to be able to plug in a keyboard so I can control scales and things like that for the measurements, not to mention I can get something like PONG running on the propeller. A power supply that can play pong, that is something I never heard of. :P

Thank you megabug, shadyman, and GeekDoc for pointing out that it is a 2U chassis instead of 1U ! :D
Title: Re: Power supply using a 2U rack chassis
Post by: hak8or on August 21, 2011, 09:03:43 am
it is the weekend, so I am working on buying some parts. I have till Sunday night to order so I am taking my time. There are no DIP adc's higher than 1 MSPS, so I am working on doing some makeshift SMD to dip thing to use the higher speed adc's. I am also working out if the propeller can handle the bandwidth of four 1 ADC's.

Turns out that I can get pretty fast ADC's that are SMD for very cheap, upwards of 40 MSPS, so I am working out how I can use a propeller chip with it. It might turn out that I can use just the propeller chip, and not bother with using a PIC at all, though polling might turn a bit problematic. Still working it out though. So yeah, this project is still ongoing, even though not much has happened lately!
Title: Re: Power supply using a 2U rack chassis
Post by: hak8or on August 22, 2011, 01:42:13 am
Hello everyone!

I have finally found what ADC to use! It is very cheap, parallel out put, it does not have the reference high and reference low things from other ADC;s, it is in a easy to manage chip package, and best of all it seems simple to use.
http://search.digikey.com/scripts/DkSea ... BRSZ-50-ND (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=AD9283BRSZ-50-ND)
There are a lot of moderate speed ADC's that use SPI, but there are no hobbyist friendly MCU's that are capable of 40+ MHz SPI ports that I am aware of. There are no DIP ADC's that are capable of more than 1 MSPS for under a $40 or so dollars. Basically, if you want a high speed ADC (more than 1 MSPS), you will have to go SMD for a few reasons. One, because there simply are no reasonable cost DIP adc's of such speed, manageable interface (Parallel), and within a reasonable price range.

So, to use that ADC I will need to have the usual decoupling caps, and wiring it up using magnet wire would prove too tedious for me right now, and I want to FINALLY make my own PCB's, so I am focusing on how to make a PCB myself. I do not have a laser printer, so the most common technique of toner transfer is out. There are a few methods that remain for me. Photo resist, which seems awesome but then I will have to purchase the layer that is sensitive to light online, and then laminate it myself, and I do not have a lamination machine. I will therefore have to purchase the boards with the layer already on them, and the only source of that is online, and from what I have seen they are not as cheap. Plus, I will have to make a UV exposure box, or have to mess with exposing it myself using a light bulb.

Then comes printing directly onto the copper clad using my inkjet with special ink, and then etching away. That is also problematic, because I cannot change the ink in the ink cartridges, since I have a Lexmark which is HORRIBLE with ink cartridges. They use a chip of sorts (apparently a MCU or similar) in the actual cartridge to prevent anyone from refilling them.
http://http://forums.hackaday.com/viewtopic.php?f=3&t=735 <-- problem

So, then I need to think of something else entirely! I am thinking of sticking the copper clad into my printer, and have the printer print the thinnest it can onto the PCB, so I can still see the trace. Then I can run over each trace with an etch resist pen. Now that I think about it though, it does not seem too reliable because the thickness of the pen tip or marker would come into play and easily limit the thickness of traces to something larger than 8 mil.

I guess I will keep looking and trying to find something out. Maybe will rethink photo resist, since I have heard lots of good things about it, and it is pretty much the only other option for me other than getting a laser printer or purchasing online. I also need to find what chemicals I can use as enchant.
Title: Re: Power supply using a 2U rack chassis
Post by: hak8or on August 22, 2011, 03:53:39 am
A small update, with something that I consider really awesome.

Batch PCB costs:
$10.00 (set up fee) + $2.50 per inch + $3.00 (shipping, they do not say so I guessed according to "shipping in the US can be quite cheap (USPS ... ) "
DorkbotPBX costs a flat $5.00 per inch per for three board including shipping.

Right off the bat dorkbot seems cheaper because you get three boards for the cost.
(http://http://8486.a.hostable.me/pictures/comparison_cost.PNG)
I made a little graph thing comparing the cost of batchpcb vs dorkbot. This does not include the other two copies of your board in the  board in^2 count, because in this situation I only care about having one board, I don't need the other three, in which case I would have given the other two boards away for free on dangers prototypes. :P Basically, use DorkbotPBX if you your design is less than 5 Inch^2.

So I looked at photo resist, and to my surprise the cost per square inch is super low, compared to the other services.
http://www.circuitspecialists.com/print ... tized-pcbs (http://www.circuitspecialists.com/printed-circuit-board-supplies-positive-photo-resist-pre-sensitized-pcbs)
I did some simple math to find the cost per inch^2 for you guys.
3 X 5 Single side ($6.46) -- $0.43 per square inch of copper
4 X 6 Single side ($7.13) -- $0.30 per square inch of copper
6 X 6 Single side ($8.09) -- $0.43 per square inch of copper
6 X 6 Double side ($11.40) -- $0.16 per square inch of copper
6 X 9 Single side ($11.91) -- $0.22 per square inch of copper
6 X 9 Double side ($15.26) -- $0.14 per square inch of copper
8 X 12 Single side ($19.09) -- $0.20 per square inch of copper
8 X 12 Double side ($21.49) -- $0.11 per square inch of copper
The cheapest overall ratio is 8 x 12 double sided.
The cheapest single layer ratio is 8 x 12 single layer

Then I checked the cost of shipping, BAM, $11.45. There is no way I am going to pay nearly twelve dollars for shipping something like that, so I checked other sites like Ebay, but Ebay has these types of boards only shipping from China, and last time I ordered something from China on Ebay, and it took nearly two weeks to get here, so that is out.

Turns out Amazon has a seller that does not overcharge to no end, and much more reasonable shipping costs.
http://www.amazon.com/gp/search/ref=sr_ ... _authority (http://www.amazon.com/gp/search/ref=sr_nr_scat_172282_ln?rh=n%3A172282%2Ck%3APresensitized+board&keywords=Presensitized+board&ie=UTF8&qid=1313974082&scn=172282&h=2911af7ba6b59f0c6ad1729d25804d4468aa53e3#/ref=sr_st?keywords=Presensitized+board&qid=1313974086&rh=n%3A172282%2Ck%3APresensitized+board&sort=reviewrank_authority)
I am going to get 6 X 9 Double sided for $17.12 with shipping being only five dollars. No reviews though, so I will most surely tell you all how they are when I get them!

I am most likely going to stick with the photo resist that I have shown above, since it is far cheaper than online PCB services, and pretty much the only way I can make PCB's at home without a laser printer or using a pen. I was thinking of the spray on photo resist, but after hearing that it needs to be pretty much Dust free and all done in a very dim room, I think that I can't use it. Mostly because I don't have dim room anywhere that is also very not dusty. :P

I hope this will be of use to anyone of you who read this!

Now, I need to worry about the chemicals. :P
Title: Re: Power supply using a 2U rack chassis
Post by: ian on August 22, 2011, 09:46:42 am
Nice price comparison graph, that is interesting. It would be super cool to have one with all the majors on there (PCB123, Itead/Seeed, Golden Pheonix, etc).

Have you checked Seeed or Itead's PCB service? You can get 10 boards starting at $13 including worldwide shipping ($1.30 per PCB). Turn around is quick, and the internal post is flying fast right now (most packages are China to me in 4 days).

Quote
in which case I would have given the other two boards away for free on dangers prototypes. :P

It's always fun to add guest PCBs to the PCB drawer :) Give me a shout if you have extras.
Title: Re: Power supply using a 2U rack chassis
Post by: hak8or on August 23, 2011, 04:29:08 am
[quote author="ian"]Nice price comparison graph, that is interesting. It would be super cool to have one with all the majors on there (PCB123, Itead/Seeed, Golden Pheonix, etc).

Have you checked Seeed or Itead's PCB service? You can get 10 boards starting at $13 including worldwide shipping ($1.30 per PCB). Turn around is quick, and the internal post is flying fast right now (most packages are China to me in 4 days).

Quote
in which case I would have given the other two boards away for free on dangers prototypes. :P

It's always fun to add guest PCBs to the PCB drawer :) Give me a shout if you have extras.[/quote]

I may be interested in making a graphic comparing other PCB vendors, but there are so much different variables in the cost, for example trace width, lead times, do I add in shipping costs, and drill sizes. That would require a lot of my to make a proper graph with all of those things. Also, most PCB fabs don't include the equations they use for determining cost, and some even don't tell you the shipping cost till after it is fabbed. 4PCB did that to me, 25 dollar shipping for a 66 (10 in X 6.6 in I think) inch PCB is just ridiculous, especially since it is a flat very thin object. Though, I will most definitely want to make such a graph even though it may be problematic to find what values to use for what for a fair comparison. I did just find some good graph thing online that also actually looks nice and is usable. Too bad you cannot set the thickness of lines.
http://http://desmos.com/calculator/#

I did do a quick look see on that PCB service, I have always heard of them but never actually tried them myself.
http://www.seeedstudio.com/depot/fusion ... p-835.html (http://www.seeedstudio.com/depot/fusion-pcb-service-p-835.html) <-- is this what you were referring to by seeed's PCB service?
Earlier I thought that it was ten dollars per board, which led me to write this.
[s:]It appears that the minimum quantity is ten boards, and each board is 9.90 which results in it costing $100 for a single design which would be 5cm by 5cm. The cost for a single board would be $25.81 per inch of board, which is far far above what batchpcb[/s:]
Then I realized that it was for all ten boards combined! That is incredibly cheap!  So, for ten dollars you get (5 cm X 5 cm) 3.88 square inches of design space, 10 dollars, leads to $2.58 per square inch.

======================================================
Here is the cost rundown for seeed's Fusion PCB service:
(http://http://8486.a.hostable.me/pictures/Seeed_pricing_an.PNG)
*Math has been fixed*

Keep in mind, this is using all the default options for seed, I am counting only one PCB instead of ten, and it does not include shipping. I had to make this as a PNG because this forum does not seem to follow spacing. :( I also just realized that dangers prototypes cut off my pictures since they were too big, so i resized them.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: ian on August 23, 2011, 09:32:12 am
Wow, thanks, that's an interesting look at Fusion. I didn't necessarily mean you should do the chart, just that it would be cool to see one :)

For the 10@ 10x10 I ususally get it is around .17 per in2 including all the PCBs, which is not so much greater than the other services you list. It's great to see PCBs coming down in price, a few years ago it seemed like it was Olimex with no plating, or nothing.

The think I like about Fusion is that the shipping is really cheap, to anywhere in the world.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on August 24, 2011, 12:52:34 am
Yeah, I normally do this type of cost comparison whenever I get a board done either way, so I might as well make it in a presentable manner so I can give it to the rest of the community. :P

If you want more than one copy of your board, then I guess seed has the absolute cheapest start up cost. Ten dollars for ten copies of your board? That is very cheap, even though the board is pretty small. :P Unfortunately I was never that interested in making boards years ago, so I cannot compare the cost of PCB's, but I do presume that it was much more expensive for the hobbyist.

Good to know the shipping is cheap. :P I will never allow myself to get screwed over by shipping again, especially after the incident with 4PCB charging me so much for shipping. The reason that I am so dis interested in getting a board done by a fab plant is because I want to have the ability to think of an idea, design a board, etch the board, solder on the parts, test, and actually use the board all in one day. I am a very impatient person. :P Granted, I may not have the parts on hand at the moment, making PCB's myself will most certainly decrease the amount of times that a project was put "on hold" due to either forgetting what the original goal was, getting discouraged by waiting more than a week for a board/parts to get here, or not wanting to because of the knowledge that it will take a very long time to complete, most of it in waiting. For me, this will be a large step forward, and will definitely make me more productive. Plus, it appears that making your own PCB for something brings a lot more self gratification at the end when it all works. :P

*it appears that I am derailing my own thread too :P *
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on August 27, 2011, 10:24:22 pm
There has not been much progress in the past few days, I was mostly checking out what parts to use, and trying to find out what CPLD or FPGA to use for taking care of the high speed data transfer (50 MSPS, 8 bits). I would want to use an FPGA because I could use the SPI flash instead of using a JTAG.

Either way, I got the pre-sensitized PCB this morning, but I cannot do much because of the latest natural disaster. Hurricane Irne right now, earlier the earthquake. If anyone here is on the East cost, I hope that the hurricane does not do any damage to you!
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: rsdio on August 31, 2011, 10:54:45 am
[quote author="hak8or"]Here is what the inside of it looks like. There was another board ontop that also had more FPGA's, but I took it out a long time ago to try to get access to the JTAG pins. It is rather heavy, and I will tell you why later. I will say now though, it was a major surprise![/quote]
I did not ever see a followup to this teaser. Why was the top board heavy? What was the major surprise?
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on August 31, 2011, 01:28:37 pm
[quote author="rsdio"]Why was the top board heavy? What was the major surprise?[/quote]
There was something like a 1/2" aluminum face plate on the front of the rack ( i think ).  it was in one of the pictures.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on August 31, 2011, 05:05:50 pm
[quote author="rsdio"][quote author="hak8or"]Here is what the inside of it looks like. There was another board ontop that also had more FPGA's, but I took it out a long time ago to try to get access to the JTAG pins. It is rather heavy, and I will tell you why later. I will say now though, it was a major surprise![/quote]
I did not ever see a followup to this teaser. Why was the top board heavy? What was the major surprise?[/quote]
Sorry, I think my wording was not too good. I was referring to the entire unit when I said "it is rather heavy", not the top PCB. If you want though, I would be more than happy to upload some pictures of the top pcb.

Yeah, the front plate was a thick slab of metal, hence being so heavy. It was surprising since I never saw such a usage of metal. Normally companies make it look heavy and very durable, but have a empty body in effort to use less metal which saves them money, but in this situation they went all out and just stuck a large slab of aluminum to the front.

Currently this project is progressing very slowly. I was hoping to have a majority of this done before college, but it turns out that I wanted more out of this, which uses up even more time. Some additions I am using for this are a 50 MSPS ADC which I will use as current measurement and a low spec oscilloscope, a CPLD for working with transferring the data from ADC to SRAM and act as a clock controller for the high speed adc, a 18 bit ADC as a very precise current/voltage monitor (3.75 SPS, heh), and I might maybe switch away from the PIC32 and instead to another micro controller due to Ian's latest post.

I was looking at the Renesas RX since it supports a full fledged opensource suite, and I have the RDK for testing code. From what I see, they have the eclipse IDE and a proper GCC tool chain for the RX, but the programmer is fully closed source. I also had nothing but bad experiences with the eclipse environment for the RX. Last time I tried to use the opensource tools for the Renesas RX MCU, all the documentation was just thrown around everywhere, and apparently to program the RX from eclipse, I had to save the project, export it to the HEW ide, open the Hew IDE, and then program through the HEW IDE, which seems ridiculous. Also, the HEW ide is closed source from what I remember. Programming the RX mcu might also be a problem, but I remember something about booting from a SPI flash by setting a mode using the pins on the RX mcu, but I cannot find anything about that.

I would consider the avrgcc tool chain, but all the AVR's out there go no faster than 20 MHz?
Are there any high speed MCU's that are also properly opensource?
I want to learn other mcu's, the RX mcu from renesas seems awesome, but the way that the documentation is thrown around, and what seems to be no proper support for the eclipse IDE, and what seems to me as a very confusing process to program the chip with open source tools, I will probably just stick with the pic32.I just need to check what PIC32 chips I can program using the Pickit2. :P

Also, this project will go along a bit slowly, since I just started college and my schedule kind of sucks, which results in me having to stay on campus for nearly four hours doing nothing between classes. At least I have all the software for designing this project on my laptop. I will see about uploading a schematic of what I have so far.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 05, 2011, 06:12:24 am
Hello there everyone!

Been a while, and I have realized that as of now, with college I have lost a very large amount of my free time. I am still rethinking a lot, and this project is more complicated than it started out as. Originally it was supposed to be a quick one week thing, simple voltage regulators, no high speed ADC, and the LCD for ADC measurements from the PIC. Instead, now I am aiming to learn about CPLD's, the IDE for xilinx, and how to set up high level functions using low level logic gates.

Some updates:
- I will end up using the pic32 I selected earlier due to it being compatible with my pickit2, and I am already familiar with the entire PIC series of MCU's as well as the IDE and whatnot. For my next project, the rover, I will use an ARM mcu probably
- I am learning how to input things for xilinx chips using the schematic view in the IDE
- Learning how to make registers and things like that from logic in a CPLD
- Learning the xilinx IDE, which is a bit confusing at first I must say. Plan ahead which displays the inner chip connections is AWESOME!
====== Design Changes ======
- the CPLD will take care of all high speed logic (address increment for ADC, clocking for the ADC, depending on use can send flag to MCU)
- Will use a PIC32 as the controller for the LCD, connect to the buttons/dials, connect to a speaker, basically the slower main things
- the Propeller will take data from each ADC and the CPLD and will display it on a separate VGA LCD as well as other things I think of
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 06, 2011, 08:15:03 am
Something quick to update everyone.
I am currently learning how to use schematic entry in the Xilinx IDE, and I am thinking out how to pack in everything I need into the CPLD.

(http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_1_SMALL.jpg)
http://8486.a.hostable.me/PSU_BIG/CPLD_PROGRESS_1.PNG (http://8486.a.hostable.me/PSU_BIG/CPLD_PROGRESS_1.PNG)
The top you see eight squares, each is a 4 bit latch, which gives me four eight bit registers. I will have seven registers total in the end which consist of: ADC value, Address register one, address register two, address register three, address register four, Clock division register, and a misc register for Enable/disable adc, enable/disable memory, memory test (writes FF and verifies), full reset, things like that. Time is very not forgiving for me lately. :P

Here is the PDF of it so far: http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_1.pdf
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: ian on September 06, 2011, 08:56:15 am
Nice looking Xilinx schematic. I bet it was an exercise in frustration to get that baby entered :)
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 06, 2011, 04:51:09 pm
[quote author="ian"]Nice looking Xilinx schematic. I bet it was an exercise in frustration to get that baby entered :)[/quote]

Oh god yes! :P It is a very frustrating experience for me. The IDE always thinks that you want the wires to be connected to the gate or macro, even when you rotate it. [s:]To get the wires to disconnect from the macro/gate, you have to cut the item and then paste it elsewhere. If you want to delete part of a wire, you can't, you have to delete the entire wire and redraw it from scratch. To move a wire, sometimes the IDE refuses to move the wire, sometimes when you drag the wire elsewhere, it drags the entire wire, sometimes only part of the wire.[/s:]

There are a few more annoyances, but yes, it was a test in my patience to get that much in so far. :P

Edit: Let me correct a few things I said earlier. After working with the IDE some more, I saw an option to "select options" which lets me fix most of the things I said above.

(http://http://archive.hak8or.com/PSU_BIG/CPLD_IDE_1_S.png)
http://archive.hak8or.com/PSU_BIG/CPLD_IDE_1.png (http://archive.hak8or.com/PSU_BIG/CPLD_IDE_1.png)

One other annoyance I have noticed is the "auto route" for schematic views. I was trying to connect a wire to another wire in a bus, but the wire kept going around the bus and connecting to it from the other direction. I had to put the wire very close to the bus, and then it would properly connect to the bus. There is maybe an option in the IDE to turn off the "auto route" feature in the IDE and I did not find it, so I will refrain from saying that the IDE was at fault.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 06, 2011, 11:39:27 pm
This is the most I can do for today I guess, here is my progress for today:

(http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_2_SMALL.jpg)
http://8486.a.hostable.me/PSU_BIG/CPLD_PROGRESS_2.PNG (http://8486.a.hostable.me/PSU_BIG/CPLD_PROGRESS_2.PNG)

PDF: http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_2.pdf (http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_2.pdf)
Lots and lots more to do, and I forgot to put in the buffers to the "registers" for the address.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: rsdio on September 07, 2011, 11:56:03 am
Do the Xilinx tools allow for the creation of a 'bus'?  In Eagle, you can create a bus and then just draw your 4 or 8 wires from a chip to a 'bus' symbol which represents the group. This make your schematic much easier to read, but you'll have to be careful to connect everything on both ends - labels help. I have no idea if a similar option is available in the Xilinx tools, but maybe someone will be able to make use of the suggestion in their Eagle use.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on September 07, 2011, 01:51:38 pm
[quote author="rsdio"]Do the Xilinx tools allow for the creation of a 'bus'? [/quote]
i was thinking the same thing - structural VHDL allows for it in the code - you'd think it would be natural for the Xilinx IDE to support it as well - i've never used the Xilinx IDE, personally, though - sounds painful!
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 07, 2011, 04:55:15 pm
The xilinx tools do allow for the creation of a bus, but I do not want to use it in this case because .. well ... wait, why am I not using a bus?

Oh, yes. I had to open the xilinx schematic entry window and look at my schematic again. It simply helps me see what I am doing. It does make sense to be using a bus when doing something like this, but I want to have each of the connections visible to me within reason to aid in understanding what I am doing.

I am using a bus for connecting the counters to the address bus, but that is it pretty much. Also, I want the bus line to be thicker than xilinx gives me, so instead I am just using individual lines in each bus. :P
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 07, 2011, 08:42:27 pm
Another update so far today. I don't think I will get any more done today. I am happy to say though that I am learning all the quirks of the Xilinx IDE. I will email Xilinx some suggestions/feedback, specifically about the movement of things in the schematic view, hopefully they can nail it like Altium did so.

I have to decrease the number of stuff I am doing in the CPLD, I originally intended for it to fit in a 36 macrocell cpld, but turns out I needed more. Then I jumped to a $2 CPLD which had 72 macrocells, turns out I needed even more. The next jump from Xilinx in digikey is a $6 CPLD with 128 macrocells (Coolrunner 2). At that price I can just get a FPGA, specifically a spartan 3A, and not worry about JTAG, instead just worry about a SPI flash which would make things much easier for me.

Anyways, here is my progress! I added in the address and counter for the RAM, I now have to work on the clock divider and if I will be using an FPGA, I will add in the button functionality instead residing in the PIC. Rethinking quite a bit lately too. Also, yes I know that the address latches are all wired up together, I am going to fix that later. If there are any mistakes, someone point them out? :)

(http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_3_SMALL.png)
http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_3.PNG

The pdf: http://http://archive.hak8or.com/PSU_BIG/CPLD_PROGRESS_3.pdf
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 08, 2011, 07:08:36 am
I got home and I wanted to quickly view the schematic again, so I opened the xilinx IDE.

[s:]It says:
ERROR: Could not find symbol "buft4"
ERROR: Could not find symbol "bufe4"

I close and open the IDE, still same error, I open the project using the 32 bit version of the xilinx IDE, and again the same thing. I check what buffers are avalible, and apparently only the single buffers are available.[/s:] So I think, maybe an update will help, it will check if anything is missing and download it. Turns out that to update the IDE to a newer revision, I have to download the entire FOUR GIG file. Really xilinx, you are a multi billion company which works with FPGA's, which to use you need to have a proper IDE, and you cannot get incremental updates?

I must say, I am extremely peeved at [s:]the symbols magically being not available suddenly, and[/s:] that to update the suite I need to re download the entire four gig file.

Edit: Turns out that that sort of buffer is not available on FPGA's. As I made the design, I went to a larger chip with every progress in the design, but I did not close the IDE. When I opened the IDE again, it just then checked that the buffers are not available on the chip I selected.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: ian on September 08, 2011, 09:02:07 am
I always have problems flipping and moving parts, and it often won't autoroute to somewhere due to some clearance you can't see at all. The frustration experienced with the cct entry is a well known bug ;) You would not be alone in hating it. I used it for a long time and eventually even learning VHDL/Verilog was less painful (not that I would encourage you to do that, it was a year with schematics before I was ready to try code).
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on September 08, 2011, 01:45:03 pm
back when i was using ISE Web Pack (not sure if that's still the name) the schematics were viewed by my professor as a cute feature, rather than something useful!  A lot of times, we would use an external flow charting tool to quickly sketch what we were making, rather than get bogged down in the tedium of schematic entry.

If you have a solid digital logic background the VHDL is a bit cumbersome, but no more than any new language - mainly due to syntax.

Then, eventually, you'll get sick of writing the repetitive VHDL (if you're doing purely structural, building everything from NAND gates) - that's where the hacked together VHDL generators come in - and the fun really begins!

I need to get back into this, it's been too long!
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 08, 2011, 07:27:28 pm
[quote author="bearmos"]back when i was using ISE Web Pack (not sure if that's still the name) the schematics were viewed by my professor as a cute feature, rather than something useful!  A lot of times, we would use an external flow charting tool to quickly sketch what we were making, rather than get bogged down in the tedium of schematic entry.

If you have a solid digital logic background the VHDL is a bit cumbersome, but no more than any new language - mainly due to syntax.

Then, eventually, you'll get sick of writing the repetitive VHDL (if you're doing purely structural, building everything from NAND gates) - that's where the hacked together VHDL generators come in - and the fun really begins!

I need to get back into this, it's been too long![/quote]


[quote author="ian"]I always have problems flipping and moving parts, and it often won't autoroute to somewhere due to some clearance you can't see at all. The frustration experienced with the cct entry is a well known bug ;) You would not be alone in hating it. I used it for a long time and eventually even learning VHDL/Verilog was less painful (not that I would encourage you to do that, it was a year with schematics before I was ready to try code).[/quote]

I am planing on learning VHDL or Verilong some time soon, hopefully within the year. The schematic entry is as your professor would put it, a fancy toy. I want to be able to get familiar with as much of the ISE as possible, including the schematic entry, and I know how to do things with visual logic instead of the language alright, so I might as well start with something that I am already able to reasonably control. I would rather learn the CPLD first through finding out what type of logic function is optimized in what way, things like that, first and then start working on learning another language. In other words, I want to get familiar with the platform first, and then start to work with it in a more controlled/complicated manner, even if that more complicated and controlled manner may be faster.

I am eager to start to learn how to code on the CPLD and FPGA, but if I do it that way I will end this power supply project in months and months instead of just weeks, heh. :P I do have some experience with FPGA's and their languages when I used the Logic sniffer as a development board. As a matter of fact, I bought the logic sniffer mainly for using it to learn about FPGA's (Development Board), while the logic sniffing part of it was not that important to me. I also bought it as a thanks to the community for making it.

I also found that I really enjoy working on this using the schematic entry. For some reason, I love to see the busses in there. I guess the reason for that is when I read the book called "microprocessors" which is about the "ancient" 8088 processors, they sometimes showed the buses, the thinking was done in terms of buses which were very clearly marked compared to individual lines. Having read that just a year ago, and loving the idea of parallel data lines, I just had to incorporate that into my design.

The external flow chart program that you mentioned before sounds very interesting, and it would surely be awesome to see how your verilog/VHDL code looks in a flow chart view. From what I remember, I think the Xilinx ISE has a code to schematic tool. I am not sure though, as I have never used it so I can't even state how useful it is, but I should have a look at that when I start writing FPGA and CPLD things in code.

Oh dear, this post is rather long, as are most of mine, I think I should shorten them. :P Any opinions on the project so far? Does it look like a waste of time, does it look awesome, is anyone other than Ian and Bearmos reading this? Advice is always welcome too! :)
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on September 08, 2011, 08:06:19 pm
[quote author="hak8or"] In other words, I want to get familiar with the platform first[/quote]
I understand completely, project scope has to be drawn somewhere:)

[quote author="hak8or"]The external flow chart program that you mentioned before sounds very interesting, and it would surely be awesome to see how your verilog/VHDL code looks in a flow chart view[/quote]
This was really just MS Visio (or Open Office Draw) - just something to quickly generate block diagrams to keep track of high-level ideas.  There was nothing fancy going on between VHDL and the diagram - it was just easier to email a visio block diagram than a napkin:)
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: rsdio on September 09, 2011, 05:36:30 am
[quote author="hak8or"]The xilinx tools do allow for the creation of a bus, but I do not want to use it in this case because .. well ... wait, why am I not using a bus?[/quote]Ha! These are the kinds of questions I ask myself all the time.

Quote
Oh, yes. I had to open the xilinx schematic entry window and look at my schematic again. It simply helps me see what I am doing. It does make sense to be using a bus when doing something like this, but I want to have each of the connections visible to me within reason to aid in understanding what I am doing.
Eagle allows you to View a signal and it will be highlighted on every copy of the bus as well as on the pins of each connected chip. That makes it easy for me, at least, to see what's going on in my Eagle schematics. I haven't used the Xilinx tools either, though, so I don't know whether they have something similarly useful.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 09, 2011, 08:57:54 pm
[quote author="rsdio"][quote author="hak8or"]The xilinx tools do allow for the creation of a bus, but I do not want to use it in this case because .. well ... wait, why am I not using a bus?[/quote]Ha! These are the kinds of questions I ask myself all the time.

Quote
Oh, yes. I had to open the xilinx schematic entry window and look at my schematic again. It simply helps me see what I am doing. It does make sense to be using a bus when doing something like this, but I want to have each of the connections visible to me within reason to aid in understanding what I am doing.
Eagle allows you to View a signal and it will be highlighted on every copy of the bus as well as on the pins of each connected chip. That makes it easy for me, at least, to see what's going on in my Eagle schematics. I haven't used the Xilinx tools either, though, so I don't know whether they have something similarly useful.[/quote]

I am not sure if xilinx schematic view has such a feature. It most likely does somewhere where I have not seen it yet.

[quote author="bearmos"]
This was really just MS Visio (or Open Office Draw) - just something to quickly generate block diagrams to keep track of high-level ideas.  There was nothing fancy going on between VHDL and the diagram - it was just easier to email a visio block diagram than a napkin:)[/quote]

Heh, now I understand what you meant. :P
What very often happened to me in high school was I was sitting in class, bored out of my mind since my teacher was explaining the same thing the third time to the students, and I drew designs on what I had at the time. So, my notebook is half notes and work, the other half was ideas that I drew, the tests I got back had schematics on them while the teacher was reviewing the test results with the students, and worst of all is when the teacher does a random note collection. Imagine the teachers confusion when I had the drawings in Chemistry slowly changing into schematics. :P


A quick thing I wanted to say, this is a very enjoyable forum! The people here are all very nice and energetic, and I am slowly starting to remember all your usernames, which has never happened on any other forum. One thing for sure, I will definitely post my project write ups on here from now on! And, hopefully within the next two years I will present something which I have been wanting to do for years, since 8th grade, which was nearly six years ago.

Quick question: Are there any replacements for a tri state buffer for Xilinx fpga's in the schematic view? Or, is it possible to have a high impedance symbol? I found that multiplexers make ISE happy but from what I understand a pin when not connected to anything gets connected to ground instead of left in a high impedance state.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on September 09, 2011, 09:24:31 pm
[quote author="hak8or"]A quick thing I wanted to say, this is a very enjoyable forum! The people here are all very nice and energetic[/quote]
I agree, I'm continually surprised by the caliber of the members here.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 14, 2011, 05:28:36 pm
Just wanted to let you guys know, this project is still alive!
I am working on learning verilog, and working on this project with what ever little time I have. I am considering leaving the FPGA design out for now (Entire high speed ADC will be left for later) and instead working on the other parts some more. The PCB will have the pads and traces for the FPGA, Memory, and ADC all on it, and the chips soldered too, but I will just program the FPGA later. :P

I also might do a simple design, like the bus pirate, as a test for my PCB skills. I nicked some large scanner from my old schools garbage on garbage day, so I think it will make a fine UV exposure box. Just need to get a photo resist developer first.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 21, 2011, 06:20:37 pm
Still not dead, I am learning verilog in the free time I have at college between classes.
Verilog does indeed seem much faster and less cumbersome than schematic entry! Always good to learn another language. :P
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on September 29, 2011, 08:30:06 pm
Hello everyone again!

I have had major internet problems for the past week and half or so, so I have been working with Time Warner Cable to get my connection back. In the meantime, I was able to spend more time on the project which resulted in almost finishing the PCB and schematic. I will upload soon, if I can upload it at all with this connection.

I needed to use a more "High end" suite for the board since I have a few 50 MHZ data lines, in which case I did trace length tuning. Thanks to all this time and thinking I got some more ideas, for example, I want to be able to test reflection in high speed traces. I can use a FPGA, a few comparators to see if a few specific voltages appear on the line, and a counter to find the gaps between sending and a reflection. The actual term for this seems to be a Time Domain Reflectometer.

(http://http://archive.hak8or.com/PSU_BIG/Schem_1_S.png)
http://http://archive.hak8or.com/PSU_BIG/Schem_1.png

(http://http://archive.hak8or.com/PSU_BIG/PCB_1_S.png)
http://http://archive.hak8or.com/PSU_BIG/PCB_1.png

http://http://archive.hak8or.com/PSU_BIG/PCB_Project4.pdf <-- PDF
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on October 05, 2011, 07:12:18 am
I am almost done with the board, just need to put in some last touches. Finished with the "expansion" side of things. I will be using a high speed SPI (40+ MHZ) from the fpga, which can be later plugged into another FPGA board. The other FPGA board will act as an I/O manager, basically the controller for additional peripherals I add in later. The same SPI connector will act as the bus between the propeller and the FPGA. The propeller will be used as the GPU mostly, and the FPGA holds the information, with the Prop fetching data from registers in the FPGA. I am using a additional connection (SPI has three) for addressing between the prop and the add on FPGA board.

Off topic, but I wanted to show you guys what I have been playing around with a bit lately, reverse lense photography. Basically, get a lens for DSLR's and shoot pictures through it with your camera. It gives you a not bad macro ability without purchasing a macro lens.

http://imgur.com/a/8WMYa#9k01n (http://imgur.com/a/8WMYa#9k01n)
First three are from a GPU (X800, first graphic card I had :D )
Anyone want to guess what the last two pictures are?
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: ian on October 06, 2011, 01:34:08 pm
Quote
It gives you a not bad macro ability without purchasing a macro lens.

Very cool!
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on November 09, 2011, 06:21:07 am
Very annoying problem for me right now, I purchased all the chemicals for making photoresist boards, and I was excited about making a test PCB. I do a test to see how small traces my printer can handle, and it turns out that the smallest traces I  can make are only maybe 8 or 10 mil! This is extremely upsetting! Not to mention that the quality of the traces is rubbish to say the least. I would have to make maybe three copies and put them onto of each other to get a good light blocking.

The main reason I am unhappy with my situation is because I purchased this printer a few years ago under the idea that it is a fantastic printer, with a decent DPI of 1600 which would give me one dot per .625 mil. I believe that thanks to this I should be able to get 6 mil without too much trouble, but I guess not. Maybe if I run over the traces with a fine pen I might be able to do better. Also, I am still interested in my idea of using a camera lens I have to make the transparency half its size on the pcb. Not to mention, I became very curious about using a metal heated head to "print" wax onto copper boards and etch that way, thanks to this presentation a while ago.http://http://hackaday.com/2011/01/31/printable-wax-as-pcb-etch-resist/

Also, for some very odd reason, I have started to get interested in the photo lithography process for making ic's, heh.
Woe is me, for all these distractions end up with many unfinished projects! :P
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: ian on November 09, 2011, 11:28:20 am
Assuming inkjet: Be sure to use "high quality black" with a mix of colors to make black, yellow is usually most UV resistant. Get photo ink, which is UV resistant. TUrn up the ink volume to make a thicker mask, but be sure to let the transparency dry or it will get hair and dust in it. Be sure to print backwards so the ink is against the PCB for best results. Be sure your light source is direct and is close to the PCB. Also, practice makes perfect ;)  I did everything at 24 and 32mil for a long time before I could etch QFN by hand.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: bearmos on November 09, 2011, 02:30:49 pm
[quote author="hak8or"]Not to mention, I became very curious about using a metal heated head to "print" wax onto copper boards and etch that way, thanks to this presentation a while ago.http://hackaday.com/2011/01/31/printabl ... ch-resist/ (http://hackaday.com/2011/01/31/printable-wax-as-pcb-etch-resist/)[/quote]

I wouldn't even go down that path if I were you, based on what I've seen its a very experimental rabbit hole.  If you'd like to do it as a project, it's a different story though.  It's all too easy to get swept off into the side projects (I'm speaking from first hand experience here ;-)).  At the end of the day, if you enjoy what you're doing that's what matters though!

I've never used the photo resist method (i've always ironed on laser printed patterns).  The finest traces i was able to produce were 16 mils and even that was very painful.  Part of the issue I have was that the printer needs a new fuser, so the quality is pretty low.  Eventually I was able to etch a 64 pin QFP, though.

Home etching definitely requires plenty of experimentation/patience.  I've been trying to get a home-brew mill setup for a while with limited success.  The idea behind "mechanical etching" is that you can theoretically panel plate the PCB before milling the traces (giving a plated through hole board).  That way you don't need to worry too much about putting vias under components, threading wire through vias and soldering, etc.  Again, this type of thing starts as a side project and then turns into a rabbit hole/time sink.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on November 09, 2011, 11:48:07 pm
[quote author="bearmos"][quote author="hak8or"]Not to mention, I became very curious about using a metal heated head to "print" wax onto copper boards and etch that way, thanks to this presentation a while ago.http://hackaday.com/2011/01/31/printabl ... ch-resist/ (http://hackaday.com/2011/01/31/printable-wax-as-pcb-etch-resist/)[/quote]

I wouldn't even go down that path if I were you, based on what I've seen its a very experimental rabbit hole.  If you'd like to do it as a project, it's a different story though.  It's all too easy to get swept off into the side projects (I'm speaking from first hand experience here ;-)).  At the end of the day, if you enjoy what you're doing that's what matters though!

I've never used the photo resist method (i've always ironed on laser printed patterns).  The finest traces i was able to produce were 16 mils and even that was very painful.  Part of the issue I have was that the printer needs a new fuser, so the quality is pretty low.  Eventually I was able to etch a 64 pin QFP, though.

Home etching definitely requires plenty of experimentation/patience.  I've been trying to get a home-brew mill setup for a while with limited success.  The idea behind "mechanical etching" is that you can theoretically panel plate the PCB before milling the traces (giving a plated through hole board).  That way you don't need to worry too much about putting vias under components, threading wire through vias and soldering, etc.  Again, this type of thing starts as a side project and then turns into a rabbit hole/time sink.[/quote]

Thanks for the information Ian and Bearmos! :P And most certainly it would be a project if I were to do it! :P It seems very interesting, but I would certainly try to make my own head, problem is making such super tiny holes. Maybe I can get someone somewhere to fabricate it for me with super super tiny holes but made of some sort of metal. From there on I could probably work on it myself such as the electronics and thing to push the ink out as well as keep the head warm. The CNCish things though might be a bit complicated, I was never that into the machining world, so yeah. :(

Also, yeah, heh, if it has any sort of gain (enjoyment and fun, some application for what you do, or just to learn something) it is fully worth it, in my opinion at least.

Also, Ian, thanks for all the information, but my printer (Lexmark crap) does not have that much control. :( Not to mention the ink is very expensive, especially the photo ink. Right now I am kind of leaving the lexmark printer idea behind and instead looking at making my own printer thing, using wax or just using a lens from designs 2x to smaller, which decreases the tolerances needed for my printer. Problem is that I have a UV filter stuck on the lens, heh. I dropped the lens a long time ago and the UV filter is stuck on the lens, have to get it off somehow. Was thinking about heating the metal rim of the UV filter hoping it expands enough to nudge it out of place, but I am not sure if the glass or surrounding material would be happy about that. :(

Anyways, thanks for all the suggestions guys! And thanks for the front page again Ian! :D
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: Sjaak on November 10, 2011, 08:09:41 am
You could use a needle from a syringe, which comes in lots of different sizes. The problem would be how to squeeze and control a supersmall droplet from it.
Title: Re: Power supply using a 2U rack chassis (56K warning)
Post by: hak8or on November 10, 2011, 04:51:11 pm
[quote author="Sjaak"]You could use a needle from a syringe, which comes in lots of different sizes. The problem would be how to squeeze and control a supersmall droplet from it.[/quote]
Fantastic idea! I did not even think of that.
I can also buy needles in different sizes on amazon for reasonable prices, but it appears the smallest size is only 3.25 mil. Not to mention that I would require a very high resolution CNC setup to be able to move it at such small increments. Maybe use a fear gears to make the axis move a very small amount but have the motor spin at a reasonable speed? This has most likely been done before, time to do some googling for myself!