Thursday, September 9, 2010

LM317 UPS power modules

I was surfing eBay this morning and ran across a lot of cheap Chinese LM317s- seems lots of people wanted to sell me 50 of them for around 15$ - I was thinking about what I could do with that many - realized that since we recently converted to Century Link for my phone - and i have lots of wireless -phones i could make a UPS - but then i also realized that all of the base stations had a little DC plug that gave them their power. As well as the ADSL modem, and the wireless router.  Who needs a 100dollar ups inverter when everything can be battery powered.

Looking next to me, I see the old lawn tractor battery i keep on a float charger. I could make little power modules with the 317's and hook all of the phones/router/modem  and then power them off the one battery - It has scads of power and would allow lots of hours of uninterrupted Internet surfing and phone when the power goes off in the spring like it does around here. - or at least until the laptops batteries go flat. Then we could all call mom - unless she has Vonage - she would like that....

The parts should cost under a dollar (less the plugs and wires) - Lets see... blank pcb - a sharpie, some etchant and ....

Friday, July 9, 2010

Who is my Phone Company????? - you are not going to believe this

Comcast sent me a $191 bill, and then a letter letting me know they were going to raise the rates again -which I decided was way to high,  so I started investigating other providers for the services that Comcast Provides.

The TV part of the spectrum would be provided by one of the satellite companies, but then there is the high speed Internet.

A little background - I live in what I thought was not all that rural of an area. (close to here)  The house is ~10 years old, and I switched to Vonage 5 or so years ago, and dropped my land line altogether. I used to have a DSL line before I went Cable.

I called Century Link, whom Dish Network uses to provide their Internet Connection. After quite a while on the phone with a very helpful representative it was determined that he can not provide DSL (or voice) to my address, and they were very sorry, and they did not know who did.

I called the FCC - very helpfully they refereed me to the PUC of Pennsylvania. The  best the PUC could do was snail mail me a list of  "providers".   Seems that some communications act allowed anybody to say they were in the phone business and to bill you for the privilege, most of these people probably are nothing more than just a phone number and a billing program..  No Luck.

The PUC suggested that I call my local Municipal Building. The helpful person at the Littlestown Town Hall didn't have an exact name - but she shared that "Almost everyone around here uses Century link."

Talk about running around in circles. 

Think about it - Hundreds of Thousands of tons of copper pairs strung all over the country, seemingly not used by anybody anymore!

I feel like a dinosaur - my first Job out of college was with Cincinnati Bell, planning how many people would need phone service 5, 10, and 15 years in the future. Seems that 40 years down the line, no one does.

Now almost anybody under 30 has only a cell phone number.  Only old folks like me even consider a wired land line. Makes me want to build a very large hobby rocket and put up my own satellite, and give away phone service....

P.S.  The next day I was perusing the Century Link site and stumbled across a slide in some presentation with the Vice President in charge of PA sales, along with his phone number.  So I called him.  He apologized profusely and indicated that indeed Century Link was my phone company and he would set it right.  The next day a very helpful person called me....  WOW - never hurts to start at the top and work down.....

Tuesday, July 6, 2010

Interesting Nova - The Spy Factory

After I watched a few episodes of Glee on Hulu - I wandered over to the Nova programs.  I found one that the last segment was about data mining and the NSA.  The things they were talking about, as next to impossible, rocket science type of stuff, we are exposed to every day via Google.

Add Words filter a message, or search results, as to content and puts a Ad for you to possibly click on.  The concept of transcribing a voice message is run of the mill on Google voice. To think Google is having to do it with scads of off the shelf hardware . NSA has a basement full of Cray Super computers.  Think they have a little more capability?  The Nova program has quite a few of shots of Cray Cabinets lined up in the NSA.  Kind neat in a techy way.  

I think that everyone has the capability to listen to anyone, but we are all hiding in plain sight.  Just don't attract attention to yourself with phrases like "blowing up the Whitehouse" or a phrase like "biological attack"
(Hi Adam, Say hi to Josh from me next time you see him...).

Check it out -

Tuesday, June 22, 2010

How to recycle Cheese Ball Container - KittenBall !!!!!

Enjoy some of the best Cheese Balls in the world.
Wash - add  one kitten.

Saturday, June 5, 2010

Oil Spill

How much is a barrel of oil worth - one pelican, 50 lbs of shrimp - a months rent? Money isn't the object - corporate responsibility is. From what I read BP knew the blowout preventer was defective - had to reduce the pressure when testing, it was just a matter of time...

My feeling is - All these undersea shenanigans are more for show than anything else - prove to everyone that they are trying. PR. They really know that each one has a minimal chance at succeeding.

What they probably know, but won't admit, is that the only true probability of success is the two relief wells. All they got do is intersect a 5 ft diameter hole 8 thousand feet down rilling at a 45degree angle. What do you think, could you imagine it working.

More likely they feel if they get close enough and relieve the pressure by pumping out all the oil that the other leak will slow dow to "manageble" levels.

what a crock.....

Sunday, May 9, 2010

CNC - a little one at least

Something i have been wanting to do for a long time, ever since I saw an instructable on home CNC was build one just for fun. Well the price of most of the materials makes it no so fun.

The pipes for the first one, would have come to 40-50$ at the local Ace hardware, so i concentrated on electronics. The board i was building in a recent post was a controller from the instructable.

I tried with drawer slides and I could never get the table square enough to do anything serious. Everything was always binding and the cheap steppers I picked up on eBay were just not strong enough to move the table without dropping pulses. The idea was still simmered in the back of my mind...

Then I ran across the Mantis 9.1. It had two secret ingredients that made it all come together. The rods/bearings idea, and the sacrificial table idea. The Rod/Bearing and match drilling made everything square up, and the bearings made everything easy to move with weak motors.

The flatness of the table was guaranteed by simply using the machine to mill the table flat relative to the spindle.

I guess the best thing about the design, was that it could be built cheap. He used 1/2" Plywood, and he evidently used a Shop Bot to cut out the basic parts. Looking over the design i kept seeing Reference line sand to here. I realized if I got a 3/4" MDF shelf it had three edges that were as square as I needed. I invested $5 on the shelf, and printed out the plans and just spray tacked them to the shelf and took after the it with a jig saw.

Couple of caveats - MDF makes a lot of dust - keep a shop vac handy and wear a mask. MDF uses up tools in a hurry. About half way through cutting the basic pieces, the cutting was slowing to a crawl. When I examined the jigsaw blade the teeth were completely worn down to nubs.

I got a cheap set of blades and kept it up. Later I realized the table saw had a blade with carbide cutting teeth, and it made short work of the rest of the square pieces.

Being the cheap person I am, :-), I wasn't about to order hardened steel bars cut to length from McMasters. I found a more than serviceable replacement in the metals bin at the local hardware store, and at Lowes. The 3/8" plated rod 36" long costs a whooping $3.69 and two is all I needed. Easily cut to length with a hack saw. The bearings cost 1.69 in brass, and 2.69 each in bronze (from two different stores).

So the initial investment in the Hardware came to all of 33$ so far. I wish the first store had more of the cheaper bearings.

The drive screw I am planning on using is standard 1/4" x 20 x 12" threaded rod I had. You have to pick over the stock to get one straight enough without nicks. I got a long nut used to join the rods and just threaded it over the selection and found one that the nut moved smoothly over the full length length.

I dry fit all the parts and took a picture. The wife took one look at it and said, "I thought it would be bigger" This mill has always been the prototype - and I don't really plan on using it for more that a try out. Refine the build, taking into account lessons learned make one for real. I'll have to make the next one bigger though - for her ;-)

Next will be finishing up the parts, mounting the electronics and trying it out. Stay tuned - film in a few weeks,

Sunday, April 25, 2010

found a board / sketch-a-matic for the power section

Over at general guital gadgets I found a perfect amp circuit. What I like about it is the common ground design and the usage of the 10ohm/coil.

When I worked at DAK they bought the brand of a very high end amplifier company, A common theme in all the amps was that all the ground traces went to a common point/solder point that was tied to the chassis. Prevents ground loops, and in a high gain chip power amp ground loops spell disaster. Who can hear the 1mz oscillation of a poorly designed board? That is until the magic smoke appears. This is the only circuit I found with the recommended 10ohm with a few turns of wire to prevent oscillation.

Another theme was torrid transformers - much better regulation of the voltage out, and quieter too. However i fear i will have to forgo this as a luxury. I am on a strict budget. I have some 25v ct transformers in the junque box, and the lower voltage means less power, and a smaller output heat sink - the chip is capable of ~68w - I am only looking for 10w or so. Even at that level the wife will probably yell - even if i could hear her :-)

Speaking of cheap I went yard saleing and found for $.50/ea a pair of 6" car speakers. I thought that they would do quite the job for this amp. They looked like they can handle the power, and with the full range - the acoustic guitar I am planning to hook up to this mini beast will probably sound more like and acoustic and not a buzz saw electric.

... off to google a pre-amp/tone controls for the project....

..... Googleing, Googleing .......

Found it - - a banaxle opp amp based design. Kewl...

Monday, April 19, 2010

Finishing up the PCB

Finishing the boards what i did was:

Drilled the holes.

The Last time I tried to drill a board I used up the entire kit of bits I got on eBay, using a genuine Dremel tool in an expensive genuine Dremel drill stand. The Dremel screws into the stand and it must have not been as perpendicular as it looked. Most of the bits broke just as the drill went through the board completely. Too much flex - plus the Dremel sounds way too much like a dentist drill for me to like them much. I had even purchased a regular looking chuck adapter that didn't help matters any. Not recommended.

Since then I got a real drill press at Harbor Freight - I got it for around $50 on sale - Nice bench top unit I have used quite a bit for regular sized projects. I figured that the bits had 1/8" ends , so I mounted up the bits, set the speed as high as it would go, and drilled all 64 holes without one broken bit. Considering I spent less on the big drill press than I did on the Dremel tool, I can't recommend the bench top unit enough. Plus while I was there I spied a grab bag of small drill bits and picked up a set that I used this time.

Tinned the traces.

I was initially to intimated to try surface mount soldering, looking at the Sparkfun tutorials and then actually doing it is sometimes very different.

For those of you out there contemplating it here are a few tips. Especially if you made you own board and it's gleaming copper traces are staring you in the face.

Buy one of the flux pens. I initially put a little dot of solder on each pad to solder down the chip, however when i tried to get it aligned these little dots got in the way - the pins wanted to fall to either side. I tried to get the solder bump a little smaller, but the iron wouldn't pick up as much as I needed - then the little over the head light bulb went on and I just covered all the traces liberally with the flux (you may need to push the pen down a few time to get fresh flux flowing I did). Then all I had to do was was drag the soldering iron along each trace, trailing a small blob of solder and leaving a nice thin coating of solder. Only once in a while did i need to refresh the blob of solder on the tip of the iron.

I brushed the Flux pen over the pads again for a fresh coat. Then I heated one of the corner pins, dropped the chip down on it, checked to see that it was stuck, and did the same to the other corner of the chip. After that it was just a matter of touching the iron to each pin , and inspecting after all were touched - they all had a little meniscus of solder from the IC pins to the pads. Touching with a pin I tested each to see that they were well and truly stuck.

I have to mention the soldering station I got. A Weller WES51 Analog Soldering Station, Power Unit, Soldering Pencil, Stand and Sponge. The analog is quite sufficient, who cares if it is 600 or 611 degrees, I don't. It is a absolute joy to use, and one of its best features is that it turns itself off after no use in 99? minutes. It cost close to $100 on sale at Amazon. As they say - you remember the quality long after you forget the price. Highly recommended.

Cutting the baoards.

Well i could have done it many ways, as soon as I get a real paper cutter I will try one of those, but I have a scroll saw, and it does the job quite nicely. Wish they made saw blades designed for cutting FR4 for the saw.

Lessons learned and notes for next time

  1. Use real tools - drill press and soldering station.
  2. Hook up a the hose from vacuum to the drill press to catch the drill dust.
  3. Look for real paper cutter at the yard sales.
  4. Get a new prescription for the glasses I use in the shop, all these tiny precision tools, parts and soldering gives one a headache.

Sunday, April 18, 2010

Fun in the shop etching Printed Circuit Boards

I started a project of documenting and organizing all the various IC's I have acquired over time. Up till now they were in a little plastic box that I consulted time to time.

I stopped by Staples and picked up a handful of report binders with pockets - they conveniently had them on sale for $.50. The binders I was looking for had a insert for three hole punched paper and pockets. I printed out the data sheet for each part, 3 hole punched it and stuck the part into the pockets. Now I don't have to run to the computer when I pick up an IC I don't remember.

Being of an age where seeing very small parts is getting harder, I tended over time to accumulate a lot of soic parts, and they sank to the bottom of the sample box.

I finally purchased an inexpensive adapter board from dipmicro electronics that let me mount most of them for prototyping. I was suitably impressed of the quality of the board and @ a quarter a piece I got a bunch. One side lets you mount soic and the other ssop.

However there were a few parts that had wider spacing and no one seemed to have a break out board for them. Or should I say in my price range - I am, after all, a cheap son-of-a-gun.

So I decided to whip up one of my own. I bit the bullet and set aside the time to finally get proficient enough at Eagle CAD to make a passable design. After a few false starts I managed to get the libraries loaded and Eagle set up, thanks in no small part to a Spark Fun Tutorial.

First I could not find an outline for the part I wanted to use (DS2321 RTC chip). Google found a person that had designed a board with the part, and I set out to modify his layout. I got all hung up on making a library out of it for later use, after all this was just supposed to be a board for any so16wide parts. A forum post showed me how to make a library from the original. I was now drawing a hobbyist quality, wildly inefficient, but functional design. I had one in an hour or so. Now it was ready for toner transfer.

The last time I made a board I had purchased some wildly expensive coated picture paper. I remembered reading someplace someone using magazine covers, I grabbed a copy of Information week - the cover seemed a bit thin to me - but I was in a hurry and decided to try it. I found a back cover that was mostly white and it printed just fine in the laser. It took a bit to realize I was not enough of a pro at Eagle - I had managed to get some stuff on the top layer and some on the bottom - But after I set it to print both the top and bottom together, everything worked out swimmingly.

I now was on familiar turf ( I thought). I tossed a pieced of freshly scrubbed PCB stock onto an old re-purposed waffle iron to heat up - and ran around to locate that darn roll of masking tape. Finally taped it to a very warm board and ran it through the laminator a few times.

Looking through the cover at the toner - there were some supicious spots that I though had not stuck sufficiency, grabbed the Clothes Iron and cranked it up as far as it would go - folded a paper towel to made a pad, and pressed hard as I could to make sure the toner was re-melted onto the board.

When I put the board into a hot water bath I was very pleasantly surprised, the last time it took almost an hour to get the photo paper soft enough to get it away from the toner and off the board. This time the paper just peeled away in a few minutes, and came away very cleanly. Just a few wipes with a sponge was all it took to rid the toner traces of any paper residue. I guess it had to do with its thinness.

I guess photo paper is meant to last and was considerably thicker. It took forever to get soft enough and stuck perniciously to the toner. I guess I will renew that Information week subscription they keep hounding me about - if for nothing than to have lots of cover paper :-)

I could see where I had pushed too hard with the iron - it looks like the toner had smeared onto the board, a few pokes with a Xacto knife and and some touch up with a fine point Sharpie and it was ready for the etchant.

Then came the fun part where I get to dress up like a serious dork. Donning lots of protective clothing, chemical safety goggles, breathing mask, and nitrile gloves. I got out some Hydrochloric acid/Peroxide etchant that had to be almost a year old, and dropped the board into the cold solution. It went slowly, I had seen in some video where someone used a little sponge brush to rub off the disolved copper and let fresh etchant at the board. So I brushed and brushed and swore to next time I would take time to heat the etchant and I would flood fill that unused part of the board so that not as much copped had to be removed.

Pretty soon the etchant was so dark it almost looked like ferric chloride. Just about then, the door bell rang and I went to the door worrying what the caller would think with me a dressed up like a toxic spill worker. Just my Brother-in-law and my sister. The board sat there in the etchant for the better part of an hour as we discussed pleasantries.

When I got back nothing seemed to have happened to the board much, so I quickly whipped up a new batch. WOW. A new batch of etchant really works fast - like in another minute the board was completely etched.

A quick wipe with some acetone and the bare copper was exposed, and the family was suitably impressed by the little lines of copper running all over the board.

This morning when I got back down to the shop - the dark murky old etchant was a bright green and almost clear. I goggled around and found this weighty tome explaining how, just by exposing the etchant to air, it re-generates it given enough time. This was about 3/4 cup in a closed plastic container overnight- not much air - but evidently enough. I grabbed an old coffee container, for it's opacity, and poured both batches together for next time (have to get an acquarium pump)

Now its time to clean up all the spills and wash down the bench-top so I can get out the drill press and Scroll saw to do the necessary machining. Etchant is very, very, very corrosive and it will rust up any tool that it touches - last time I managed to spill some unknowingly onto my favorite set of needle nose piers - that will never happen again.

Time to go break lots of little expensive carbide drill bits.

So lessons learned, and notes for the next time
  1. Spend some time with Eagle cad futzing around - just to get comfortable.
  2. Use magazine covers to print.
  3. Don't press so hard with the clothes iron, or try not using it at all.
  4. Make sure to regenerate your etchant with a cap full or two of Hydrochloric acid before starting to etch.
  5. Heating it up first wouldn't hurt.
  6. Look at the yard sales for an aquarium or other small air pump to regenerate the etchant.
  7. Find really, really, cheap place to get all those tiny carbide drill bits that are so fragile.

Sunday, April 11, 2010

Photo Circuit Boards

Custom Photo Circuit Boards

I have been investigating how to make precise homemade circuit boards. I have tried toner transfer and have been disappointed more time than not.

Back in the day when I had a full blown dark room setup – making boards was easier, partially because you could actually see the parts, and you could run down to any number of local distributors and get chemicals and boards. Plus a 1/16” drill did the job for most off the drilling.

25 years later I am in the mood to try my hand at it again. When there is no PCB for sale, there is usually an eagle cad brd and sch available.

So I installed Eagle Cad from here. Impressive package, a steep learning curve to make you own boards, but since I had the artwork already I just opened the files and looked at them. Printing them yields a positive – perfect for toner transfer but I am a little more adventurous.

To convert the positive to negative – I installed ghostscript and gsview. Eagle cad can output Postscript files so these applications interpret them into a printable version.

How I did that

Open the brd file in Eagle – then from the File Menu select Cam Processor. The layers ( in this case there was only one side so I selected bottom, pads and vias. Some people recommended that the fill pads be checked – but I find that it makes drilling easier if the holes are there to help position the drill.

On eBay there was a place that sold 6”x8” sheets of resist that could be applied with a laminator or with a hot iron – the critical piece of information that I gleaned from their page was you could use velum or tracing paper to creative the negatives.

A United states source on ebay (jaded_caveman) Dry Film Photoresist Sheets+Developer

Here is a link to a great video – using positive pre-sensitized boards. Circuit Skills: Circuit Board Etching

A lot of good information here : PCB Processing Manual