Happy - zap - Birthday - zap - Nikola - zap - Tesla

I don't normally celebrate the birthdays of people that I haven't personally met, unless, of course, I get a day off work because of them, but I was over on the RF Cafe website this morning and they noted today as being Mr. Tesla's birthday back in 1865. On the other hand, the "never in err" Wikipedia lists Tesla's birthday as July 10. Hmmm. In any case, we should all know that without Tesla, electrons would only go in one direction, and that would be boring.

RF Cafe also notes (Ok, I'm paraphrasing to the (n-2)^th degree) that if you transpose the last two digits in the year of Tesla's birth, you get the deathday of Count Amedeo Avogadro. Without Mr Avogadro, millions of chemistry students would have been denied the pleasure of relieving boredom during long lectures by attempting to calculate the depth that a mole of moles would cover the earth. (Quick - who has the answer to that calculation?)

Duane Benson
Approximately 2.62 feet???

Ohm the Eskimo

...or, one of the best website names ever.

I ran across www.mightyOhm.com while checking out my web traffic source statistics. First, I love the name. Second and more important, the site and blog has some cool content centered around DIY electronics and a good set of other electronics blogs worth checking out.

Back in my day - in the dark ages (or golden age, depending on your perspective) of DIY electronics, everybody was building stuff. Our building blocks were discreet logic chips, op-amps and eight bit microprocessors and that was about it. I was an RCA 1802 guy myself. That was an odd duck processor, but it was good enough to go to Jupiter, so that's good enough for me.

If we needed to write code, we just used an assembler provided by the manufacturer or hand assembled and entered the machine code through a hexadecimal keypad. The barriers to entry were very low.

In the '80s, every thing became much more complex. The tools got expensive and DIY was set back quite a bit. In the '90s, it was all about the Internet and software DIY was king. But now, thanks in large part to companies like Microchip and Atmel, DIY is back with a vengeance. And it's both hardware and software these days. It's both analog and digital.

So here's a question: Why should a PCB assembly company encourage DIY electronics? Well, for one, it's very cool. I build junk too (I'm a Microchip PIC guy). Second, it encourage the spread of geekdom into mainstream society, and that's a very good thing. This is the technology century and the more people that get it, the better we'll all be. Finally, the commercial side of me says: engineer by day, hacker/bender by night.

Along with the MightyOhm, here are a couple of other DIY sites I spend some time on:

• www.hackaday.com
• www.evilmadscientist.com
• blog.makezine.com
• www.instructables.com
• www.electronics-lab.com/blog

These aren't the only DIY web sites, but it's a good, fun set of them. Gobs of useful information.

Duane Benson
When Ohm the Eskimo gets here
Everybody's gonna jump for joy

ESC, Day Two on April One

In past years, ZigBee, BlueTooth and WiFi have been hot wireless topics here at ESC, and those radio standards are still around. But the big news this year in wireless seems to be the re-emergence of TRF (Tuned Radio Frequency). Both Atwater Kent and Philco are demonstrating TRF systems in their booths. Atwater Kent is just down the aisle from us (or up the aisle, depending on which way you are facing) in booth 262 and Philco is doing invitation only demonstrations in meeting room C8.

I haven't had time to stop at the Microchip (booth 416) or Atmel (booth 316) booths to see if they are developing software stacks for the AK or Philco TRF systems. If anybody has done so, feel free to pass me a note here.

Bluetooth is of course widely used in consumer devices and ZigBee is mostly used in custom embedded applications. TRF looks to be targeted more along the lines of applications that would have been ideal for WiFi or WiMax, such as broad-based information distribution. The TRF systems typically will not fit a star or point-to-point model, but more of a one-to-many or server to many client connectivity model.

One of the primary advantages of the TRF is in spectrum utilization. While most other standards are set to a very specific frequency and have bandwidth limitations to go with that specific target, the TRF will vary the bandwidth with the frequency. This allows for a greater number of receivers to be set in place and allows for multiple transmission stations to coexists with simple adjustment to the individual tuned frequency. Further, with a set of relatively easy to manage adjustments, receiving units can be converted to receive analog data from any of available transmitting stations within a reasonable range.

Unlike WiFi which has usable range of maybe a couple of hundred feet, in a field, going down hill with the wind at your back, or WiMax which can achieve city scale range with a large set of transmitters, TRF requires only a single transmitting station to reach receiving units for miles and miles. It is also a scalable system. Increasingthe power of the transmitting unit will increase the specific range. It is subject to the inverse square law like any other propagating signal, but through appropriate power devices, ranges in the dozens and even in some cases, the hundreds of miles can reliably be achieved.

If you have a chance, stop by the AK and Philco booths. Tell them Duane over a Screaming Circuits referred you. They're giving me a kick-back for everyone I send over.

Duane Benson
Danger! 50,000 Ohms

Zap Goes the Large Hadron Collider

And, we're still here! Well, of course we are. They didn't actually collide anything today. All of the conspiracy theorists and doom sayers will have to wait a while for the earth to be swallowed up by a black hole. Bad wolf.

In case you have been in a black hole and don't know what I'm talking about, I'm referring to the first beam being produce over at the CERN Large Hadron Collider (LHC).

I won't go into all of the detail because a million other people have already written about it, so just go here or here. According to Wired, we may get to see the black hole sometime in late October.

Duane Benson
It sucks to be a singularity

ESC Show Design Features

Speaking of the Embedded Systems Conference, if you are attending and happen to have a cool circuit that you've been working on, drop by our booth and tell me about it. I like to show off interesting designs when I can and if yours looks like something our audience would be interested, I'll try and write something up about it.

Bring along an actual board, stuffed or not, and if you like, I'll take some pictures while on the floor.

Duane Benson
Solder is as solder does

Vacuum Tube Contamination Warning

It has been brought to our attention that a certain number of assembled pc boards have been subject to accidental contamination with vacuum tubes. It is not known at this time if the tubes are original manufacturer devices from the 1950's or reproductions recently imported from Russia. (Ref: US DOCpet0820-492.45gh.99ac138). Clearly, however the suspect vacuum tubes are not wanted and were not specifed in the original electronic design.

As shown in the photograph in the left, vacuum tubes are glass envelopes with metal plates, grids and filaments. While mostly harmless on their own, when connected to an electronic circuit, such devices have been found to consume valuable coulombs that are needed in other areas of the electronic circuit.

The contamination tends to be more extreme and more prevalent with circuits that utilize compact packages such as 0201s, Micro BGAs and QFN parts. The US Department of Commerce has estimated that upwards of 82.3% of all circuits that utilize CSP (chip scale package) devices have some level of vacuum tube contamination. Further, it is not believed that these vacuum tubes are fully RoHS compliant.

In most cases, the contamination is clearly visible and quite easy to identify. However, in some of the more extreme infestations, you may need to dim the room lights and look for glowing filaments, as seen in the photo below.

Mitigation: If you do find that your pc boards contain unwanted vacuum tubes, remediation involves a simple three step process. Fortunately, vacuum tubes tend to utilize sockets rather than thru-hole or surface mount solder. Step one, is to remove power from the circuit. Step two is to wait five minutes to allow the glass envelopes to cool. Step three is to carefully grasp the glass envelope and pull up to remove it from the circuit board.

Gordon Freeman

Who does the PCB Layout?

We've done some PCB layout surveys with our customers recently; how long it takes, what is the most tedious task, where do mistakes happen, etc.  One thing we've noticed is that you are tasked with the design and layout for most projects; and sometimes you choose to outsource the PCB layout.

We’ve been doing blog posts that help schematic designers with layout; starting with a five part series titled “5 Basic Steps to a Successful PCB Layout,” with posts on "BGA Layout" and "QFN CAD Libraries".

What makes you choose to outsource a layout?  What have been some of the biggest pitfalls and successes in bringing in an outside resource?  What have you learned from all this?  What are the costs you didn’t account for?

We are asking you to email your stories and experiences to us, to: info @ screamingcircuits.com  and are taking stories for this up to April 30, 2008.

Submitted stories will be compiled for articles in May, if you have something you’ve learned the hard way with outsourcing PCB Layout please share it with us so we can post it for others.

Thank you,

Jered

Product Development Manager

Screaming Circuits

Ouch! Shipping Can Hurt.

There really isn't much you can say about this other than what I said in the post title. (although, I'll probably end up saying a lot more than just "ouch") I don't know what kind of parts were in here but regardless, this looks seriously squished. Sometimes, though, outside appearances can be deceptive.

If it was a bag full of strips of parts, I could certainly see everything coming though the ordeal okay. Even raw PC boards could have survived, provided that are small enough. And, as it turned out, everything did survive this treatment. The parts and pcbs were fine.

Granted, this was an International shipment and it was not only handled by DHL, but also by our friends at U.S. Customs and probably a broker or other country's inspection station here and there, but it speaks to the value of good secure packaging no matter where you are shipping to or from. The box got crushed handily but there was plenty enough room for compressibility.

Duane Benson
Danger, Will Robinson
Crush, kill, destroy...

Rain Isn't So Bad

I can get pretty tired of the rain and drizzle out here in Oregon. Sometimes it seems like we spend half the year living through 40 degrees and raining. Yuck. Nothing bad, as you can see in this photo of our parking lot. Just drizzly and annoying.

Every now and then though, someone reminds me that 40 degrees and raining isn't so bad.

 

Mark from the Milwaukee, Wisconsin office of our parent company, MEC, just sent over some pictures of the place. Here's what one of the company picnic tables looks like about now. Yikes. If we had that much snow here in Oregon, they'd shut the whole state down for a month.

Duane Benson
The grass is greener on this side of the fence

Is PCB Assembly Del.icio.us?

Mmmm... Mom's delicious pumpkin pie...

Sorry. No, that's not the delicious that I'm talking about. I'm referring to the social book marking site del.icio.us. Do any of you use it? If you're not familiar with it, it's kind of like Internet Explorer's "Favorites" but portable and on steroids, but with out all th heart-damage risks of real steroids.

On of the cool things is that when you save a site to del.icio.us, you add tags, which can then lead you to other similar sites that you've saved. So if you have a bunch of game sites saved and a bunch Screaming Circuits pages saved, you click on the "pcb" tag and it filters and only shows the Screaming Circuits pages.

It also lets you know who else has saved those pages so you can go and see what other interesting and related things they have saved. You can turn off the public sharing of bookmarks, but it's a pretty cool feature. If you want to see what we've saved, you can go to del.icio.us/screaming.people.

If you want to save any of our blog articles, we have a "save to del.icio.us" link right at the bottom of every article.

Duane Benson
Delicious and nutritious