Hi again friends. Before we spotlight the 2 remaining Rings of the Big Top,  I thought it would be helpful to share another popular overview / construct. 

We already discussed SOURCES and that they come in 2 flavors : Conducted & Radiated .  That forms 1 dimension or axis of the MATRIX of EMC.

( No, this is not quite “THE MATRIX” Warscharski brothers’ movie. But alluding to a movie is a surprisingly powerful concept, as in a creative thinking mash-up tool called “Movie-Minds” from . Yes , mixing work with play & fantasy can be quite productive. But more on that in a later Sideshow .)  

Turning back to the other problem axis or dimension, we noted the physical actors fall into 2 colors :   Sources & Affected Devices. That forms the other *orthogonal* EMC MATRIX axis.

To unify this all using a popular presentation rubric:  Its a 2 by 2 MATRIX or a 4-quadrant world. Thus all EMC problem / challenge phenomena fit into one of those 4 boxes. This just one more way of getting your mind wrapped around the problem . Its not the quick and easy answer,  but it helps the thinking.  

                   ||        Source        |      Affected Device _______________________________________________

Conducted     ||             x           |               y


Radiated       ||             z           |                t

Some examples : A cell phone transmitting can be a Radiated-Source,  z . An automotive control is a Conducted-Affected Device,  y.  A CFL bulb is a Conducted-Source, x . A consumer radio is a Radiated-Affected Device,  t.

Now, yes , as we’ve previously warned , a physical device can exhibit aspects of both flavors – Radiation and Conduction *and* both colors – Source and Affected Device.  Our job as the EMC Engineer is to determine which of the quadrant behaviors  dominates the problem and Pareto rank-order the possibilities down to the most likely root cause & effect in the situation. This is the intersection Art and Science. Where Experience teams up with Analytics . Where you put on those RF-Sunglasses and *visualize* the waves traveling from Source to the Affected Device. Where like Nicoli Tesla, you see the schematic  and drawing of the machine visualizing how the electrons flow around properly  *or not* when the Source is present.

So take the Blue Pill like Neo and follow Morpheus down the (EMC) rabbit hole and see just how far it goes. Don’t be like Switch and regret not taking the Red pill so you could wake up and believe whatever the Matrix wants you to. There is no turning back now anyway. You already swallowed the Blue pill, that’s how you got here.

So relax and have a snow-cone from a midway vendor or a cookie from The Oracle . Come-on and follow me , Top Hat and Microphone into the next spotlighted Ring where we’ll amaze and dazzle you with more of The Greatest EMC Show on Earth .

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I Direct Your Attention To The First Ring, Sources !

Hi it’s me again, the guy in the Top Hat , standing in the spotlight of the First Ring under the Big Top. There see the Lions, Tigers, Bears and Elephants who roar, snarl , growl and trumpet. Their sounds travel well beyond the ring and powerfully impress the audience. The animals  paw and pound the ground under the watchful eyes of their trainers .  If they were to escape , they would wreak havoc on the crowds and the whole circus grounds. Even just their voices and movements already affects some of the audience. These animals are metaphorically the Sources in the EMC Circus.

Sources include the licensed Radio information Broadcasts on frequencies covering  AM,  Short-Wave, FM , Television, Police, Fire , Public Safety , Cellular Phones , 3G, EDGE, WiFi, Bluetooth, GPS, Radar, more… 

Sources also include *unintentional* broadcasts or Emissions that  do not carry information . That includes the 60 Hertz AC power distribution system or the variable frequency drive power to an electric motor in an assembly line or in a hybrid-electric vehicle. There’s the high voltage spark that ignites fuel mixture for internal combustion engines. Even a simple electric motor in a home hair dryer has spark-generating commutator and brushes as well as the myriad of small DC motors in automobiles and toys. The happy Neon Sign or ( CFL ) compact fluorescent lamp has an interrupted voltage and current flow creating the glow from within their glass tubes .

Nature’s Sources includes spectacular Lightning and its weaker cousin Electro-Static Discharge or ESD from those dry days when you rub your feet across the carpet and your finger discharges a spark to the door-knob .

Whenever there is a difference in Voltage or driving force or Potential  across a path-way , then a current will flow . When that path-way includes other unintended devices, they will experience the voltage and current . Additionally the voltage and current flow action will launch a field which will radiate through space , again potentially exciting an unintended device.

So to the EMC engineer,  the First Ring of Sources is all around us , made up of many different animals . One or another of them can be a threat to the normal functionality of a device. The trick is determining which ones are the likely threats to the device of choice, based upon the nature of the device as well as the likely animal acts in the First Ring when the device must operate. Happily we have Standards which specify which sources are likely to influence a device based on its nature and intended use . The Standards “alphabet soup” as I lovingly refer to it , includes contributions from many agencies of governments and industry such as SAE, IEEE, ISO , EIA, CISPR, VDE, VCC, CE , EU, CSA , … There is even a subdiscipline of EMC Engineering devoted to developing , managing and selecting Standards .  I leave that to those experts.   I personally prefer to look to the physics and product application aspects to guide “design for EMC” efforts. 

So as the spotlight follows me stepping out of the First Ring,  I know I have only tantalized you with a brief story of the Sources. You were hoping to see a lion leaping through a flaming hoop ? All in good time . First we need to visit the other 2 Rings to get the big picture before we can understand how and why to get the lion to jump, let alone thru a hoop and then with fire to boot. Patience Grasshopper ! See you soon..

Copyright 2010 JDM LABS LLC , all rights reserved

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Rosetta Stone : Guide to the EMC Circus

Here I’ll describe a Roadmap, Guide or Rosetta Stone to help you navigate the ongoing EMC discussions.

The Circus Big Top archetype has 3 rings . Here its the over-arching Model , Construct , Analogy or Metaphor to the EMC World. In Ring 1 are the “Noise Sources” such as radio and TV broadcasts; hear the road of the lion ? Ring 2 the “Signal Path” includes the air around us and cables ; watch the high trapeze athletes leap astoundingly and effortlessly from swing to swing. Ring 3 the “Device Affected” could be your laptop or iPod ; watch a clown get wacked with the oversized mallet.  Please note these few examples are not all-inclusive ; we’ll come back again to show you lots more. Also some devices and systems have elements of 2 or all 3 rings within. That gets pretty exciting but we can still deal with it , just keep your head. We’re confident that all EMC problems and physical pieces can be broken down and categorized into those 3 big groups .  Finally under the Big Top the person in the spotlight with the Top Hat and megaphone directs the audience’s attention to the important actions. I’m that guy , so please follow along now and do watch for the elephant droppings.

Surrounding the Big Top are the Sideshows. These small tents accommodate a single performer giving an intimate audience experience. There you can focus on a single skill like card magic or fortune-telling. It’s really up close , fun and personalized with interactions. In the EMC Circus, Sideshows deliver focused lessons; expanding and drilling down into the Big Top’s 3 rings : Source , Path and Affected.  For example, the “Path”  Sideshow will reveal your good or bad fortune , using Dr. Tom VanDoren’s crystal ball of the 4 Coupling mechanisms.

Moving on to the Midway there are games of chance & skill . Shooting at moving targets or knocking down <weighted> milk bottles. In the EMC Circus Midway we’ll entertain with examples of applying the skills and principles you learned in the Sideshows but with real-world twists & fun. You can even win gaudy prizes by playing the games over and over.  

Of course there are the Amusement Park Thrill Rides like the Ferris Wheel and Tilt-a-Whirl. We’ll be doing EMC  Demonstrations and Experiments of physical principles that will have you breathlessly hanging on to your inverted seat. The 2010 IEEE EMC Symposium featured a gaggle of such heart-pounders.

And what would the Circus be without Street Performers wandering the Midway ? Here’s a chance to interact with a Captain Jack Sparrow impersonator . Yes interpersonal skills and communications are part of the EMC craft. If you cannot convince your audience you’ve got the goods on the problem , you’ll never be able to sell the solution. So we’ll give you some perspectives and tools to be most convincing.

Refreshments !  Take a Break. Sip a cool drink and have a “so bad its good” Funnel Cake . We all need a bit of diversion during the tough job of problem solving . A brief change of venue often provides that something to get un-stuck or see the problem in a new and useful light. So here we’ll have some creativity aids and diversions but no time wasting video poker , thank-you.

So there’s a quick guide to the EMC Circus. Grab your stuff , get your season pass admission ticket (sign up on the right-hand column for your RSS Feed) and join me in the Big Top as we direct your attention to the Big 3 phenomena in the ever-moving spotlight .

Hurry! Hurry! Hurry! Step This Way . As ELP Sang ” Welcome back my friends to the show that never ends … come inside , come inside”

Copyright 2010 JDM LABS LLC , all rights reserved

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Welcome to the EMC Circus !

Why “EMC Circus” , you may ask ?

Stories of the Circus tell of multiple rings , each with simultaneous and different kinds of entertainment. You cannot watch it all but you try. EMC is kinda like that. So much going on in IC’s and circuits and boxes and systems and the world around . How do you sort it out ? What’s a cause vs. an effect ? What is truly important vs. what’s a don’t-care. So little time , so much input overload.

To succeed with this EMC stuff you need an approach , a method, a viewpoint ; a way to sort it out and get to the bottom of things,  to get the design working smoothly and meet the triple constraint : Cheap, Fast & Good .   That’s where I come in,  applying  decades of experience looking for EMC effects and providing effective solutions .  As time goes on,  I’ll share performances from my EMC Circus experience that will inform, inspire and amuse .  Looking forward to engaging with you , to best serve your needs .  jdm

Copyright 2010 JDM LABS LLC , all rights reserved

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Hello world!

Well fans , I’m starting on

I’ll be sharing my thoughts and observations on EMC , ElectroMagnetic Compatibility and other related important subjects over time .

So what is EMC anyway ? It is the design capability of electronic devices to not create signals and waves of sufficient strength to interfere with other devices. Conversely , an EMC compliant design will operate fully & normally in the presence of signals and waves from other devices . Other folks refer to the subject and phenomena as EMI ElectroMagneticInterference  or RFI Radio FrequencyInterference.  I prefer the positive spin word  “Compatibility” because engineers are taking action to assure all things work together.

For example , using your cell phone does not cause your MP3 player to do strange unintended operations or deliver distorted music , right ? Likewise using the MP3 player does not cause your cell phone to drop a call,  right ? Or,  your car drives & works like normal and expected when you use your cell phone , despite the presence of 50 <or more> microprocessor controlled black boxes running your car while your cell phone emits a Radio Frequency (RF)  signal linking it to the cell tower. Conversely all those car’s black boxes do not emit enough signal energy to upset your cell phone call.  

This happy harmonious world exists because EMC engineers do a good job designing and verifying performance , by testing against well-developed standards and physical principles.

A great source of EMC info is the IEEE EMC Society   In the Chicago area , the local chapter is

Soon I’ll have a fact , opinion or technical tidbit to share.  Till then you can find out more about me at  

Have a compatible day !   jerry

Copyright 2010 JDM LABS LLC , all rights reserved

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