Category Archives: Reviews

Really Small Drill Bit Set

For those of you who could use a set of really small drill bits, you might consider this set that ranges from 0.3 to 1.2mm in diameter. The cost is just $3.99 at Amazon. The company selling these is based in Asia, so the shipping time is about three weeks.

FullSizeRender

Pros:

They come in a very nice plastic case and the bits themselves are cushioned.

They fit the 1/8-inch jaws of a standard Dremel tool.

Cons:

The size markings are etched into the shank, so are difficult to read until just the right angle of light hits it – a magnifying loupe is a plus. They thinner bits break very easily, so it’s best to use a sturdy drill press for these, rather than a Dremel tool.

2014 Blog Highlights (Part 2)

Using current probes to estimate E-fields – Current probes are one of my most-used EMI troubleshooting tools. Frequently, a product’s I/O or power cables are often an appreciable fraction of a wavelength, so are a source of radiated emissions. This occurs if common-mode currents are allowed to travel along the cable or cable shield. Current probes may be used to measure these small (frequently in the uA) currents. Reducing such noise currents on those lines can often reduce the radiated emissions from the equipment under test.

Current probe Fig1-600

Gaps in return planes – yes or no? – As a participant during the panel discussion on EMC versus SI at the recent DesignCon 2014, I sensed (along with some in the audience) that there was disagreement as to whether it was OK to cross a gap in the return plane with a high speed, fast-edged, signal. Unfortunately, there was too little time in which to come to an agreement or to illustrate the conditions in which it was OK, or not OK. This article explains why this is NOT a good idea.

Gap in Plane-CM

Troubleshooting EMI on your bench top – If your product is failing radiated emissions at the test lab, it’s often more cost-effective to perform any detailed troubleshooting at your own facility where you can take time to methodically isolate the source and try out several potential fixes. Unfortunately, many companies don’t have the equipment or training to make these simple measurements. This article describes a easy method for measuring radiated emissions and providing a rough estimate of pass/fail.

Fig1-TS RE

Review: Signal Hound BB60C real time 6 GHz spectrum analyzer (Part 1) – The Signal Hound series of spectrum analyzers are about as small as three large-size Hershey chocolate bars stacked on top of each other. The unit offered for review is the recently released model BB60C real time analyzer, which can tune from 9 kHz to 6 GHz with a dynamic range of +10 to approximately -158 dBm (DANL, which is dependent on resolution BW). It can easily fit within a standard briefcase with room left over for a medium sized laptop.

Signal Hound BB60C 20140701-104

Review: Signal Hound BB60C real time 6 GHz spectrum analyzer (Part 2) – In Part 1 of this review, we discussed the basic architecture, specifications and controls of the Signal Hound BB60C real-time spectrum analyzer. In Part 2, we’ll show you some actual measurements and several screen captures.

STM32-F4 Controller 1 to 500MHz-600

 

 

2014 Blog Highlights (Part 1)

Sorry about getting a little behind in postings. Here are some of the highlights of postings on the EDN.com site:

Review: inexpensive RF generator – During one of my presentations on low-cost EMC troubleshooting tools at the IEEE EMC Symposium last August, one of the attendees, Doug Miller, mentioned a small PC-controllable RF generator for just $190. Of course, I had to buy one and try it out!

Fig1-TPI Synthesizer-600

Review: Windfreak Technologies SynthNV RF generator – Every once in a while, I discover a product that is so incredible I wonder why it hasn’t been publicized more widely. This is the case with Windfreak Technologies $599 miniature RF generator, the model “SynthNV” (Figure 1). In case you’re wondering, their company is named after the owner’s sailboat!

WF Fig1

Detecting ESD Events – In my experience, electrostatic discharge (ESD) issues have now become the second-most prevalent issue other than radiated emissions. If you find your product has exhibits random upsets, such as loss of data or unusual circuit resets, it could very well be caused by ESD. This article describes several methods to detect these events.

ESD Detector

Harmonic Analyzer Tool – Because of their typically fast edge rates, crystal oscillators can generate a large number of high-order harmonics. This harmonic analyzer was created by my coauthor, Patrick André, with additional formatting tweaks by myself. I find this really handy to calculate harmonics from clock oscillators.

Review: TTi PSA2702T handheld spectrum analyzer – One thing that I find handy is a small hand held spectrum analyzer for use in troubleshooting EMI issues. As I travel a lot in my job, I like to take the minimum amount of test equipment possible. Unfortunately, most good quality analyzers are large, heavy and expensive. About ten years ago, I ran into the Thurlby Thandar Instruments (TTi) PSA2701T and have used it extensively since then. During that time, I reviewed it several times. In May 2013, TTi completely redesigned and repackaged this analyzer and released it as the PSA2702T. This is a review of the new PSA2702T, which I have used for several months now.

PSA2702T

Review: Right the First Time (Ritchey)

One of the most common questions I receive as an EMC consultant have to do with PC board design. And, no wonder. As clock and data frequencies increase towards 10 GHz, proper PC board design becomes an imperative for proper functioning of the system. The typical “rules of thumb” we used for low frequency boards no longer seem to apply.

RFT_coverweb

So, when I ran across Lee Ritchey’s self-published book, Right The First Time – A Practical Handbook on High Speed PCB and System Design (Volume 1), I was intrigued. Both this book and the follow-on volume 2 (Advanced Topics) are available on his web site. Volume 1 is now out of print, but available separately as a 295 page PDF file for just $25. However, both volumes may be purchased for the special price of $95 (the price of volume 2, alone) – a deal I highly recommend.  I’ll be reviewing volume 2 later. More…

Book Review: The LTspice IV Simulator [Handbook]

I recently published a review of the following book in EE Times.

One of the most popular versions of SPICE today is Linear Technology’s LTSpice IV. This free and full-featured SPICE modeling software runs on PCs and includes schematic entry, great graphical plotting, and is very fast. While Linear Technology provides a basic on-line user guide, until now, there really hasn’t been a very comprehensive resource on using the software. Earlier this year, components supplier, Würth Electronik, alleviated this missing reference with their 700+ page book, The LTSPICE IV Simulator – Manual, Methods and Applications by author Gilles Brocard.

The software will run on either PC or Mac. To read more and add your comments, click here…

 

The book, The LTSPICE IV Simulator, by Wurth Electronics.

The book, The LTSPICE IV Simulator, by Würth Electronics.

Review: Grundig Mini400 AM/FM/SW Radio as ESD/EMI Detector

I recently upgraded my old Radio Shack AM radio, which I used for ESD detection, for the Grundig (Eton) Mini400 AM/FM/SW pocket radio. This $30 (street price) pocket-sized radio (4.25 x 2.75 x .5 inch) seems to have plenty of sensitivity to nearby ESD events. By tuning off-station, you can clearly hear the “clicking” from the ESD from several feet away. Using one of these radios is handy for correlating random product glitches with possible ESD events.

Grundig Mini400

I’m also finding it’s quite useful in locating low frequency switch mode power supply (SMPS) EMI. The shortwave bands are especially sensitive to this noise. For example, the CFL and newer LED lamps each have a SMPS built in to their bases. The multitude of these lamps in homes today can create a cacophony of EMI well above the shortwave spectrum. This is a real issue for amateur radio operators and those who enjoy radio astronomy.

The radio has an analog tuner with digital display. It runs on a pair of AAA cells and seems to have plenty of audio. It also comes with a padded case with belt loop. The only caution I might point out is that the power switch is a momentary button, which could get pressed inadvertently if pressed during shipping or if packed tightly in your troubleshooting kit. The radio does have a “Lock” switch on the side that disables the power button, so that ought to alleviate that issue. You just have to remember to unlock the radio prior to use.

Frequency ranges:

AM: 517 to 1782 kHz (1 kHz steps)

SW1: 5.700 to 10.380 (5 kHz steps)

SW2: 11.600 to 18.450 (5 kHz steps)

FM: 85.8 to 108.7 MHz (0.1 MHz steps)

I bought mine from Radio Shack for $40, but you can find one on Amazon.com for $30. Recommended.

NEW! EMC Pocket Guide Published

IMG_2318

Randy Jost and I just released our new EMC Pocket Guide, which includes some basic product design guidelines and a whole bunch of reference data, charts and graphs that a product designer or EMC engineer might require on a day to day basis. The guide is available directly from the publisher, SciTech Publishing, for a special price right now of just $20 (regular price is $21.95). I’m not sure how long this special pricing will be in effect, so you may want to order a copy now.

DESCRIPTION

Every electric product designed and manufactured worldwide must meet electromagnetic compatibility (EMC) regulations, and yet, EMC compliance staff levels have been cut to the bone in companies large and small. If you are a working engineer or technician, the Electromagnetic Compatibility Pocket Guide is the first place to look while designing for EMC and your guide to thwarting electromagnetic interference.

KEY FEATURES
* Concise, constant-use guide addressing the most common reasons for compliance failure.
* Get needed answers quickly and move on to other design issues.
* Pocket-size, easy to carry and use, made of durable stock for continual service.
* Available for customization with your logo and marketing copy if you order in quantities.

TABLE OF CONTENTS

EMC Fundamentals
EMC Design
EMC Measurements
EMC Standards
Using Decibels
Frequency vs. Wavelength
Commonly Used Equations
Miscellaneous Information
Useful Software
References
* Books
* EMC Magazines
* EMC Organizations
* EMC Standards Organizations
* LinkedIn Groups
* Common Symbols
* EMC Acronyms