Tales From the Cube

The boss is always right, even when he's wrong
By Steve Lubs, Department of Defense, 6/11/2009
It's hard to teach an old, analog-oriented manager new, digital tricks.

Full speed ahead!
By Walter Lindenbach, 5/28/2009
Tales From The Cube: A rattled engineer needs to make sure his fix is just right for a failed over-speed sensor on an 1800-hp Solar Saturn jet-turbine-driven gas compressor.

Filter-feedthrough-failure flash
By Wayne Miller, Wayne Miller Associates LLC, 5/14/2009
Tales From The Cube: A trip to Indonesia helps one engineer solve the case of a high rate of feedthrough failures.

Mismating mix-up makes for monstrous military mission
By Bob Mason, Schneider Electric, 4/23/2009
Tales From The Cube: A technician mates together two mismatched connectors, damaging an aircraft and yielding an impossible task.

Flip-flop flap
By Holger Steffens, Ident Technology, 4/9/2009
Tales From The Cube: A USB controller in an FPGA hangs up after just a couple of seconds of operation. Simulations showed that everything was fine.

Conspiracy theory
By Garry Motter, SciMeasure Analytical Systems, 3/19/2009
Tales From The Cube: An engineer must figure out what to do when his computer lies to him and his oscilloscope covers up for it.

A lesson in humidity? No sweat
By Richard Rice, Independent Contractor, 3/5/2009
Tales From The Cube: Humidity proves to be the culprit when a medical device experiences an outrageously high failure rate.

Reversal of fortune
By Glen Chenier, Teeter Totter Tree Stuff, 2/19/2009
Tales From The Cube: Synchronous-FET rectifiers teach one designer a lesson about dc/dc converters and current flow.

Getting real with the real-time clock
By Vishwas Vaidya, Tata Motors, 2/5/2009
Tales From The Cube: The engineering team responsible for real-time motion control of 30 giant antennas composing the world's largest radio telescope must determine why antennas are drifting off target.

Noisy radio link puts brakes on racing-crew communication
By Roy Gardner, Superior Technical, 1/22/2009
Tales From The Cube: Interference is hampering driver-to-pit-crew communication via a 460-MHz FM system. Even disconnecting the driver's mic doesn't help. So where is the noise coming from?

A bad-capacitor story ends happily
By Samuel Kerem, The Johns Hopkins University, APL, Space Department, 1/8/2009
Tales From The Cube: When the same capacitor ends up charred in too many systems to dismiss the failures as statistically possible, an engineer must approach the problem via old-fashioned layout inspection.

Mysterious data errors
By Ron Tipton, TDL Technology Inc, 12/15/2008
Tales From The Cube: Input of 12 sequential 1s causes a data-collection system to output garbled data. This looks like a job for 12-gauge AWG wire.

All analog, all the time
By Jim Delmonico, General Electric, 12/5/2008
Tales From The Cube: A young engineer enamored with the simple, deterministic nature of digital design soon learns that everything, at some level, is analog.

All fail down: ESD-induced failures lead to a logical trap
By Larry Baxter, Capsense.com, 11/27/2008
Tales From The Cube: When terminals in low-humidity cities fail, it's not hard to finger ESD as the cause. Figuring out the fix turns out to be more of a challenge, especially when engineers assume a single design change should do the trick.

Align up: The case of the out-of-sync synchro amps
By Arnold N Simonsen, Electrical Engineer, 11/13/2008
Tales From The Cube: An Apollo-program engineers struggles to straighten out a system that suffers from repeated misalignment of antenna synchro amplifiers.

Stick to the schematic
By Barry Harvey, Intersil Inc, 10/30/2008
Tales From The Cube: How do you get a 1.6-GHz oscillation from a 1.2-GHz part? When you assigned an intern to build your circuit.

Repeat offender
By Glen Chenier, Teeter Totter Tree Stuff, 10/16/2008
Tales From The Cube: A T1 multiplexer generates an unrecognizable waveform when driving a new repeater. The repeater vendor repeatedly swears nothing is wrong, and the boss is getting anxious.

Good as gold
By Thomas Black, Digital Products Company, 10/2/2008
Tales From The Cube: When a vendor obsoletes a critical ADC, a system designer finds himself becoming an IC-packaging expert—and learns not to skimp on bond wires.

Passive part becomes aggressive
By Craig Hermann, Engineer, 9/18/2008
Tales From The Cube: A compterized phone-answering system works but fails diagnostic tests, while its 'backup' passes the tests but won't work. The engineer tasked with resolving the conundrum eventually corners a surprising villain.

The case of the stolen capacitor
By Glen Chenier, Teeter Totter Tree Stuff, 9/4/2008
Tales From The Cube: An engineering change order erases a design's input stabilizing capacitance, with costly results.

It’s an electromagnetic-mechanical world
By David R Bryce, Dataram Corp, 8/21/2008
Tales From The Cube: A father's lesson helps to reveal the culprit causing a noise spike in a magnetic pickup.

Dumping the noise
By Jim Christensen, Kris Design Services, 8/7/2008
Tales From The Cube: Tabletop rap elicits a puzzling click from a solid-state ultrasonic receiver design.

Ghost busting on the ocean floor
By Hugh Shane Mitre, 7/24/2008
Tales From The Cube: Spurious images in a side-scan sonar system lead to a further mystery: Why did it take so long for someone to try putting the unit into self-test mode?

Too many cooks spoil the circuit description
By Steve Lubs, Department of Defense, 7/10/2008
Tales From The Cube: It started out as a simple design idea describing a receiver for a TDM data stream. Then my boss got involved. And his boss. And his boss.

Theory of relativity visits “real-time” clock
By Vadim Demidov, Giesecke & Devrient, 6/26/2008
TALES FROM THE CUBE: What would make a logic analyzer's internal clock run faster than real time, but only while being set?

One giant leap for “enhanced” hybrid
By Stephen Tomporowski, Kaman Measuring Systems, 6/12/2008
Tales From The Cube: Space-bound product nearly fails to launch due to an "improved" circuit design that is anything but.

Temperature: Your worst enemy?
By Clark Robbins, GS Engineering, 5/29/2008
Tales From The Cube: Temperature-induced system errors gave this design team cold sweats. After realizing that identical units were failing at different temperatures, the engineers learned a valuable lesson.

Laser goes to (trim) pot
By Glen Chenier, Teeter Totter Tree Stuff, 5/14/2008
Tales From The Cube: The laser in a SONET transponder begins to behave erratically with varying temperature. Should the engineers blame the climate, or the human element?

Watch those power leads!
By Doug Marsh, Consultant, 4/25/2008
Tales From The Cube: Accidental backward filter test proves detrimental to DIPs.

In EDN's Tales From The Cube, engineers relate their most vexing design challenges— and how they conquered them. From the cubicle to the test bench to the field, hear how your peers solve real-world problems.

What's your story? If we publish it, you'll receive $200. (Target word count: 700.)

EDN gratefully acknowledges the contributions of all the engineers who share their stories here.

We also thank illustrator Daniel Vasconcellos, who delivers on short notice and adds an oft-needed note of levity.