My company once dispatched an engineer to solve an intermittenly working cell site issue. He soon figured out it worked when it was raining and stopped when it was dry again. Figuring it was a grounding issue, he rounded the corner outside the building to check the site's earth ground. What he found was a large copper cable stripped at the end lying in a puddle of water. The thing was, the site was mostly operational, as it was in the tropics of Bolivia. A good grounding rod and clamp solved the problem.
I saw a picture of my dad at work at GE in the 60's. I knew he was a manager when the picture was taken - he had a skinny black tie with LONG sleeved white shirt. Before, when he was an engineer, he wore a skinny black tie with a SHORT sleeve white shirt.
One of the things I like about being an engineer: I don't own a tie.
Dress codes; how quaint that sounds today. I must admit that I often long for the days when you could tell the office personel from the janitorial staff by the clothes they wore. Let me be clear, I am not putting down the janitorial staff. There is something disheartening when a man shows up for an interview as anything other than a lifeguard, wearing flip-flops and a T-shirt. It is equally disturbing to me when I see a teacher wearing the same styles as the students, ie torn & faded jeans and the like.
It is amazing what a difference grounding can make. Years ago I swapped out a changer in my console stereo and was shocked to hear a 60 cycle roar drown out any vinyl disc I tried to play. I had just paid big bucks for the changer so I decided to read the instructions (instructions are only for people who do not know what they are doing) and found a note about grounding and viola end of trouble. It seems the original changer had a gounding wire incorporated in the connection which was missing from the replacement.
Jerry Weinberg (of IBM and "Psyc of Computer Programming" fame) tells a couple of stories:
The first one had to do with women operators having a high failure rate with early IBM mainframes. Remember, these were in carefully controlled computer rooms.
Turns out, the dress code required the women to wear wool skirts and nylon hose. The keyboards would happily conduct those big static charges right to the input boards. The dress code was changed && IBM later beefed up the static protection.
The other one was really weird. The mainframes would overheat in a random manner. Much wailing and nashing of teeth, because the AC and room design was IBM standard. Jerry gets sent to investigate. The operators were nuns, wearing full habits. He noticed a couple standing over the floor grates, then the system overheat warning going off. The nuns were just trying to get cool, but the full skirts were altering the airflow enough.
I was having a look at safety boots at our local work clothing store. apparently there are various specialties including high voltage insulated for electricians and anti-static for electronics techs. I asked if I could a combination of both. It took the guy about ten seconds to say no, that wasn't possible.
Cabe - I had the same thought. Ground problems manifest in interesting ways. I once spent days chasing an ungrounded pin on an IC that produced a slight capacitive load with an 18 hour time constant that caused the output to exhibit a slight jump. If you need a ground - make sure it is a solid ground!
A secretary at a company I worked for several years ago would tell people not to walk by on the left side of her desk. One day it was me. When I asked why, she told me her computer would shut down. Not believing her, I asked her to save her work so that I could see if it was true. When I walked past on the left side of her desk, the computer did shut down. I checked to see why, and found an extension cord ran on that side, and the cord was losing connection with the receptacle.
What should be the perception of a product’s real-world performance with regard to the published spec sheet? While it is easy to assume that the product will operate according to spec, what variables should be considered, and is that a designer obligation or a customer responsibility? Or both?
Biomimicry has already found its way into the development of robots and new materials, with researchers studying animals and nature to come up with new innovations. Now thanks to researchers in Boston, biomimicry could even inform the future of electrical networks for next-generation displays.
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