My uncle was in the Signal Corps in the Pacific in WWII. He used to tell me about how the rats would try to get into the transmitters to get warm and dry out. Of course the results of a rat getting across a several KV plate supply is somewhat more spectacular than an insect across a low voltage switch.
I had a similar experience when I lived in the Dallas TX area. My house had a LV lighting system (12VAC) around the exterior and walkways. There was a 300VA or so transformer that fed the system, with 2 separate outputs (dual secondaries on the xfmr). I started having intermittent outages on some lights, but the bulbs were OK. There wasn't much voltage at any of the fixtures on one of the outputs. I traced the apparent short down to a specific point (all wiring as buried so I really wanted to only have to excavate where the problem was likely to be) by locating the first fixture that had minimum VAC at it. I started to dig, and was quickly attacked by a bunch of fire ants! After I did away with them (took a full day for all to die), I dug down and found their nest had been located surrounding a splice insulated with some badly chewed away electrical tape. Thus a short between the conductors was created. Unfortunately, the long-term overload had weakened the one secondary; a couple of weeks after the wires were re-taped (very heavily!), that secondary winding opened up. I sent it back to the manufacturer, who was amazed that the primary protection hadn't tripped, and so the fusible link inside the winding had opened. The resistance of the wiring to the short location was apparently just enough to let the winding overheat without tripping the circuit breaker in the transformer primary. They sent me a brand-new transformer at no charge! When a similar outage occurred some time later, I concluded that the ants really loved the AC field (maybe got high on it!), and made future repairs with even more protection on the splices.
Ann, when I was designing appliances I would sit down with the marketing guys and have them press buttons on a sheet of paper. I would have them step through the keystrokes needed to implement what they had specified, and often times their fingers were doing a dance that looked like a version of "Twister" made for hands. If the feature they wanted proved too complicated they would sometimes add a special button or knob just for that feature. From their standpoint, now the nifty new feature was advertised because the consumer would see that feature button right on the front panel.
I don't understand why the industry can't realize that the american consumer just wants something that is easy to run. I really don't need 17 different cycles to wash my clothes in. I do want to be able to lock it out so my child doesn't accidently run the cat through the wash, but I don't have a PHD in unlocking my washing machine. Is it really that tough.
Buttons and options can be difficult. On our GE front loader, a certain button combination will lock the control panel. Unfortunately, this option is not shown in the manual and required a service call by a technician to show me how to reset the lock.
A friend of mine was visiting another guy one saturday morning and his friend remarked that his power bill was about zero the month before. My friend (a EE) said they should check to see if the meter was turning. Sure enough a moth had expired and was stuck in the meter works. My friend banged his hand on the meter and the bug fell out as the home owner screemed "OH No".
I recall the issue of the fire ants, notarboca. Some time in the last 20 years, a linear accelerator was planned for Texas (I believe it was eventually built there), but it ended up getting bogged down in debate about fire ants. Apparently, some engineers believed that the accelerator's large magnets would attract ants.
Wal-Mart will hold its second Made in the USA Open Call July 7-8, at its headquarters in Bentonville, Ark. The event will be a repeat effort by the world’s biggest seller of consumer goods to increase the amount of US-made products it sells in Wal-Mart stores, in Sam’s Club members-only wholesale outlets, and on walmart.com.
From design feasibility, to development, to production, having the right information to make good decisions can ultimately keep a product from failing validation. The key is highly focused information that doesn’t come from conventional, statistics-based tests but from accelerated stress testing.
There’s a good chance that a few of the things mentioned here won't fully come to fruition in 2015 but rather much later down the line. However, as Malcolm X once said, "The future belongs to those who prepare for it today."
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