January 15, 2012
Category:
This is one of those medical diagnostic
mystery stories. Except, as you can tell from the picture, it is
not about diagnosis of a human. Rather, it is about diagnosis of
a machine. The photo shows the inside view of a Fellowes SB-87Cs
paper shredder. I bought this several years ago to shred several
boxes full of old charts. Given the intended purpose, I paid
extra for a heavy-duty model that could shred many sheets of paper at
once, cutting them into tiny diamond-shaped flecks. It worked
perfectly well, for many years. However, it eventually developed a problem. It would still shred,
but it would shut off after about five seconds of operation.
Repeatedly.
Due to the fact that the shredder mechanism itself was still fine, I
couldn't bring myself to throw it out. But I also couldn't
imagine paying for a repair.
After some investigation, I noticed that there is a sensor
inside, The sensor shuts off the machine when it detects that the
bin is full. The bin holds the shreds of paper. When the
level of shredded paper gets to the top, the paper pushes up a little
plastic flap. On one side of the flap, there is a light-emitting
diode (LED). On the other, there is a photo sensor. When
the flap goes up, it blocks the light, which causes the sensor to stop
conducting electricity. This causes the shredder to stop, and
causes an indicator light on the top to go on.
The indicator light would go on after about five seconds of operation,
even though the flap was still in the down position. Why?
After a little investigation, I found that the LED was burned
out. Aha! I checked my diagnosis by shining a flashlight at
the photoresistor. The machine worked when the sensor was
illuminated. Simple enough.
Even though the unit is not really built in a manner that would make it
easy to repair, I did manage to remove the LED, check the voltage (it
operates at 3 volts) and find a replacement. A quick trip to the
parts store was in order. I then managed to get the replacement
fitted back inside. I confirmed that the LED would light up, and
reassembled the whole thing.
Problem.
The new LED did not make any difference.
Even though the sensor was getting light, the machine turned itself
off, and the indicator light indicated a full bin when in fact the bin
was not full.
I noticed something odd. The LED would remain on, even when the
machine was turned off. That explained, perhaps, why it burned
out. It had been on constantly for several years, with the
machine being plugged in. But it did not explain why the machine
would turn off after five seconds, with a functioning LED.
More investigation. I had to defeat safety mechanisms that
prevents the machine from being turned on with the door open and the
bin removed. Mindful of the possibility that the thing could
destroy my fingers, I turned it on and watched a piece of paper get
shredded. It would shred about a half sheet, then stop.
Bizarre. When the operating switch was turned on, the LED
stopped
shining steadily. Instead, it would blink every five
seconds. I figured the blinking caused the machine to shut off,
although it was not entirely clear why it did not restart itself.
Perhaps it was designed to wait for some indication of human
intervention before it would restart.
After another trip to the parts store, I attached a little battery pack
to the LED, bypassing its internal power source. That way, with a
steady power source, the LED would not blink. (Also, I could
remove the battery after using the shredder, thus preventing the LED
from burning out.) That
had to work.
Except it didn't. I confirmed that a steady, bright, light came
from the LED, and hit the sensor. The LED no longer blinked,
given the power from the battery. Even so, The shredder continued
to malfunction in exactly the same way.
So, although I could not figure out exactly what the problem was, I did
at least localize the problem. The problem was in the circuitry
that powers the LED and interprets the sensor. In other words, it
was not a problem in the peripheral nervous system; rather, it was in
the central nervous system. There is a little circuit board that
connects to the sensor and the LED, which has some relays and other
stuff. The problem was somewhere on that board or its components.
For a few moments, I thought about how I was going to establish a more
precise diagnosis. But there were problems with that. For
one, I don't know much about digital stuff. I don't think I could
have figured it out. Two, I was not in the mood for a third trip to the
parts store, for yet another part. So I just took the two wires
that go from the circuit board to the photoresistor, cut them, and
soldered them together.
I was not sure that would work, but it does.
Posted by Joseph j7uy5 at 10:08 PM • 2 Comments • 0 TrackBacks
August 14, 2011
Category:
Last February, we had a very unusual hard freeze. It killed a lot of plants.
The prior year, I had gotten an agave from a local nursery. It was a nice specimen, about 12 inches wide; it cost $25. In the freeze, it died. So I removed all the dead matter above ground. In the springtime, I watered it sparingly. After a couple of months, there was no visible growth.
One weekend, I went and bought a plant to replace it. The new plant is a
Dasylirion wheeleri, aka sotol, or desert spoon. These things grow in the mountains, where it actually snows sometimes. Ought to be able to tolerate a freeze or two.
When I dug a hole for the sotol, I found a lot of thick, moist, viable-looking root from the agave. Somewhere, sometime, I had read about propagation from root cuttings. So I used some cactus potting mix, in a 12-inch terra cotta pot. I put the root cuttings in a coil, about an inch below the surface. I placed them outdoors, in dappled shade. Then, I waited. I watered them sparingly, occasionally.
Last week, I noticed that two of the four have sprouted new plants.
At this point, I only have to wait about ten years, and I will have two decent specimens.
Posted by Joseph j7uy5 at 12:47 PM • 4 Comments • 0 TrackBacks
April 25, 2011
Category:
The good folks at Shrink Rap are conducting
a survey about attitudes toward psychiatry. I would appreciate it is some of you would participate.
Posted by Joseph j7uy5 at 12:39 AM • 22 Comments • 0 TrackBacks
April 24, 2011
Category:
Agave
lechuguilla,
commonly called lechuguilla or shin dagger, is a type of agave that
grows in northern Mexico and southwestern USA. It is highly
tolerant of drought and alkaline soil; it is somewhat tolerant of
cold. Each plant blossoms exactly once, then the entire plant
dies. I have read that if you cut off the stalk when the plant
starts to blossom, it won't die. Instead, it will form little
pups (offsets) from the roots.
We had a hard freeze in February that killed most of the century
plants, all of the oleander, and severely damaged many other
plants. The temperature got a bit below zero °F at night, 19 °F
in the day, on 3 February 2011. On 31 January, it had been 35 °F at
night, 57 °F in the daytime. On 16 February, it was 33 °F at
night, 78 °F in the daytime. Thus, the plants were stressed, not
only by the cold, but also by the rapid, wide temperature
fluctuation.
This photo shows a lechuguilla that survived perfectly well.
Flanking it on either side, are two
Spartium junceum, Spanish
broom.
Note that I rarely water the lechuguilla, but I do water the Spanish
broom every couple of weeks. (The Spanish broom was damaged a bit
by the cold, but is coming back nicely.)
I have read that lechuguilla is difficult to grow from seed. I
did collect some seeds last year, but haven't tried them yet, thinking
it will be hard to get them to germinate. In order to get more of
these plants, I could wait until they bloom, then cut off the stalk,
but that could take many years.
What I noticed, is that the lechuguilla near the Spanish broom now has
several (five) pups. The other lechuguilla, scattered about the
yard, have no pups. My conclusion is that you can get the
lechuguilla to form pups by watering the ground near the plant.
This seems to cause the roots to come up a foot or two from the main
plant. When they get to the surface, they form new plants.
It ought to be possible to dig into the ground between the mother plant
and the pup, cut the root, then transplant the pup.
Posted by Joseph j7uy5 at 12:30 PM • 1 Comments • 0 TrackBacks
March 19, 2011
Category:
A little less than one year ago, the major environmental news pertained
to the Deepwater Horizon oil spill. From Wikipedia:
The Deepwater Horizon oil spill (also referred to as the BP
oil spill, the Gulf of Mexico oil spill, the BP oil disaster or the
Macondo blowout)[4][5][6] is an oil spill in the Gulf of Mexico which
flowed for three months in 2010. The impact of the spill continues even
after the well has been capped. It is the largest accidental marine oil
spill in the history of the petroleum industry.[7][8][9] The spill
stemmed from a sea-floor oil gusher that resulted from the April 20,
2010 explosion of Deepwater Horizon, which drilled on the BP-operated
Macondo Prospect.
Of course, the huge environmental news today is the nuclear crisis in
Japan, stemming from damage to the
Fukushima
Dai-Ichi power plants.
It occurs to me that both of these disasters have a common cause: they
were caused by desperate efforts to wring cheap energy from
nature. The Macondo well was drilled in very deep water.
This is difficult and hazardous. We would not do it if we were
not desperate.
The Fukushima Dai-ichi power units were built in the late 1960s to late
70s. One could argue that the continued operation of the units
reflected a desperate need for more cheap energy. The units were
old; their designs, obsolete .
Both
BP
and
TEPCO
have histories of malfeasance and cover-ups.
Debt-based economies require a positive growth rate in order to keep
functioning. That is, if the economy does not grow enough for all
the accululate interest-on-debt to be paid, defaults inevitably
occur. But economic growth requires either even-increasing energy
expenditures, or ever-increasing improvements in efficiency.
Therefore, there is a great need to constantly increase energy supply,
given the political impracticality of getting people to become more
efficient. We are trying to increase supply, despite a stread
decline in energy return per unit of energy invested (
EROEI).
Hence, the desperation, hence the disasters. We have had two
major disasters now in less than a year. This is not a good sign.
Posted by Joseph j7uy5 at 11:45 AM • 7 Comments • 0 TrackBacks
February 27, 2011
Category: Environment • Politics
After the 2010 elections in the USA, headlines proclaimed, "
With
new Republican majority, let the investigations begin," and "
New
Republican majority Congress promises a tough ride for Obama."
One of the big targets for investigations:
climate
science.
"There's a huge appetite among the rank-and-file to raise
fundamental questions about the underlying science," said Michael
McKenna, a Republican strategist and energy lobbyist.
Sen. James Inhofe of Oklahoma, the top Republican on the environment
committee, pressed for investigations into "
Climategate."
Never mind that the whole thing already has been
investigated ad
nauseum.
So one of the investigations has ended. The conclusion: "
GOP
inquiry finds no evidence that 'climategate' scientists misused data."
"None of the investigations have found any evidence to question the
ethics of our scientists or raise doubts about NOAA's understanding of
climate change science," said Mary
Glackin, the agency's deputy undersecretary for operations,
according to the New
York Times.
Note that Dr. Glackin was appointed to her position, at the National
Oceanic and Atmospheric Administration, by the Bush administration.
Posted by Joseph j7uy5 at 11:33 AM • 4 Comments • 0 TrackBacks
February 26, 2011
Category:
This is a
photo
of a blonde zebra, or
albino
zebra.
Some
rights reserved
Judging from the tags on the photo, it appears that this was taken at
the
Pana`ewa
Rainforest Zoo in Hilo, Hawaii. The author, John Schroedel, indicates that the mutation results in one blonde zebra
out of 2.5 to 3 million.
Posted by Joseph j7uy5 at 11:35 AM • 1 Comments • 0 TrackBacks
February 21, 2011
Category:
Ok, here's an idea. The Dervaes family have decide to make the phrase "urban homestead" a registered trademark (
1 2 3 4 5; also see the
EFF post). Presumably, they are doing this to make money. They have gone so far as to send DMCA takedown notices to other persons...persons who, presumably, thought they all were colleagues of some sort. I guess not.
So, if it is possible to make money off of something that is rather commonplace (About 179,000 results on Google) on the Internet, I've got an idea that is even better. I am going to trademark Insufferable Arrogance®. Not the phrase, mind you; rather, I am going to trademark the
concept.
Anytime I see anyone displaying Insufferable Arrogance® on the Internet (currently comprising about 35% of all web pages), I will have my legal team send them a Sharply Worded Memo®. If this works, we should see a precipitous decline in the incidence of Insufferable Arrogance® on the Internet.
Posted by Joseph j7uy5 at 10:09 PM • 1 Comments • 0 TrackBacks
February 4, 2011
Category:
This is decidedly ironic:
Rolling outages affect most chilly Texans all day
By ANGELA K. BROWN Associated Press
FORT WORTH, Texas -- A high power demand in the wake of a massive ice storm caused rolling outages for more than eight hours Wednesday across most of Texas, resulting in signal-less intersections, coffee houses with no morning java and some people stuck in elevators.
The temporary outages started about 5:30 a.m. and ended in the afternoon, but "there is a strong possibility that they will be required again this evening or tomorrow, depending on how quickly the disabled generation units can be returned to service," the chief operator of Texas' power grid said in a release.
Because of the problems, Mexico's Federal Electricity Commission agreed to transmit 280 megawatts of electricity to Texas between Wednesday and Thursday night.
This is a direct result of deregulation, as well as chronic under-investment in our national infrastructure. We are lucky that Mexico is better-managed than Texas.
Posted by Joseph j7uy5 at 12:14 AM • 4 Comments • 0 TrackBacks
