|IR video camera||the xenotron XVC2 area composistion system|
A pioneering and revolutionary system in its time
|made from a $50 ccd camera module||my recollections from the early eighties|
|ZINC WHISKERS..... yes, they do actually exist|
|Zinc whiskers do actually exist. These were found on some old radio equipment that I was sending to landfill and discovered this switch shaft that had been electrolytically plated with zinc. This equipment had been manufactured in the the late sixties and had been in service until about 1990. Do zoom into the pictures. These whiskers took nearly 50 years to form. They were quite firmly attached to the base metal, however I am quite sure that many would have broken off and rendered this equipment disfunctional due to intermittant faults. This was not ROHS equipmentwhich has the same , if not worse problem with pure Tin solders growing whiskers on a far shorter timescale. The whiskers have sprouted from areas of slight corrosion, my hunch is from salt in the sweaty fingers of the assembler of this equipment. I have also noticed this effect in things that I have constructed, my fingerprint can be found chemolithically engraved, just from a sweaty unclean finger after many years.|
What is the electronics inside a compact flourescent lamp ?
Take a little time, next time you have one of these lamps cease to function, and gently cut away the plastic base to reveal a whole lot of electronics. It has been amazingly well packaged to fit into a lamp base and lamp socket. If you are collectiing electronic components for your junkbox you get all these parts for free. Two high voltage switching transistors, numerous 400V 1A diodes, a bobbin ferrite core (usefull for RF inductors !) , a DIAC, a ferrite core and a largish ferrite inductor that would be usefull for simple buck regulators. This particular lamp even had a MOV to protect it from transients, cheaper lamps normally omit this component. I am very relieved to see that the inline fuse is still there. Keep in mind that the conventional tungsten filament lamp failed as an open circuit...they were inherently safe. The CF lamp will fail
as a short circuit and you must hope that the "cheapest manufacturer of the day" included a fuse...a link works just as well as an expensive fuse, and you cannot visually inspect the lamp for compliance.
I reverse engineered this circuit during a rainy afternoon recently. The circuit is quite sofisticated, it has to do quite a few things. The CF lamp has a hot cathode. There is a tungsten filament that must be heated to emit electrons. It only has to stay heated long enough to permit the arc discharge to commence. Once the arc is established, heater current must be removed or be deminished so as to obtain a reasonable service life of the lamp. It takes a high voltage to initiate the arc, but an arc has a very low impedance once struck. The lamp must be supplied from what is an AC constant current source. The is the purpose of the large inductor. The ferrite ring which has three windings provides the positive feedback required for the power oscillator which I think runs at about 40Khz. The power oscillator output is a push-pull arrangement. The ferrite ring transformer thus also provides the essential function of ensuring that both transistors are not conducting at the the same time. The main filter capacitor will charge up to mains peak to peak voltage which is about 360Volts here. The DIAC is there to force the oscillator to start. The circuit also , very thoughfully, includes bleeder resistors for the main capacitor. The PTC (positive temperature control resistor) is there to provide a start current for the lamp filaments. Soon this resistor heats up and becomes a high resistance effectively taking itself out of the circuit after the arc ignites.
Why did this lamp fail ? I cannot say, the components look and measured good. Perhaps the vacuum seal of the lamp failed, in which case the arc cannot ignite at atmospheric pressure, which is just as well.
what could go wrong with the CF lamp ?
Just about anything but looking the failed lamps the people have brought my way I would say the root cause is thermal stress causing the switch transistors to fail under load. There is no ventilation, it is located next to a warm lamp bulb. In this example the bakelite circuit board had been toasted to a uniform brown color and the polyester "greencaps" had become a nice toasty brown. Suprisingly, the one component that everybody now expects to fail, the main electrolytic filter capacitor, which for this application appears to be correctly specified survives this application. I have not seen one fail yet. This lamp had TO220 style power transistors which had a good thermal rating. I have seen TO92 style transistors in the cheapest lamps which simply cannot be expected to last very long. It is a sobering thought to consider that just about every component here can and will fail , and will fail as a low resistance or short. It it shorts you are lucky, the service fuse will trip. If the component fails as a low resistance the assembly may emit a self sustaining arc, below your service fuses' trip point and this must result in a fire.
It is very hard to see how one of these units can be manufactured, wharehoused, transported, shipped and retailed for a few dollars without the use of forced or sweatshop labor.
|Natural carnivorous plant grows in the suburbs of Melbourne Australia|
|A carnivorous plant found growing in Melbourne! (of all places)|
|tiny 10mm sundew plants found growing in Melbournes' Churchill National Park amongst the moss|
|A walk in Melbournes Churchill National Park is a delightfull escape from the suburban tedium that now surrounds it. The famous Bell Bird track seems to be closed now which was a real shame. Closer inspection of beds of moss revealed these tiny sundew plants growing on infertile south ward facing slopes that must have been getting some ground seepage to keep them watered. Zoom in these hi res pictures and see that those plants have been dutifully helping to remove the mosquito menace.|
|A miasmic aggregation of flies.|
A walk through the marvellous Mornington Peninsula National Park revealled this scene of a miasmic mass of flies at Cape Shank. This park links the Arthurs seat reserve through to the ocean beach via a narrow strip park to Cape Shank. This is a very pleaseant walk in a place that carries the illusion of remoteness and seclusion, even though it is at the tip of the mornington peninsula which has been heavily cleared, farmed and now suburbia inexoribly encroaches. During a recent walk done in January 2010 this remarkable mass of flies was discovered and the base of a 50 Meter cliff along the ocean beach (Bass Strait) at Bucanneers' Bay. In a rock alcove were sheltering this mass of flies. I estimated the flies covered at least four square meters. The flies were densely packed in a thick double layer with their heads towards the rock face. A quick calculation would put the number of individual insects at about 2.5 million. The insects were easily disturbed, with the air becoming thick and black with flies, which quickly re-alighted onto the same place. There was no immediate reason why the flies had gathered here. There were no animal corpses around, there was no fetid odour about the place that might have attracted them. I could see no flies in the act of mating. This was an ocean beach and there was the usual amount of kelp that had washed up, but no large decaying piles.
At the time I had no idea what had caused this mass of flies to aggregate like this. My only hypothesis is that they were attracted to a natural seep of fresh water originating high above the cliff face. The air temperature was about 34 degrees. The flies were particulary attracted to deep fissures in the rock face where the fly density was the greatest. Click and zoom in these images and you see inumerable fly abdomens sticking out. There was another layer of flies beneath these. The area was in partial shadow and the flies avoided direct sunlight.
A new kind of giant orb weaving spider recently discovered in Melbourne Australia, February 2011.
I have never seen this spider before in Melbourne. What is it ? Could it be the American Banana Spider ? nephila clavipes .
If so, what is it doing here ? Has it come here as a sto-away on cargo ?
The orb is about 70cm across, the silk is bright yellow and is immensely strong. It is similar in strength to Redback Spider silk. This large female shares her orb with a number of smaller male suitors, caught in the act, their corpses are stored in the middle of the orb along with egg sacks and remains of past meals. The spider is quite shy and will leave the web to seek shelter if disturbed.
The males are much smaller, elongated, stick-like , black without interesting markings and it would appear from the scheme of things, expendable.
|what am I ?|
|what flower is this ?|
|a "stink arum" growing in Melbourne !|
the flower in the background was a demure female, that about 3 weeks after the male flower wilted, has grown small green berries, later turning bright orange.
also known as a "corpse lilly". I still have not learned the proper name for this plant, any feedback would be welcomed.
|one of the flowers was female. Berries are now growing||one of the flowers was female. Berries are now growing, see below what becomes of it now||foliage erupts about 3 weeks after the bloom has wilted|
|will this sinister looking stalk become another flower ?||No, it became foliage||later stage foliage|
|stink arum berries. The actual color is bright orange which my camera makes to be more yellowish. Judging by the complete lack of insect damage, I would expect these berries to be highly toxic.||where the seed stalk is now hiding||the bulb that gave rise to the large male flower has now completely sprouted its lush foliage. The ruler is One Meter.|
What flower is this ?
November 2012-Jan 2013
My late father has been trying to grow these very ordinary brown bulbs for about 10 years. Each year they sprouted with a fungoid looking purple green and pink mottled stalk that initially penetrates up through the ground. Then, in about 2 days the stalk unfolds into one large leaf that remains untill the start of the cold weather whence it shrivels and dies. This year two of these bulbs did something differant. A sinister looking purple fungoid stalk appeared. After about half a day in bright warm sun this extraordinary 50cm flower erupted from the stalk. And what a remarkable flower it is. It stinks! The stench is hard to describe, but suffice it to say that it is unpleaseant, but not quite as nauseating as some stink arums are reputed to be. I shall attempt to describe the stench. Imagine, if you would, rotting onions, rotting ham, mix in a hint of cheap toilet cleaner scent than cap of the after-smell with chlorine ! The plume emitted from this flower causes my eyes to water, not only from the chlorine-like stench, but from a cloud of purple pollen which can be seen if the sun is at the right angle. The colour of the flower petal resembles fresh horse meat, which my camera does not really capture. The flower during daylight hours has a cloud of flies in attendance. The stench is abruptly switched on in the morning as soon as direct sunlight hits it and the stench is abruptly turned off at sundown. The flower has ,so far, persisted for seven days and small ovules are beginning to form so I expect this one could be self pollinating (nope...male and female flowers from seperate bulbs) as there is nothing else like this plant in the neigbourhood. I do not know from whence my father obtained this bulb, perhaps from a stranger in the pub ! I have never seen this variety for sale in Australia. Nurserymen that I have spoken to know of this and like flowers but no one has ever seen anything like it for sale. Any ideas of what this stranger is ?
A few weeks after the big flower wilted, the smaller one at the rear of the pictures reveals itself to be a female. There is a small bunch of bright green berries now growing.I wonder if the seeds are viable ? The berries have now turned bright orange, the seed stalk a vivid green with white spots. Insects are utterly unattracted, so I expect these berries to be highly toxic.
|Welcome back. It is the year 2014 ! this year in october it was warmer than usual in Melbourne. Right on cue, from what is now a very large tuber ,it produced this amazing bloom again. This time it was a monster over 1 meter tall as you can see from the meter stick. There was only one hot day and on that day the flower emitted the stench. It was overpoweringly awefull this year . There was only one suitably warm day. The bloom was attended by a large cloud of blowflies. The really amusing thing about this year's stench was the behaviour of our local murder of crows. These large corvids are most likely the most hightly advanced avian intelligence on the planet and some of the locals have become quite tame. They gathered around this flower and they appeared geniunely puzzled. I wish I could understand crow. They were obviously attracted by the smell of corpse and road-kill and were busy scolding me for blocking access to it and were irate that they could not find the lovely carcass. This year the bloom persisted for almost two weeks before wilting, the stench was (mercifully) emitted for only one day.|
|what is wrong with this sign ? This notice was placed inside an e-waste dumpster that I visited some time ago. Names are smudged to protect the guilty.|
A most irregular and unusual copper SFP
Ok folks, what is wrong with the above picture ? My fellow network engineers will see the silliness here.
If you cannot you should not be a network engineer. (Hand back your CCIE)
Ullo Ullo Ullo whats all this then ? ! Youre Fibre is Nicked !
My job as network engineer takes me to many strange places and reveals interesting sights. I was called to a site that had experienced a total network outage. A quick test with my optical fault locator showed that the optical biulding uplinks had been severed. No matter, we have redundant fibres. No good, they too were open circuit. My colleague who is significantly taller than me, at my suggestion mounted a chair and opened the fibre tray. He instinctively leaped backwards. Obviously there was something there with slavering, venomous fangs, bug-eyes and tentacles ! I had the pressence of mind to whip out the smartphone camera and was fortuneate to catch the entity responsible for our network outage. The wanna-be network engineer then hi-tailed his sorry butt out of here. I believe he sought alternative employment as a lines-mouse at one of our commercial Telcos . Perhaps all he wanted was free internet access or a hi-fibre dietary supplement.
At Monash we endure about 0.75 outages per year due to rodent damage throughout are widely scattered campuses. Most of the fibre trays are open at the rear, and in a network rack , warmed by allways on equipment, the rodents are attracted to fibre trays where they begin to chew the fibre ends. I believe that that first play with the fibres, get board, nibble, then move on . The damage in not random but follows in sequence. The damage is allways directly behind the connector. There is something about rodent pschycology here. The rodents around the university are not hungry as there is enough trash containing good junk food.
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