Sunday 30 October 2011

I have seen the light

After forty days and forty nights in the wilderness, wandering from website to website, wondering about the complexities of electronic lighting and winding up at least one sales rep on the way, the system worked!

Through the ingenuity of our electrician, making a test bed using two wires tied to a step ladder at one end, and a couple of nails on the wall at the other end, we were able to test the parts: the tension wire fittings, bought from the UK, made in Germany; the light bulbs, bought from the US, made in China; the power supply, bought in Japan, also made in China; the LED driver, bought in Japan, and probably made here. The parts were no doubt from Taiwan though. 

I had three worries about the system not working. One was that it would not work at all. Another was that there would be no dimming, and the elaborate current variation system would ultimately only give us an on-off switch. The third was that we would get dimming, but there would also be flickering as the different frequencies of the power supply, current control circuit and the electronics within the bulbs would cause beats and interference patterns. Another minor worry was that the bulbs would not produce even light, so one bulb would be at full brightness with another dimmer. 

In fact, we got bright, clear and even light from the three bulbs, which dimmed obediently as we turned down the volume. Unfortunately, the current control circuit we used will only dim to 50%. AudioQ have completely dimmable circuits, but only to lower currents: 0-350 mA, 0-550 mA, 0-700 mA and 0-1000 mA. These lower-current circuit boards are open, rather than in a box, which causes my electrician to pull excruciated faces.  Anyway, for three bulbs at full whack, we need 1500 mA, (12 Volts, 6 Watts), so 1000 mA is probably not enough. We chose their 1400 mA supply, which will only dim to 50%. In practice, dimming to 50% is probably good enough, although it's tempting to twist the electricians arm and get a 0-1000 mA dimmer circuit for the other three lights, which will effectively give us dimming from 30% to 100%, or brightness from 0 to 70%, in the other circuit. Now that the wires are in parallel, we could add extra bulbs, and for example have two bulbs on one light circuit and four on the other. The four bulbs wouldn't give any more light overall than than three, but would be able to spread it out more. 

The test took place in daytime, and the three lights certainly seemed bright enough, although it's impossible to give any idea of the brightness through a picture.  It's also difficult to be sure exactly how bright the lights will be when they are in place, and whether 70% of that really would be enough.

Tuesday 25 October 2011

"We applaud the well-mannered box"

This was something else that Daniel Libeskind said that resounded.

I'm really struck by the nature of buildings as boxes. This has been highlighted several times by our west wall, that is a few degrees off right-angle and has caused a never-ending stream of problems.  

It seems a deeper part of the problem of a society that seems to always want to put us into boxes. 

In terms of design, two of my favourite structures are the geodesic dome and the teepee. I've never actually been in a geosesic dome, but I have been in a few teepees. I think the first time was in the teepee field at Glastonbury festival. I asked the owner how long it took him to put up. "The last time," he told me, "took twenty-five minutes.
"The first time took thirty-six years."

Another was at a harvest festival in a village whose name translates to "Beautiful Hemp", where over a dozen people were sat around a raging fire, in the middle of a giant teepee. 

The best thing about them is that they are not square. 

The geodesic dome is probably the most efficient structure known to man, in terms of providing the strongest volume of building with the minimum building materials. Its strength derives from triangles that join each other into the dome. Here's a picture of one. 

I can imagine building a house out of a geodesic dome, but there would be endless problems finding fittings for it, as everything, from beams and plasterboard panels to windows and doors, is made for square rooms. 

I should tell you the one about the architect who had the house made backwards, so he could watch television, but that loses a lot in the spelling.

Sunday 23 October 2011

Architecture: Political, risky and unexpected? No, thank you!

Young-mi just sent me this link of Daniel Libeskind talking about architecture, which I liked about half of, but I'm glad he's not building my house.


He claims that architecture should be radical, political, unexpected, risky...

"Architecture is that complete ecstasy that the future can be better."

This may be true, but looking at modern architecture, at the risk of sounding like a reactionary or a royalist, a lot of it seems like it is political and unexpected, but that is all.

Political without an agenda, just politics.

Unexpected. Not unexpectedly good, unexpectedly useful, unexpectedly spacious. Just unexpected.

Risky without a large potential gain, just a big risk.

So no doubt there are architects with agendas producing functional buildings, but most people want houses that will house them comfortably, and work-places that work. If architects keep their heads in the clouds then perhaps they should not be allowed to build buildings that people will actually use. 

Fair enough if you're building something like the Berlin Jewish Museum, designed to create a sense of unease and disorientation, and make people aware of horror. Not very helpful in most other buildings in the world.

At the moment, most buildings are nowhere near ideal for their inhabitants. We don't complain because we know no better. Humans are incredibly adept at adapting to their environments, and given a little time, we can make ourselves happy in any structure of any size, shape or material.

What we need to design them is experts in ergonomics, the study of movement of the human body. Buildings should fit people. We need experts in thermodynamics, because in most cases people don't want to live in the elements and we need buildings to protect them. We need experts in housework, so that our homes are easy to clean and maintain. 

But what do I know about architecture?

What does my architect know about architecture?

Lotte sent me a message about "Against architecture" (original title "Contro l'architettura") by Franca LaCecla which has been published in Japanese.
Details on the English version here: pmpress.org.

Another one for my reading list! Not sure which language to read it in. My Japanese reading ability is limited, but I think I might already know a lot of the vocabulary in this book. And if I don't, I will want to.

Thursday 20 October 2011

Dimmers getting dimmer and dimmer and I'm not sure I can see the light any more

The problem is that all the decisions are interrelated, and it's very difficult to make one without having already made several others. Change one and the whole house of cards comes tumbling down and needs to be built up again.

Having given up on the idea of the great low-voltage series cable light system and chosen some LEDs that will dim, I then had to go back to find a suitable dimmer and power supply. The site that sells the LED was very insistent that I needed a magnetic dimmer switch and a magnetic transformer. I did a little research into these and found that they are difficult to find in Japan. Where I could find them, they were for hundreds of watts, while I'm looking at around 20 watts for each of my circuits. This may or may not be a problem in terms of delivering reliable low current and low voltage, but it seems like using a pneumatic drill for dental surgery, and may lead to a system that hums but doesn't dim. 

Because the dimmers work on mains voltage, I would need two of these transformers, each one literally more highly rated than all the lights in the house.

Kingdom of consumer electronics that it is, in Japan wire-wound transformers are like antiques, and difficult to find among the slim and efficient switching transformers on the market here. They are at a premium, perhaps due to all the copper in the wire windings.

It seemed a much better bet, and around 10% the financial risk, to go back to AudioQ and get one or two of their constant current power supplies, sending it straight to the row of lights but this time putting them in parallel. While they had nothing for 36 volts, they do have some adjustable power supplies for 1400 mA, between 5 and 25 volts, which should get the LEDs going.  

I wanted to get some idea of whether this would work or not with the circuit inside the LEDs, which are from Earth Leds and I even emailed them for technical support. I asked a couple of times about their Leds with their wonderful and trademark Lumiselect dimming technology, and whether it would respond to a variable current signal.

The only answer I got, in increasing tones of frustration, was that I needed a magnetic dimmer and a magnetic transformer, and everything would be fine. 

And perhaps they were right, and everything would have been fine if I'd spent over the odds for their LEDs, a transformers and dimmer switches, which I may also have had to import from the US.

As for the transformer, copper's quite valuable at the moment, so it might have been a good investment. 

But we'll see. 

Or not, if the lights don't work at all.



Further Reading for the Link-Lustre

Here are a few of the magnetic dimmers I was looking at, but didn't buy. Click at your own risk.

6613 PLW

 
Reading the reviews reveals that some of these switches are very delicate, or perhaps they guy runs a karate school. This is a really good one. I should spend more time reading product reviews on Amazon:


Lutron 

Diva DVLP 600P

Maestro family

29.99 on Amazon

In Japan:

info on them

Tuesday 18 October 2011

Please help me, I know too much

It would be so much easier if I'd just believed it when I heard it was impossible to dim LEDs.

Apparently when motor cars first came out, they had to have someone walking in front with a red flag.

I'm sure in a few years, it will be really easy to get cheap LED lights that work. 

Maybe this whole process has been filled with too many obstacles to sense and reason, and maybe the science is all just too difficult. It's also very likely that I'm going out of my way to make things complicated.

In the meantime, I have to take solace in Einstein's words.

"There are only two things that are infinite," he said, "the universe, and human stupidity." 

Then he added: "And I'm not sure about the universe." 

Sunday 16 October 2011

Pictures of windows - not recommended for any over-excitable readers - contains explicit pictures (of windows)

Just been going through the photos again and making many more albums and removing a tiny number of photos. Not sure if progress is going in the right direction.

I had just been throwing any pictures of windows into a "windows" folder--eat your heart out Bill Gates--but decided they should really be grouped with pictures of the same window. It was a bit tricky in a few places to work out which rectangular shape on a flat wall was being represented. I wish the computer would help, as it tries to do with pictures of people. They're getting better and better at face-recognition, but wall-recognition and even angle-of shot recognition in general have a lot of work to do. Perhaps it should be up to GPS and direction-sensors in the camera.

 

Anyway, among over 300 shots, there wasn't much fairness in the distribution between the 18 windows in the house. There were over 30 of the upstairs window on the west wall. I think my desk may end up under this, so I will probably continue to spend a lot of time looking at it. I've just noticed that in around the third shot the handle suddenly switched from the right side to the left side. This must have either been put in upside down, or switched for another window.

There were only two shots of this window in the washitsu, the Japanese room, at the north of the house. Here's one of them. I should probably start taking more pictures of this.

Actually the most pictures were taken of this window on the north, although most of them were taken, at around 10-second intervals, while it was being installed.  As usual, among most of the pictures several were identical, where I've been diligently charting progress on a daily basis of a process that is characterised by weeks of stagnation and then rapid change.

I think my favourite is this one in the kitchen though. Notice the sockets to the right creeping around with our prevarications.

Thursday 13 October 2011

Early house guests

I started writing this message on July 28th, the day after a visit to
the house by a delegation viewing plus-energy houses.

I didn't take any pictures of them, but here is a list of the people
who visited the house to see the insulation and airtightness work. I
may have some of the names wrong. Sorry!

Hiroshi Ishiguro from Kyoei House in Chitose city, Hokkaido, the
northernmost island of Japan.
株式会社 協栄ハウス 北海道千歳市 石黒浩史
http://www.kyoueihouse.jp/

Takahiro Suzuki and Shigeichi Saruta from Suzukiyo in Noshiro city,
Akita ken up north.
株式会社 鈴喜代 能代市秋田県 鈴木隆宏 猿田茂一
http://www.suzukiyo.com/

Mr. Mikame and Mr. Kabashima of Tokyu Homes in Shibuya ward, Tokyo.
株式会社 東急ホームズ 東京都渋谷区 三瓶 樺島
http://www.tokyu-homes.co.jp/corporate/profile.html

Hideo Tomita from Hideo Tomita studio in Nerima ward, Tokyo.
富田秀雄建築アトリエ 東京都練馬区 富田秀雄

Hideyuki Motobashi from Altas Ever in Yokohama city, Kanagawa, South
west of Tokyo.
アトラスエヴァ株式会社 神奈川県横浜市 本橋秀之

Kei Kato from Atelier Kei in Kamakura city, Kanagawa.
アトリエけい 神奈川県鎌倉市 加藤景

Two Kusakaris and a Mr Yoshida from Macklife in Yokohama city, Kanagawa.
株式会社 マックライフ 神奈川県横浜市 草刈 x 2 吉田
http://www.macklife.co.jp/

Mr. Sekine of Channel Original, Wooden siding manufacturers in Yokohama.
チャンルオリジナル株式会社 神奈川県横浜市 関根
http://www.channel-o.co.jp/

Messrs. Ishizaka, Oyama, Higashino, Odanaka from Gadelius in Minato ward, Tokyo.
ガデリウス 東京都港区 石坂 尾山 東野 小田中
http://www.gadelius.com/

Mr. Sasaki from Nagano P.S. in Nagano city.
長野ピーエス 長野市 佐々木
http://www.dcn.ne.jp/~ren/text/menu.html

and of course Messrs. Egawa and Kobayashi from Shinetsu BIB in Nagano.
信越BIB 江川、小林

It felt nice to have so many visitors, and a few of them said thank
you, that they had learnt something and that it had been interesting.
Some of them just scowled. None of them introduced themselves.

To give some context, apparently the purpose of this visit was to
persuade a skeptical group of the merits and techniques of glass wool
insulation, so their scowling may have been towards the host of their
tour and his apocryphal techniques, and not just a sign of rude guests
in my house.

One guy brought some cakes as a gift. I wish I knew who, so I could
say thank you.

Perhaps I should have been a bit more assertive, although it seemed
like a good opportunity to talk to the electrician and site foreman,
and actually get some practical decisions made, so I stayed out of the
house when they were all inside. Also, I felt there was a danger of me
breaking into some kind of argument either with the architect or the
insulation guy, so it seemed safer to avoid the conflict and loiter
under the scaffolding.

As it was, my architect was evidently standing there holding court
about why and how he'd made all the decisions on his house, when in
fact for most of the time he has been misunderstanding or sneering at
them.

Meanwhile under the scaffolding some important solidarity was built up
with the site foreman and electrician, who are doing a lot of the real
work to build the house, rather than drawing pictures that aren't even
particularly pretty.

Tuesday 11 October 2011

Science East and West

While we were trying to work out the window problem, there was a moment of cultural mismatch where the Europeans sat down, having solved the problem and thinking about the solution while the Japanese were trying to see the problem.

It reminded me of Tanizaki  complaining about western science, and how much more suited it would have been to Japanese sensibilities and the Japanese temperament if science had been invented in the east.

The Fenstermeister said that science worked the same in Japan as in Germany. I understood exactly what he was talking about, and could see the cause of the problem. We share the same physics, although what I may attribute to Newton, they would claim for Leibniz. 

And perhaps it goes back to Leibniz and his contemporaries Descartes in France and Spinoza in Holland who turned the world upside down by putting rational thought at the foundation, and building a world in our heads where our observations fall in place to support abstract theories.

Or maybe it was a language barrier and I failed to translate what they were talking about into Japanese.

Or perhaps the Europeans were wrong and their explanation of a sagging rail was not the reason for the problem. Having laid the probable blame on installation in this post, I also wonder whether design was a factor. 

There are only two hinges and a slider on a rail holding three window panes of 80 kg. That's a total of 240kg. Each hinge will take a maximum weight of 130kg, so if the weight is all being held by the hinges, there is not much margin for error. When the window is closed there should be no problem, but when the window is open or moving, the load is not static but is dynamic as 80 kg panes are twisting, turning, accelerating and decelerating. 

I suggested it may be sensible to have three hinges on this kind of door, and asked how many triple-leafed, triple-glazed windows they have produced of this size, and I'm still waiting for an answer.

Sunday 9 October 2011

Buying lights

Just spent about 300,000 yen on lights and fittings for the house. It took most of my Sunday morning.

It seemed like a good idea to get these directly for three reasons. Mainly, getting light fittings straight from the internet saves money. The builders charge at least 80% of the list price, passed on from the electricians. You can usually get lights for about 40% of list price on the internet. So this should have saved a fair bit. There is probably some hidden cost somewhere, and the electricians may charge extortionate corkage.

I used kakaku.com, which is a site for finding mostly electrical goods. This usually took me to a merchant on Rakuten.com, which is a large online shopping site, the Amazon of the East. I also searched directly on Rakuten. 

The process of choosing lights was a labourious one. Different manufacturers have huge numbers of subtly different products. One of the big electrical manufacturers in Japan brought out 120 new LED fittings in April. 

The main numbers that can be compared are wattage, lumens, CRI, angle of beam and price. They seem to be getting better, but in some cases, some of the figures were missing for some manufacturers.  Of course design is also an issue, especially for brackets and spots, but for down lights there's not much to chose from.

We want lights that will come on and switch off automatically in seven places around the house: the entrance, the kitchen, the utility room, the bottom part of the staircase, the top part of the staircase and the two toilets. In terms of design we wanted single fittings that included a light and a sensor, but at first these were not available with LED fittings, and we needed separate sensors to the lights. Since then, Koizumi brought out single-fitting light sensors, which came out a little cheaper than buying lights and sensors separately, and superior in terms of installation and design.

All of these decisions went into drawing up the list of fittings over the past six months, with a lot of help from the architect who found a lot of them. I had been talking about LEDs for the previous 18 months, mostly to derision,as I mentioned before. There are many calculations showing that it's not worth switching to LED, but those are mostly out of date already, and if not will be very soon.

The revolution in lighting design, heralded on Panasonic's webpages with their snippets of useful information, does not yet seem to have brought many revolutionary products, although it's early days.

I decided to stick to the lights we'd chosen on the list we talked to the electrician about at the end of August. I'm sure in the interim some better ones have come out. Some of the prices had dropped since then. 

I managed to find almost all the lights from one merchant, Prizuma, which had the cheapest every time. Things were going well until I hit the "next" button with my full shopping cart, and went onto the instructions to pay. No space to enter credit cards. Bank transfers or cash-on-delivery only.

Another reason for getting the lights myself, rather than putting them into the builder's invoice, was that I can pay for them with a credit card. Part of the financing, unfortunately, is coming from sterling. At the moment, the value of sterling seems to be falling in the same direction at the cost of LEDs is, but that is another story, that I shall tell sooner or later, with great pain.

One way of getting sterling into yen is to buy things on a UK bank credit card. The credit card companies charge something for the exchange, although it's often less than the banks charge, and there is no transfer fee. 

So, having spent the whole morning getting all the LEDs lined up into the order for Prizuma, to no avail, I had to go back to Rakuten and find other merchants who would take credit cards. This didn't take as long, now that all the lights were decided.

That was not the end of the story, as Rakuten still had my old credit card on their records, which expired last January.  

Buying things online has got a little easier in recent years, with auto fill in functions and websites that will remember data you entered on their forms. I remember my first experiences having to completely re-enter several pages of forms, several times, for example for missing out a hyphen from the middle of a telephone number. I also remember having problems on Japanese sites with my name, as it did not contain any Chinese characters, which the field required. 

When I went back to try to correct the credit card expiry date, I noticed some recommended purchases, which Rakuten bases on what I've been buying, in much the same way that Amazon does. The number one recommendation was medicated scalp-d shampoo for oily hair. Something surely wrong with their algorithm.

I sent the new card details in, but since got a message that the payment had been refused, so I had to call my bank in the UK and ask them very nicely to let me use my money. They quite often query payments made in Japan, even though I've lived here for over a decade.

The lights should all arrive in the next couple of days, which will be exciting!  


Friday 7 October 2011

Low-voltage tension cables. Back to parallel not series

The electrician has been correspondeding with Nayuta, manufacturers of constant current power supplies, and they had the perfect model, with the right voltage and the right range of currents that could be varied. The problem was, they did not know how to vary the current. The power supply has a screwdriver trimmer wheel on it, and there are terminals to connect something to vary the current, but they do not have the something, nor could they, or the electrician, find one. If you can understand that, please explain it to me, because it does not make sense.

I also found some power supplies from AudioQ (Japanese only), with volume controls, which looked promising. They put out up to 350 milliamps, which should be about right for a 12 volt, 4 watt bulb, between 2 and 26 volts.

We want 3 bulbs on one circuit, which at first I thought would be no problem--they would just not come on at full brightness. Then I remembered the VI curve for LEDs and that the D is for diode. If there is much less than 12 volts going through each LED, or 36 volts total, then they will not come on at all, however many amps are available.

So this would only work if we had two bulbs on each circuit. Also, the electrician seemed much happier with something in a box, rather than having to install a bare circuit into the wall.

There is another nagging worry though. Even if the current could be adjusted, and the voltage kept at suitably high, would the bulbs actually respond properly, or would their circuits mess things up?

I'm sure the parts must be out there somewhere, but after a few months of searching we haven't been able to find them, so it's time to go to plan B, which is to use a standard voltage dimmer switch, get LED bulbs that work with dimmer switches and hope for the best. The danger with this is incompatibility between dimmer and bulbs, leading to flickering. As there are three bulbs, one of them may flicker at any level, and we'd be left with an elaborate on/off switch. 

I'm about to order some lumilux fully dimmable LEDs from EarthLED, which apparently work with magnetic transformers and dimmer switches. These seem to be available, although the electrician's first suggestion was a switching power supply and a pulse wave modulation (PWM) dimmer switch. As each of these, and no doubt the controller within the dimmable LEDs, are electronic circuits, each with their own frequencies, the chances of interference, harmonics or beats is quite high.

Not at all relevant, but  here's another constant current, non-variable, power supply.

Wednesday 5 October 2011

Prevarication, procrastination and still in the same house at the beginning of another winter

Looking back over the records, the original moving-in date on the architect's schedule was October. That's October, 2010, so we are now a year late. When we finally got a contract with the builder, the finishing date was the end of June. This became September. September became October, and we're now looking at a November completion. The only positive side I can think of is that we can send a change of address notice on our New Year cards, rather than sending out a separate one. 

The reasons for the delays are complex, and I don't want to apportion blame on anyone, but I can't help feeling that if I said I was going to have a lesson from 9am to 10:30 and it didn't start until 4pm, there may be some complaints.

As awkward and indecisive customers, I'm sure we must hold some of the blame. 

For example, we spent about half an hour of the electrician and site foreman's time discussing the position of one socket in the kitchen.
We have a counter running along the back of the kitchen, the far wall in this picture.  The counter is going to be granite, which should be really nice. The sink and cooker are opposite, facing into the room. The cooker is under the duct, that is going to have an extractor fan on it. 

The fridge is going to be in the far corner, where the cardboard box is. Next to the fridge is something our architect calls a "tall cabinet", which is actually a  tall drawer with several shelves that can be accessed from each side. Then there is the granite counter. I think it's granite. Some kind of stone, anyway.

There's a window in front of the counter, and cupboards with things called "down walls", which are racks that fit in high cupboards that swing down to a level that people less then 217 cm tall can get things in and out of. 

To the right, there was going to be a microwave, up on a shelf, with space under the shelf for things like rice cookers and toasters. 

Since then, we have moved the oven to where the microwave was going to be. The original plan was to have the oven underneath the cooking tops, but this was foiled when we decided on Toshiba cooking tops. Toshiba have nice simple designs for cooking tops, but they don't make ovens to go underneath them any more. Because fitted ovens use the ventilation in the cooking tops above them, and part of Toshiba's simplicity is not having a wide ventilation grill at the back, this meant it was impossible to put an oven underneath the cooking tops. 

So the oven moved where the microwave was going to be, and there is another drawer under the cooking tops, which will be useful for putting pans in. The oven also works as a microwave, but it is deeper and higher, and the space underneath has become less useful, especially when it comes to placing a rice cooker, which gives out steam from the top, and which needs its lid to be able to open when the rice is ready. 

That's the situation, and I haven't even started talking about the sockets yet. 

In the plans there is one socket to the left of the window, which includes a switch for the lights above the counter, and there is another socket to the right, underneath the oven, as you can see in the picture above. This would have been a great place for the socket with a microwave on a shelf above, but now the oven has put the wall 60 cm back from the front of the shelf, and the gap is less than 30 cm high. If things are going to be plugged in there, and left plugged in, it's not such a bad place for a socket.

If the socket moved to the left, out from under the oven, and next to the window, it would be a lot easier to plug things in. It may look a bit busy though with all those sockets.

If we're going to put the rice cooker there, we may be able to keep it under the oven when we're not using it, then slide it out when we are using it, so it could be plugged in permanently. 

But that may not be the best place for the rice cooker. It should probably go to the left of the window. 

But that's OK if the person doing the cooking is also going to serve the rice, but if somebody comes from outside the kitchen, it's going to be much easier to get to the rice cooker if it's to the right of the window.

So, where are we actually going to put the rice cooker?

Are we trying to build the kitchen around the rice cooker, or are we going to try to build the kitchen first, then decide where to put the rice cooker when it's finished?

As far as this one socket is concerned, either the rice cooker is going to be to the right of the window, or it's not. If it is to the right, do we want the socket exposed, next to the window, or hidden under the oven? If the rice cooker is not going to be there, where do we want the socket?

Actually, if there is one socket to the right of the window, and one to the left, it will look quite well balanced, and look good.

So let's do that then!

Monday 3 October 2011

Dimmable bulbs

I visited Hisashi's bar, Oread, in Tatsuno the other day, and he was saying he wanted to change his lights to LEDs, but had been told it was impossible. He puts on live music in his bar and would like to use LEDs for his stage lights, and adjust them with the row of dimmer switches.

So, if all you need to do to dim an LED is change the current, then why would any LED NOT be dimmable?

The problem is that whenever an LED is packaged into a bulb or fitting, some electronics are added. This is essential to put a cap on the current or voltage and stop a melt down. So the question is whether the bulb has a one-size only approach, and will only send a specific current through the LEDs, or whether it has a cap, and will allow any current to go through, as long as it is no more than the limit.

If the electronics will only send the designated current, then all bets are off regarding dimming. If there is not enough power going into the light, the required voltage will not be reached and no current will flow. LEDs may not obey Ohm's law, but they do obey P = V I. The power will always be the product of the voltage and current. This is sometimes erroneously referred to as Watt's law, but Watt actually had nothing to do with electricity, and the unit we use for electricity was given his name posthumously. P = V I is actually a Joule's law, or a combination of P = I2 R with Ohm's law, V = I R. Back to the LEDs with fixed current internal power supplies, either there will be enough power, and the voltage will be high enough for the full current to flow, or there will not be enough, and no voltage will flow. However fancy the dimmer circuitry on the outside is, dimming won't happen.

If, on the other hand, the electronics put a limit on the current and will only allow current to flow below the meltdown level, then we're in with a chance.

Anyway, there are plenty of dimmable LEDs, in the sense of dimming with a conventional dimmer. Here's one from the US:

I'm only really looking at MR16 GU5.3 bulbs at the moment. These are low-voltage halogen types that I need for the tension wire system.

I got some E17 bulbs for around eight or nine hundred yen to play around with and try out in various appliances we already have. On the bulb instructions, it said we should not, under any circumstances, use the bulb in a fitting with a dimmer, so we tried it in a desk light with a dimmer. Nothing really exciting happened.

As we turned the switch up, first of all, nothing at all happened. Then the light came on, flickering very quickly, almost too quickly to notice, a little below full brightness, then it flashed in one pattern, then flashed in another fashion, then came on at full brightness. What seemed to be happening is that the dimmer on the desk light was interfering with the circuit inside the bulb.

Sharp have a regular lightbulb-like LED, left, which will apparently change brightness.

This site from KC Lightech  also boasts dimming LEDs, in GU5.3. It looks like Cree LEDs inside. They recommend a Panasonic power supply. I wasn't sure how I could actually buy them so I called. They have no stock and will ship an order of a hundred. I only want six!

 

There is a Philips light here for 6,384 yen a throw, 10W, which can dim, depending on the power supply. They don't always work, but do with Maxray, Daiko, Endo and Koizumi.

This 5.5 W light from Decolight is only 1,200 yen. although it doesn't mention which power supplies it will work with, and careful inspection reveals that it is 100 volts AC. And I thought MR16 GU5.3 was a 12 volt DV size.

 

Saturday 1 October 2011

Fred took some photos of the house the other day with his old Nikon and wide angle lens. It was a terribly rainy day, so the pictures are all inside. Apparently that's not a bad thing as the light is well dispersed. He was using a flash anyway.

These pictures are unusual as I'm in them. Also, there is an incredibly rare shot of me actually doing something useful in the house, rather than getting in the way, complaining and giving impossible demands.

I will always look at the bookshelf on the balcony with pride, as I had a part in its construction, even though it was only holding it up for about five seconds. I hope you like the way the carpenter and I wore matching T shirts too!