Mad scientist: "...Back when I was conducting research at the university, I always insisted that the children be allowed out of their containment tanks for Christmas."
Everyone: shocked expressions.
Mad scientist: "Oh please! What do you take me for? I am obviously not talking about the control group."
Everyone: Expressions of relief.
I spent today at the Texas (formerly Unitrode) power supply design seminar. The UK one this year was held in the motorcycle museum near Birmingham. It was at least a floor below the slightest phone signal, or glimmer of daylight.
From my point of view it was the best such seminar I have attended in at least the last ten years, because they covered two topics that I want to use in my work soon, and others that gave me useful extra understanding and analysis and modelling techniques that are likely to be useful frequently.
I'll try to avoid making everybody's eyes glaze over, but the part of my work I most enjoy is where the laws of physics meet the product. In my line of work, that normally means designing switched mode power supplies. Energy efficiency has always interested me, and a major design aim for switched mode is efficiency.
One useful feature of some types of smps is that they can provide more than one output, by making a transformer with extra windings on it. For example, the power supplies used in most desktop computers provide +5V, +12V, and -12V. Hear the wisdom of ancient Plautus! It is well known that if you draw lots of power from the main output of a power supply and none from the other outputs, those outputs normally provide much more voltage than expected. A 12V output could reach over 20V. It is easy enough to measure to what extent that happens, and then determine if remedial action is needed, once the power supply is designed and assembled. However, it is helpful to be able to calculate what will happen in advance, and, perhaps, calculate that simply adding a small LED to indicate that the 12V supply is present will draw enough power to prevent the voltage reaching an excessive level.
The first session covered a way to model transformers having multiple windings, and calculate this aspect of what a power supply will do before one is built and tested.
All the other sessions were at least interesting and thought provoking, but the case study of a solar powered lighting application demonstrated just how much better power supply design can be if, instead of analogue circuitry such as has been used for decades, you use a digital controller and make it all work using software. I expect to start designing something with a Piccolo DSP very soon. Some aspects of it may initially be difficult and confusing, but once I have learned what is needed I will be able to design some items a useful amount better. Cheaper and more energy efficient - which my customers always need. I await an evaluation kit.
In the limited extent to which I have had to use embedded processors in my work, apart from on use of an 18 pin PIC processor years ago, which was programmed in assembly by someone who was used to PIC assembly, from my flow chart, I have used Atmel processors. Now I have to design something that is high value, and probably destined for low volume production, and which is as complex as anything I have designed single handedly. It needs a processor, and maybe a later model will need a screen, though the first model only needs a row of indicator lamps and a three digit power readout.
It seems very likely that an Arduino, probably the Mega 2650, will reduce development costs and time, though I may decide to program it in C rather than using the Arduino language. Timing of one event needs a response within 500ns *absolute maximum*, so at least one of the interrupt service routines needs to be efficient. I could even start on some of the software while waiting for the printed circuit boards full of power electronics to be made.
Arduinos are typically designed with connectors that allow peripherals, called "shields" to be fitted. There is one with an OLED graphic screen and a mini joystick on it - probably suitable to control the model of machine that needs a screen and more advanced menu options.
Since I first learned of its existence maybe 2 or 3 years ago, the Arduino has seemed like a solution looking for a problem, for my applications. Now it looks as if there is a problem that it is the solution for.
I was interested and amused to see "Lillypad" Arduino hardware, intended to be sewn into clothing. There are several peripherals available, and even conductive thread. Who can think of something silly to do with it?
The pdf, expanded from the parts database, was titled "BOM Explosion".
They were a support band when we went to see The Treatment, a few weeks ago. Yes, we enjoyed them as much as The Treatment, and it was worth seeing them again.
As it turned out, they were making a video of the band that evening. Who knows, we may get to hear more of them, at larger and more prestigious venues, at some time in the future.
I could not even switch it off, because the touch panel did not respond any more.
Searching the net for repair options, I found a cheapie repair kit costing £9.99 from Amazon, and ordered that so that it arrived in time for me to be home from holiday. It had the necessary tools, including the tiny screwdriver and plastic tools to prise the display out of the case.
The repair worked, and took me about an hour, but it turned out that the touch screen does not have the oleophobic coating (and, from the correct angle, it is possible to see a faint pattern that is, presumably, the conductor pattern). My finger stuck as I used it, and left very obvious marks. After a time searching the net for an answer, and finding nothing inspiring, I had what I believe to have been a bright idea:
After cleaning the glass as thoroughly as possible, I applied a coating intended to repel rain and dirt from car windows. I used to use this on the windscreen, and in some situations of rain found that the windscreen was clearer using the coating, before switching on the windscreen wipers, than it had been with the wipers on but without the coating. I quit using it because the effect was worse when it began to wear off. However, the limited wear on other windows makes it a benefit on side and rear windows, and, it turned out, on the iPhone screen. Not quite as good as the proper coating, but not far off.
I had hoped to partly catch up on my sleep this morning, but had limited success. The credit card bill arrived, and Hibernia opened it and found another fraudulent transaction, for more money, than the one that the fraud department had contacted me about a couple of days ago. Nothing would do but that I get up and phone the fraud department instanter.
After ordering parts (to arrive on Monday) for the prototype power supplies (output: 11V, input: 11.5V to 60V) we scrapped the 20 year old diesel Peugeot, which has been a low cost second car for ages. Now it needs a significant repair to continue working for much longer, so we scrapped it just before the tax, MOT, and insurance become out of date.
Now I have to upgrade an item of embedded software, written in C, and find I need to learn about the use of pointers first. I'm too tired to fully understand the details of coding. As long as it works before the end of Monday...
We went to Melbourn - not the one in Oz, the one near Royston. The Treatment were playing - and the support were good as well.
The bar even had a decent beer on handpump, not the fizzy stuff that is sometimes all you can get at such events. It was a long journey, but a very good evening.
Last Friday was my mother's 90th birthday. We had a celebration on Saturday, at http://www.westmidbridge.co.uk/ the bridge club that she helped to start, back in the days of my dim and distant youth. (I see that the photograph on their home page is the one I took for them.)
I was her only relative present. In fact, I am her only known living relative, though she may have some second cousins living in Sheffield, if it were possible to trace them. There were many relatives from my father's side of the family, including my half brother and his children and even some grandchildren. What a tribe! My father would have been 103 by now, if I remember correctly.
Then there were my cousins, many of whom live in Luton, but one from as far as Devon.
My mother is still in good health, still drives her car far enough to visit us occasionally, and has better eyesight than she had for most of her life (because her eyes no longer need an unfeasible amount of correction for astigmatism – just generic reading glasses – after the cataract operation replaced her lenses).
I remember her being worried that she would need a horribly expensive set of spectacles immediately after the cataract operations, until I pointed out that it would not be logical for the replacement lenses to be designed with astigmatism. Now she has one set of generic reading glasses for actual reading, and another for playing bridge, and can see much better than the legal requirement for driving with no glasses at all.
On Sunday her friends at the bridge club held a celebration lunch for her, which we attended, then left her to play a game of bridge, which I gather that she and her partner won.
She is anguished that she does not play bridge nearly as well as she used to, and that is certaily true. However, she was once lady champion of Britain, has been a grand master for longer than I can remember, and, even though there certainly used to be a degree of sexism in bridge, was a county level player in competitions for many years. Without the sexism, she might have played in international competitions whenever they were held. [sigh]
Obviously, at 90, the short term memory is no longer so good, and she cannot remember every card played. However you can decline a long way from the level she reached and still be a good player by many people's standards. She also taught bridge for many years, and ran the bridge school for much of the time as well.
If she understood how to set her central heating thermostat/timer, use the TV remote control, or read what is on a web page before guessing which button or link she needs, even 5% as well as she understands bridge, she would rarely, if ever, need to call me for tech support. [sigh again] But she can, for example, check the balance in her current account online successfully, for most of the time. If the necessary button is moved from its normal position, specially if there is an announcement of some sort so that she has to scroll for the button, that is when there can be problems.
I realise that I had been searching a bus capture made using demo software incorrectly. Though one part of the programming manual tells me that a certain set property command starts with a two byte command and is followed by 8 arguments, I naturally assumed that SET_PROPERTY_FOO: 0x0602 would mean that the bytes 0x06 and 0x02 would be sent in order before the arguments.
It is in the order 0x02 then 0x06, then followed by the arguments. It must be that way round, because the first line of the example on page 243 or whatever is the address, so it must be starting from the top, not the bottom. Because it is transliterated from the original Japanese, I should have guessed that 0x0602 actually means 0x0206. Of course! I should have instinctively known.
It is beginning to make sense, but I still think that power electronics, or even RF, makes much more sense. [sigh]
It was good to see him again, because we hadn't crossed each others paths for a while. He hadn't experienced a Christmas gathering of this type before, which probably shouldn't have been surprising. Yes, he is another engineer who likes reading science fiction. Of course ;)
It was altogether a good day, and the diet starts
If this happened in a novel, I suspect that many people would think it was too pointlessly dystopian for the suspension of disbelief.
Please read, and consider signing the petition.