23/02/2007 by peter.

For those of you mad enough to be building PCBs you probably want to check out these 2 sites. KiCAD which is a free, yes free, schematic capture, PCB tool with auto route. Its a bit quirkey and takes some getting used to but once you do its great!! The other site is PCB POOL who put your design in with other peoples so you get a good price. i wanted a 1″ x1.5″ PCB and PCB123 would charge me $200 +pp for 10 or PCB POOL would charge me €25ish.

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23/02/2007 by peter.

For years now BEAM style electronics has used energy harvesting as a power source. The idea is to take some source that produces a very small, yet continuous, supply of electricity and use that to charge up a low-leakage capacitor or battery and then use the  power to do a burst of work. Now Advanced Linear Devices have announced an advanced module that does more or less the same thing for powering wireless sensors. This is not all they can power though. Connect a magnet to a spring and attach the spring to a coil and you have an inertial generator, power as you walk. Connect it to a piezo stack and mount this on the chassis of a vehicle and you get power from road noise. One of the most interesting things you can do however is make a thermopile and paint one side black and one side white and the temperature difference will generate electricity which this unit will then turn into usable chunks. The other interesting idea is to attach a small inductor to this harvester and leave it in any built up area, the stray radio waves and magnetic coupling to power lines will give you a free source of power.So could this mean the end for batteries? Could charging your phone in the future just be a mater of leaving it on the window/radiator/ putting it in your pocket or just leaving it on your bed side table?

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22/02/2007 by peter.

Do you remember the James Bond film with the safe cracking machine? These guys have built one. Not very complex for a modern mechatronic system but it works.

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18/02/2007 by peter.

The monster in question is the Rank Organisation. For those of you who don’t know, everyone who grew up from the 1950’s to 1980’s bought something from the Rank Organisation. They pwned everything form Hovis Bread and Sharwoods Sauces to Butlins, CetreParks and Oasis holiday resorts. From Xerox to Pinewood studios, Deluxe Film Services and Odeon Cinemas. over the last 2 decades however they have been selling off all these companies the last 2 being Deluxe and Hard Rock for $750m and $965m respectively. This is however still not enough as they are still $800m in debt. From its start in film and media, through its diversification and now its decline it has always been known for being very influential both socially and politically, buying up it’s competitors and becoming as much, if not more, of a monopoly as P&G are today. Interestingly, the UK government has just passed a bill making “Las Vegas style super casinos” legal and lowe and behold what are Rank Group Plc interested in now but gambling. Owning only 4 companies, Mecca Bingo clubs, Grosvenor Casinos, Top Rank Espana bingo clubs and Blue Square. One has to wonder whether the J. Arthur school of gong beating has struck again…

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15/02/2007 by peter.

No not that one, the other one. The anniversary of D-day February 1971 (36 years ago) they day the world went to hell in a handcart and Britain changed from L-S-D to decimal money. On that day the everyone thought that there would be chaos and the news papers would be reporting Armageddon with everyone engaging in rape, looting and pillaging (and other fine British traditions). The news rooms sat and waited. Then they waited some more until the story came in. A woman accidentally swallowed one of the new coins and was admitted to hospital but was soon released in perfect health. Whether you want to look at this as one of the least painless major changes in recent times or the efficiency of the NHS is up to you…

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12/02/2007 by peter.

People have commented to me about my post on PWM and wondering how it works. The basic idea it this. A byte of data is allocated to each colour red, green and blue giving 256 discrete levels for each or 16.7M coulours in total. A third byte is used as a counter. Firstly all three LEDs are turned on, then as the programme cycles it takes the counter value away from each of the RGB values and if the result is zero for one of these it turns off the appropriate LED. Once the counter reaches 255 it is reset and the LEDs turned on again. If you want more info on this i have written a programme for the PIC10F202 (the teeny wee microcontroller in a SOT23 form factor) which cycles through all 16.7M colours. what’s more the chip is so small you can actually embed it behind the LED!!

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09/02/2007 by peter.

At various times I have heard the media say that you can kill a virus. Now this is an interesting issue considering it is not realy alive. A virus basically consists of one or more protein molecules acting as a little shell and a strand of DNA or RNA inside. The data in the this strand of DNA or RNA codes for the proteins and how to assemble them along with a copy of this data to make a new virus. It is analogous to a factory making manufacturing machinery. In this factory there is a store of stock materials and parts and a shop floor consisting of machines that can request these parts from store and then assemble them based on a set of plans fed into it creating a new machine. Now what happens is some little malicious person inputs some plans for a machine that bumbles around with a copy of the plans to build itself and feeds it into one of these assembly machines. Once the assembly machine is finished its job the new bumbler will go off and find another machine. now if each set of plans says “make 1000 bumblers” then before you know it the factory will be over run with little wheeled things going around getting these big assembly machines to make 1000 copies of each of them. The are apparently reproducing and causing all other production to halt. Finally, if the bumbler tells the assembler to use parts of itself then the assemblers will die out and the bumblers will have nothing to “infect” but the only thing that needs to survive to get to a new factory facility and cause the same damage is the plans for this bumbler. one wouldn’t say the plans are alive but still they reproduce and cause havoc. In viral infections, the virus causes the cell it injects its DNA or RNA strand into to start producing copies of itself until the cell dies, bursts and all the new viruses escape. the argument over whether or not it is alive tends to centre around the reduction of entropy in their location (lots of ordered structure and behaviour happens in an infection) however they are no more alive than thet little machines trying to copy themselves.

Of course where theses plans came from in the first place is a far more interesting question….

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05/02/2007 by peter.

Many years ago in the dark and distant past the thermionic valve was king. The number of separate electrical connections were used to identify the type of valve, so a 2 electrode valve would be a diode, 3 would be a triode etc… Now the properties of Germanium crystals were known about but until manufacturing processes were sufficiently developed and the little people at bell labs found out about the fun things that happen at NPN and PNP junctions they were rarely used. The germanium diode was the first to be developed as a logical step from the crystal detector in the early radios. so called crystal diodes as they showed similar properties to the thermionic diodes but made from crystals. The next advance was when the “transistor” effect was discovered. The component seemed to behave like a triode and was therefore named the crystal triode. The name was soon replaced with “transistor” and people got down to finding uses for then and the manufacturing problems began. One fundamental problem problem was “how do we package these things”. Standard packages soon followed and were named Transistor Outlines. The different outlines were given an identifying number. The first was TO1 then TO2 and TO3. The Most common ones now are TO92 and TO220. Diodes were similarly treated
with the DO series of packages. When smaller and smaller transistors were made for surface mount a new series of packages was designed Small Outline Transistor or SOT. The one I am interested in at this moment is SOT23 which is 1.63mm wide x 2.95mm long x 1.10mm high and has 6 legs (originally designed to have 2 on one side a 1 on the other for a single transistor or able to have 2 transistors squeezed into it.)

Now that digression explains that this little black epoxy package should hold 2 transistors but the PIC10F series micrcontrollers are now avalable in SOT23 packae. Thats an entire CPU,programme and ROM Memory and other things like 8 bit ADC, clock generator and power management hardware all crammed into the space of one small or two tiny transistors!!!

I now that is impressive!!!!

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03/02/2007 by peter.

For those of you out there who have mastered PWM outputs on your μC and now have little RGB LEDs giving out 16777216 different colours and wondering what to do with this technology, you could build something like these people use in their shows. Seen them a couple of times on TV and they look rather good.

Just a thought….

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03/02/2007 by peter.

Here is an interesting list of power stations UK for all you wind farm fans. One wind turbine is about 2MW so go and tot up how many we need to replace one or two of our ageing coal or nukes. (Thankfully Chapplecross has since gone off-line after operating since 1959!!) And remember that a wind turbine doesn’t work in calm hot days (like the ones that killed 15000 people in France a few years ago and are now being prepared for with air con systems which guzzel power) or on stormy days where there are very high winds or gusting and blustery conditions with wind constantly changing direction like those we tend to get in winter here.

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