Yeah I know I brought this on myself but if I'm never given another chance am I supposed to do manual labor making 9 dollars an hour the rest of my life as punishment?
Or you can start your own business. If you have knowledge - start off small - perhaps just repairing computers for the small businesses in your area, and work up from there. Traditional employment isn't your only route. If you build up a reputation of being reliable and giving good service, and eventually want a traditional job in some company doing IT - being able to demonstrate this would maybe mitigate your earlier record.
If, on the other hand, you lie - then get caught, you've just demonstrated to everyone that you've not reformed at all, and are still willing to be dishonest to get what you want. That really will doom you to the minimum wage job for the rest of your life. Having 'been fired for lying about background' on your record really will stuff you up for good.
No, there's nothing wrong. A fixed solar panel will only provide peak power when the sun is square on to it (I have mine set up on a south facing roof). Peak output is only available within around half an hour of mid day - after that, the angle of the sun will start to reduce output. By 4pm in mid summer, you're down to about 1/3rd of peak. A layer of cirrus cloud - such that it's still a bright sunny day, with sharp shadows being cast - will reduce power at mid day to something like 50-60% of peak. A bright, cloudy day with blurred shadows being cast, you get no more than 20% peak at mid day. Needless to say, at night, you don't get anything. Even in the long summer days, after 9pm you don't really get much worthwhile from the panel - the panel load ammeter is barely off the peg at that time.
There are very few days in northern Europe with completely clear sunny days with absolutely no cloud at all.
So yes - averaged over 24 hours, even on a bright, cloud free, haze free (even visibility down to 10 miles makes a measurable decrease in peak output) day you're not going to get anywhere near 30 watts averaged over 24 hours! Considering completely cloud free, haze free days are rare (the sunniest periods in Britain are always rather hazy) - yes, 5% averaged out over the summer months is probably the best you'll get. Maybe 10% if you're really lucky. If you don't believe this - then try it, a small panel won't break the bank, just instrument it with an ammeter and voltmeter, and give it a load to power, and take measurements through the day. I've actually done this so I know first hand.
A tilting system will help greatly, as it'll be possible to keep the panel pointed square on to the sun throughout most of the daylight hours. You could probably get the daily average on a bright, hazeless, cloudless day to something like 40% of peak when averaged over 24 hours when tracking the sun. Maybe up to 60% around mid summer. That's practical with my 80 watt panel, but it wouldn't be practical with 1000 watts worth. You can't just tilt each panel individually in a 1000 watt array unless you've got loads of space to spare, because then the sunward panel would start shading the panels behind it - so you have to tilt the entire array. It's going to take a serious system to do that with any reasonable amount of wattage - we had winds of 90mph last weekend, and the sail area of, say, 1000 watts of panel would be quite considerable. (And then try getting planning permission for a tilting panel system that large!) Even if you have the space to be able to tilt individual units of your array, a tilting system then adds an awful lot of maintenance you don't have with a simple fixed installation.
My garden electronics project for next year will be to build a sun-follower for the panel (it won't be that difficult electronically, a couple of LDRs and a voltage comparator, driving a small motor/jackscrew assembly to move the panel, and a circuit to drive it back to the home position when lighting conditions are no longer worthwhile) to increase the output - certainly a lot cheaper than buying two or three extra panels.
I may well do that - it won't be too hard to build a system to do it (a couple of LDRs, a voltage comparator and a small motor drive). Certainly a lot cheaper than buying two extra 80 watt panels!
No, it's not that. Microsoft Research DOES do some truly interesting and innovative things. However, the rest of Microsoft ignores Microsoft Research. Out of all the interesting things I've heard that Microsoft Research has done - none has ever actually got into a Microsoft product - instead the products are usually just bought off someone else and have the Microsoft brand slapped on. So Microsoft Research might innovate, but the rest of Microsoft simply ignores them and copies or buys someone else's ideas. It's almost if Microsoft Research is there to soak up talent so no one else can have them.
Unfortunately, you are being far too optimistic. I have an 80 watt monocrystalline panel on my shed roof as an experiment. You can expect to get roughly 2% to 5% of peak output when averaged out over 24 hours - and that's during the middle of summer. You only get peak power within about an hour or so either side of mid day on an absolutely haze free and cloud free summer's day. Three hours off mid day you're lucky to even get 50% peak. Even just a little daytime haze (say, 10 miles visibility) cuts output at mid day down to about 60% of peak.
You could extend the amount of time you get a decent amount of power by adding a system to tilt the panel so it's always directly facing the sun, but that's only really feasable for a small system if you're doing it at home.
If you stick the panels on already existing structures (like rooves - most of them in these parts are black slate), it won't make a change to the total. There is no reason why you'd want to cover huge tracts of land, when there is plenty of roof space going begging and otherwise unusuable.
My 80 watt panel has a 25 year manufacturer's warranty - i.e. they will replace it for free if it fails within that time period, or falls below (IIRC) 80% of new capacity.
At current prices, you'll need a little more than 6 months on your mortgage. Assuming you're in Britain, which by the usage of your language is probably reasonable...
I bought an 80 watt peak solar panel in the summer, basically as a fun project and to investigate the practicality of generating some of my own electricity. Here is how it works out, using a monocrystalline panel (the most efficient panel commercially available at present):
Peak power is produced only within about an hour or so each side of mid day on a bright, cloudless, hazeless sunny day. Three hours before or after mid day, the unit produces about 50% of peak. Five hours before or after mid day, the unit produces around 10-15% of peak At mid day, summer time haze with 10 miles visibility will cut output to around 80% of peak At mid day, with thin cirrus clouds (still bright sunshine), output is around 50% At mid day, on a bright cloudy day where shadows are still cast, output is around 15% At mid day, on an overcast day, output is generally 5% or less. In the winter, I've never seen the unit capable of producing more than about 25% of peak on the brightest winters day.
All in all, the average output even in the summer will only be 5% of peak (because of night time, and cloudy days). Winter time is even worse. So if you want to make sure you have an average of 200 watts - which really isn't a lot, but if you can store it or put it back on the grid it'll make your house more or less neutral in terms of the electricity you use, if you have the normal domestic cycle of being out and not using much electricity during the day. To get that average of 200 watts, you'll need 4000 watts peak of solar panels.
80 watt panels cost (in quantity) around £250 a piece. That'll cost you £12,500 *just* for the panels, without a grid tied inverter and storage system or installation (probably another 4 to 6 grand) - to get a measly average of 200 watts - i.e. just enough to power one Pentium 4 computer continuously. It's simply not worth doing at all unless you can put it back on the grid (not many electricity companies let you do that - yet), or store it in batteries - since if you have a normal domestic cycle, while your solar panels are producing near peak you will be away from the house and letting three or four thousand watts go wanting. You'll probably need three grand's worth of batteries if you can't sell back to the grid - and even deep cycle leisure batteries are going to need replacing at least once every 10 years. This is for a system which will only work reasonably well in the summer. In the winter, when the days are short and you need the most power, it'll hardly contribute anything - perhaps you'll get 50 watts average from £12,500 worth of solar panels.
If solar panels were 1/10th of the price they are now - yes, it'd be worth it. I'm waiting for the breakthrough in price, not efficiency (if the efficiency brings the breakthrough in price all the better). Even a moderate sized south facing roof - I've calculated just my shed roof replaced with solar panels could produce 1kW peak - is large enough for a decent peak output using current monocrystalline panels. Price is everything. If I could get the panels at 10% of what they cost now, you bet my shed roof (my only south facing roof) would be covered by the spring. But at the current price point? It's simply not affordable for the meagre amount of electricity you get. It's a shame because the panels aren't visually intrusive and they are silent and almost maintenance free, unlike wind turbines. I really really want solar panels to be worthwhile - but at the moment - at current prices, they simply aren't.
Photovoltaics are probably more robust than you give them credit - the monocrystalline 80 watt unit I have on my shed roof has a 25 year warranty. The "coating" on the cells is a sheet of glass.
Additionally, power inverters have no moving parts and these days are pretty robust semiconductor devices which should last at least a couple of decades.
The main problem with solar panels isn't practicality, but expense. They are fantastically expensive for the energy they make. The efficiency in conversion really isn't the nut that's most important to crack - the expense is the important nut to crack (unless of course, the increase in efficiency addresses that). For solar panels to be economic as a useful power source for most of us, they need to be about 1/10th of the price per peak watt that they are now.
Efficiency of solar panels isn't really the problem - my roof, for example, even in the Isle of Man - if completely covered in solar cells and with a suitable storage system could more or less run my house (and in the summer have plenty to spare).
The problem with solar panels is PRICE. That is the nut that needs to be cracked. If a panel is only 10% efficient, but not much more expensive than a similar sized roofing slate, it suddenly becomes economical to re-roof the house the next time the roof needs attention. However, it's not even near that price. An 80 watt panel currently costs around GBP£250 which is fantastically expensive. There is no way I could even remotely afford solar roofing at those prices, however much I'd like it. The price per peak watt needs to be about a tenth of what it is now.
Since no one has posted this yet, sorry, I'll have to. I was on a major C++ project for 7 years - I enjoyed developing in C++ (yes, including operator overloading which was VERY USEFUL, and people who moan about operator overloading simply just don't get it), but I must admit this spoof always brings me a smile - and will do for anyone who's been on a large C++ project because it comes awfully close to the truth:-)
Interviewer: Well, it's been a few years since you changed the world of software design, how does it feel, looking back?
Stroustrup: Actually, I was thinking about those days, just before you arrived. Do you remember? Everyone was writing 'C' and, the trouble was, they were pretty damn good at it.. Universities got pretty good at teaching it, too. They were turning out competent - I stress the word 'competent' - graduates at a phenomenal rate. That's what caused the problem..
Interviewer: Problem?
Stroustrup: Yes, problem. Remember when everyone wrote Cobol?
Interviewer: Of course, I did too
Stroustrup: Well, in the beginning, these guys were like demi-gods. Their salaries were high, and they were treated like royalty..
Interviewer: Those were the days, eh?
Stroustrup: Right. So what happened? IBM got sick of it, and invested millions in training programmers, till they were a dime a dozen..
Interviewer: That's why I got out. Salaries dropped within a year, to the point where being a journalist actually paid better..
Stroustrup: Exactly. Well, the same happened with 'C' programmers..
Interviewer: I see, but what's the point?
Stroustrup: Well, one day, when I was sitting in my office, I thought of this little scheme, which would redress the balance a little. I thought 'I wonder what would happen, if there were a language so complicated, so difficult to learn, that nobody would ever be able to swamp the market with programmers? Actually, I got some of the ideas from X10, you know, X windows. That was such a bitch of a graphics system, that it only just ran on those Sun 3/60 things.. They had all the ingredients for what I wanted. A really ridiculously complex syntax, obscure functions, and pseudo-OO structure. Even now, nobody writes raw X-windows code. Motif is the only way to go if you want to retain your sanity..
Interviewer: You're kidding...?
Stroustrup: Not a bit of it. In fact, there was another problem.. Unix was written in 'C', which meant that any 'C' programmer could very easily become a systems programmer. Remember what a mainframe systems programmer used to earn?
Interviewer: You bet I do, that's what I used to do..
Stroustrup: OK, so this new language had to divorce itself from Unix, by hiding all the system calls that bound the two together so nicely. This would enable guys who only knew about DOS to earn a decent living too..
Interviewer: I don't believe you said that....
Stroustrup: Well, it's been long enough, now, and I believe most people have figured out for themselves that C++ is a waste of time but, I must say, it's taken them a lot longer than I thought it would..
Interviewer: So how exactly did you do it?
Stroustrup: It was only supposed to be a joke, I never thought people would take the book seriously. Anyone with half a brain can see that object-oriented programming is counter-intuitive, illogical and inefficient..
Interviewer: What?
Stroustrup: And as for 're-useable code' - when did you ever hear of a company re-using its code?
Interviewer: Well, never, actually, but....
Stroustrup: There you are then. Mind you, a few tried, in the early days. There was this Oregon company - Mentor Graphics, I think they were called - really caught a cold trying to rewrite everything in C++ in about '90 or '91. I felt sorry for them really, but I thought people would learn from their mistakes..
I did the same, but with the Z80:-) Mainly the paper and pen (and hexloader) because I needed to buy an assembler for my Sinclair Spectrum and didn't have enough pocket money to buy GENS - so a small hex loader written in ZX Basic had to do. It all got a lot easier when someone gave me a pirated tape with GENS 3 on it!
If that's a computer science course, or any other degree that purports to teach fundamentals, that's so wrong it's not even wrong.
You have to learn the fundamentals, not use ready made components. Indeed, I'd advocate at least some assembly language programming, because this forces you to think HOW the machine actually does things. It needn't be x86 or anything particularly fancy - but something that will at least teach the student on an absolutely fundamental level what happens when you get a buffer overflow that starts overwriting the stack.
I bought a multimeter from the hardware store (B&Q - they sell some quite good ones now for all the home electricians - they even have a transistor tester, and go down to microamp range). The 'scope, I got off a guy on eBay - £60 for a 20MHz dual trace oscilloscope (they cost around £400 new!). I'd have been lost without the oscilloscope. There are cheaper ones listed on eBay, but I think my decision to get a dual trace one was a good one, especially when it came to debugging why my serial data receiver wasn't working quite right (I could send 0xAA continuously from the computer, hook up one probe to the incoming RS232, then hook the other probe to my circuit and find out where it was trying to sync to the signal).
My EPROM burner is home made - I made it yesterday, using the Z80 experiment I currently have on breadboard. It's just a matter of putting the right things on the address and data bus to give it the commands it needs to start a write or erase operation. I have the Z80 board sort of backwards - RAM mapped in at 0x0000 to 0x7FFF (so the Z80 starts running from RAM), and the Flash ROM starting at 0x8000. I made a circuit to load the RAM from RS232 without the need of a processor - it's a matter of decoding the incoming byte, and having a simple binary counter made of two 4520 counters and four 74HCT125s (the latter to be able to tri-state the counters outputs). So I send the program I want to run over RS232, then move a few wires on the breadboard to disconnect the counter/RS232 sender, then let the reset pin on the Z80 go inactive and it runs whatever I just loaded into RAM. (My next step will be to switch the RAM and Flash ROM, so the processor boots off ROM).
I'm not sure exactly, since the nixie project used only a subset of what's in my parts bucket (I tend to order 5 off everything, especially 4000 series or 74 series logic since they are useful and cheap). Nixie tubes themselves can be expensive - or dirt cheap. Depends on the type. I just got 50 Russian IN-12b tubes for US$35 from Ukraine. The IN-16s I'm using in that project were about £1.50 each (that was before I discovered the Sovcom shop in Ukraine - they are selling a lot of 50 IN-16s for less than US$50!) To guess - I think the complete nixie tube project would have been around £30 in parts at a guess. The most expensive single part was the Maxim MAX233 which converts logic levels to RS232 levels - that cost about £5.
Mucking with this stuff needn't be expensive. My current Z80 project consists of about £10 of parts - the most expensive being the 128kbyte Flash ROM (which I'm just about to program) - I think that was about £2.50 from RS Components.
The best thing to do is get a decent sized breadboard, and a selection of inexpensive components - a selection of NPN and PNP transistors, resistors, capacitors etc. Each component is quite cheap. "Lucky bags" of these sort of thing can be quite good for experimentation (but avoid the lucky bags of ICs!). I've seen people selling selections of 4000 series logic (100 ICs) for not a lot of money. 8-bit processors can be had quite cheap too, especially things like the Z80 which is still made.
I started off by learning with discrete components - making logic gates out of transistors and resistors, then moved onto logic ICs, and have now started with microprocessors.
I did it the way I did it so I could run it off a 12v wall-wart. The reasons why I did it this way: - I don't trust my electronics skills enough yet to have 240 volts AC off the mains on my circuit board:-) - I could power the whole thing AND feed it data via cat5 cabling - the spare wires in the cat5 cable can carry the power from the wall wart, which will live with the computers in the under-the-stairs closet.
The switch mode supply is 555 based and works very well - the regulation's pretty stable, and the power MOSFET runs cool enough it doesn't need a heat sink.
I live in the Isle of Man. I've not yet turned on the central heating - it simply hasn't got that cold yet. We actually have milder winters than the south of England thanks to the moderating effect of the Irish Sea.
That's BS. Electric cookers are fine - I have a fan assisted electric oven. Baking is consistent, takes the same time every time, and is faster than in a gas oven. I have a gas hob though, I prefer gas for pans - but I've used electric hobs and they are perfectly servicable.
PICs would almost certainly be easier and lower power - but I'd learn less using a PIC. Besides, PIC assembly wants me want to claw my brane out, but I'm familiar with Z80 asm.
A few months ago, I started learning electronics. My first project is (electronically) complete - it just needs some finishing off to the housing. It's a Nixie tube display, with 7 nixie tubes. I built an RS-232 reciever/sender out of 4000-series logic ICs (not a CPU or microcontroller in sight) - mostly counters and registers, and a few AND gates and inverters.
Pictures of the project's progress are at http://www.alioth.net/pics/nixies/nixies.html (two pages of photos - the working project is on page 2). I've also kept a journal of building and learning in my Slashdot journal.
The hardest part of it was probably getting the 170 volt switch mode power supply to work correctly (mainly getting it to regulate) and not put so much noise back into the 5 volt supply to cause latches and registers to lose their values. Some help from the NEONIXIE-L group on Yahoo was invaluable here, and I now have a decent 170 volt supply.
I'm now learning how to make things with microprocessors, and once I've done some breadboard experimentation, my next project is to build a logging weather station for the glider club, using a Z80 processor, a flash EPROM, some RAM and probably compact flash for mass storage (not that it'll use a lot of it!), and a small graphics LCD module for display. Currently, I'm at the stage where I've breadboarded a very basic Z80 system that can output values on a crude output device. But it works!
But that's retarded: MM in Roman numerals is 2000 not 1,000,000. So instead of having wrong pretences to Roman numerals, just take 'M' as meaning million (as virtually everyone does) and just write $100M for 100 million.
If you carry on reading, you find the LETHAL dose is 520uCi or so. It would cost you over $300,000 to buy a lethal dose from UnitedNuclear. The body burden figure quoted is probably the 'legal safe limit' which is well below the limit that would even make you immediately ill.
Slashdot Mirror
Or you can start your own business. If you have knowledge - start off small - perhaps just repairing computers for the small businesses in your area, and work up from there. Traditional employment isn't your only route. If you build up a reputation of being reliable and giving good service, and eventually want a traditional job in some company doing IT - being able to demonstrate this would maybe mitigate your earlier record.
If, on the other hand, you lie - then get caught, you've just demonstrated to everyone that you've not reformed at all, and are still willing to be dishonest to get what you want. That really will doom you to the minimum wage job for the rest of your life. Having 'been fired for lying about background' on your record really will stuff you up for good.
No, there's nothing wrong. A fixed solar panel will only provide peak power when the sun is square on to it (I have mine set up on a south facing roof). Peak output is only available within around half an hour of mid day - after that, the angle of the sun will start to reduce output. By 4pm in mid summer, you're down to about 1/3rd of peak. A layer of cirrus cloud - such that it's still a bright sunny day, with sharp shadows being cast - will reduce power at mid day to something like 50-60% of peak. A bright, cloudy day with blurred shadows being cast, you get no more than 20% peak at mid day. Needless to say, at night, you don't get anything. Even in the long summer days, after 9pm you don't really get much worthwhile from the panel - the panel load ammeter is barely off the peg at that time.
There are very few days in northern Europe with completely clear sunny days with absolutely no cloud at all.
So yes - averaged over 24 hours, even on a bright, cloud free, haze free (even visibility down to 10 miles makes a measurable decrease in peak output) day you're not going to get anywhere near 30 watts averaged over 24 hours! Considering completely cloud free, haze free days are rare (the sunniest periods in Britain are always rather hazy) - yes, 5% averaged out over the summer months is probably the best you'll get. Maybe 10% if you're really lucky. If you don't believe this - then try it, a small panel won't break the bank, just instrument it with an ammeter and voltmeter, and give it a load to power, and take measurements through the day. I've actually done this so I know first hand.
A tilting system will help greatly, as it'll be possible to keep the panel pointed square on to the sun throughout most of the daylight hours. You could probably get the daily average on a bright, hazeless, cloudless day to something like 40% of peak when averaged over 24 hours when tracking the sun. Maybe up to 60% around mid summer. That's practical with my 80 watt panel, but it wouldn't be practical with 1000 watts worth. You can't just tilt each panel individually in a 1000 watt array unless you've got loads of space to spare, because then the sunward panel would start shading the panels behind it - so you have to tilt the entire array. It's going to take a serious system to do that with any reasonable amount of wattage - we had winds of 90mph last weekend, and the sail area of, say, 1000 watts of panel would be quite considerable. (And then try getting planning permission for a tilting panel system that large!) Even if you have the space to be able to tilt individual units of your array, a tilting system then adds an awful lot of maintenance you don't have with a simple fixed installation.
My garden electronics project for next year will be to build a sun-follower for the panel (it won't be that difficult electronically, a couple of LDRs and a voltage comparator, driving a small motor/jackscrew assembly to move the panel, and a circuit to drive it back to the home position when lighting conditions are no longer worthwhile) to increase the output - certainly a lot cheaper than buying two or three extra panels.
I may well do that - it won't be too hard to build a system to do it (a couple of LDRs, a voltage comparator and a small motor drive). Certainly a lot cheaper than buying two extra 80 watt panels!
No, it's not that. Microsoft Research DOES do some truly interesting and innovative things. However, the rest of Microsoft ignores Microsoft Research. Out of all the interesting things I've heard that Microsoft Research has done - none has ever actually got into a Microsoft product - instead the products are usually just bought off someone else and have the Microsoft brand slapped on. So Microsoft Research might innovate, but the rest of Microsoft simply ignores them and copies or buys someone else's ideas. It's almost if Microsoft Research is there to soak up talent so no one else can have them.
Unfortunately, you are being far too optimistic. I have an 80 watt monocrystalline panel on my shed roof as an experiment. You can expect to get roughly 2% to 5% of peak output when averaged out over 24 hours - and that's during the middle of summer. You only get peak power within about an hour or so either side of mid day on an absolutely haze free and cloud free summer's day. Three hours off mid day you're lucky to even get 50% peak. Even just a little daytime haze (say, 10 miles visibility) cuts output at mid day down to about 60% of peak.
You could extend the amount of time you get a decent amount of power by adding a system to tilt the panel so it's always directly facing the sun, but that's only really feasable for a small system if you're doing it at home.
If you stick the panels on already existing structures (like rooves - most of them in these parts are black slate), it won't make a change to the total. There is no reason why you'd want to cover huge tracts of land, when there is plenty of roof space going begging and otherwise unusuable.
My 80 watt panel has a 25 year manufacturer's warranty - i.e. they will replace it for free if it fails within that time period, or falls below (IIRC) 80% of new capacity.
At current prices, you'll need a little more than 6 months on your mortgage. Assuming you're in Britain, which by the usage of your language is probably reasonable...
I bought an 80 watt peak solar panel in the summer, basically as a fun project and to investigate the practicality of generating some of my own electricity. Here is how it works out, using a monocrystalline panel (the most efficient panel commercially available at present):
Peak power is produced only within about an hour or so each side of mid day on a bright, cloudless, hazeless sunny day.
Three hours before or after mid day, the unit produces about 50% of peak.
Five hours before or after mid day, the unit produces around 10-15% of peak
At mid day, summer time haze with 10 miles visibility will cut output to around 80% of peak
At mid day, with thin cirrus clouds (still bright sunshine), output is around 50%
At mid day, on a bright cloudy day where shadows are still cast, output is around 15%
At mid day, on an overcast day, output is generally 5% or less.
In the winter, I've never seen the unit capable of producing more than about 25% of peak on the brightest winters day.
All in all, the average output even in the summer will only be 5% of peak (because of night time, and cloudy days). Winter time is even worse. So if you want to make sure you have an average of 200 watts - which really isn't a lot, but if you can store it or put it back on the grid it'll make your house more or less neutral in terms of the electricity you use, if you have the normal domestic cycle of being out and not using much electricity during the day. To get that average of 200 watts, you'll need 4000 watts peak of solar panels.
80 watt panels cost (in quantity) around £250 a piece. That'll cost you £12,500 *just* for the panels, without a grid tied inverter and storage system or installation (probably another 4 to 6 grand) - to get a measly average of 200 watts - i.e. just enough to power one Pentium 4 computer continuously. It's simply not worth doing at all unless you can put it back on the grid (not many electricity companies let you do that - yet), or store it in batteries - since if you have a normal domestic cycle, while your solar panels are producing near peak you will be away from the house and letting three or four thousand watts go wanting. You'll probably need three grand's worth of batteries if you can't sell back to the grid - and even deep cycle leisure batteries are going to need replacing at least once every 10 years. This is for a system which will only work reasonably well in the summer. In the winter, when the days are short and you need the most power, it'll hardly contribute anything - perhaps you'll get 50 watts average from £12,500 worth of solar panels.
If solar panels were 1/10th of the price they are now - yes, it'd be worth it. I'm waiting for the breakthrough in price, not efficiency (if the efficiency brings the breakthrough in price all the better). Even a moderate sized south facing roof - I've calculated just my shed roof replaced with solar panels could produce 1kW peak - is large enough for a decent peak output using current monocrystalline panels. Price is everything. If I could get the panels at 10% of what they cost now, you bet my shed roof (my only south facing roof) would be covered by the spring. But at the current price point? It's simply not affordable for the meagre amount of electricity you get. It's a shame because the panels aren't visually intrusive and they are silent and almost maintenance free, unlike wind turbines. I really really want solar panels to be worthwhile - but at the moment - at current prices, they simply aren't.
Photovoltaics are probably more robust than you give them credit - the monocrystalline 80 watt unit I have on my shed roof has a 25 year warranty. The "coating" on the cells is a sheet of glass.
Additionally, power inverters have no moving parts and these days are pretty robust semiconductor devices which should last at least a couple of decades.
The main problem with solar panels isn't practicality, but expense. They are fantastically expensive for the energy they make. The efficiency in conversion really isn't the nut that's most important to crack - the expense is the important nut to crack (unless of course, the increase in efficiency addresses that). For solar panels to be economic as a useful power source for most of us, they need to be about 1/10th of the price per peak watt that they are now.
Efficiency of solar panels isn't really the problem - my roof, for example, even in the Isle of Man - if completely covered in solar cells and with a suitable storage system could more or less run my house (and in the summer have plenty to spare).
The problem with solar panels is PRICE. That is the nut that needs to be cracked. If a panel is only 10% efficient, but not much more expensive than a similar sized roofing slate, it suddenly becomes economical to re-roof the house the next time the roof needs attention. However, it's not even near that price. An 80 watt panel currently costs around GBP£250 which is fantastically expensive. There is no way I could even remotely afford solar roofing at those prices, however much I'd like it. The price per peak watt needs to be about a tenth of what it is now.
I did the same, but with the Z80 :-) Mainly the paper and pen (and hexloader) because I needed to buy an assembler for my Sinclair Spectrum and didn't have enough pocket money to buy GENS - so a small hex loader written in ZX Basic had to do. It all got a lot easier when someone gave me a pirated tape with GENS 3 on it!
Grrr.
If that's a computer science course, or any other degree that purports to teach fundamentals, that's so wrong it's not even wrong.
You have to learn the fundamentals, not use ready made components. Indeed, I'd advocate at least some assembly language programming, because this forces you to think HOW the machine actually does things. It needn't be x86 or anything particularly fancy - but something that will at least teach the student on an absolutely fundamental level what happens when you get a buffer overflow that starts overwriting the stack.
I bought a multimeter from the hardware store (B&Q - they sell some quite good ones now for all the home electricians - they even have a transistor tester, and go down to microamp range). The 'scope, I got off a guy on eBay - £60 for a 20MHz dual trace oscilloscope (they cost around £400 new!). I'd have been lost without the oscilloscope. There are cheaper ones listed on eBay, but I think my decision to get a dual trace one was a good one, especially when it came to debugging why my serial data receiver wasn't working quite right (I could send 0xAA continuously from the computer, hook up one probe to the incoming RS232, then hook the other probe to my circuit and find out where it was trying to sync to the signal).
My EPROM burner is home made - I made it yesterday, using the Z80 experiment I currently have on breadboard. It's just a matter of putting the right things on the address and data bus to give it the commands it needs to start a write or erase operation. I have the Z80 board sort of backwards - RAM mapped in at 0x0000 to 0x7FFF (so the Z80 starts running from RAM), and the Flash ROM starting at 0x8000. I made a circuit to load the RAM from RS232 without the need of a processor - it's a matter of decoding the incoming byte, and having a simple binary counter made of two 4520 counters and four 74HCT125s (the latter to be able to tri-state the counters outputs). So I send the program I want to run over RS232, then move a few wires on the breadboard to disconnect the counter/RS232 sender, then let the reset pin on the Z80 go inactive and it runs whatever I just loaded into RAM. (My next step will be to switch the RAM and Flash ROM, so the processor boots off ROM).
I'm not sure exactly, since the nixie project used only a subset of what's in my parts bucket (I tend to order 5 off everything, especially 4000 series or 74 series logic since they are useful and cheap). Nixie tubes themselves can be expensive - or dirt cheap. Depends on the type. I just got 50 Russian IN-12b tubes for US$35 from Ukraine. The IN-16s I'm using in that project were about £1.50 each (that was before I discovered the Sovcom shop in Ukraine - they are selling a lot of 50 IN-16s for less than US$50!) To guess - I think the complete nixie tube project would have been around £30 in parts at a guess. The most expensive single part was the Maxim MAX233 which converts logic levels to RS232 levels - that cost about £5.
Mucking with this stuff needn't be expensive. My current Z80 project consists of about £10 of parts - the most expensive being the 128kbyte Flash ROM (which I'm just about to program) - I think that was about £2.50 from RS Components.
The best thing to do is get a decent sized breadboard, and a selection of inexpensive components - a selection of NPN and PNP transistors, resistors, capacitors etc. Each component is quite cheap. "Lucky bags" of these sort of thing can be quite good for experimentation (but avoid the lucky bags of ICs!). I've seen people selling selections of 4000 series logic (100 ICs) for not a lot of money. 8-bit processors can be had quite cheap too, especially things like the Z80 which is still made.
I started off by learning with discrete components - making logic gates out of transistors and resistors, then moved onto logic ICs, and have now started with microprocessors.
I did it the way I did it so I could run it off a 12v wall-wart. The reasons why I did it this way: :-)
- I don't trust my electronics skills enough yet to have 240 volts AC off the mains on my circuit board
- I could power the whole thing AND feed it data via cat5 cabling - the spare wires in the cat5 cable can carry the power from the wall wart, which will live with the computers in the under-the-stairs closet.
The switch mode supply is 555 based and works very well - the regulation's pretty stable, and the power MOSFET runs cool enough it doesn't need a heat sink.
No, I'm not married, and not in imminent danger of it either :-)
I live in the Isle of Man. I've not yet turned on the central heating - it simply hasn't got that cold yet. We actually have milder winters than the south of England thanks to the moderating effect of the Irish Sea.
That's BS. Electric cookers are fine - I have a fan assisted electric oven. Baking is consistent, takes the same time every time, and is faster than in a gas oven. I have a gas hob though, I prefer gas for pans - but I've used electric hobs and they are perfectly servicable.
PICs would almost certainly be easier and lower power - but I'd learn less using a PIC. Besides, PIC assembly wants me want to claw my brane out, but I'm familiar with Z80 asm.
A few months ago, I started learning electronics. My first project is (electronically) complete - it just needs some finishing off to the housing.
It's a Nixie tube display, with 7 nixie tubes. I built an RS-232 reciever/sender out of 4000-series logic ICs (not a CPU or microcontroller in sight) - mostly counters and registers, and a few AND gates and inverters.
Pictures of the project's progress are at http://www.alioth.net/pics/nixies/nixies.html (two pages of photos - the working project is on page 2). I've also kept a journal of building and learning in my Slashdot journal.
The hardest part of it was probably getting the 170 volt switch mode power supply to work correctly (mainly getting it to regulate) and not put so much noise back into the 5 volt supply to cause latches and registers to lose their values. Some help from the NEONIXIE-L group on Yahoo was invaluable here, and I now have a decent 170 volt supply.
I'm now learning how to make things with microprocessors, and once I've done some breadboard experimentation, my next project is to build a logging weather station for the glider club, using a Z80 processor, a flash EPROM, some RAM and probably compact flash for mass storage (not that it'll use a lot of it!), and a small graphics LCD module for display. Currently, I'm at the stage where I've breadboarded a very basic Z80 system that can output values on a crude output device. But it works!
But that's retarded: MM in Roman numerals is 2000 not 1,000,000. So instead of having wrong pretences to Roman numerals, just take 'M' as meaning million (as virtually everyone does) and just write $100M for 100 million.
A bit OT: but why do some people write million MM? (Like $100MM instead of just $100M). No one has ever told me the answer...
If you carry on reading, you find the LETHAL dose is 520uCi or so. It would cost you over $300,000 to buy a lethal dose from UnitedNuclear. The body burden figure quoted is probably the 'legal safe limit' which is well below the limit that would even make you immediately ill.
So the majority is so pissed off with US foreign policy and our own administrators that go along with it...we voted them in for another term?