What Electronic Projects are you working On

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by John Stevenson on 26/05/2014 15:00:42:

Second project is an open source [ at the moment ] CNC system that works on Windows, linux and some tablets that uses USB.

Called EasyCNC the link is here **LINK**

Interesting project John.

EasyCNC looks as if will be good when the bugs are ironed out. Less geeky than EMC2 (LinuxCNC) and cheaper than a Mach3 license. I don't have the interface but I've played with the software in simulation mode. Running it on Linux the toolpath display is blank, it's OK in Windows7 and runs programs with straight lines OK but programs I have tried with arcs throw up errors and won't run. Those programs were generated from dxf2gcode and run OK on EMC and on Mach3.

I like the idea of using an Android tablet keyboards are a pain in the workshop.

Russell.

[Peter G. ShawParticipant @peterg-shaw75338]

I'm now going to upset a lot of people.

In my opinion, the amateur who generally does not have fancy test & design equipment, should restrict themselves to discrete component designs, eg transistors, resistors, capacitors etc, and the simpler ic's such as the CMOS 4000 series, 741 op-amps and CMOS 555's. The advantages of this approach are that a) you know how it works; and b) it does not depend on specialized components which may not be available a few years down the line. Other advantages are that you can then tailor the design to suit your parameters/requirements and not what someone else has decreed, and that you can generally use a higher working voltage.

The downside is that performance may not be as good but for a one or two-off circuit does that really matter? Another problem is that of having to learn how to design using what some would describe as obsolete technology and here I would recommend two books, both out of print as far as I know, but should be available through the library service: these are T. K. Hemingway's Electronic Designer's Handbook and the companion Circuit Consultant's Casebook.

Personal experience, ok from the mid-'70's, is that TTL is best left alone, whilst standard 4000 type CMOS is easier to use. BiPolar 555's can produce very heavy current spikes which the CMOS version overcomes, and 741's are reasonably easy to use. Using CMOS allows for voltages up to 15-18V which makes design very much easier. Transistors can easily be obtained which will work, within reason, at any voltage you care to use. In the mid '70's I was using them on plus & minus 50V, mainly the latter, in an environment which was pretty harsh electronically. (Huge spikes flying around.)

I have a 9 speed belt driven lathe. Barring complete motor failure, this lathe is likely to be still running when I fall off the perch. I also have a variable speed electronically controlled milling machine. Should the electronics fail on that, unless I can decipher the circuit and either repair or redesign, then an electronic failure may well result in an expensive door stop. And before anyone says that electronics don't fail, I would point out that this particular series of milling machines is/was noted for electronic failure (and plastic gear failure).

I'm well aware that there are people on this forum who are into electronics professionally – I'm simply suggesting that the amateur without the benefit of formal electronics training and/or facilities should either stick to discrete component designs that can be readily understood, or go out and buy professionally made items.

For what it's worth, I wouldn't even attempt an electronic design, even with discretes, without my trusty oscilloscope to analyze the circuit when it fails to work as hoped.

Regards,

Peter G. Shaw

[Anonymous]

Posted by Peter G. Shaw on 30/05/2014 20:56:14:

I'm now going to upset a lot of people.

Not me!

A few random thoughts:

1. In some ways FPGAs are easier to use than the modern processors; smaller datasheets for a start. Smaller FPGAs can be useful for soaking up functions that can't be done in software, but require more than simple logic. The last FPGA I used implemented a clock distribution scheme and synchroning logic for voltage measurements. There were 12 channels of measurement, all isolated. For each channel I designed a very simple open loop, ie, on/off, at a fixed duty cycle and no feedback, power supply. To prevent large current pulses if all the supplies switched together I used an FPGA to create a time shifted clock to each supply. The FPGA also implemented steering of the SPI channels and some other random logic. At the lower end the design software for FPGAs is free and you can design in logic diagrams or write the code in VHDL or Verilog.

2. I would think that standard TTL is dead in the water. For general purpose stuff I use the HC family; TTL functions, but runs over the wider voltage range with low quiescent currents and uses CMOS voltage levels. There are also some useful single gate logic functions available which are useful for getting one out a hole when there is a conflict over logic levels, or you need to level-shift or tri-state a signal.

3. I would think that the Art of Electronics would cover all one needs to know about the theory and practise of logic design unless you're going to get involved in much faster and more complex systems.

4. There are way better opamps around than the 741. Why design with both hands tied behind your back? For el cheapo, and bomb proof, devices use the LM2901/2/3/4 series. Dual and quad opamps and comparators. Not particularly good specs or fast, but cheap and robust. Opamps running from 1V to over 100V are widely available with specs that are orders of magnitudes better than the 741. A lot of old design techniques for opamps are simply there to get round limitations of the old ICs, they're just not needed now.

5. I wouldn't be seen dead using a 555.

6. I suspect that a lot of the problems associated with 'hobby' level electronic motor control is down to poor design, rather than the reliability, or otherwise, of the electronics. Two things that will kill electronics are heat and over-voltage. Good design can solve these issues, as well as taking account of faults, like the motor stalling, and designing the circuit to cope with that.

7. A 'scope is definitely useful, particularly for things like switch-mode power supplies which can have a habit of going do-lally, while still providing an output voltage.

Regards,

Andrew

[Peter G. ShawParticipant @peterg-shaw75338]

Andrew,

A lot of what you have said simply proves what I am saying: that for the amateur, a lot of modern day stuff is of no use at all. What's an FPGA? Clock distribution? Synchronizing logic? SPI channels? VHDL? Verilog? I don't know, and frankly I don't want to know.

Look at it this way. What proportion of people in this country understand anything about subjects beginning with electr*******, comp******, tele*****. The answer is that a very high proportion can use this stuff, but have no idea how it works. Just look how the wool was pulled over some peoples eyes with digital TV. The small proportion of people who do have an idea are immediately hamstrung by the lack of information about what's inside the little black boxes: they simply have to either guess or, if a data sheet can be found – and that's not always easy to do – they are then confined to the black box designer's design parameters. It's all right if you have all sorts of design aids readily available as a professional, but does the amateur? This is why I say that the amateur is best sticking with discrete components because generally the design rules are perhaps well known, more flexible, and one can design to ones own parameters.

I understand that yes there may well be "better" op-amps than the 741 available, that some people wouldn't be seen dead using a 555, but strangely, both are still available so someone must be using them. Don't know about TTL as I haven't even looked at them for nigh on 40 years.

I've just had a quick look at a well known mail order amateur electronics firm and note that the venerable TO3 2N3055 is still available although some of the other transistors I have used in the past are not.

I agree that good design should be able to guard against failures, but if it is not a good design, and the circuit diagram is not readily available, what then? I understand that some boards have even had the part numbers removed from the active elements, presumably to stop people attempting a repair. Expensive doorstop?

In respect of switch-mode power supplies (SMPS), as an amateur, I would not use them if possible as I much prefer the simpler linear system of transformer (which also acts as an isolator), rectifiers, smoothing capacitors followed by, if necessary, a discrete transistor regulator. I am aware that SMPS are supposedly more efficient – but when I feel the heat coming off my laptop supply, I begin to wonder – but they are more complicated, and I understand that elsewhere in the world, there have been reports of an increase in catastrophic failures of electronic equipment caused by the failure of the SMPS. Which does indeed make me wonder about the economics of them. Let's face it, it's not allright saving a few poundsworth of energy if at some point down the line the complete item has to be scrapped because it's been blown up!

I think, Andrew, that if you are a specialist designer using fancy design tools and can have specialist PCB's and IC's knocked out by the million or so, then that is one thing. But when you are an amateur without those tools, then you are stuck with either using someone else's designs, eg the Arduino kit, or reverting back to simpler basic components that don't rely on specialist boards or items and for which spares are likely to be available for a long time to come. I suspect that there are a number of people around who can indeed understand discrete component circuitry, but are completely hamstrung when it comes to specialist stuff.

An interesting aside for you Andrew. I learn't how to design switching circuits using transistors in the 1970's. In 1980 I was promoted and promptly stopped doing anything like that. In 1982 I bought myself an oscilloscope for use at home, but never actually used it that much due to other constraints, mainly time. Two years ago, I had occasion to use it and discovered it was faulty. Now this is an analogue device, yet by studying the circuit diagram, and careful noting of what did, and didn't work, I was able to get to within one transistor of the one which had failed. It turned out that the casing had cracked, maybe it had been like it from new, dunno. Anyway, surprisingly I found some identically labelled transistors seven miles from where I live. I bought 10, set to with variable voltage supply and multimeters and managed to sort out some matched pairs at dc conditions. Replaced the broken transistor and its matching partner and now the oscilloscope is working again. Obviously I can't check it's high frequency response etc, but at least it is working. Speaking to the importer later, I discovered that the modern equivalent is totally ic. What chance would I have had of repairing that? Probably none – unless they still use medium power output transistors in a balanced push-pull output stage.

Regards,

Peter G. Shaw

[John HaineParticipant @johnhaine32865]

Well, some of those amateurs will be young people – should we condemn them to using obsolescent components and techniques? Do you think they would be at all interested? Just how long do you think 4000 series CMOS will be around? Or maybe they should use valves?

[Neil WyattModerator @neilwyatt]

Surely it all depends what you want to do.

No one is forcing people to use modern chips if they don't want to. Thing is, it's so easy to do parametric searches these days you can find a 'best fit' op amp or transistor in seconds on Farnell, for example.

I started off with three things: Antex iron, Dad's Heathkit scope and a high-end Eagle multimeter. A mate and I cracked the boot sequence of the Amstrad PCW with a 555 toggling the reset line and inspecting the data and address lines one by one on the scope.

Hameg 50Meg scope, quite a lot of nice analogue multimeters (rarely used as the Clarke digital is more accurate and has higher input impedance), home-made DDS and analog frequency synthesisers and my trusty 15W antex iron. Home made UV light box and these days I drill pcbs on my 6-speed bench drill (yes, really!)

Extra to that for microcontrollers I've got an STK500 and now an AVRISP which runs off USB (leaving precious serial ports free for projects). These cost peanuts compared to typical model engineering tools.

I have never actually touched an Arduino -(I did see one at Harrogate!) The simpler AVRs are ideal for learning on and have no more pins than a 555.

I have another project, rarely used, called Beeb Scope it's a box with a fast A2D that wires up to the user port of a BBC computer and just dumps data as fast as the beeb asks for it. A special free-run mode gets 256 samples at about 500Ksamples (if I recall correctly). I managed on this as my scope for about seven or eight years.

Electronics is fundamentally cheap, and ingenuity is worth more than the latest gear. What components you apply your ingenuity to, is up to you.

Neil

[MuzzerParticipant @muzzer]

If you look at how technology has exploded over the last 50 years, it's difficult to imagine what will happen in the next 50. However, you can be sure it isn't about to suddenly come to a complete stop just because we (here) can't imagine what will happen next. The way it will continue is by the next generation(s) starting where we left off. Our kids grew up with computers, powerful software, smartphones, internet etc and they take them almost for granted. It's come to the point where no single individual can claim to understand every aspect of a modern product. Even the software has got to that point. Modern cars have between 50-100 microprocessors in them (you possibly didn't realise that). It's not about to stop…

I started out playing with discrete transistors like the OC71, AC128 and was messing with switching power supplies back in the late 70s. Now I develop smart motor drives, chargers etc that have dedicated SMPS controllers, microprocessors, comms ports, displays, diagnostics, data logging, thermal protection etc. Things have come a long way! SMPS and other switching power electronics products can be very reliable indeed, not least because we understand a lot more about failure mechanisms nowadays. Modern components are effectively defect-free as far as product reliability is concerned. Generally, failures are the result of poor design or inappropriate application. Might sound controversial that statement but that's the long and the short of it.

Today's engineers have to design with highly integrated devices, like it or not. There is still the need for discrete devices in almost any product but there's very little these days that you can do with a handful of discretes alone. Apart from inverted snobbery or nostalgia, there's really no benefit from sticking to decades-old technology. That's not to say I'm not nostalgic myself (I have "several" boxes full of nostalgia) but what has always really, really excited me is thinking about what we could do if we build on what we have – and going out and making it happen. In this context, that's perhaps the difference between an engineer (tackling new challenges) and a technician (sticking with the same)? No disrespect meant to technicians, BTW.

Murray

[Geoff TheasbyParticipant @geofftheasby]

All very interesting. I still play with small projects like regenerative radio receivers, sirens, simulated steam whistles, for a bit of fun in an evening. However, in the real world, an acquaintance of mine is working on rewiring a Land Rover with single-bus electrics run by an Arduino. I am inclined to go the Raspberry Pi route, having read the Haynes Manual about it. My radio amateur self wants to get a Funcube Pro Plus dongle, a wideband miniature computerised radio receiver!

Regards

Geoff

[Neil WyattModerator @neilwyatt]

When championing my AVR projects, i should mention my 'other' project on the go is a 'Fuzz Face' using teh original 1960s circuit and vintage germanium transistors

Neil

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Andrew Johnston on 31/05/2014 15:19:36:

2. I would think that standard TTL is dead in the water.

TTL? New fangled stuff. Why not stick to using Mullard Combi Blocks for logic? Personally I'll stick with red spot and white spot transistors.

Russell.

[Gordon WParticipant @gordonw]

Why wire a Landy with single -bus electrics? ( I'm assuming a proper one)It must be cheaper to use decent gauge wire, and a lot easier to fix on a cold wet night. Still recovering from trying to wire trailer socket on these new fangled things.

[Peter G. ShawParticipant @peterg-shaw75338]

John Haine,

I wonder why all the valves as used in my very first amplifier are now readily available again. Could it be because the sound is perceived to be better that semiconductors?

Like a lot of other stuff, the 4000 series has been around for something like 40 years which to me says something about its usefulness. As to how long will it be around, who knows. As I said some valves are still available.

Muzzer,

And of course, that's why home maintenance of cars is falling by the wayside. As is home maintenance of almost everything else.

Of course things will change in the future, but not necessarily for the better. In my opinion, we are rapidly heading towards a situation where the man in the street will not be able to do anything for himself: instead anything that goes wrong, and they will regardless of how much improved they are, will require the attention of a highly trained, and expensive, person to sort it out. We already have people who can't change a plug for example. Or change a tapwasher. Or sew a button on (I'm married to one).

Inappropriate applications. And that brings it home. Do it this way, or it won't work properly and might fail. Where's the creativity there for the amateur – there is none. Where's the incentive for the amateur to learn anything new if all you can use are little black boxes. It's a similar argument in respect of CNC against manually controlled equipment. I get enjoyment and increase my skill level by doing it manually whereas programming a CNC machine does nothing for me at all as once you've satisfactorily programmed it, what then? At least with discrete components I can learn and adjust to suit my requirements. I've nothing against programming by the way: I keep looking at a project at the moment, but realistically, it won't happen because of time constraints, both in the immediate future and lack of future years. But nevertheless, thinking about it does help to keep the braincells ticking over.

If you want to use black boxes and simply make it work without understanding what's happening inside, then fair enough, you do that. For me, that isn't good enough as I want to know and understand the totality of what I'm doing. And by the way, this doesn't mean that I need to know all the ins and outs of my computer, my television, my Freeview adaptor, my …… etc. I am referring purely and simply to anything I might wish to do as an amateur.

Regards, and bye-bye,

Peter G. Shaw

[Neil WyattModerator @neilwyatt]

I hope you're not waving goodbye for good Peter?

I'm afraid I have to take a different view on some of those issues. Valves sound great. They are useless for accurately reproducing sound at volume, but they sound nice when they distort.

I have one of the new breed of guitar amplifiers. it uses a small valve amp with a microprocessor to simulate 33 different guitar amplifiers. The microprocessor is damned clever and can imitate anything from a Fender Twin, and AC30 to a Marshall stack – but it still needs to overdrive a real valve to get the authentic sound. ironically, the power amp stage is solid state – so that it reproduces valve-distorted sound correctly at any volume.

So the latest and the oldest technologies live together side by side in harmony (or infernal racket, depending which amp model you choose). Why can't they do so in our hobby, especially as this isn't 'electronics for electronics sake'. This topic is 'electronics as an aid to the workshop', so the right choice for anyone is what makes their hobby more satisfying, and only each individual can decide that.

I knew someone who claimed my 'computer' I made wasn't a real one as I should have programmed the processor into an FPGA. Well I have come across a guy who made a microprocessor out of TTL and wire wrap…

But then you could argue that Acorn didn't make the BBC computer because they used Rockwell's 6502 instead of their own processor, or I didn't 'make' my 10V because I bought the castings from Stuarts, or Norden, because someone else poured the castings from my patterns..

It's all a matter of degree and personal satisfaction. It's also means to an end. Microprocessors let you make a lot of things you just couldn't, practically, do without them, but as I said earlier, you need to understand 'discretes' if you want your black boxes to talk to the outside world.

Jack Spratt would eat no fat, his wife would eat no lean, yet between the both of them, they licked the platter clean.

Neil

[Peter G. ShawParticipant @peterg-shaw75338]

Neil,

No I'm not leaving for good, just not taking an active part anymore in this particular thread.

It's obvious that my ideas on simplicity, ease and understanding for amateurs are not well received so there's nothing more to be said.

Regards,

Peter G. Shaw

[Anonymous]

I have experimented with one of the processors embedded within an FPGA; just to see if it worked, I never used it in a real design. I think it is probably a solution looking for a problem. A basic processor is fine, but not very useful. Gone are the days of adding support chips; now everything is expected to be on the processor IC.

There seem to be some mis-conceptions within this thread regarding professional versus amateur. So here are a few thoughts on the matter.

I have used high end design tools (£100k+) in the past, often at the behest of the client. However, for my current designs I use Geomagic (Alibre as was) for 3D CAD and Easy-PC for schematic capture and PCB layout. Not much different to the keen amateur I suspect. I do all my own PCB layout. That's one big change that has happened over the years; the glory days of external PCB bureaus are over. It's part of a trend, you don't see many typing pools these days.

I don't have access to much more information than the amateur. I use datasheets, apps notes and the like from the web. I do have contact with suppliers and reps, but that's more to do with component availability and costings than technical. There are online help forums, but they generally reply with a pointer to the datasheet – useless, I've read the datasheet, and the answer isn't there, which is why I asked the question!

In some cases you have to register to get data; I think the last time I had to do that was for DDR SDRAM, not something I suspect the amatuer is likely to be using. There are also ICs for which NDAs are required even to get a datasheet, but these tend to be highly specialised RF and consumer type devices, which very few amateurs, or professionals, would be using. There's a whole range of semiconductor companies out there that exist to supply the high volume consumer electronics markets, and rarely sell via normal distribution. In the past I've been told that they were not interested because I was 'only' asking about 100,000 parts per year.

Mention has been made of designing with black boxes. Modern electronics is like that, analogue or digital. There is no way one is going to understand the detailed internal design of even a fairly simple microcontroller. But then again how many people really understand the internals of an opamp? And no it doesn't look like a conventional amplifier circuit with transistors, resistors and capacitors. Think more in terms of current sources, current mirrors, active loads and circuits that rely on transistor parameters that are set by the physical size of the device.

One big difference between amateur and professional is that the professional has to deal with a number of 'soft' factors that the amateur can ignore. These include things like cost, ease of assembly, component supply chains, performance across temperature, EMC and ESD, the list seems never ending!

One last thought before I head back to the workshop (all for work unfortunately, the traction engines sit neglected in the kitchen) is the question of creativity. To be honest there isn't that much scope for creativity in general electronics. The really exciting areas are in IC design, where it is still possbile to be blown away by a design features or a new approach.

Here is an example; I recently had a requirement for a power supply to generate 0 to 10V at 500mA, and to be controlled by a microcontroller via a DAC. The classic feedback loop in a power supply uses a potential divider to sample the output voltage and compare it with a fixed reference. So far so good, we just need to 'interfere' with the voltage on the potential divider to control the output. But there are two problems. One the output voltage is unlikely to be a simple function of the control voltage, and two what happens when the output voltage reaches the reference voltage? The answer is that the minimum output voltage is set at the reference voltage. After trawling the internet I found a Linear Tech switcher IC where the reference voltage has been replaced with a 50µA current source. Drive that current through a resistor and the IC will drive the output to match the resulting voltage, possibly through a potential divider. But there is no limitation on the voltage, if we choose a resistor that only generates 100mV, the output can be set at 100mV. Now, suppose we drive the current source pin from an opamp that will sink at least 50µA, the output will follow whatever voltage is at the output of the opamp, right down to zero. Really, really neat. The output versus control voltage is linear, and the output will go to zero. Even better, although not relevant in my application, is the opamp output doesn't have to be DC. I bought the devkit and adapted it to my design to check out the performance, the output voltage into a 10 ohm load will follow the control voltage up to several hundred Hertz.

Good grief, that was a bit longer than anticipated, I expect everybody is now asleep – Zzzzzzzzzzzzz.

Regards,

Andrew

DDR SDRAM = double data rate static dynamic random access memory

NDA = non-disclosure agreement, usually between companies to protect IP

IP = intellectual property

DAC = digital to analog converter

[jason udallParticipant @jasonudall57142]

Mmmm…andrew…Powerop amp maybe…I made myself ( back when you sometimes needed to build test gear)..a dual channel 50 -0 -50 5 amp”programmable” power supply.. based on a power op amp… .nice chip..10 MHz gainbandwidth product…fine for me only asking gain of five and bw of 100 K….
.
I also remember the 700 series op amps..even has to do a lab at uni ob them making a replica in discreet transitors……
Ahh the nostalgia. .
But then again portability and design cycle is the thing…so code for fpga..is where it’s at…most of the time…
There are still times requiring…finesse. ..
But for one off’s ..well chuck a micro controller at it and get it done in code

[Neil WyattModerator @neilwyatt]

Hi Andrew,

What you end up with sounds suspiciously like a Class-D audio amp…

As for the cost of getting into 'black boxes' Arduino Uno is £49+VAT bundled with breadboard and enough components for anyone to get started, from CPC.

Neil

[Les Jones 1Participant @lesjones1]

Hi Neil,

The TI MSP430 Launchpad is less than 10 pounds but the development software is much less intuitive than PIC or Atmel software. I bought one of these but have not yet done much with it.

Les.

[Steve WithnellParticipant @stevewithnell34426]

I've just picked up another transceiver to restore. The thing is that choked with nicotine/cigarette tar you need an NBG suit on before removing the covers. How the hell to you get rid of all that crap on the pcb's and interstage wiring? The radio looks like it's had a 60 a day senior service habit for the last forty years.

Steve

[Billy MillsParticipant @billymills]

Steve

You need to wash it. Electrolube used to make a very good water based flux remover in aerosol cans called Safewash which had an attatched brush. We used to clean up pcb and monitor chassis/pcb's without issues although LOPT's were not cleaned because the focus assembly is not hermetic. Providing that you can compleatly rinse and dry -if you know what you are doing- you can wash clean almost any electronic equipment that is water safe. Washing should remove trace lubes on rotary switches and mechanical parts so remove or relube.

For cleaning at home warm water and washing up detergent works well, Would not want to wash any LCD displays or non sealed relays however, too many layers, nooks and cranies to drain.

Back in the days of rental tv some service departments used to dunk the insides of tv's in ultrasonic cleaners that used an innert liquid. The liquid was demonstrated on Tomorrow's World by lowering a working TV into the liquid. Most U/S cleaners were run with water and detergents for equipment cleaning, very much cheaper.

Was amused to read about valve amplifiers and their wonderful sound!!!!! well back in the day… I had holiday jobs in the electro-music industry when I was a kid. Used to fix Hammonds, Vox, Marshall, Fender, CopyCat et al…. The main design principle used in most equipment was that you could not make it any cheaper. They got away with it because amplifiers ony ever worked on one signal source so the intermodulation, limited bandwidth and resonances were not apparent, only part of the "instrument" sound. Made a bit of money cutting Hammonds in half- called "splitting" and adding pedal sustain and other effects.

Billy

[Geoff TheasbyParticipant @geofftheasby]

In the matter of solving simple but clunky problems by throwing technology at them, the current Practical Wireless has a news item on proposals to control the peripherals of a motor vehicle using Bluetooth equipment, incorporating specially designed electronics capable of coping with the harsh environment in such a situation. Much less copper wire and complex harnesses or looms, no relays, no individual switches, but presumably supplying the current through a single bus wire.

Geoff

[Neil WyattModerator @neilwyatt]

I came across a professional electronic engineer who used to wash boards in the dishwasher.

Neil

[Neil WyattModerator @neilwyatt]

> control the peripherals of a motor vehicle using Bluetooth equipment,

Authentication required. If you wish to continue braking, please re-enter your PIN.

Neil

[Danny M2ZParticipant @dannym2z]

Posted by Geoff Theasby on 08/06/2014 12:54:31:

In the matter of solving simple but clunky problems by throwing technology at them, the current Practical Wireless has a news item on proposals to control the peripherals of a motor vehicle using Bluetooth equipment, incorporating specially designed electronics capable of coping with the harsh environment in such a situation.

I remember when the U.S. lost a bunch of the first Blackhawk helicopters in Europe. (At $6M a pop)

Turned out that the 'fly-by-wire' systems picked up the Megawatt signals pumped out towards the east by Radio Free Europe, powerful enough to inductively develop dc voltages in the servo control circuits.

I hope the Bluetooth is only going to control the back seat movies.

* Danny M *

[Billy MillsParticipant @billymills]

There was an Aircrash Investigation show on the Air France Airbus into the Atlantic on a few days ago. This was a very carefully designed aircraft and the crew were especially trained to fly the aircraft using sidestick controllers.

They flew through some weather that iced the pitot tubes, one of the pilots misread the instruments and pulled the sidestick hard back. The aircraft stalled at 33,000 ft. The co pilot then applied nose down on his side but the first pilot still held the stick hard back which negated the second stick input. The aircraft fell into the sea, everyone died.

Had the controllers been mechanical or had some feedback it would have been obvious what the first pilot had done, the incident would not have happened.

So Bluetooth and car designers?

Billy.

[Author]

Posts