120 Degree Phase Shift Osc.

What kind of points do you score from messing with Sloman?

VLV

You're a liar. I gave you the part number of the part I was using. No, I didn't do your homework. You're an unemployed couch lizard, look up the information yourself, if you can. It's clear to everyone exactly why you're unemployable, though.

IKWYABWAI. It is your best argument. Keep using it.

I didn't bother to look anything up. I *know* how to design. OTOH, all you can do is lie and pontificate on your lies.

Negative popularity ratings :-) I'm always pleased to note that I'm the highest standard for Slowman's disdain, but please don't feed the jerk. Let him die that most unpleasant of deaths... alone ;-)

-- ...Jim Thompson

| James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

| 1962 |

GIMP's UI is a bit convoluted, too.

800x600?! I haven't used anything less than 1024x768 since '94. That was a 15" monitor. Everything I have now is at least 1680x1050 (my 15" laptop) and mostly 1920x1080 or 1200. My eyes aren't a good as they used to be, so I got glasses. ;-)

That usually happens when you whack off a lot! ;)

(PST),BillSloman

happenedBillSloman

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Obviously not. He's claiming that I said something that I didn't.

Delta-sigma is just a particular form of pulse-width modulation. If you want 10-bit sine waves at 10Hz, you seem to need to generate new waveform values at about 20kHz and which means clocking the pulse width modulation hardware at 20MHz. The examples we've had so far seem to need at least a few mA to run at this kind of speed. This isn't a tiny amount of power. Mark Weaver's three coils look as if they'd draw some 11mA on average, so a few mA is a tolerable amount of power in this context, but not tiny.

I was too pessimistic about the curren they draw, but not pessimistic enough to qualify as an idiot

Why? Micropower DACs are an off-the shelf part - Farnell stocks a bunch of quad 10-bit parts with settling times around 10usec, that draw a few hundred uA. Analog Devices, Texas Instruments, Linear Technology and Maxim parts are all in stock.

Even the lowest power Analog Devices DDS chip, the AD9833, does draw about 5mA. Slowing down its clock doesn't reduce the power consumption significantly. Mark Weaver would need three - or two if he adopted Martin Brown's scheme of making the three phase-shifted outputs as diffeently weighed sums of a 10Hz sine and cosine outputs.

This isn't a great deal more power than any of the specific uPs we've talked about - scarcely enough to qualify me as an idiot.

John Devereux's ADUC7021 - a fairly hairy uP from Analog Devices with four built-in DACs - could be programmed to generate all three waveforms by DDS, but it seems to have minimum current draw of around

7mA.

It is a ridiculously powerful processor for the job. A 16-bit processor would be plenty powerful enough, and 8-bits would do, though you'd have to do double-precision accumulation.

Packing all the digital processing into a Xilinx CoolRunner pld would do the job at very little cost in current drawn - the smaller 64- and

128-macrocell parts would draw around 50uA at 20kHz, driving parallel input DACs. Serial input DACs would push that up to closer to 600uA, as you'd have to clock the parts a lot faster to push out new 10-bit words every 50usec

My guess is that the 128-macrocell part could do the whole job - by PWM at 20MHz - while only drawing about 4mA.

The CoolRunner doing digital DDS plus three serial DACs is the scheme I proposed in the third post in this thread, and it still looks perfectly feasible, if perhaps a bit of an over-kill when Martin Weaver's three pairs of coils are going to be drawing about 11mA anyway.

-- Bill Sloman, Nijmegen

(PST),BillSloman

happenedBillSloman

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Insanely wrong.

John

You should know. You're as whacked as they come, on these groups.

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

Sloman

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The part number, but not the alphabetic part of the part number which might have told me which manufacturers part that you were talking about

ok up the

There no problem finding an an 8052 data-sheet, from Intel, Matra- Harris, Intersil and Atmel, amongst others. I don't fancy browsing through all of them to find out which one you had in mind. It isn't as if it is going to tell me anything useful.

I don't flatter the right right-wing nitwits?

Unfortunately for you, it is an excellent argument. Your idea of what I've been saying is simply wrong, apparently because you are too dim to understand the not-particularly-subtle difference between using pulse-wiith moudulation or resistor-divider DACs to set up a stair- case approximation to a sine wave. This is tolerably obvious to most of the people who post here, and makes it very clear just how depressingly stupid you are.

all you

Sure you know how to design. We've not seen a shred of evidence of any kind of design skill in all the years you have been posting here, but we are supposed to take your word that you can actually do practical electronics. An uncharitable observer might suggest that you might be deluding yourself, just as you are when you claim that I've been lying in this thread.

-- Bill Sloman, Nijmegen

Jim flatters himself. He's ignorant, but he doesn't post enough stupid misconceptions for this to worry me very often. He's a right-wing nitwit, but he's nowhere near as committed to idiotic right-wing conspiracy theories as Jim Yanik. I've yet to hear him claim that Barak Obama is a communist, or not born in the USA.

And he doesn't think that the 555 is the best integrated circuit ever designed.

There's a certain amount of competition for my disdain, and I'm afraid that Jim is merely an also-ran, rather than a front-runner.

-- Bill Sloman, Nijmegen

Probably not too many - it's kind of like having a battle of wits with an unarmed man.

Cheers! Rich

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Hopelessly clueless.

I told you *exactly* which one, moron. Well, there were three, differing only in onboard EPROM.

Since you can't bullshit people with something they know about, change subjects to something else you don't know anything about and hope to lose them too. Doesn't work, moron.

It is your only argument; a two-year-old's.

You're a liar. ...and wrong.

More lies from Slowman.

messagenews: snipped-for-privacy@30g2000yql.googlegroups.com...

Ignorant Mr S. for Stupid and misspelled surname is trolling again.

Rheostat is antidiluvian. I had assumed at first that for some reason our transatlantic cousins still used this old word in modern day electronics. Potentiometer has been pot here in the UK for many decades.

The last rheostats I saw were rickety old wire wound variable resistors on some prehistoric condemned stage lighting. They were incidentally operating as two terminal devices. And ran dull red near the low end.

I still have a couple on Scalextrix model car hand controls somewhere.

Regards, Martin Brown

messagenews: snipped-for-privacy@30g2000yql.googlegroups.com...

Yet you don't understand that is the part's name, but it can be used for either function.

Good for you.

--
Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

messagenews: snipped-for-privacy@30g2000yql.googlegroups.com...

Rheostats are about as out of fashion here as condensers.

I think you will find that strictly the term rheostat is reserved for a two terminal variable resistor for adjusting current flow that in ancient times was drawn as a resistor with a diagonal arrow through it.

That is certainly the usage in British English (when it is used at all). More efficient solid state control circuits have replaced them.

Potentiometer (pot) comes from the long resistive wire voltage measurement apparatus of the same name and is a three terminal device.

Regards, Martin Brown

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That was the example you adduced.

I haven't needed one recently. When I was last in work, we designed a broad-range conductivity meter (from 300uS/cm to 300mS/cm) that ran from a non-rechargeable Li-Thionyl Chloride battery for about a year - the expectation was that it would be active for one hour per day, five days per week, so it wasn't all that low power. My part involved an AD8031 and a MAX941. The PIC involved came from the sub-contractors, who should also have designed the analog part, but couldn't be persuaded to come up with a viable design, but could be persuaded that my design was practical.

We were stuck with the non-rechargeable battery because the circuit had to work at ambients up to 85C - at the time I posted a query here to see if anybody knew of a rechargable battery that could survive that kind of temperature.

-- Bill Sloman, Nijmegen

Rich would knows all about being an unarmed man in a battle of wits, if he had a few more wits to his name. Like krw, he's too dim to recognise when he's been out-thought.

-- Bill Sloman, Nijmegen