Re: Obama doesnt want you to know the real truth about Global Warming

On Mon, 28 Sep 2009 04:35:22 -0700 (PDT), Bill Sloman
<bill.sloman@xxxxxxxx> wrote:

On Sep 28, 2:23 am, John Larkin
<jjlar...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sun, 27 Sep 2009 16:37:43 -0700 (PDT),Bill Sloman





<bill.slo...@xxxxxxxx> wrote:
On Sep 27, 9:24 pm, John Larkin
<jjlar...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sun, 27 Sep 2009 11:44:52 -0700 (PDT),Bill Sloman

<bill.slo...@xxxxxxxx> wrote:
On Sep 27, 6:29 pm, John Larkin
<jjlar...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sun, 27 Sep 2009 03:55:25 -0700 (PDT),Bill Sloman

<bill.slo...@xxxxxxxx> wrote:
On Sep 27, 2:02 am, John Larkin
<jjlar...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sat, 26 Sep 2009 15:54:37 -0700 (PDT),Bill Sloman

<bill.slo...@xxxxxxxx> wrote:
On Sep 26, 4:52 pm, John Larkin
<jjlar...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
On Sat, 26 Sep 2009 00:27:41 -0400, "Martin Riddle"

<martin_...@xxxxxxxxxxx> wrote:
<http://blog.heritage.org/2009/06/29/an-inconvenient-voice-dr-alan-car...>

Cheers

How would a lawyer and community organizer know the real truth about
anything?

Listen to the best available advice? Dubbya was exposed to the same
quality of advice, but chose to ignore advice that he found
inconvenient or distasteful.

You have shown signs of a similar problem.

Idiot. You know nothing about my life except that I have a job and
design good electronics. I know nothing about your life except that
you don't, and you don't.

There you go. You know that I haven't got a job because I've told you.
You know very little about the electronics I've designed because
you've seen very little of it, but despite this you are willing to
claim that I don't design good electronics.

Post something and show us. Something not 20 years old.

Since I'm complaining that you don't draw logical conclusions from the
evidence available, it would be waste of time for me to present you
with evidence for a proposition that obviously wouldn't take your
fancy.

Convenient evasion. You'd rather talk about climate and economics,
untestable studies where you can cite other peoples' "peer reviewed"
work as evidence of your intelligence and fuel for insults. How
dreary.

And what's wrong with twenty year old circuits? You seem to boast
about developing the same kind of stuff I was doing thirty years ago -
since then the  bleeding edge of technology has moved on a bit so your
stuff goes a bit faster, but you don't - for instance - claim to be
using the sort of auto-calibration tricks that we were using back then

You conclude that we don't use autocal from the fact that I don't talk
much about autocal?

See any trimpots?

ftp://jjlarkin.lmi.net/DSC01786.JPG

The SO-8 under the eprom socket is a serial eeprom. It holds the
serial number, dash number, and the cal table, full of polynomials and
tempco factors and such. All this sort of stuff is obvious and
mandatory these days, not to mention tedious, so there's not a lot to
say about it.

That's not auto calibration, that's just replacing trim pots and screw
drivers with digital pots

none of them, either

I was using "digital pot" in th broad sense of a device with a
programmable impedance, in the same sense that "trim pots" in this
kind of context has to include trimming capacitors and moveable slugs
in inductors.

Don't use them on this design, rarely ever. Most cals are pure
digital, in the FPGA. Some analog offset type things use dacs. The
only "variable impedance" things we commonly use are varicaps.

I've been searching for a good wideband (true DC to a GHz or so)
programmable attenuator, but nothing wonderful so far.



and an eprom programmer.

The eprom holds the code, same for all units. The cal factors and
serial number and options mask are in serial eeprom.

Autocalibration is
where the circuit monitors its own off-sets and delays and reprograms
the equivalent of your serial eprom every few minutes (or whenever).

Genuine calibration has to be tracable to - in the USA - NIST primary
standards.

So what. This sin't the kind of calibration that I was talking about.

No device can calibrate itself.

Why not? If it were to include a primary standard it could certainly
do just that.

You've suggested that before. How do I add primary standards to a
20-square-inch board that sells for a few K$? Hell, I could sell that
part alone for $100K.


Few devices can afford to
stop working whenever they feel like and re-zero or linearize
themselves; customers wouldn't like that, and we *do* have customers.

This obviously depends on application, and on how fast the re-
calibration can be done. I once put togheter a scheme where we should
have been able to measure all the 128 fine time delays we could
generate within one millisecond

One millisecond timeout is planty enough to make a product useless, or
dangerous. One nanosecond could, ditto.



Some things can get done quietly in background, like tempco tweaks,
but the intervention must not compromise signal quality. It's better
to design stuff that doesn't drift much, which isn't real hard these
days.

What's the non-temperature-sensitive equivalent of the MC100E195

http://www.onsemi.com/pub_link/Collateral/MC10E195-D.PDF

The Micrel parts are much better, but still but have TCs that vary
with programmed delay. But the compensations have to be non-intrusive
on continuous signal processing... no timeouts, no tap switching
allowed.



For the record, I did the concept, the architecture, the target specs,
schematic, the firmware, the cal procedure/firmware/PC software, and
the manual myself. I worked with two other people on the FPGA and the
pcb layout. One of my resolves in life is to never have to drive the
ghastly Xilinx software myself. No cuts, no jumpers, no breadboard, no
prototype: rev A works.

Sure. I've done all of that, and laid out a one or two printed circuit
boards as well. Am I supposed to be impressed?

I myself hate writing manuals, and know at least one guy who is
brilliant at it. At least he was brilliant at it when I knew him in
Cambridge, when I managed to get him the job of writing the manual
that my boss wanted me to write.

http://www.interface.co.uk/

I haven't written any software worth talking about since 1976, though
I've tinkered with other people's code once or twice since then, but I
don't have any problem with assembler and programming programmable
logic devices.

This arbitrary waveform generator also has BIST - note the relays -
the coding of which was pretty tedious. Hardly cocktail party
conversation.

Relays? Couldn't you use some kind of analog switch? Relays do have
their virtues, but they are big.

These aren't very big. Their on/off ratio can't be touched by any
semiconductor I know of. Zero failures so far, too.

The on-off ratios can be very good. The life-time is finite, but 10^7
operations is often enough, and there ae always mercury wetted reed
relays if you need 10^8.

Mercury is illegal these days, and DPDT mercury relays were never
plentiful. Many were position sensitive. The little telecom relays are
small, cheap, and very reliable. The latching types have unmeasurable
thermal offsets; reeds are rotten thermally.


I designed this dc/dc inverter for this project

ftp://jjlarkin.lmi.net/Inverter.jpg

which was fun because it's "real circuit design", not just plugging in
a commercial regulator chip. I did breadboard this bit.

Pretty crude. You use the +5V rail plus the Vbe of Q1 as your voltage
reference.

It's not crude, it's elegant.

A 5V rail is never an elegant voltage reference, and throwing in an
uncompensated Vbe doesn't improve it.

How do you get to make statements like that?


Max duty cycle is controlled by design,
it's dead stable, and load regulation and efficiency are excellent.
It's fine for its purpose, which is powering opamps.

Show us a switcher you've designed, and we'll grade its
sophistication.

That you think that the circuit you posted is "elegant" confirms my
comments about the self-gratifying nature of your "judgement". Your
conclusions about the sophistication of any circuit I might produce
are a little too predictable.

Show us.


You could check out the switch-mode curent drive that I published in
Measurment Science and Technology back in 1996 - Meas. Sci. Technol. 7
(1996) 1653?1664 "A microcontroller-based driver to stabilize the
temperature of an optical stage to within 1 mK in the range 4?38 C,
using a Peltier heat pump
and a thermistor sensor" by A W Slomany, Paul Buggs, James Molloy and
Douglas Stewart.

Post it somewhere.


The switched mode driver than can send up to 3A through the Peltier
junction has an element of sophistication.

Gosh. 3 amps.


What made it necessary to "design" this rather than finding a
commercial regulator chip?

Positive-to-negative inverters are rare, especially at 12 volts and
close to an amp. And I did it because I enjoyed it.

A rather perverse pleasure, considering the result.

Do I have to give all the money back?

John


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