Chip with simple program for Toy

[Lars Torben Wilson]

mike wrote:

John Popelish wrote:
I think you can mechanically broaden the response of the piezo and
also increase its sensitivity by putting an exponential horn on it.

Agree. Fixing it mechanically is likely better than trying to patch
up a high Q response after the fact.

OK, that's two votes for the horn, so it's probably not a bad idea at
all. However, I have both a space limitation and a horn-manufacturing
limitation, not to mention a limitation in my understanding of acoustics
which I figure would help me work out the size needed for best
performance from ~30kHz to ~100kHz. Quicky paper horns (pretty much
linear) seem to help with the sensitivity, though.

First thing I'd try is to run the piezo into the virtual ground of an
op-amp. But the intrinsic series impedance of the transducer may make
this unfruitful.

I'll give that a shot on my breadboard. I still have to check the actual
response of the transducer; I've been assuming so far that it has a
fairly tight spike around 40kHz, but I've also read that some work
just fine with no detuning at all. Given that I'm already fairly
happy with the sound, what I'm trying for now is to solidify my
understanding of the detuning. I'm currently under the (probably
wrong) impression that it's mostly phase games. Am I close?

May have to resort to mechanical damping. Glue
the piezo to a piece of foam rubber and load it with a horn as
described above.

Cool.

I have a commercial ultrasonic leak detector. Can't see in the hole too
well, but it looks more like a plastic dome on a voice coil than a piezo
transducer.
The transmitter and receiver transducers "look" to be the same, but
that's not necessarily a valid conclusion. I never found any data on
the setup, so don't know what the claimed bandwidth is.

Might be interesting to plug on a capacitor microphone element and see
what that does. Most of the microphone specs I've seen are still going
strong at the 20 KHz. end of the graph.
mike

Hm...that sounds neat. I'll see if I can find one.


Thanks for the tips,

Torben

 

[Anthony Fremont]

"BillW50" <BillW50@aol.kom> wrote in message
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Date: Sun, 30 Oct 2005 22:10:17 GMT


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"Mxsmanic" <mxsmanic@gmail.com> wrote in message
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Date: Fri, 28 Oct 2005 20:42:43 +0200

mark349@lycos.com writes:

OS/2 is dead and gone, and although it was superior in
design to the old versions of Windows, it was not
superior to NT.

Supposedly better in design, but OS/2 sucked in real life
for
many of us! As only one OS/2 Win session had sound while
the
others was soundless. And a good number of Windows
applications would routinely crashed under OS/2, but
stable
as a rock under Windows 3.1. Then the OS/2 GUI was
unstable
for at least a couple of years and crashed the whole
system.
Then the FixPaks often caused more problems than they
fixed.
IBM programmers are morons!

Am I the only guy that was working with this crap back then?

Nope!

IBM contracted with M$ to write OS/2 for them in like 1987.

It might have been in '86 actually. And MS had been working on
Windows since about '84. Although MS couldn't give the
development
time it deserved because those MS programmers were mostly
working
on OS/2. MS lost 3 years in Windows development because of
OS/2.

I suppose that's one way to look at the time that M$ spent
sucking
money from IBM and using it for their own gains.

IBM paid Microsoft by the K-line. Which means by the lines of code
they produced. IBM got the lines and MS got paid. Anytime MS
didn't
produce code for OS/2, MS didn't get paid. So how could MS get
paid
for their own gains by IBM? That's impossible.

No, it's not impossible. M$ got paid by IBM to write code for IBM.
They also were able to use much of the same exact code in Windows.

Well okay, you have me there.

M$ drug their feet on the release, while spending IBM's
money, so that they could get Win 3.0 out before OS/2, by
saying that OS/2 just wasn't stable enough for release
yet. Yeah, no conflict of interest their.

IBM only paid MS for the lines of code MS produced. IBM
didn't care if MS spent more time to make the code lean,
mean and faster. As IBM would

I think IBM had visions of stability that M$ will never attain,
ever.

pay you less if you did so. IBM was cutting their own throats.
IBM
is full of a much of morons. Impossible to work with and to
get
paid fairly for. Hell I would work slowly and drag my feet as
well
for those morons.

Yeah, morons. They only own the mainframe market even though
Honeywell made better hardware. IBM's only moronic move was to
allow M$ to screw them for a second time. The first time being
with
MSDOS/IBMDOS games.

Who screwed whom again? IBM only paid MS $80,000 for everything
(including DOS, Basic, etc.). And IBM paid no royalties to
Microsoft
no matter how many copies IBM sold.

As far as I can remember, I've never heard that before so I need to
see
a link to back that statement up. M$ had to pay $50,000 to Seattle
Computers just to buy the thing that they turned into DOS 1.0. How
could they have possibly done the whole job for $80,000 with no
royalty
income? I'm sorry, I just can't buy that without some kind of
proof.

Bob Cringely produced "Triumph of the Nerds" for PBS back in '96. It
was truly a great documentary. Cast of characters included were:

I saw this once, I wish I had it recorded.

Robert X. Cringely...Himself (host/interviewer)
Douglas Adams...Himself (author)
Sam Albert...Himself (former IBM executive)
Paul Allen...Himself (co-founder, Microsoft)
Bill Atkinson...Himself (designer, Macintosh Development Team)
Steve Ballmer...Himself (vice-president, Microsoft)
Dan Bricklin...Himself (VisiCalc inventor)
David Bunnell...Himself (founder, PC World and Macworld magazines)
Rod Canion...Himself (co-founder, Compaq)
Jim Cannavino...Himself (former head, PC division, IBM)
Christine Comaford...Herself (CEO, Corporate Computing International)
Eddy Curry...Himself
Esther Dyson...Herself (computer industry analyst)
Larry Ellison...Himself (founder and president, Oracle)
Chris Espinosa...Himself (manager, Media Tools, Apple)
Gordon Eubanks...Himself (former head of language research, Digital
Research)
Lee Felsenstein...Himself
Bob Frankston...Himself (VisiCalc programmer)
Bill Gates...Himself (co-founder, Microsoft)
Adele Goldberg...Herself (former Xerox PARC researcher; founder, PARC
Place Systems)
Marv Goldschmitt...Himself
Andy Hertzfeld...Himself (designer, Macintosh Development Team)
Steve Jobs...Himself (co-founder, Apple Computer)
Gary Kildall...Himself (founder, Digital Research)
Joe Krause...Himself (president, Architext Software)
Bill Lowe...Himself (Head, IBM PC Development Team 1980)
Roger Melen...Himself
Bob Metcalfe...Himself (former Xerox PARC researcher; founder, 3Com)
Gordon Moore...Himself (co-founder, Intel)
Dana Muise...Himself (founder, Hypnovista)
Doug Muise...Himself (software designer)
Bill Murto...Himself (co-founder, Compaq)
Tim Patterson...Himself (programmer)
Vern Raburn...Himself (former vice-president, Microsoft; president,
The Paul Allen Group)
Jeff Raikes...Himself (vice-president, Microsoft)
Jean Richardson...Herself (former VP, corporate communications,
Microsoft)
Ed Roberts...Himself (founder, MITS)
Arthur Rock...Himself (venture capitalist)
Jack Sams...Himself (former IBM executive)
John Sculley...Himself (president, Apple Computer, 1983-1993)
Rich Seidner...Himself (former IBM programmer)
Charles Simonyi...Himself (chief programmer, Microsoft)
Sparky Sparks...Himself (former IBM executive)
Claude Stern...Himself (Silicon Valley attorney)
Bob Taylor...Himself (former head of computer science lab, Xerox PARC)
Larry Tesler...Himself (former Xerox PARC researcher; chief
scientist, Apple Computer)
Mark Van Haren...Himself (programmer, Architext Software)
John Warnock...Himself
Jim Warren...Himself (founder, West Coast Computer Faire 1978)
Steve Wozniak...Himself (co-founder, Apple Computer)

You can find the transcript at: http://www.pbs.org/nerds/

The quote of $80,000 is in Part 2:

Bill Gates: "The key to our...the structure of our deal was
that IBM had no control over...over our licensing to other
people. In a lesson on the computer industry in mainframes was
that er, over time, people built compatible machines or clones,
whatever term you want to use, and so really, the primary
upside on the deal we had with IBM, because they had a fixed
fee er, we got about $80,000 - we got some other money for some
special work we did er, but no royalty from them. And that's
the DOS and Basic as well. And so we were hoping a lot of other
people would come along and do compatible machines. We were
expecting that that would happen because we knew Intel wanted
to vend the chip to a lot more than just than just IBM and so
it was great when people did start showing up and ehm having an
interest in the licence."

I can't help but think of "the incredible liar" from Saturday Night Live
fame. Yeah, that's the ticket. ;-) $80,000 still seems a bit low to
me as they would have had more than that invested themselves. But I
will concede that you actually did back up your statement, even though I
don't believe Bill for a minute. ;-) I certainly will never believe
that DOS 2 and DOS 3 were included in that $80K.

http://www.pbs.org/nerds/part2.html

Finally IBM got fed up and took the project away from M$.

Yeah, IBM got fed up alright! As Microsoft didn't want to be a
slave to IBM (who always makes slaves or crushes anybody that
gets
in their way

Too bad that isn't true since they would have done the world a
great
favor by crushing M$.

Actually Bill Gates did the world a favor by saving all of us from
IBM. As nobody else was willing to do it. Including Gary Kildall.

IMO Kildall was 100 times the human being that B.G. could ever hope
to
be. That's taking into consideration B.G.'s charity work.

Well I don't know if I would say that about pot head Kildall?

Oh come on now, are you suggesting that those geeky kids, flying a jolly
roger over their corporate headquarters weren't toking it up a bit, are
you?

Getting into bar room fights and all.

I don't recall seeing his mugshot anywhere. Sure can't say the same for
B.G. though, huh? ;-) No nasty anti-trust suits either.

up to this point in time). And IBM wanted MS to create OS/2
which
would be made to run on only true IBM PCs after they have the
world hooked on OS/2.

Yeah that is a great plan for us, NOT! Bill Gates had taken
the
biggest risk in his career. As nobody ever bucked IBM and had
survived. Although he did it! And thank goodness he did! As we
all
would be using real IBM machines and OS/2 by now.

Actually, if Gates wasn't so good at being greedy, we'd all be
using something that actually worked. OS/2 was crap too. Too bad
Xerox didn't have sense enough to stay in the game, they had the
best product for the office in 1980. Apple didn't have anything
that could come close for around 10 years. It took M$ almost
another 5 years on top of that to catch up.

Gates being greedy? Since IBM only paid Gates $80,000 for millions
of
copies of DOS, Basic, Fortran, etc. So IBM *only* spent about a
nickel
for all of the MS software per computer. So if anybody got ripped
off,
it was Gates.

Like I said, I'll have to see something backing that up. M$ got
plenty
for each and every copy of MS-DOS they FORCED onto OEMs.

Yes MS did make money from the clone market. But there was no clone
market when Gates and IBM made the deal.

M$ was so late with DOS 1.0 that the clone market was probably already
booming in Korea. Remeber those days? The Peach computer?(an
apparently perfect Apple II clone) If it hadn't been for Compaq and The
Compatible, the clone market wouldn't have done so well so quickly.

And since you mentioned Xerox, those foolish Xerox executives gave
Steve Jobs all of Xerox's GUI secrets for nothing! That is right,
NOTHING!
Then Apple has the balls to turn around a sue Microsoft for
stealing
Apple's GUI, when Apple had stolen it from Xerox in the first
place.
Yup, Xerox could have had it all and they (bozos in management)
didn't
even know it.

They certainly had the right to intervene on the Apple vs. M$ battle
for
"look and feel".

That battle cost both Apple and MS lots of money and nobody won. And

Sure we all won. Look and feel is freely copyable, it's the only piece
of sanity left in the trademark/copyright/patent/ip scandal that's
taking place these days.

then Apple needed money and MS bailed them out. Go figure.

Sure IBM was ticked that Bill Gates wasn't going to play
along. So
they parted ways. And IBM wouldn't sell any IBM computer with
Windows installed for a short time. Until IBM realized that
they
couldn't sell IBM computers with either crappy PC-DOS or OS/2
on
them. As people wanted Windows instead, plain and simple.

The only reason being that M$ delayed OS/2 was so that Win 3.0
could get the jump on it. If OS/2 would have shipped on time, it
would have possibly eliminated windows.

Yes probably this is true. Although MS still would have gotten
third
parties to write applications for Windows instead of OS/2. Which
did

Right, nothing like ludicrous binding legal agreements to crush free
trade and capitalism.

Yeah well nobody put a gun to their heads to sign any agreements
either. And companies do this all of the time and I don't like these
agreements either. For example Coke gets stores, restaurants, etc. to
sell only their brand. So you can't throw stones at just Microsoft.

Except that to survive as an OEM you need to not piss of M$, it's that
simple. Even after the courts ruled that OEMs couldn't force you to buy
an OS with hardware, many of the smaller OEMs continued to do it out of
fear of retribution.

happen anyway. And IBM had the balls to threaten third parties to
write applications for OS/2, but wasn't willing to pay them to do
so.
Well I wouldn't listen to big bully IBM either.

Who's the greedy bully now?

I don't know? Redhat? <grin

I'll give you that. ;-) I do the Gentoo thing myself. I guess I've
been tinkering with Linux for a little over ten years now, wow time sure
flys when you're having fun. My favorite computer toys are
microcontrollers though.

There are very many suspicious similarities in "bugs" within
the
graphics system calls of Win 3.0 and OS/2.

The same MS programmers wrote both OS/2 and Windows 3.0. So
why
should this be a surprise?

It's not a surprise to me. I think it just goes to show that M$
had
no qualms about directly lifting the code that they originally
wrote for IBM using IBM's money and, AFAICT, IBM's design goals.
I'm not saying that was illegal back then, but it certainly
wouldn't happen in today's IP obsessed world without bringing
about
major court battles.

Here was a true visionary: http://www.cadigital.com/kildall.htm

Yes I know all about Gary Kildall! I was a big supporter of his
until he
killed off CP/M without any warning! Then Gary had become a big
creep to

And I thought DOS killed it with the "here have DOS free with your
PC,
or send us money and we will send you CPM". Well that, 8" diskette
drive issue and the fact that CPM was limited to using 64K of RAM.
I
could be wrong though.

No you got it close enough. But lots of folks just purchased and
supported CP/M. But one day Gary said we are not doing CP/M anymore
because we lost interest. That wasn't right! Take their money and
then refuse support. I'm sure that was totally illegal.

Illegal? It seems to work well for M$ and most other vendors out there
today. Read your EULA, software is never guaranteed to be fit for "any
particular purpose". ;-D

me and other developers. Later I learned he often screwed his
other
customers left and right as well. SCP was one company that he
burned
badly. Luckily it burned him in his ass, now didn't it?

Given that you feel that way about the insignificant "damage" that
Kildall did, how can you be so bubbly when talking about M$ and
their
"success"?

Because when I added it all up and all the other companies who had
taken my money and then dropped support. Microsoft turned out to be
the cheapest bang for the buck. And it still is true today IMHO.

But the extent of "support" is to provide some security fixes, but not
too many bug fixes. You have to upgrade for that. How about all those
poor people that bought 3.0 and then had to turn around and pay for 3.1?
Or the really unfortunate people that bought ME?

And talk about being greedy, Gary almost invented the word. As you
had
to pay him big bucks to make him do anything. And it wouldn't be
to
your

So what? He was good and he knew it. Are you saying that his
efforts
weren't worth big bucks?

No... not really. But what I'm saying that Microsoft was cheaper. So
you can't ask for big bucks with competition.

Well it certainly proves the old adage about getting what you pay for.

liking, but his. And while Gary Kildall and Bill Gates were
playing
around with DEC computers. I was working on the VTAS computer
which
got the US to the moon. So as far as I was concern, both were
playing around with kids' stuff at the time.

I didn't start getting paid for tinkering with computers until 1980.
Before then it was me and my COSMAC ELF and whatever else I could
get my
hands on. When the PC came along, I was already into mainframes so
I
really didn't pay the PC any mind until pretty much the end of the
80's.
Once I had a mainframe to control, I could hardly treat any micro
seriously.

Well I was building my own PCs from scratch as a side hobby (as
being an EE). Although I never thought about selling the damn
things. But when others were mass producing them, I started buying
them instead of building my own.

I was too young and poor to play with the 8080 stuff. Stuff like my ELF
was all I could afford to build back then. I could only dream about
building an Altair or an Imsai.

BTW, I searched Google for VTAS computer and it seems that you are
the
only person in the USENET archive that ever mentioned it. I also
can't
find any links on the web either.

Well I know there was virtually nothing about it on the net. So I
had taken a peek and I found this (forgive the long and broken link
you will have to piece together).

http://groups.google.com/group/rec.aviation.military/browse_thread/
thread/c80a6dfb833506f0/7f48902fead1d2fa?lnk=st&q=VTAS+computer&rnum
=30&hl=en#7f48902fead1d2fa

Yes the VTAS computer was so great, they used it for military
purposes too like in the F4.

Ah the infamous mud shark, proof that with a big enough engine, even a
brick can fly. ;-)

Now having said the above, I do admit that Gary was nothing less
than
one great programmer without a doubt. Although everything had to
be
done his way, or forget it. And that is why Gary did well without
any
competitors, but failed once someone else was in the OS game.

That's the problem with genius, it usually doesn't come with greed
and
"good business sense" attached.

You're right there.

Kildall needed a cut throat business man to be really successful. Gates
and Allen, Jobs and Wozniak, it's how it works. Interestingly enough,
it's not who has the best techy stuff that wins. It's he who can tell
the biggest lies, cut the most throats and stab more backs that usually
comes out on top.

Funny IBM also does well without competition, but also fails once
competition arrives. And oddly enough, Microsoft only gets better
when

They seemed to do ok against Burroughs, Honeywell and the rest.

Isn't that like saying Apple does okay against the IBM clones?

IBM completely killed of Honeywell and Burroughs with good marketing
skills, not better hardware. The competition lay in salesmanship and
brainwashing, not making better stuff or even trying to be cost
competitive.

there are competitors. Otherwise they basically just sit on their
butt
doing nothing.

You obviously really like M$ so there probably isn't much point
in
continuing this until it becomes a real pissing contest. I run
windos on some machines because I basically have to. When
I need something that really works, I use Linux.

I actually use Windows because it does work. Linux has way too
many
lacks and wants to keep me happy. And did you know that Linus
Torvalds
also uses Windows? Yup he said so right in his own book.


__________________________________________________
Bill (using a Toshiba 2595XDVD under Windows 2000)
-- written and edited within WordStar 5.0

 

[mike]

Lars Torben Wilson wrote:
snip

Might be interesting to plug on a capacitor microphone element and see
what that does. Most of the microphone specs I've seen are still going
strong at the 20 KHz. end of the graph.
mike


Hm...that sounds neat. I'll see if I can find one.

Good place for microphones is an old cellphone, cordless phone, cassette

tape recorder...
mike

Thanks for the tips,

Torben

--
Wanted, Serial cable for Dell Axim X5 PDA.
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[The_Truth]

John G wrote:

The quick answer is ... Electronics 101 starts at you nearest teaching
institution next year.

You have to understand a lot of electronics to pick the devices you need
so before that you will have to rely on circuits designed by people with
the required experience.

well, I plan on starting as of january... but electronics comes natural
to me... I just don't understand how to judge what needs to be used...
I mean... I know there are different types of transistors... switching,
amplification... etc... I just don't understand the difference in
operation well enough to decide "what" to use.

 

[Andy Baxter]

Terry Pinnell said:

Seems to be. This works:
http://www.fidalgo.net/~garyr/pyascii/?N=D

this works under linux also.

--
http://www.niftybits.ukfsn.org/

remove 'n-u-l-l' to email me. html mail or attachments will go in the spam
bin unless notified with

 or [attachment] in the subject line.

 

[Terry Pinnell]

Tom MacIntyre <tom__macintyre@hotmail.com> wrote:

On Sun, 30 Oct 2005 16:45:17 +0000, Andy Baxter
news4@earthsong.null.free-online.co.uk> wrote:

Terry Pinnell said:

Seems to be. This works:
http://www.fidalgo.net/~garyr/pyascii/?N=D

this works under linux also.

What happened to the other method proposed.coded by someone who
posts/posted in these sci.electronics groups? Does anyone remember any
details about this? Thanks.

Tom

Well, two methods have been suggested so far. Are you referring to a
third?

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Rob B.]

"The_Truth" <gigabite1123@hotmail.com> wrote in message
news:1130693718.739964.268770@o13g2000cwo.googlegroups.com...

because I've worked with electronics since I was 5... I have just
recently started trying to create circuits... ;-D

and now that you have turned 6
you are ready for circuit design

 

[dAN]

well..

 

[The_Truth]

Tom MacIntyre wrote:

Well, I did, with my Dad for starters, and later on my own, since I
was a kid too, but when I studied for my EET there was nothing natural
about it - it was hard work.

Tom

well... dad is an HVAC tech... so I know basics from him... but I'm
trying to get a head start on the college portion... (HVAC is a bit
different... you just "know" that the capacitor infront of you will get
you good... and if you don't... you will as soon as you touch it...:-D )

 

[JeffM]

::::win32 software to make ASCII circuit diagrams ?
:::: erik

Andy´s ASCII-Circuit www.tech-chat.de
Chris (cfoley1064 @ yahoo.com)

Does Andy have an English version of his web site?
kell

Try this:
http://translate.google.com/translate?u=http://www.tech-chat.de/aacircuit..html+&langpair=de%7Cen

 

[Anthony Fremont]

"dAN" wrote

Hi,

I'm writing a library for an easy use of my 240x128 LCD display with
the T6963C controller.

I can display pixels and character where I want. No problems with
that.

I would like to develop with 8 bits display in graphic mode and 6*8
display in text area.

I don't think I fully understand what you mean. If you are asking if it
is possible to have text and graphics on the screen simultaneously, then
the answer is yes. I played with one of these a few years back so I
don't remember the details now, but I do believe that text and graphics
together is possible as long as there is enough RAM.

Can I do that?

The only way to change the font is by modifying the state of the FS
Pin
by hardware. But when I modify the font, it also modify the graphic
area (for example, if I display 11001111 in the left upper corner it
will be shrinked to 001111)

After reading this a few more times, I think I understand now. You are
saying that the FS pin affects the appearance of the graphics that are
displayed when you toggle it. I think I remember something like this
happening to me as well, but that was so long ago I don't recall for
sure. It should be documented in the datasheets, did you read them
thoroughly?

 

[ahonda55]

the cap. is .074 + .047 uF connected in parallel.
i made it today and the result was very good .
next step is to connect the comparator-transistor-relay circuit to
make the shift light

honestly, i made all that and learned many things in electronics
because of the good guys in this forum especcialy ED(ehsjr) Jonathan
Kirwan , Jon Poplish and more

Thanks you very much.

 

[Captain Blammo]

Yow!!! Where's that 1000V coming from? Surely the flash unit
doesn't expect the camera to discharge its (the flash unit's) caps
through the hot shoe and hold that voltage off until it's flash
time.

I've no idea why the older units use so much voltage. I think I've only
really heard of them hitting 400v or 500v, but I thought I'd be on the extra
safe side

Also, if you want to fire a relay from the hot shoe you need to know
how much current for how long a time the hot shoe can handle.

Basically, you need to look at the spec's for the camera and the
flash unit and, if you can't figure out how to hook them up with
that documentation in hand, post the spec's and we'll tell you how
to do it.

The Canon aren't very forthcoming with that information, which is rather
annoying. Information gleaned from the web, however, reliably indicates that
anything under 6v is fine. Actually, I found a diagram for an optoisolated
circuit, so I think I'll give that a try:

http://www.carlmcmillan.com/Optoisolated_Adapter.htm

Since you can't figure out the "mystery variables" of the relays and
the camera is "irreplaceably expensive", we'd (me anyway) be
irresposible if we were to make a suggestion without getting more
data. Do you have data sheets for the camera and the flash unit?

Unfortunately, all I know is the 6v limit. What kind of voltage would it
take to bust up thae above referenced circuit to the point that it got to
the camera? Something insanely high, I should think. I really don't to take
any significant risk, but I also refuse to pay $50 for an item that I'm
fairly positive uses <$5 worth of components when I'm as poor as I currently
am.

I think the biggest risk with that circuit, though, is that it won't fire
rather than fry my camera. That's acceptable! Please do let me know if you
think otherwise.

CB

 

[John Fields]

On Mon, 31 Oct 2005 15:45:12 GMT, "Captain Blammo"
<eas6@nbnet.nb.ca> wrote:

Yow!!! Where's that 1000V coming from? Surely the flash unit
doesn't expect the camera to discharge its (the flash unit's) caps
through the hot shoe and hold that voltage off until it's flash
time.

I've no idea why the older units use so much voltage. I think I've only
really heard of them hitting 400v or 500v, but I thought I'd be on the extra
safe side

Also, if you want to fire a relay from the hot shoe you need to know
how much current for how long a time the hot shoe can handle.

Basically, you need to look at the spec's for the camera and the
flash unit and, if you can't figure out how to hook them up with
that documentation in hand, post the spec's and we'll tell you how
to do it.

The Canon aren't very forthcoming with that information, which is rather
annoying. Information gleaned from the web, however, reliably indicates that
anything under 6v is fine. Actually, I found a diagram for an optoisolated
circuit, so I think I'll give that a try:

http://www.carlmcmillan.com/Optoisolated_Adapter.htm

Since you can't figure out the "mystery variables" of the relays and
the camera is "irreplaceably expensive", we'd (me anyway) be
irresposible if we were to make a suggestion without getting more
data. Do you have data sheets for the camera and the flash unit?

Unfortunately, all I know is the 6v limit. What kind of voltage would it
take to bust up thae above referenced circuit to the point that it got to
the camera? Something insanely high, I should think. I really don't to take
any significant risk, but I also refuse to pay $50 for an item that I'm
fairly positive uses <$5 worth of components when I'm as poor as I currently
am.

I think the biggest risk with that circuit, though, is that it won't fire
rather than fry my camera. That's acceptable! Please do let me know if you
think otherwise.

---
I wasn't aware that the trigger voltage on flash units could get so
high, so I stand corrected on that one.

The circuit looks OK, and with a maximum forward voltage of 1.5V
across the diode, it looks like the current the camera contacts will
have to handle will be:


Vcc - Vf 6V - 1.5V
I = ---------- = ----------- ~ 14mA
Rs 330R

The MOC3010 is guaranteed to fire its internal switch with 15mA
through the diode, but it's specified to do that with a 150 ohm load
fed from a 3V supply across its internal TRIAC. I don't know how
that would change with a higher voltage across the TRIAC, so I
suppose the best thing to do would be to put one together and try
it.

Also available are the MOC3011 which is rated to fire with 10mA of
diode current, and the MOC3012 with 5mA, so I'd be tempted to go
with the 3012 if I wasn't sure about how much current the camera
contacts could take. OTOH, depending on the camera's leakage
current out of the hot shoe in the OFF state, it might keep the 3012
ON, so perhaps a 3011 would be a better choice. ???

All the parts are rated with 7500V of isolation between the LED and
the TRIAC, so no matter what (if the thing was wired right ) the
camera would be safe.

The only other concern I'd have would be that the absolute maximum
the MOC's TRIAC can stand off is 250V, so if the flash unit's
trigger voltage rose above that it could/would fry the MOCXXXX.

--
John Fields
Professional Circuit Designer

 

GTR <nospam@noone.com> wrote:
: Thanks for your response. I was just curious if you thought it was common
: for 1.5V devices, for example the Rio MP3 player, to use the MOSFET
: technology you described or rather a charge pump or similar technology?

: The root of my questioning in this matter is that my formal education is in
: Chemical engineering and Computer Science, electronics is just a hobby to
: me, and I suspect I will never have the training or practice to consider
: myself truly competent in it. Perhaps one day I will achieve the level of
: 'hack', but time will tell

: I had always thought, when I further explored the hobby (to me) I would
: discover a series of off the shelf chips (Similar to jumping from TTL to
: CMOS) that would make the existence of these 1.5 volt devices evident, but I
: never did.

Devices like Rio MP3 players are highly integrated, and may
contain as little as a single IC on the board. Regardless, all
contain a CPU/microcontroller (which may be integrated with other things
like audio CODECS/amplifiers, etc, or it may not be) on which I will focus
my attention in this post. This CPU is is almost certainly fabricated
using a low-voltage CMOS process, rather than a charge-pump, followed by a
"high" voltage CPU/microcontroller.

One reason is simply efficiency, which translates to battery life.
No charge pump converter is 100% efficient (I don't think that most are
even close) so that doing things that way would result in a
significantly shorter battery life.

On the economic side of things, like I may have mentioned, CMOS
devices in modern processes cannot tolerate higher voltages (because of
their thinner gate oxides) so if a process with a smaller geometry is used
(which will result in a smaller chip area = lower cost for the
manufacturer = desirable for the manufacturer) lower supply voltages MUST
be used.

Therefore, for this type of application (low-voltage digital CMOS
design) the economic and the technical aspects of the design re-inforce
each other, making it VERY likely for that the be the prevailing method of
design.

Does that make sense? Things ARE more complicated than that, but
this is a "basics" newsgroup, and those are pretty much the basics of what
drives/helps drive modern low-voltage IC design, which has made (and
will continue to make) lots of new low-voltage products available
recently.

Take it easy,

Joe

: <jwelser@ccwf.cc.utexas.edu> wrote in message
: news:djtrt7$om9$1@geraldo.cc.utexas.edu...
:> GTR <nospam@noone.com> wrote:
:> : I was curious, I have seen a number of devices which simply took a
: single
:> : AAA battery as a power source(Rio MP3 player, some IR remotes etc..).
:>
:> : What is the technology behind these low voltage devices? I thought even
: HCT
:> : CMOS needed 2 volts or higher?
:>
:> : Thanks
:>
:> GTR,
:>
:> Every CMOS technology/fab is different, therefore, it is not
:> correct to generalize the characteristics of HCT (which IS CMOS-based
:> logic) to all CMOS fabs. It's also likely that the different fabs of
:> different manufacturers of HCT devices are different, and thus, the
:> performance of even those two different brands is very different (although
:> it probably wouldn't be speced differently.)
:>
:> That being said, assuming all devices operate in strong inversion,
:> the only constraint that the technology places on the voltages is that,
:> roughly speaking, the supply is greater than the threshold voltage of the
:> devices (Vt.) Practically speaking, some additional headroom would be
:> required, but let's not worry about that for now.
:>
:> Modern CMOS processes (0.18 -> 0.13 -> 0.09 microns -&gt typically
:> have Vt values of approximately 0.5V for "normal" devices, but they also
:> have "low-vt" devices with Vt values as low as 0.2V, or even native
:> devices with Vt of 0V (or even negative -- yes, for an NMOS device,
:> meaning that the device is always on.) In fact, many of these devices
:> can be damaged by any voltage significantly higher that 1.5V, due to their
:> very thin gate oxide! All of these different "flavors" of MOSFET devices
:> are useful in low-voltage CMOS design, but they have their problems.
:> Lower Vt means larger leakage current, those native devices that I
:> mentioned above basically can't be turned off, etc, all of which are
:> additional challenges that need to be dealt with by the designer. My
:> point is that modern processes give a designer lots of options that have
:> made the design of very low voltage circuits practical.
:>
:> I am an IC designer with an interest in low-voltage/low-power (not
:> the same thing!) IC design, and I can tell you that a previous design
:> that I worked on, in a modern process, is able to run comfortably at 0.8V.
:>
:> So, 1.5V (which is usally speced down to 1.2V or less to deal with
:> the inevitable droop of the power supply as the battery drains) operation
:> is a piece of cake!
:>
:> Take it easy,
:>
:> Joe
:>
:>

 

[:-)]

wrote:

Hi,

I got my marvellous application working fine on my breadboard ;-)
It's around 25 TTL LS type ICs, plus few connectors strip and 5V PS.
It's not an high freq application ....

Now I need to transfert all that stuff on something but I never did that
before (I will need 2 boards)...

What should I use ?
I was thiking wirewrap, (is it still a good solution ?)

Any suggestion ?

Oopps sorry abou the wrong date for the last message :-(

 

[David Maynard]

clifto wrote:

David Maynard wrote:

In fact, the 'Windows' GUI was originally developed as a means to run
Microsoft's 'Apple' business software, like Word, on PC clones and that is
not a trivial distinction. While IBM was trying to sell an 'O.S.', because
you 'have to' in order to sell hardware, Microsoft was selling Word (and
the rest), which happened to run on Windows.


Microsoft Word existed and was sold long before Windows 1.0 was on the
market.

Yes, but as a DOS application, which limited it's functionality, and it
didn't sell well. Wordperfect was the most common DOS word processor at
that time.

On the MAC, however, Word was selling like hot cakes because of the WYSIWYG
editor (plus cut/paste, data transport, et al) made possible by Apple's GUI
and to get the same functionality on a 'PC' one needed similar GUI
capabilities, I.E. 'Windows'.

WordPerfect was doomed by their failure to make a windowing version and, as
a result, MS Word became the defacto standard on both the MAC and 'PC'.

But the point remains that 'Windows' was developed to sell their business
apps. And it (eventually) succeeded in doing so.

 

[Dan Hollands]

Wire wrap should work fine with the correct wire and tools

--
Dan Hollands
1120 S Creek Dr
Webster NY 14580
585-872-2606
QuickScore@USSailing.net
www.QuickScoreRace.com
"" <a@b.c> wrote in message
news:Scw9f.66776$7z1.809127@wagner.videotron.net...

Hi,

I got my marvellous application working fine on my breadboard ;-)
It's around 25 TTL LS type ICs, plus few connectors strip and 5V PS.
It's not an high freq application ....

Now I need to transfert all that stuff on something but I never did that
before (I will need 2 boards)...

What should I use ?
I was thiking wirewrap, (is it still a good solution ?)

Any suggestion ?

 

[Jasen Betts]

On 2005-10-29, Patrick O Shane <spb19@juno.com> wrote:

Hi,

I was wondering if anyone here could explain capacitors to me. I have tried
for a long time to understand exactly what they do. I 'think' I have a basic
understanding. I could be totally wrong here.

Basically they store a charge and release it and the Farad rating determines
how big of a charge it can hold and for how long. I've noticed that the
voltage ratings do not necessarily have to match what is being applied to
it.

What is there purpose in an energized circuit?

they behave like springs in a mechanical device

- soaking up bumps,
- thec can also be used to block DC - because a capacitor won't pass DC but
will pass AC.

What do the Farad ratings mean?

the softness of the spring, how much electtricity will flow into (or outof)
the capacitor for every volt of charge.

What do the Voltage ratings mean?

how many volts they can survive.

How are the two related or are they related at all?

only in that more volts or more farads means a physically larger device
(also capable of storing more energy)

How does amperage effect capacitors?

the time it takes to charge them.

Do I need more of an understanding of circuitry and circuit design to be
able to understand what a capacitor does and how it does it?

How would a 25v capacitor effect a 2.5v LED?

it depends on how they are connected to the rest of the circuit.

I asked for help regarding putting an LED on an HO scale train. Some very
generous people worked up a circuit for me that had a capacitor in it to
stabilize the light intensity when the train slowed down or hit a dead spot
on the tracks. They suggested a 25v @ 400uF capacitor assuming the maximum
input voltage to the circuit would be 16v.

I think they also put something between the capacitor and the led to protect
it from the 16V track voltage.

Bye.
Jasen

 

[Jasen Betts]

On 2005-10-29, Captain Blammo <eas6@nbnet.nb.ca> wrote:

I'm trying to put together a protective device for the hotshoe on my digital
camera. All that triggering an external flash requires is connecting its two
terminals together through the camera, but most digicams will fry if exposed
to more than 6v fed down the line by the flash unit.

that's a silly design...

I'm thinking that one or two AA batteries and a relay connected to the
camera would be just fine to protect against overvoltage, but the relay
needs to operate as close to instantly as possible and be able to pass
voltages from, say, 3 to 1000v on the flash unit side with no ill effect.

you'll need something faster than that, possibly something with an
opto-coupler.

I had a look in the digikey catalogue, and just ended up getting confused by
the vast array of relays and mystery variables listed with them. Since I'll
be staking the life of the irreplaceably expensive camera on this, I was
wondering if someone could do me a huge favour and recommend the appropriate
part.

it's likely none of the relays will be fast enough unless they're
solid-state relays.

I'd just use the hot shoe as is unless it's documented somewhere that this
is a bad idea... if the camera fails demand a refund.

Bye.
Jasen