Driver to drive?

[legg]

On 28 Oct 2004 17:27:44 -0700, leonlai2k@yahoo.com (terry) wrote:

Hi,

Anyone could teach me the following?

1. What is the advantage of using metal capacitors?

2. I also want to know the range of values of metal capacitors.

Thanks!

foil capacitors will have a higher current rating, with the same
dielectric.

metal casings are used for safety (flame and explosion control)
reasons, and for mounting ruggedness.

ranges of values are best gleaned from your distributors' catalogs or
stock lists, as theoretical ranges are just that - theoretical.

RL

 

[Stephan Goldstein]

<snippage of discussion regarding the availability of 24-bit audio dacs
with 100dB SNR for use in MP3-players>....

Um, perhaps my question is a little obtuse, but *why*? I was under the
impression that MP3 was a lossy compression and that the sound quality
was not as good as a standard CD under the best of conditions. If true,
wouldn't a CD-quality audio dac be a bit of a waste?

Steve

 

[Don Pearce]

On Thu, 28 Oct 2004 17:46:14 -0700, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

Superregens are the amazing ones. One triode and a few parts, and you
can listen to the BBC from Louisiana.

John

And another millimetre on the regen cap and you are transmitting right
back to the Beeb!

d
Pearce Consulting
http://www.pearce.uk.com

 

[Paul Burridge]

On Thu, 28 Oct 2004 17:46:14 -0700, John Larkin
<jjlarkin@highSNIPlandTHIStechPLEASEnology.com> wrote:

Superregens are the amazing ones. One triode and a few parts, and you
can listen to the BBC from Louisiana.

There's probably a relay station in Mississippi.
I recall being thrilled to bits by my first attempt, at the age of 8,
to build a crystal set. I immediately picked up a good, strong signal
of the BBC World Service. For some reason the set, though tunable,
would only pick up this one station. Still, I didn't care, since it
was so strong and clear. Only much later did I discover the source of
the signal was the BBC's 1MW transmitter located about 3 miles away.
Some old folks in the area could pick it up with the fillings in their
teeth!
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Paul Burridge]

On 28 Oct 2004 17:27:44 -0700, leonlai2k@yahoo.com (terry) wrote:

Hi,

Anyone could teach me the following?

1. What is the advantage of using metal capacitors?

For the dielectric or the plates? It makes very poor dielectric, but
quite good plates. It always helps to have a conductor for the plates.
;->
--

"What is now proved was once only imagin'd." - William Blake, 1793.

 

[Winfield Hill]

Stephan Goldstein wrote...

snippage of discussion regarding the availability of 24-bit audio dacs
with 100dB SNR for use in MP3-players>....

Um, perhaps my question is a little obtuse, but *why*? I was under the
impression that MP3 was a lossy compression and that the sound quality
was not as good as a standard CD under the best of conditions. If true,
wouldn't a CD-quality audio dac be a bit of a waste?

Well, maybe, maybe not. But given that Newark sells the 8-pin cs4334
24-bit stereo DAC for just $2.01 each (single pieces), why not?


--
Thanks,
- Win

(email: use hill_at_rowland-dotties-org for now)

 

[John S. Dyson]

In article <3vkgd.26122$R05.25515@attbi_s53>,
Robert Monsen <rcsurname@comcast.net> writes:

Jim Yanik wrote:
Robert Monsen <rcsurname@comcast.net> wrote in
news:AfZfd.537183$8_6.394341@attbi_s04:


Jim Yanik wrote:

Michael Moore is the epitome of dishonesty.



No, he isn't. Show me one lie.



Bowling for Columbine.


That's not a lie, it's a movie. What exactly didn't you like about it?

Michael Moore is an excellent storyteller, but too bad that his

stories (in documentary form) aren't factually accurate. This is misleading
and is either very close to explicit dishonesty, if it hasn't crossed
the line to being actual explicit dishonesty.

One aspect of someone who is dishonest is that they are very good
at mixing true facts and knowing untrue facts. Michael Moore goes
out-of-his-way to mix the truth and untruth in carefully constructed
material, unlike someone in conversation who, on notrivial subjects,
will very often mistakenly mix truth and untruth.

John

 

[Martin Brown]

In message <Uycgd.36206$QJ3.16619@newssvr21.news.prodigy.com>, Joerg
<notthisjoergsch@removethispacbell.net> writes

Hi Tim,

On a side note, something that blew me and others away: A visitor
from Europe had problems adjusting his analog 'atomic' wrist watch.
Their transmitter works on 77.5KHz so the clock didn't adjust to PST
and since he forgot the manual we didn't see how to do that manually.

Typical Euro-doofus.

They chose a different frequency for a time signal radio beacon. So
what?

Well, I don't know which was first or is better, WWVB or DCF77.
Sometimes our stuff wins, sometimes theirs. All I know is that the
European version is not so limited to sync at night but that won't make
much of a difference in real applications.

There is also MSF Rugby on 60kHz. I have had receivers for MSF60 work
well in Belgium and also self setting DCF77 European clocks working fine
in Northern England. MSF is usable in Gibraltar with suitable kit.

I don't know offhand if the Rugby time signal code is the same as that
expected by US decoders. MSF also stays in lock almost 24/7 (except when
the transmitter is down for urgent maintenance as happened recently).

Regards,
--
Martin Brown

 

[Fred Bloggs]

Steve Sands wrote:

Oh my God. Bush shot Kenny!

Kenny?

After all your foolishness here making a complete ass of yourself for
all these weeks you now want us to believe Drudge is part of this
story?

I am not concerned with what you think- don't flatter yourself- you're a
friggin retarded p.o.s. and can go to hell.

Oh ya after all his work in creating the site where the news gets
their news, Drudge is going to gamble it all on some fabricated tape?!

Ooohh- why such a complicated theory, retard boy? Can you handle it?

Drudge is no Dan Rather.

Why don't you just hang a sign on your ass saying "kick me" ?

Your name has become synonymous with ignorant p.o.s. Go away and go to
hell- damned foreign scum.

 

[Fred Bloggs]

dd wrote:

In message <41806274.5050206@nospam.com>, Fred Bloggs
nospam@nospam.com> writes

So let's see here- we invade this place on trumped up WMD stories and
the military is given no direction whatsoever to secure this facility
that may have materials used for the mother of all WMDs, nuclear
weapons. Sounds like someone wasn't even pretending to believe their
own trumped up propaganda. Then by fall of 2003, it should have been
obvious to everyone that something is going on with systematic removal
of 100's thousands of *tons* of conventional explosives and ammunition
from unsecured depots all throughout the country, and these idiots did
not see that they had one heck of a massive storm brewing over the
horizon.

Clearly the whole Iraq fiasco was a cunning plan/ruse to concentrate
terrorists in one place so they could be exterminated in one easy
detonation.

Nah- the Iraq fiasco is just what it seems- no cunning involved at all.
It is a plain and simple example of incompetence on the grandest of
scales. The evangelicals truly believed they would install democracy in
Iraq.

Suggestions that the 9 11 event was a means of getting the US to remove
Saddam a well known enemy of Islam should be discounted.

Apparently Bush telegraphed his intention to start a "small" war for

political gain in 1999 in interviews with a contract biographer- and
this was well-known to the powers that be throughout Islam. Now you take
that bit of information and link it to the fact that terrorist
sympathetic funding was channeled into the Bush 2000 campaign, and you
have something.

 

[Fred Bloggs]

Tom Seim wrote:
[...snip...]

 

[John Miles]

In article <b83b4153.0410250733.4a8c3e01@posting.google.com>,
burnboy1000@hotmail.com says...

burnboy1000@hotmail.com (Jumbaliah) wrote in message news:<b83b4153.0410241924.5ca822f3@posting.google.com>...
Hey there,

I'm thinking of making a DDS function generator using one of the AD9x
chips. All of Analog's DDS chips are in SMD packages. I've emailed
others who have made these in the past based on the 50 and 125MHz
10bit chips and they recommend going with one of the better chips for
a cleaner output. So I'm possibly leaning towards the 400MHz 14bit
chips.

I wanted opinions on mounting one of these on a homemade pcb ( similar
to this: http://protoboards.theshoppe.com/qfp_0_8_mm.html ) then using
short jumper wires to connect it to the rest of the circuit. This way
I would only have to solder the chip once (by hand). The board and
chip could easily be removed for use in other circuits or revisions.

My worries are it may cause too much noise or interference in the
output. I don't have much experience in these frequencies so I wanted
to ask what others thought.

Thanks,
Burnboy


Thanks for the comments guys.

Right now I'm looking for a fuction generator to give me some sort of
signal I can test other circuits with. I'd say 0-20Meg would be
great. I just saw these DDS chips and with the 400Meg ones I may get
something like 0-50Meg out of it (never know what bandwidth you'd need
down the road). With the price of the eval boards I may be better off
just getting a MAX038 (? forgot the part number) based kit.

I've used those nice Agilent function generators in a lab and thought
this DDS would be a great way to get the similar features.

How about the 180MEG AD9851? I'd feel more confident soldering that
SSOP to the main board over the QFP parts. At least there would only
be 2 sides to work on if I needed to remove the chip. Any thermal
lugs on these packages?

What's would be a realistic estimate on max frequency clean output on
these DDS chips? eg. I've read websites where the 9835 50Meg chip was
used and the author was hoping for 0-20Meg output. (
http://hem.passagen.se/communication/dds.html ) I've been
guestimating 1:5. I guess it comes down to the output smoothing
filter's design?

Thanks for the help,
Burnboy

You can hand-wire DDS chips of any speed, as long as you mount them
above a solid copper ground plane. The only constraint is your
eyesight! "Proto-board" of any variety is out of the question.

Chips like the AD9852ASQ will need to be underclocked somewhat, because
of the lack of thermal bonding to their heat sink tabs.

Use chip caps as bypasses directly from the DDS pins to the ground plane
-- no jumpers.

Study the data sheet for the part you're using. The usual rule of thumb
is that the maximum clean output frequency is around 40% of the clock
rate, but higher clock rates are still preferable. An AD9835 or AD9851
will be fine from DC-20 MHz.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

 

[Fred Bloggs]

CFoley1064 wrote:

Enough of the El Ka-ka stuff. Five more days, gentlemen. Who you gonna
believe, the administration or your lyin'eyes? You're all engineers,
designers, technicians. You're the ones who are supposed to believe in pure
d***ed facts, and leave the spin and unsupported "argument by assertion" to the
finance MBAs and marketing PHBs in the front office. Let's look at the facts,
just like we do to earn a living.

Chris

HEAR! HEAR!

 

[Fred Bloggs]

Jamie wrote:

Why don't you just hang a sign on your ass saying "kick me" ?

then how could i see who i am talking too ? or was the intent to
kick out some teeth ?

This coming from the illiterate who wrote:
"go to your plumbing supply and get your
self some PVC, end caps and then to
your Hardware store to get your self
some plexy glass.
dice the PVC pipe to your liking .
glue on end cap.
get your self one of those nice
circle cutters that use a bit and then
cut out the top of on cap and then
cut out a round piece of glass to
glue in the cap..
etc..
P.S>
you mite consider using AB plastic incase
you need some extra strength.
and be sure to get the plumbers glue for the
PVC etc.. "

You juz' come on, low-life, looking for a beating I see...

 

[john jardine]

"Steve" <aeroman10@yahoo.com> wrote in message
news:1099032144.807368.174190@c13g2000cwb.googlegroups.com...

john jardine wrote:
"Steve" <aeroman10@yahoo.com> wrote in message
news:1099003721.067016.22050@c13g2000cwb.googlegroups.com...

clip

I changed the Q1 and Q2 resistors to 220 ohms
Based on this circuit diagram can you show me what you mean by the
following:
Stick a 2k2 resistor in Q3 Q5 base. Change Q4 Q6 resistor to 2k2.
http://users3.ev1.net/~srudenko/img/hbridge.gif

I also have the EWB file (maybe if you have EWB you can show me what
you mean by making the changes in there).

Or just explain exactly where to plug in the resistors you are refering
to.

Thanks

Q1Q2 keep as 220ohms, then bridge resistors like this ...

-----+---------------------+-------- +V (eg 12V)
| |
| |
| Q4 Q6 |
| NTE262 NTE262 |
___ |< >| ___
,-|___|--| |-|___|--,
| 2k2 |\ /| 2k2 |
| | | |
| | | |
| | | |
| | Motor | |
| | ___ ___ | |
to Q1-----+ +-----o-|___|--UUU-o--+ +--to Q2
| | | |
| | 9ohm 30mH | |
| | | |
| | | |
| | | |
| ___ |/ \| ___ |
'--|___|-| |-|___|--'
2k2 |> <| 2k2
| |
| Q3 Q5 |
| TIP110 TIP110|
| |
---------+---------------------+-----0V
created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

This setup's not optimum as it's a wee bit reliant on the actual base
current pulled by Q3 or Q5.

A nicer and simpler design (by Antonio Raposo) can be found at ...
http://www.cs.uiowa.edu/~jones/step/circuits.html

Antonio's circuit design uses a total of only 4 transistors and all could
be say TIP110 Darlingtons.
regards
john

 

[Clarence]

"Dirk Bruere at Neopax" <dirk@neopax.com> wrote in message
news:2tvhb4F238hjdU1@uni-berlin.de...

kell wrote:
I would hate to think that martial law might be declared in this
country. Sure there are a lot of left-wing kooks out there, but if it
happens it ain't gonna be the kooks that set the wheels a-turning.
It's going to be the hard-headed people doing what they think is
right. Ouch!

I thought all those US survivalist nuts and militias waiting to repel a UN
invasion or New World Order were 'Right Wing' - not 'Leftists'.

Everyone is Militia! It is "The Body of the people." Extremists use the term

to describe anyone who oppose them.

But if you want to be bored, listen to the audio he posted. They are totally
Kooky!

 

[Rich Grise]

On Fri, 29 Oct 2004 01:42:10 +0000, ChrisGibboGibson wrote:

Winfield Hill wrote:

I *really* know my stuff,

And I doubt there would be a single person here who would argue with that.

but as a group moderator I certainly would not
get rid of any so-called "shite."

Which is a shame. Because surely, the political stuff belongs elsewhere?

I have no objection to people wishing to discuss politics, afterall, it *is* a
serious subject. But surely in it's rightful place?

I can only speak for myself, but I do it here because this is where the
smart people are. Can you imagine the kind of riffraff that would hang out
in a politics NG? ;-)

Thanks,
Rich

 

[john jardine]

"Terry Given" <my_name@ieee.org> wrote in message
news:UYhgd.467$op3.23256@news.xtra.co.nz...

Steve wrote:

[clip]

the original circuit was even worse, for the same reasons I outlined -
except with no base resistors at all (as opposed to half the amount you
require) its a recipe for frying transistors whilst maintaining a
stationary shaft on the dc machine.

John's fix is essentially the same as that I proposed - base resistors
about, but choose values wisely; some semblence of understanding is
required.

Cheers
Terry

I've wondered if newcomers are ever put off the subject, after spending
hours trying to wrestle some sense out of useless designs.
I take a mechanical engineering mag' that recently did a short series on
'electronics in the workshop'. The author showed an H bridge circuit with
just the same problem as Steves. Poor proof reading or whatever, the author
should have known better. Shame on him .
(ps, If I'd seen the group posts 'updating' I wouldn't have bothered with my
post. I was wasting bandwidth just repeating what you had said)
regards
john

 

[john jardine]

"ChrisGibboGibson" <chrisgibbogibson@aol.com> wrote in message
news:20041028232101.18151.00005464@mb-m03.aol.com...

"john jardine" wrote:

[clip]

Yer bluddy northerner.

Reminds me of summat mi grandad use fo' say...

"'appen as like as not for them's that can as will"

I still have no clue what the hell he was talking about.

Gibbo

Better just to ignore it and think of it as Tyke-shite. Nubbdy noes what
weir on abaht anyway, so we just talk complete bollocks and 'ave dun wi
it.
regards
john

 

[Fred Bloggs]

Tom Seim wrote:

Since you asked me in such a polite way, I'll tell you. While you were
doing drugs I was involved in top secret national defense projects at
the Hanford Nuclear Reservation after graduating from Oregon State U.
in 1969. I am not a vet and never pretended to be one.

Tom

Right- another boondoggle job in a joke of a facility that has created a
500,000 year toxic wasteland-very unimpressive resume.


Well you better hope were are more competent than you would have us to
believe and dealing with high-level radioactive waste. Otherwise a
whole shit-load of some very nasty stuff is heading downstream your
direction.

Recent developments (last week):

All nuclear fuel has been moved out of the K Basin storage pool.

Successful test of the Vitrification plant using real high-level
radioactive waste.

You idiots screw everything up you get your hands on- no hope at all
except for disaster.