Driver to drive?

[Winfield Hill]

Mike wrote...

... Unfortunately, most transformers I've come across do not
produce the 50V AC. Everything is 5V, 12V, etc. - far less
than what is needed. Furthermore, the few that I found all
operate at low current levels. ...

http://www.signaltransformer.com/

These guys stock the MPI-series transformers rated from 200 to
900VA. Given that your duty cycle isn't 100%, their MPI400-48
48Vrms 400VA version (page 7 of my catalog) might be sufficient.
This is still a pretty large transformer (weighs 10 pounds),
and was $111 each at my last price check.


--
Thanks,
- Win

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

 

[martin griffith]

On 22 Oct 2004 06:14:17 GMT, in sci.electronics.design you wrote:

Hey, how many of us have ever been incarcerated?

I have - that's one, so far.....


Two..........

Gibbo
maybe you should ask

Who hasnt been caught yet




martin

Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.

 

[Bob Stephens]

On Fri, 22 Oct 2004 07:57:10 -0700, Jim Thompson wrote:

On 22 Oct 2004 06:14:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

Hey, how many of us have ever been incarcerated?

I have - that's one, so far.....


Two..........

Gibbo

I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing the
neighborhood for a burglary. Does that count?

...Jim Thompson

Just out of curiosity. Did you file a complaint?

Bob

 

[Bob Stephens]

On Fri, 22 Oct 2004 08:58:54 -0700, Jim Thompson wrote:

On Fri, 22 Oct 2004 15:32:30 GMT, Bob Stephens
stephensyomamadigital@earthlink.net> wrote:

On Fri, 22 Oct 2004 07:57:10 -0700, Jim Thompson wrote:

On 22 Oct 2004 06:14:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

Hey, how many of us have ever been incarcerated?

I have - that's one, so far.....


Two..........

Gibbo

I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing the
neighborhood for a burglary. Does that count?

...Jim Thompson

Just out of curiosity. Did you file a complaint?

Bob

Naaah. It was in Paradise Valley, a police state for the filthy rich
here in Phoenix. But I did write every restaurant that I frequented
and told them sayonara... and I kept my promise... I don't spend a
dime in that city.

...Jim Thompson
I went to school at UC Irvine in SoCal. I made the mistake of driving a

non-Mercedes Benz automobile in nearby (big time ritzy) Newport Beach. A
cop appeared on my rear bumper and basically pushed me through a yellow
light and immediately pulled me over. He swaggered up and demanded to know
why I ran a red light. I explained that if I hadn't run the *yellow* light
we would have been having this discussion in my backseat through his
windshield. He said "I'm not going to argue the 'semanics' of it with you
mister Stephens." The sorry idiot not only misused the word but
mispronounced it as well. I damn near bit my tongue off to avoid a retort.

still pisses me off...


Bob

 

[Anders F]

"Clarence" <no@No.com> wrote in message
news:gZSdd.17012$nj.16940@newssvr13.news.prodigy.com...

"Anders F" <af-spam@hi5.dk> wrote in message
news:2tpa29F22p8f4U1@uni-berlin.de...
"Frank Bemelman" <f.bemelmanx@xs4all.invalid.nl> wrote in message
I'm surprised that one exists. Small package too, 7mm x 4mm. It
looks challenging to get rid of the heat, even at 95% efficiency.

Say 8A @ 30mR (didn't check the actual value) - that's under 2W...
And powerplanes/copper fills are quite effective heat-spreaders (try
solder
a plane with a tiny tip ;-)

/Anders

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)



The App note shows 16 components external

True. This is not uncommon though... Flexibility cost!

and it is a sole source part.

I find very few switchers with second sources...

At least the alternate with external Power switches did not take so many
additional parts

They're available yes! And probably cheaper as Sipex are the first with
integrated fets in those currents. I've asked for a price though - I might
actually use it as I can use every mm2 I can get ;-)

and there are other sources for a similar component.

Similar - but not compatible. Not much better than a single-source to me!

Price comparisons?

Patience my friend ;-)

Cheers,
Anders

 

[Don Pearce]

On 22 Oct 2004 09:52:32 -0700, andrea8090@gmail.com (Andrea) wrote:

Does anyone know why there isn't a channel 1 on American TV dials?
I've seen many different answers, but which is right?

When they decided that it ought to go up to 11, the easiest way was to
drop the 1.

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

 

[Guy Macon]

Andrea <andrea8090@gmail.com> says...

Does anyone know why there isn't a channel 1 on American TV dials?
I've seen many different answers, but which is right?

Whenever you see different answers, goto the Straight Dope website.
Cecil Adams is always right,

Here is your answer: http://www.straightdope.com/classics/a1_372

 

[Rich Grise]

On Fri, 22 Oct 2004 17:05:13 +0000, Guy Macon wrote:

Andrea <andrea8090@gmail.com> says...

Does anyone know why there isn't a channel 1 on American TV dials?
I've seen many different answers, but which is right?

Whenever you see different answers, goto the Straight Dope website.
Cecil Adams is always right,

Here is your answer: http://www.straightdope.com/classics/a1_372

That's the same answer I had, so he must be right. ;-)

Cheers!
Rich

 

[Rich Grise]

On Fri, 22 Oct 2004 06:39:03 -0700, Winfield Hill wrote:

Mike wrote...

... Unfortunately, most transformers I've come across do not
produce the 50V AC. Everything is 5V, 12V, etc. - far less
than what is needed. Furthermore, the few that I found all
operate at low current levels. ...

http://www.signaltransformer.com/

These guys stock the MPI-series transformers rated from 200 to
900VA. Given that your duty cycle isn't 100%, their MPI400-48
48Vrms 400VA version (page 7 of my catalog) might be sufficient.
This is still a pretty large transformer (weighs 10 pounds),
and was $111 each at my last price check.

I'd bet that there's some surplus dealer within an hour's drive of
the OP that has exactly the right transformer for ten, maybe twenty
bucks.

Good Luck!
Rich

 

[Rich Grise]

On Fri, 22 Oct 2004 07:57:10 -0700, Jim Thompson wrote:

On 22 Oct 2004 06:14:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

Hey, how many of us have ever been incarcerated?

I have - that's one, so far.....


Two..........

Gibbo

I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing the
neighborhood for a burglary. Does that count?

Yeah, in my book. I've never had a gun pointed at me, but the trauma
has to be practically the same.

Thanks!
Rich

 

[Frank Bemelman]

"Jim Thompson" <thegreatone@example.com> schreef in bericht
news7din0hggglkqm1kk09cpad5fceep400bm@4ax.com...

On Fri, 22 Oct 2004 16:13:14 GMT, "Clarence" <no@No.com> wrote:


"Jim Thompson" <thegreatone@example.com> wrote in message
news:eebin0l54s3lcmuq5skh4lq9q9d68cvvct@4ax.com...
On Fri, 22 Oct 2004 15:32:30 GMT, Bob Stephens
stephensyomamadigital@earthlink.net> wrote:

On Fri, 22 Oct 2004 07:57:10 -0700, Jim Thompson wrote:

On 22 Oct 2004 06:14:17 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

Hey, how many of us have ever been incarcerated?

I have - that's one, so far.....


Two..........

Gibbo

I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing
the
neighborhood for a burglary. Does that count?

...Jim Thompson

Just out of curiosity. Did you file a complaint?

Bob

Naaah. It was in Paradise Valley, a police state for the filthy rich
here in Phoenix. But I did write every restaurant that I frequented
and told them sayonara... and I kept my promise... I don't spend a
dime in that city.


Funny, I lived in Paradise Valley for several years, never even saw a
cop. So
they don't bother residents?


Mostly they just run photo-radar speed-traps ;-)

Make sure you aren't confusing the area of Phoenix colloquially called
"Paradise Valley" and the actual "Town of Paradise Valley"... big
difference.

If you lived north of Shea Boulevard you didn't live in the "Town of
Paradise Valley".

99% of the police business is just a very expensive form of
getting the unemployment rate down. It's the same everywhere.
They do nothing about real problems and go 100% for easy
targets, like photo-traps for drivers doing 54KM/hr where the
limit is 50KMhr. They should all be hanged and fed to the dogs.

--
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

 

[CBFalconer]

Mark Borgerson wrote:

.... snip ...

I've managed to get 230KB async from a UART through a kilometer
of intercom wire (simulating an oceanographic cable) by putting
out full cycles of pseudo sine waves for 1 bits and nothing at all
for zero bits. The signals were transformer coupled for impedance
matching and DC isolated so the cable could be used for HV power.

You should be able to go a lot further and faster with balanced
pairs, provided you avoid DC effects. The basic driver is a
differential pair, with a current source 2I in the emitter
circuit. The normal current mirroring methods can be used to
generate currents I from the positive rail into the collector
circuits of that pair, so that each output line now switches a net
+-I. There is only one switch, avoiding nasty crossover
distortions, which can make the receiver get slowly varying signals
just at its most sensitive point. The DC component of injected
signal is zero over the differential line pair. Other methods can
ensure the average on each half of the line is also at zero net DC.

The drive is then high impedance, so the line conditions depend
solely on the line termination. In particular any biases set for
receivers are set for the overall line, in just one place, with
current injection. Most cables have well defined impedances, in
particular almost all twisted pair telephone cable looks like 100
ohms or so at 1 Mhz up. With the above configuration the single
line is a buss, and you can fairly freely add transmitters and
receivers, provided you can compensate for the varying point to
point propagation times. There are ways to handle this. One is by
defining a transmission direction and adding a master clock line.
Now all you have to do is put all transmitters to the left of all
receivers, assuming direction is left to right. No tuning.

--
Chuck F (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

 

[Clarence]

"Jim Thompson" <thegreatone@example.com> wrote in message
news7din0hggglkqm1kk09cpad5fceep400bm@4ax.com...

On Fri, 22 Oct 2004 16:13:14 GMT, "Clarence" <no@No.com> wrote:
"Jim Thompson" <thegreatone@example.com> wrote in message
news:eebin0l54s3lcmuq5skh4lq9q9d68cvvct@4ax.com...
On Fri, 22 Oct 2004 15:32:30 GMT, Bob Stephens

<snip>> >> >>

I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing the
neighborhood for a burglary. Does that count?

...Jim Thompson

Just out of curiosity. Did you file a complaint?

Bob

Naaah. It was in Paradise Valley, a police state for the filthy rich
here in Phoenix. But I did write every restaurant that I frequented
and told them sayonara... and I kept my promise... I don't spend a
dime in that city.


Funny, I lived in Paradise Valley for several years, never even saw a cop.
So
they don't bother residents?


Mostly they just run photo-radar speed-traps ;-)

Make sure you aren't confusing the area of Phoenix colloquially called
"Paradise Valley" and the actual "Town of Paradise Valley"... big
difference.

If you lived north of Shea Boulevard you didn't live in the "Town of
Paradise Valley".

I'm sure, I lived in Phoenix for 29 years, moved to Paradise Valley the last

six.

 

[Jim Thompson]

On Fri, 22 Oct 2004 19:40:25 GMT, "Clarence" <no@No.com> wrote:

"Jim Thompson" <thegreatone@example.com> wrote in message
news7din0hggglkqm1kk09cpad5fceep400bm@4ax.com...
On Fri, 22 Oct 2004 16:13:14 GMT, "Clarence" <no@No.com> wrote:
"Jim Thompson" <thegreatone@example.com> wrote in message
news:eebin0l54s3lcmuq5skh4lq9q9d68cvvct@4ax.com...
On Fri, 22 Oct 2004 15:32:30 GMT, Bob Stephens

snip
I've had a cop point a gun at me and tell me to get out of my car...
put hands on hood and was frisked; for daring to stop in a ritzy
neighborhood and watch the sun set. The cop thought I was casing the
neighborhood for a burglary. Does that count?

...Jim Thompson

Just out of curiosity. Did you file a complaint?

Bob

Naaah. It was in Paradise Valley, a police state for the filthy rich
here in Phoenix. But I did write every restaurant that I frequented
and told them sayonara... and I kept my promise... I don't spend a
dime in that city.


Funny, I lived in Paradise Valley for several years, never even saw a cop.
So
they don't bother residents?


Mostly they just run photo-radar speed-traps ;-)

Make sure you aren't confusing the area of Phoenix colloquially called
"Paradise Valley" and the actual "Town of Paradise Valley"... big
difference.

If you lived north of Shea Boulevard you didn't live in the "Town of
Paradise Valley".

I'm sure, I lived in Phoenix for 29 years, moved to Paradise Valley the last
six.

Whereabouts? I lived at 66th St. and Desert Cove for 25 years, then
moved here to the Ahwatukee Foothills in 1994. Prior to 1969 I lived
in Old Town Scottsdale (downtown, Vernon and 68th St., and 69th Pl.
just south of Thomas).

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Rene Tschaggelar]

Harry Nguyen wrote:

Hello ,
Anyone ever use LTC1982 to build a ADC system. It's a 12bit serial
interface ADC chip from Linear Technology. They have an application
note that gives the schematic to couple the chip to PC for data
logging but when I do as they follow the result I get is very noisy.
Does anyone have experience dealing with this chip. Thanks a lot
Hope to hear from you

I didn't use this particular type yet. Apparently it is a n ADC with
capactive input. In order to get satisfying results you need the
caps over the supply. 100nF parallel 22uF. Plus you need the caps
at the input. Note that opamps do not like capacitive loads. So when you
drive the input with an opamp, make sure to have a series resistor.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

 

[Rich Grise]

On Fri, 22 Oct 2004 14:11:30 -0700, Ghazan Haider wrote:

I am trying to learn DSP development by trying to build an ISDN TA (or
even a POTS interface) using DSP chips. So far my troubles are finding
the right documentation with the specification of ISDN line
modulation, protol, and POTS line modulation for V.32.

Where can I find these specs? Are they specified in IEEE, ISO, or does
the FTC specify them? Do I have to fork out $$$ for specs that are
internationally used?

Call your local phone company and ask to talk to "vertical engineering."
They have all those answers.

Good Luck!
Rich

 

[Guy Macon]

Don Pearce <donald@pearce.uk.com> says...

When they decided that it ought to go up to 11, the easiest way was to
drop the 1.

Incorrect. See http://www.straightdope.com/classics/a1_372

 

[Guy Macon]

Dave Holford <mylastname@.deletethis.sympatico.ca> says...

Before political correctness there was superstition.

A senior FCC official did not like the idea of 13 channels and ordered
that one was to be deleted - in accordance with his directive ONE was
deleted.

Urban Myth. See http://www.straightdope.com/classics/a1_372

 

[Dbowey]

ghazan posted:

I am trying to learn DSP development by trying to build an ISDN TA (or
even a POTS interface) using DSP chips. So far my troubles are finding
the right documentation with the specification of ISDN line
modulation, protol, and POTS line modulation for V.32.

ANSI makes their money by selling the Standards. However, Documents "in the
works" can sometimes be had for free. Are you after the ISDN Basic Rate
Network Interface line code and protocols, or are looking for the exchange
between a TA and NT2, or is the NT2 in your TA, or ?? I will check out my
usual haunts to see what's available for free. Do you work in the industry?
If so, what is your company? With that I might get you more goodies. If you
don't wish to post it here, pls email me direct.

Don

 

[Roger Larsson]

Yeah, I've been meaning to test DMA writes as well, but haven't gotten
around to it yet.
... and I don't think that it will lead to better results.

Mike S. wrote:

Me neither, but maybe I gather some clues on how to proceed. Anyways,
I'm going to ask Spectrum Digital and TI about this, but thought I'd
ask here first if there were any obvious EMIF traps one could fall
into when trying to get the full specified performance out of it.

[I have only used 6711, yet...]

Beginning with basics: I am pretty sure that the cycles of async. accesses
can be programmed. (Manuals are at work) Have you done that?

When accessing CACHED memory, like SDRAM, the EMIF is s smart and loads the
full cache line, and thus you will see only one full overhead.
(But of cause you cant read from ONE location using that scheme...)

For the CPU the EMIF can never really know when a new request will come.
(CPU is stalled some of the time - it assumes four cycle access but it takes
more...)

But since the DMA knows exactly what it is supposed to do it could work
ahead.

I would recommend to use DMA to move stuff to and from of the SRAM. This way
the processor can do what it is good at - number crunching...

Note: The cache is of good use for code and data that are used in batches.
But take care and prioritize what is more important DMA (that usually has
to have moved data from one external port to memory before next arrives) or
DSP core - I think the default is that the core is prioritized higher.
And that a high frequency core together with cache can cause high EMIF load.
But on the 6713 you can configure this.

/RogerL