Driver to drive?

[Guy Macon]

Mark Jones wrote:

Curious, out of the different CPU's that are compatible
with QNX, is there a "best" match?

I haven't studied this question, but I know that as soon as I
can get my hands on a processor and OS that supports the Execute
Disable Bit, I am going to switch top that and never look back.

 

[w_tom]

Lightning gonna go where lightning wanna go.
So give lightning what it wants ...
so that lightning does not take what you want.

A plug-in protector that will stop, block or absorb what
three miles of sky did not is a myth. Effective protection
gives lightning what it wants - earth ground. So routine and
so well understood that lightning damage is directly traceable
to human failure. Insure only because humans make mistakes -
such as wasting money on plug-in protectors.

Andreas Hadler wrote:

artie <artie.m@gmail.com> wrote:
Lightning gonna go where lightning wanna go!
Do your best. Insure the rest.

 

[Rusty]

On Sun, 12 Dec 2004 16:32:49 GMT, Mac <foo@bar.net> wrote:

I have nothing concrete for you, but I have noticed that Maxim seems to
have tons of parts which are difficult to get in small volumes. For
example, if you go to digikey, most of the MAX parts are non-stock. I am
half-way convinced that Maxim doesn't make some of these parts until they
are already sold.

Which would tie in with the statements in the quote I was emailed.
Still, you'd think they _are_ already sold if Digikey wanted to buy
some for their stock. I dunno.

In your case, maybe you should call a Linear Technologies applications
engineer and find out if the part in question can operate at your worst
case voltage. Probably they specifically targeted 3.3 and 5.0 Volt
operation, so that is all they specify. In any event, you have nothing to
lose by asking.

You could well be right. I'll check with them and see.

 

[Richard Henry]

"Winfield Hill" <hill_a@t_rowland-dotties-harvard-dot.s-edu> wrote in
message news:cph95a0g29@drn.newsguy.com...

Frithiof Andreas Jensen wrote...

... China is one huge dot.com bubble running on credit, the only
"business plan" is to go for market share; however the US "Land Grab"
in the Middle East pushing up energy prices and the falling US Dollar
will ensure a grim end for the Chineese economy within this decade.

I seriously doubt this. While they may have some fun sorting things
out, in their managed way I'm sure they will, perhaps using the cash
they've built up with years of a massively-positive balance of trade.

Do you have access to Chinese bank accounts to see what they are doing with
that cash?

 

[Nicholas O. Lindan]

Hi - just a quick simple question. Are standard .1" pin headers safe for a
breadboard?

AMP (of Tyco fame) makes 0.1" headers made from round wire. They should
work just fine in push-in experimenters' blocks.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/

 

[Winfield Hill]

Spehro Pefhany wrote...

They're currently running an overall trade deficit, so
presumably the value of the yuan is a touch on the high side.

Is that right? I thought it was the other way around.


--
Thanks,
- Win

 

[mark thomas]

The artist formerly known as Rich Grise wrote:

| I can't help but wonder, how much lightning is this guy trying to measure?
|
| Geez, put the thing in a metal box, put up a lightning rod, and live with
| it, like everybody else does.
|
| Good Luck!
| Rich

I'm not trying to measure lightning...

Wouldn't a metal box make it more succeptable to lightning? (i.e. versus a
plastic box)

--
MT

To reply directly, take every occurrence of the letter 'y' out of my
address.

 

[Mike Harrison]

On 12 Dec 2004 10:06:28 -0800, eduardm76@pop.com.br (Edward) wrote:

Hello!

Does anyone know an equivalent IC for the TDA3047 from Philips? It's an
infrared pre-amplifier receiver.



Thanks in advance.

Might be easier to just use/replace with an integrated IR receiver module (e.g. Vishay TSOP series
etc. )

 

[Genome]

"Ken Smith" <kensmith@green.rahul.net> wrote in message
news:cpemc9$p1u$1@blue.rahul.net...

I have been re-reading Mr. Cuk's book and it looks like I owe DNA an
apology. In Mr. Cuk's paper he does say that the "naturally sampled"
modulator has zero phase lag.

kensmith@rahul.net forging knowledge

Why?

Not because CUK says so....... Does he say why and does it make sense?

Why, as you understand it yourself, is there zero 'transport delay'?

Explain....

DNA

 

[John Larkin]

On Sun, 12 Dec 2004 20:55:54 +0100, "Jeroen" <jayjay.1974@xs4all.nl>
wrote:

I have had a number of problems getting Maxim parts, and one huge
headache when they discontinued a part without notice *after* our
order was long overdue.


"What's the status of that overdue order?"

"You'll never get it."


I think they are designing more parts than they can support in
manufacturing.

I worry that the linear IC manufacturers are introducing so many
specialized sole-source parts at such a rate that they won't be able
to justify making them for long, so many unique parts will be
discontinued.

They do have a non-obsolence policy... don't know much it is worth though..

Jeroen

There was an interview with the President of Maxim in one of the mags
a couple months ago. He did mention a policy of making their parts
pinout-incompatible with the competition so customers would be locked
into their expensive components. That means that when they discontinue
a part, you're in trouble.

John

 

[Genome]

"ChrisGibboGibson" <chrisgibbogibson@aol.com> wrote in message
news:20041211133220.16224.00001784@mb-m02.aol.com...

kensmith wrote:

[snip]

"I remember the subject from uni. I also remember a lecturer showing quite
clearly that Cuk's original paper with the explanation for it being due to
BJTs as being wrong. It exists even with mosfets."

Gibbo

Something about the RHPZ in CUK converters.......



"I remember the subject from uni. I also remember a lecturer showing quite
clearly that Cuk's original paper with the explanation for it being due to
BJTs as being wrong. It exists even with mosfets."


Go on then..... if you think you're hard enough?

DNA

 

[Ken Smith]

In article <GU%ud.492644$nl.247632@pd7tw3no>,
Curtis <curtis@dangonay.com> wrote:

I'm building my own version of a home theatre system with bi-amplified
speakers. I will be using several amplifier modules to power the various
drivers.
I want to power the amp modules off a single central power supply. This
supply
will provide +/- 35 volts with some basic filtering. Some amp modules will
be in
the same case as the power supply while others will be remote mounted in
speakers.
For these remote amps I will run a DC power cable with the +/- 35 volts &
GND.

Let me see if I understand what you are planning. Is the cable to a
remote box like this:

Main Remote
Box Box
---- ------
! +35V !
O!----------------------------!O
! -35V !
O!----------------------------!O
! GND !
O!----------------------------!O
! Signal !
O!----------------------------!O
! GND !
O!----------------------------!O
---- ------


If this is what you are trying, there is likely to be trouble. Some of
your return current will flow down the signal's GND line. This will
create offset voltages in the signal that depend on output circuit
current. This is going to be trouble.

If this what you intend:

You really should send the signal differentially and have the amplitude as
large as practical. The CMRR of the differential input section in the
remote box has to be quite good. Beware of the high frequency (~20KHz)
CMRR it has to be good too. This signal should go on a "bell foil"
shielded twisted pair.

The output section in the remote box should be designed as to pass current
between the +35V and -35V and not return much (if any) current on the
ground. Using a full bridge or half bridge output does this.

One of the really troubling parts of the design is the fact that you will
have a lot of distortion products in the power wires. The power really
needs to be a twisted pair also and all other anti-crosstalk measures
observed in this area.

However, I want each local amp module to have its own reserve of filter
capacitors even though it gets its power from the main supply.

This filter needs to include a series impedance to reduce the high
frequency AC currents flowing in the cable. The power amplifier will have
some power supply rejection ratio. If the high frequency PSRR of the
amplifier isn't high enough and the ripple on the capacitors isn't low
enough, the harmonics on the power supply will show up as harmonics in the
output signal.

[...]

What I don't want is to have one amplifier draw power from the capacitors in
another amp module during music peaks. What I want to know is the easiest
way to
isolate the local power supply filter caps in each amp from other amps so
they don't
rob each other of power. I know how to do this with a single supply
(diodes), but
how do I do this with a split supply?

Each remote box should have rectifiers in its power input connections.
This prevents the current from returning down the wires. It does not
completely protect you though.

Assume an amplifier is drawing, lets say, 1A through the diode, If
another amplifier suddenly draws enough power to reduce the main supplies
voltage, the current through the diode stops. This means that the tweeter
boxes have to contain extra capacitance to carry through the power dips
caused by the bass amplifiers.

Having the inductors at the inputs more or less forces you to also include
rectifiers across the supply lines. Imagine that someone (you would
never) unplugs the connector with the power on. The inductors prevent the
current from stopping and can make quite a large voltage spike. If you
don't take care in the design, this spike could break the electronics or
arc weld the end off connector pins.


--
--
kensmith@rahul.net forging knowledge

 

[Winfield Hill]

Mark Jones wrote...

Hi. I have this old 1981 H&R General Electric 15kV/1mA DC supply.
It works like a charm, although I have no idea what it came out of.
But I've been thinking of using it for electrostatic air filtration.

In the furnace return-air duct...

I don't think that old 1mA supply has a high enough power capacity.
You'll also need large a pulse-rated high-value 20kV glassmike cap.


--
Thanks,
- Win

 

[Guy Macon]

Winfield Hill wrote...

...perhaps using the cash they've built up with years
of a massively-positive balance of trade.

Leaving aside the question of whether this one particular country
has a positive trade balance, a trade imbalance means that the
other country is sending us TVs, VCRs, steel, wood, etc. and in
return we are sending them little slips of paper. We seem to be
getting the better end of the deal.

 

[Rich Grise]

On Sun, 12 Dec 2004 16:46:20 -0500, mark thomas wrote:

Sorry, I'm replying to my own post...
| The artist formerly known as John Popelish wrote:
|
|| This grounding system should
|| tie to the power entrance ground, so that there is a limit on the
|| voltage between various parts of your home system.
||
|| You limit the voltage peaks on the signal lines with surge suppressers
|| (grounded to the same line that grounds the lightning rod and weather
|| station)

Everything I've read says to ground the lightning rod into the soil.

That is correct, and AFAIK, there is a ground rod at the entrance panel.
So you ground the lightning system to it.

Also, I think since I don't care about the weather station being
damaged, I'm just going to go with the opto isolators, and forget about
the lightning rod and surge suppressor.

Bad idea, but it's your house.

Good Luck!
Rich

 

[Allan Herriman]

On 12 Dec 2004 18:01:55 -0800, "Tara" <tara_book_publisher@yahoo.com>
wrote:

What, no mention of SAW oscillators?

Allan

 

[Ken Smith]

In article <toadnSnZpuOIPCHcRVn-rw@golden.net>,
mark thomas <marycoy4@execyulinky.comy> wrote:
[...]

I'm using an embedded serial driver, so I am limited by 50-100feet, which is
more than enough to reach my roof from my computer...

I've used RS-232 over 1500 foot cables, so 100 feet should be no problem
for you. You can trade off some of the drive by putting RC circuits on
the ends of the cable to route spikes to ground through capacitors and not
through the chips.

--
--
kensmith@rahul.net forging knowledge

 

[Ken Smith]

In article <pan.2004.12.12.23.51.42.858956@example.net>,
Rich Grise <rich@example.net> wrote:
[...]

That is correct, and AFAIK, there is a ground rod at the entrance panel.

This varies from place to place and with the age of the house.

Some places there is a wire from the fuse box to the water pipe. Some
have a ground rod directly below the power meter. Some places, there are
two ground connections. The OP really should loook at what he actually
has before going forward. Placing a grounded conductive object up on the
roof is a good way to fool Mother Nature into thinking it is a lightning
rod. Mother Nature doesn't like to be fooled.

--
--
kensmith@rahul.net forging knowledge

 

[Ken Smith]

In article <41BCF94C.28CE6F0E@rica.net>,
John Popelish <jpopelish@rica.net> wrote:
[...]

The lightning rod should go as directly as possible with a healthy (#8
or larger) copper wire

Most places, they use an iron wire or a "copper weld" wire. Iron vapor is
harder to make than copper vapor. The difference in resistance isn't
super important in this case.



--
--
kensmith@rahul.net forging knowledge

 

[keith]

On Sun, 12 Dec 2004 12:22:03 -0800, John Larkin wrote:

On Sun, 12 Dec 2004 20:55:54 +0100, "Jeroen" <jayjay.1974@xs4all.nl
wrote:

I have had a number of problems getting Maxim parts, and one huge
headache when they discontinued a part without notice *after* our
order was long overdue.


"What's the status of that overdue order?"

"You'll never get it."


I think they are designing more parts than they can support in
manufacturing.

I worry that the linear IC manufacturers are introducing so many
specialized sole-source parts at such a rate that they won't be able
to justify making them for long, so many unique parts will be
discontinued.

They do have a non-obsolence policy... don't know much it is worth though..

Jeroen


There was an interview with the President of Maxim in one of the mags
a couple months ago. He did mention a policy of making their parts
pinout-incompatible with the competition so customers would be locked
into their expensive components. That means that when they discontinue
a part, you're in trouble.

The last time (perhaps 12 years ago) I *tried* to use a Maxim part our
purchasing people laughed me out of the office for even suggesting such
foolish ideas. Hell, all I needed was a few hundred parts and would have
bought a few thousand. ...at any price.

I tired to get a few simple battery controllers just to play with. The
purchase order came back at something like 100 weeks. I never seriously
looked at Maxim again. I'm sruprised they're still in business.

--
Keith