Driver to drive?

[Rich Grise]

On Sat, 11 Dec 2004 12:31:02 +0000, Robert Baer wrote:

mark thomas wrote:

My problem is that I am building a remote weather station, which will be
stationed up on my roof once it's completed. I've chosen to connect it to
my computer through the serial port (RS-232), mainly for financial reasons
and simplicity. I always figured that once I got it working with the serial
port, I could worry about making it lightning-proof later.

I've already purchased the microcontroller board (which is serial port
only!), but I haven't started building the system yet.

So now my options are, I suppose:

1) Buy a new microcontroller board that has Ethernet, then connect it to a
wireless transceiver which will then connect to my wireless home network
(expensive).

2) Create an RS-232 to fiber optic link, have 2 transceivers at either end
of a long fiber cable which convert the signal back to serial (time
consuming).

3) Buy an off-the-shelf serial-to-wireless system (very expensive).

Ideally I don't want to have to do any of these things. What if I simply
grounded the weather station, would that work? I don't care about the
weather station getting damaged from a lightning bolt, I just want my
computer and home to be safe...

Any thoughts, ideas?

--
MT

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

You just tossed out two excellent solutions.

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

 

[Ken Smith]

In article <pan.2004.12.11.20.22.52.998843@example.net>,
Rich Grise <rich@example.net> wrote:
[...]

write or scrounge some kind of autocad substitute, I think I might not
ever need windoze again.

QCAD is free and has an adventure game like user interface. If you like
solving riddles and doing crosswords, you may like the user interface[1].

[1] you may also have to be a masochist on drugs.


--
--
kensmith@rahul.net forging knowledge

 

[Mike Monett]

Guy Macon wrote:

[...]

Either you got lucky, or your "standard PC" was by a company such
as Compaq which was making PCs to the high quality levels needed
for embedded work back then (today's Compaq / HP hybrid is another
matter). Try that with a modern asian motherboard and you are
unlikely to see it survive to its 5th birthday.

I've no worries with hardware reliability of the commmercial PCs.

You should have worries.

[...]

What would you suggest for a hard disk drive? Most of the hi-rel ones I'm
aware of are only warranteed for three years.

Best Wishes,

Mike Monett

 

[Andreas Hadler]

artie <artie.m@gmail.com> wrote:

Lightning gonna go where lightning wanna go!
Do your best. Insure the rest.

ROTFLMAO!
May I sig this?

Andreas
--
A clever person solves a problem.
A wise person avoids it.
- Einstein

 

[Ross Herbert]

On 11 Dec 2004 14:56:14 -0800, fredrik_aldrig@hotmail.com wrote:

I intend to build a simple dawn simulator for my wife. She likes the
idea of waking up to the increased brightness of the bedside lamp
rather then the alarm clock noise, and that sounds good to me

I'm thinking basics here: an off-the-shelf household timer (to set
the wakeup time) and a custom dimmer circuit that brings my lamp from 0
to 100% in, say, in 20 minutes time or so.

I've looked around all the usenet groups for directions on how to
build this thing: most of solutions points to various home automation
solutions. That might work fine, but I'd like to put my old soldering
iron to use again - it's about time .

The problem is that I can't find a detailed schematic description.
There are references to alt.binaries.schematics.electronic but nor
Google or my ISP allows access, so I can't see if that would do it.

I plan to use Bill Bowden's (url below) dimmer circuit schema, I just
need some help with the dimensions of the diodes and some capacitors.
I've put the schema up, with all items marked, at:
http://www.designpending.com/fredrik/dawn.htm

Anybody that can suggest roughly which diodes to use?
BTW: do you expect this solution to be noisy?

Thanks,
.fredrik

For a start I wouldn't be using that circuit. It is totally
inefficient, electrically noisy and potentially hazardous.

Do some calculations on that 2K resistor when supplied from 230V.
Assume the nominal 10V dc across the zener thus leaving 220V across
the resistor. This means the resistor must dissipate in excess of 24W
(not 10W) which means it should ideally be rated at 40W or better. It
would need to be a metal-cased component (Arcol) and bolted to a
heatsink to dissipate the heat. All in all this component is wasting
power and functioning purely as a room heater.

There is absolutely no electrical isolation or barrier between the
mains supply and the low voltage components so everything must be
assumed to be "live", particularly if something goes wrong and a
component fails short circuit. While Bill Bowden may like to use it on
110V and think it is safe, it certainly isn't safe when connected to
230V and I don't think it would meet the European/UK electrical safety
standards.

 

[Robert Monsen]

fredrik_aldrig@hotmail.com wrote:

I intend to build a simple dawn simulator for my wife. She likes the
idea of waking up to the increased brightness of the bedside lamp
rather then the alarm clock noise, and that sounds good to me

I'm thinking basics here: an off-the-shelf household timer (to set
the wakeup time) and a custom dimmer circuit that brings my lamp from 0
to 100% in, say, in 20 minutes time or so.

I've looked around all the usenet groups for directions on how to
build this thing: most of solutions points to various home automation
solutions. That might work fine, but I'd like to put my old soldering
iron to use again - it's about time .

The problem is that I can't find a detailed schematic description.
There are references to alt.binaries.schematics.electronic but nor
Google or my ISP allows access, so I can't see if that would do it.

I plan to use Bill Bowden's (url below) dimmer circuit schema, I just
need some help with the dimensions of the diodes and some capacitors.
I've put the schema up, with all items marked, at:
http://www.designpending.com/fredrik/dawn.htm

Anybody that can suggest roughly which diodes to use?
BTW: do you expect this solution to be noisy?

Thanks,
.fredrik

As other's have mentioned, I think your power supply needs some work.

If you use a transformer to get your 9V supply, you can isolate the
logic from the power elements using an optoisolator designed to run a
triac, like a MOC3011. This is much safer. It's easier to isolate just
the triac, MOC3011, and fuse than the entire circuit.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Paul Burridge]

On 11 Dec 2004 18:17:45 GMT, chrisgibbogibson@aol.com
(ChrisGibboGibson) wrote:

I'm not sure whether that was supposed to be insulting or not. If it was, it
kinda failed. If it wasn't then fair enough.

To clarify, I suspect he's *not* as stupid as he appears to be from
his written contributions here and his infamous "papers" - I have
little doubt that he can sort out electronic intricacies perfectly
well in his own head; it's just communicating ideas in writing that
defeats him. I've never spoken to the bloke, so he may well have
problems with verbal communication as well, but I rather suspect not,
having encountered others with the same disability.
--

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

 

[Fred Bloggs]

Terry Pinnell wrote:

I am certain that you cannot TOGGLE those latches.

But if I rebuild (as is looking increasingly likely), I'm still rather
keen on the current limiting idea. What do you think? Big attractions
are that it would get rid of both limit switches, and provide
protection in the event of jamming. So far my project hasn't been
immune from that. The basic mechanism I've improvised has been
basically sound. But, as you see here
http://www.terrypin.dial.pipex.com/Images/CurtainControlMechanics.jpg
the Open Stop (OS) microswitch is being forced well beyond its correct
operating point. I've improved this since the photo by reducing motor
voltage (and hence the associated over-run), but jamming remains
possible.

I would stay with the limit switches and clean up the packaging. Is
there some reason why you can't use a reed switch(s)? Is the motor
interfering with it? Forget the current limiting and use a PTC
resettable fuse for protection against some kind of stall malfunction.
And for unattended operation put a thermal fuse in line with the 12V
that melts at 150oF motor case temperature.

For completeness, I'd also add that one other requirement is to retain
the versatility of being able to trigger operation electronically.
That's why I went for a bistable approach rather than the inherently
more reliable method I'd used for my window opener project years ago,
with NC microswitches actually disconnecting *power* at the limits.
For example, I've added a simple LDR/Schmitt circuit for automatic
dawn/dusk operation (when we're away).

You can add an external overdrive of the basic circuit for an LDR
triggered mode like shown below. The logic is that if the LDR commands
OPEN and the circuit is in any state except O.LIMIT then the motor is
driven into O.LIMIT where the STOP_LATCH overdrive, SODR, is removed
which turns the motor off- and similarly for CLOSE. The nice thing is
that there is no memory in play so that it is immune to prime power
failure - the shades will always end up in the right position when power
returns. This EXT interface overrides everything else so the only way to
turn it off is to throw the EXT SW to the OFF position. There can be no
over limit failure with the motor commanded beyond the stops because the
LIMIT switches over drive the 4013 output via R/S so that the motor is
commanded away from the limit once it is reached- it doesn't move away
because the STOP_LATCH kills the motor drive. It is important that the
LIMIT switches close and remain closed regardless of motor over travel-
reeds are ideal for this. This is a total of four chips 2x NOR, 1x OR,
and 1x 4013. You can easily simulate this- just omit the 4013 one shot
which is not needed to verify logic operation. Hopefully CM has switches
you can open/ close interactively.

View in a fixed-width font such as Courier.


.
.
. __
. +------------+-------\ \
. | | | o->CLOSE
. +--4013-+ | +--4013--+ | +---/__/
. | | +-|D /Q|-+ |
. | | | | | __
. +------+-------+---|CK Q|----|CK Q|---------\ \
. | | | | | | FF | | | o->OPEN
. | [1K] | | ONE | | | +---/__/
. | | | | SHOT | | SET RST| |
. | GND | +-------+ +--------+ |
. | | | | |
. | | | | |
. | +--------------------------+ |
. | |TGL C O| | 12V
. | | | | |
. T | EXT>--|EXT | | +-----+
. O | | EXTERNAL OVERDRIVE | | | |
. G o | | | [10K] e
. G |- | OL CL SODR | | | |/
. L o +--------------------------+ | +---|
. E | | | | | | |\
. | | | | | [10K] c
. | | | | | | |
. | | | | +-----+ | | |
. | | | +--------|R Q|----+---+ |
. | | | | | |
. | C.LIMIT | | | NOR_| +-RUN
. +----o/ o------------+---|>|--+-----|S Q| |
. | | | | +-----+ [1K]
. | | | | STOP-LATCH |
. | O.LIMIT | | | GND
. 12V-+----o/ o------+---------|>|--+
. | | | |
. | | | |
. | STOP | | |
. +--o o-------|-----|--------+
. --- | | |
. | [10K] [10K] [1K]
. | | |
. GND GND GND
.
.
.
.
. +----------RS LATCH-------+
. | +----------------+ |
. | | | _ |
. | | __ +--------|--Q |
. | +-\ \ | | |
. | | o-+--\ \ | |
. |S ---/__/ | o-+--Q |
. | +--/__/ |
. | | |
. |R ---------+ |
. +-------------------------+
.
.
. +--------------------- EXTERNAL OVERDRIVE --------------------+
. | __ |
. | OL --------------------------------------------\ \ |
. | | >- C |
. | +--------------/__/ |
. | | __ |
. | CL -----------------------------|--------------\ \ |
. | | | >- O |
. | | +----------/__/ |
. | | | |
. |TGL -----------------------------|---|-------+ |
. | __ | | | |
. |EXT ---+---|>|---+-------\ \ | | | |
. | | | | o---|---+ | |
. | OL ---|---------|-------/__/ | | | |
. | | | | | | __ |
. | | | | | __ +--\ \ |
. | | | __ | +--\ \ | >-SODR |
. | CL ---|---------|-------\ \ | | >---/__/ |
. | +-\ \ | | o---+------/__/ |
. | | | o---|-|>|-+-/__/ |
. | +-/__/ | | |
. | | | |
. | | | CLOSE |
. | | | ----- |
. | [10K] [10K] | | |
. | EXT | | EXT-> | | |
. | OPEN=OFF +-----+ | | |
. | | OPEN | | OPEN |
. | EXT SW __ | ----- ------ |
. | +12V--o/ o--+-\ \ | |
. | | | o --+ (from LDR ckt ) |
. | +-/__/ |
. | | |
. | [10K] |
. | | |
. | GND |
. +-------------------------------------------------------------+
.

 

[Ross Herbert]

On 11 Dec 2004 16:37:55 -0800, fredrik_aldrig@hotmail.com wrote:

Ouch! I suppose I should look at other solutions, thanks Ross for
making that clear!
Does anybody know whether there were more useful solutions at
alt.binaries.schematics.electronic?

I don't know of any diy designs for a sunrise alarm lamp but unless
you are really determined to build your own I would recommend
something already available for 230V operation. Such as
http://www.bodykind.com/productdetails/CatIDx67/ProdIDx463/dawn-simulator-natural-alarm-clock-1x.htm

Believe me, it will be a lot cheaper than starting from scratch and
building your own.

 

[Frithiof Andreas Jensen]

"Nicholas O. Lindan" <see@sig.com> wrote in message
news:Gnpud.1378$Sp3.123@newsread3.news.atl.earthlink.net...

BTW: QNX is the only system to use with embedded PC
architecture, don't bother with anything else, sorry
Linus.

Go tell that to Linksys - I'm sure they care (not)!

....or here fwiw...

QNX et. al. are for people who want to write Infrastructure - i.e.
Engineers - and that's not The Game anymore.

The real money are made by Integrating what is already there and making it
usable or applicable for "normal people". That vein is only beginning to be
tapped; there would be products for the next 3-5 years even if Linux
development was frozen today, which it is not.

 

[Frithiof Andreas Jensen]

"normanstrong" <normanstrong@comcast.net> wrote in message
news:Hl2ud.541131$D%.253933@attbi_s51...

I have a difficult time understanding how
they can be sold at that price,

Had me puzzled for a while also - until I studied the econnomics of China a
bit:
The bad debt in Chinese banks was at Sep. 2004 running at 40% of BNP!!!

So The answer is:

It was made at at Loss; the Chineese manufacturer Lost Money on it, but he
did not really care: His "game" is to get turnover, which he will use to
borrow more money to fund his "business" ... 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.

Them "Strategic Interests" again.

 

[Winfield Hill]

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.


--
Thanks,
- Win

 

[YD]

On 8 Dec 2004 10:57:40 -0800, "Dave" <galt_57@hotmail.com> wrote:

cfoley1...@aol.com (CFoley1064) wrote:
[...]
So if Sunday you're free,
Why don't you come with me,
And we'll poison the pigeons in the park.
[...]


Not good since it might get into the food chain.

Who eats pigeons? Well, the occasional cat may do it but IMO that's
all for the better. Since AFAIK nobody eats cats the problem stops
there.

- YD.

--
Remove HAT if replying by mail.

 

[Winfield Hill]

Rich Grise wrote...

Keith Williams wrote ...

I'm pretty sure this one was from before 1820. ;-)
http://neo.jpl.nasa.gov/images/meteorcrater.jpg

You can determine speed and angle of impact from the characteristics
of the crater itself. I've been there, and for several miles along
the road, there are some of the weirdest-looking rocks I've ever seen
- I speculate that they're frozen globs of condensed ejecta. It's a
pretty impressive hole, after all.

Did you go down into the crater? How should one spend his time if he
only has a few hours at the site? Or should more time be planned?


--
Thanks,
- Win

 

[Leon Heller]

"normanstrong" <normanstrong@comcast.net> wrote in message
news:Hl2ud.541131$D%.253933@attbi_s51...

Have you ever bought one of those strings of 100 lights that sells for
$1? I just purchased 8 strings of them for 50 cents a string, on
sale--normal price: $1. I have a difficult time understanding how
they can be sold at that price, even if the entire manufacturing
process is automated. The raw materials alone would seem to cost more
than $1.

They tend not to automate that sort of production, they have lots of very
cheap labour and an artificial exchange rate.

Leon

 

[Guy Macon]

Frithiof Andreas Jensen wrote:

"Nicholas O. Lindan" wrote...

BTW: QNX is the only system to use with embedded PC
architecture, don't bother with anything else, sorry
Linus.

Go tell that to Linksys - I'm sure they care (not)!

I am with Frithiof on this one. QNX is a fine product, but it
is no longer the only game in town, and the various flavors of
Embedded Linux are really outstandingly good.

On the other hand, if I was designing a control system for a
nuclear reactor, I would quit if they didn't let me specify QNX.

 

[Frithiof Andreas Jensen]

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

I seriously doubt this.

Of course China will be there as a nation in 30 years, but the pension money
people put into China funds will not be there. China's "economic miracle"
will not go pretty much the same way as it did in f.ex. Mexico, Argentina,
Turkey, Brazil and the "new economy".

(Japan is somewhat similar and yet different - here the problem is vast
losses on property investments buried in banks that cannot write off those
losses witout going bancrupt - yet "everybody" knows that is the way things
are, so nobody dare invest in Japan just in case the lid blows off that
particular economic septic-tank).

Asia times online are quite good on China:
http://www.atimes.com/atimes/China.html

 

[CFoley1064]

Subject: are pin headers breadboard safe?
From: Michael Noone mnoone.uiuc.edu@127.0.0.1
Date: 12/12/2004 8:55 AM Central Standard Time
Message-id: <Xns95BD5AB73B68Cmnooneuiucedu127001@204.127.199.17

Hi - just a quick simple question. Are standard .1" pin headers safe for a
breadboard? They seem a bid thick, so I'm worried about the possibility of
them wearing out the contacts, which is something I'd really like to avoid.
Thanks,

-Michael

Not ideal. The spring clips underneath can get stretched out of shape a
little, and might not make as good a contact with the next, smaller wire. I
try to avoid doing that, because poor contacts on the protoboard can be very
difficult to diagnose, and can waste enormous amounts of troubleshooting time.

I like using these boards for low frequency stuff, and what I'll do is solder
the header to a scrap of perfboard, then solder wires to the perfboard to make
the connection to the solderless breadboard.

Questions of this type usually get a better reception on
sci.electronics.basics.

Good luck
Chris

 

[Rusty]

On Sun, 12 Dec 2004 15:04:00 GMT, Rusty <invalid@nowhere.com> wrote:

Anyway, they want $50 shiipping and handling to the UK, which I
consider out of order as Linear Technology on charge $24 to the UK. So

Further to this, it's worth mentioning that Linear Technology seem
more speedy. I ordered 2 off LTC4150 from the US at 16:00 on the
Thursday and received them here in the UK at 11:10 on the following
Monday. Maxim quoted me 2 weeks even for the MAX5035DASA, which they
say they have stock of anyway!

 

[YD]

On Sat, 11 Dec 2004 05:29:25 GMT, Rich Grise <rich@example.net> wrote:

<snipperoo-DAH!>

I'm about to embark on another website design, and I'll probably use an
ordinary text editor, as I always have. HTML isn't hard at all: check out
http://werbach.com/barebones/

Good Luck!
Rich

Try Max's HTML Beauty http://www.htmlbeauty.com/. Text editor with
syntax highlighting, picture drag'n'drop and lots of shortcuts and
wizards for the frequently used thingies. The price is unbeatable
unless you demand being paid for using it.

- YD.

--
Remove HAT if replying by mail.