Re: Thoughts on changing a remote RX and TX.

Stefan Trethan

On Sun, 11 Apr 2004 07:00:14 -0700 (PDT), Barry Savage <sofistic@...> wrote:

Hi Gary and All:

If you have a phone at each location, and you are using Windows, why not just use Virtual Private Network.

Barrymaybe because in some countries you have to pay for phone calls ;-)

ST

Re: Thoughts on changing a remote RX and TX.

Barry Savage

#9537

Hi Gary and All:

If you have a phone at each location, and you are using Windows, why not just use Virtual Private Network.

Barry

Re: Thoughts on changing a remote RX and TX.

Stefan Trethan

#9536

look here if you plan to build one:

<>

<>

This is a very simple design, but very bad too.
2kHz they say is the bandwisth, maybe there are ways to increase.

they claim 30m is the range.

it costs 15eur at conrad.de, you can find pictures if you go to www.conad.de
and enter 130428 at the top left field.

again, this is the lowest quality unit you will find.
but it is very cheap.

ST

Re: Thoughts on changing a remote RX and TX.

Stefan Trethan

#9535

OK, so no CB, and no wires allowed.

The garage door operating thingys are possible too high integrated to
feed a tx before the HF stage.
Do you need handshake (duplex transmission)?

Take apart such a garage door thing, but there are no guarantees.
in most units there is some "changing key" generating mechanism which decides
what is to be sent, somewhere after that and before the HF stage you might feed your
signal.


You also can look out for RC remote controls (RC planes, cars, etc.)
i think it should be possible to feed a RS232 in there, and get it out inside the RX.
i would know where to feed in in in my TX but not exactly where in the RX to find it.
I'm also not sure about the speed, you have to check the bitrates, RC pulses are rather slow.


Last version would be to build a TX and RX from scratch, but that would be hardest
to do and i'm not sure if you have the neccesary tools and skills (then you wouldn't
ask i reckon).


Fot the garage door thing: keep in mind they are only designed for a short range..
might not work throgh concrete etc.

Optical transmission is impossible too i guess (laser)


ST

Show quoted text

On Sun, 11 Apr 2004 11:55:42 +0200, Gary Anderson (G) <andersg@...> wrote:

Hi Stefan..

Opps sorry for spelling your name wrong in previous message.

Well CBs in this country are as dead as hens teeth. I still have a
Midland running but listening to a hiss is no longer fun. We don't
have a freq on 27Mhz for data. That would be illegal.

Iam sure I would be able to get a module posted to me but it a really
expensive solution noting the exchange rate R7 to 1 US dollar. Stange
enough we can buy parts cheaper than other countries. This leave me
with trying to use a cheap solution by trying to build a circuit or
use a device which is fairly cheap and made locally like the RX TX
units used for garage doors.
Also I have these at present and thought it would be nice to learn how
they work.

The reason I can run a wire is if it were possible it would have to
lie in the road. Iam trying to link two buildings without installed a
wireless network which will require another PC.  I have a need to be
able to print to another printer located on the other side of the
road.

Thanks for the ideas so far.

Gary


-----Original Message-----
From: Stefan Trethan [mailto:stefan_trethan@...]
Sent: Sunday, April 11, 2004 11:40 AM
To: Electronics_101@...
Subject: Re: [Electronics_101] Thoughts on changing a remote RX and
TX.

On Sun, 11 Apr 2004 11:08:10 +0200, Gary Anderson (G)
<andersg@...> wrote:

Hi All..

Any ideas on being able to change the remote control units we use to
open the garage door to be able to conver/use this circuit to TX and
RX a PCs COMS ports signal??

Thanks Stephan.. The web site you supplied has given to the capacity
to convert parallel to serial signal. Now I need to TX  this over a
distance of about 50m or more.


Any thoughts and ideas???

Thanks
Gary
Get a old CB (ham) radio, like the handheld units or the ones for car.
you can find them for next to nothing at ebay. there should be
channels for
data communication. there are also already modems available, and i am
sure
circuits
for making them. it would be the easy solution.

I could get such wireless modules here like described in the elektor,
where you just
connect rx and tx an that's it.
It would be the better solution, because you are not using CB
frequency
(not sure if this is legal)
and you have a much smaller unit, less power consumption etc.
I haven't followed the whole converstion, can't you get these modules
anywhere?
i would reckon ther must be vendors shiping to .za.
(you could try the german supplyers like reichelt or segor, ot the
austrian RS components
if you really have none locally. of course you can also try american
like
digikey which will
be cheaper.

I strongly oppose any wireless transmission if there is a posibility
to
run a wire.
especially if both rx and tx are stationary it is simply stupid to use
up
frequencys.

I dunno why you can't run a wire, but i would think twice.

st








Yahoo! Groups Links









Yahoo! Groups Links

Re: Thoughts on changing a remote RX and TX.

Gary Anderson (G)

#9534

Hi Stefan..

Opps sorry for spelling your name wrong in previous message.

Well CBs in this country are as dead as hens teeth. I still have a
Midland running but listening to a hiss is no longer fun. We don't
have a freq on 27Mhz for data. That would be illegal.

Iam sure I would be able to get a module posted to me but it a really
expensive solution noting the exchange rate R7 to 1 US dollar. Stange
enough we can buy parts cheaper than other countries. This leave me
with trying to use a cheap solution by trying to build a circuit or
use a device which is fairly cheap and made locally like the RX TX
units used for garage doors.
Also I have these at present and thought it would be nice to learn how
they work.

The reason I can run a wire is if it were possible it would have to
lie in the road. Iam trying to link two buildings without installed a
wireless network which will require another PC.  I have a need to be
able to print to another printer located on the other side of the
road.

Thanks for the ideas so far.

Gary

Show quoted text

-----Original Message-----
From: Stefan Trethan [mailto:stefan_trethan@...]
Sent: Sunday, April 11, 2004 11:40 AM
To: Electronics_101@...
Subject: Re: [Electronics_101] Thoughts on changing a remote RX and
TX.

On Sun, 11 Apr 2004 11:08:10 +0200, Gary Anderson (G)
<andersg@...> wrote:

Hi All..

Any ideas on being able to change the remote control units we use to
open the garage door to be able to conver/use this circuit to TX and
RX a PCs COMS ports signal??

Thanks Stephan.. The web site you supplied has given to the capacity
to convert parallel to serial signal. Now I need to TX  this over a
distance of about 50m or more.

Any thoughts and ideas???

Thanks
Gary
Get a old CB (ham) radio, like the handheld units or the ones for car.
you can find them for next to nothing at ebay. there should be
channels for
data communication. there are also already modems available, and i am
sure
circuits
for making them. it would be the easy solution.

I could get such wireless modules here like described in the elektor,
where you just
connect rx and tx an that's it.
It would be the better solution, because you are not using CB
frequency
(not sure if this is legal)
and you have a much smaller unit, less power consumption etc.
I haven't followed the whole converstion, can't you get these modules
anywhere?
i would reckon ther must be vendors shiping to .za.
(you could try the german supplyers like reichelt or segor, ot the
austrian RS components
if you really have none locally. of course you can also try american
like 
digikey which will
be cheaper.

I strongly oppose any wireless transmission if there is a posibility
to
run a wire.
especially if both rx and tx are stationary it is simply stupid to use
up
frequencys.

I dunno why you can't run a wire, but i would think twice.

st

Yahoo! Groups Links

Re: Thoughts on changing a remote RX and TX.

Stefan Trethan

#9533

On Sun, 11 Apr 2004 11:08:10 +0200, Gary Anderson (G) <andersg@...> wrote:

Hi All..

Any ideas on being able to change the remote control units we use to
open the garage door to be able to conver/use this circuit to TX and
RX a PCs COMS ports signal??

Thanks Stephan.. The web site you supplied has given to the capacity
to convert parallel to serial signal. Now I need to TX  this over a
distance of about 50m or more.


Any thoughts and ideas???

Thanks
Gary
Get a old CB (ham) radio, like the handheld units or the ones for car.
you can find them for next to nothing at ebay. there should be channels for
data communication. there are also already modems available, and i am sure circuits
for making them. it would be the easy solution.

I could get such wireless modules here like described in the elektor, where you just
connect rx and tx an that's it.
It would be the better solution, because you are not using CB frequency (not sure if this is legal)
and you have a much smaller unit, less power consumption etc.
I haven't followed the whole converstion, can't you get these modules anywhere?
i would reckon ther must be vendors shiping to .za.
(you could try the german supplyers like reichelt or segor, ot the austrian RS components
if you really have none locally. of course you can also try american like digikey which will
be cheaper.

I strongly oppose any wireless transmission if there is a posibility to run a wire.
especially if both rx and tx are stationary it is simply stupid to use up frequencys.

I dunno why you can't run a wire, but i would think twice.

st

Thoughts on changing a remote RX and TX.

Gary Anderson (G)

#9532

开云体育

Hi All..

?

Any ideas on being able to change the remote control units we use to open the garage door to be able to conver/use this circuit to TX and RX a PCs COMS ports signal??

?

Thanks Stephan.. The web site you supplied has given to the capacity to convert parallel to serial signal. Now I need to TX? this over a distance of about 50m or more.

?

Any thoughts and ideas???

?

Thanks

Gary

?

Re: Yahoo seriously messed up

#9531

I get a search that goes back a screenfull of messages or 1 month of 
postings - from the home (showing the 4 messages). It still 
shows "next".   I wonder why you dont get that?

--- In Electronics_101@..., "ghidera2000" 
<ghidera2000@y...> wrote:
--- In Electronics_101@..., "Phil" <phil1960us@y...> 
wrote:
Sorry, danger, We will just have to disagree that the search function 
is ok.  
Actually, Danger is correct. I didn't know it before but, if you 
search from the home page (the one showing the posts each month and 
the latest 4-5 messages), it works identically to the way it did 
before. Not to say that it was ever great, but at least I can search 
as well as I did prior to the search changes.

Its only when you're looking at the message list pages that the 
search is buggered.

Re: A3977 Stepper driver (finally) updated.

#9530

--- In Electronics_101@..., "ghidera2000"
<ghidera2000@y...> wrote:
Waiting for parts on other projects and I've finally digested a lot 
of the information provided in previous discussions so, I went back 
to work on the stepper driver board. The schematic (pdf) is in the 
Stepper Driver folder of the files section.

The big change was in changing over to an optoisolated interface 
with the parallel port. Still a few things about it that I'm shaky 
on though I think I'm probably pretty close to PCB time. I created a 
Readme file with all the details as well.

Love to get some feedback!
Looking good. I currently use a Xylotex, which is an A3977 3-axis
driver, but doesn't have optoisolation or the integrated power
supplies and spindle control. I have one suggestion, since you haven't
put the work into the PCB yet: if possible, do not use the PLCC
package. There is also a surface-mount package that is equally rated.
The A3977 is pretty easy to blow up, I blundered and fried two.
Desoldering a PLCC is fine with a heat gun, but soldering them is
never a picnic, especially if other components don't let you get a
nearly flat angle with the iron. The surface mount package would be
much easier to solder since you can come down from the top, and you
don't get invisible solder bridges underneath the chip.

The A3977 is susceptible to more than just back EMF; if you mess with
the motor cables even while only 5 volt power is applied, you can
still fry them. So it would be a good idea to control the logic and
stepper supplies at the same time, so that when it's off, it's OFF.

You might also want to provide solder point where people can just wire
in their own motor supply. Sometimes you can find really good deals on
24V supplies, possibly free, and not have to worry about building the
supply portion of the circuit.

A3977 Stepper driver (finally) updated.

#9528

Waiting for parts on other projects and I've finally digested a lot 
of the information provided in previous discussions so, I went back 
to work on the stepper driver board. The schematic (pdf) is in the 
Stepper Driver folder of the files section.

The big change was in changing over to an optoisolated interface 
with the parallel port. Still a few things about it that I'm shaky 
on though I think I'm probably pretty close to PCB time. I created a 
Readme file with all the details as well.

Love to get some feedback!

Re: Yahoo seriously messed up

#9527

--- In Electronics_101@..., "Phil" <phil1960us@y...> 
wrote:
Sorry, danger, We will just have to disagree that the search function 
is ok.  
Actually, Danger is correct. I didn't know it before but, if you 
search from the home page (the one showing the posts each month and 
the latest 4-5 messages), it works identically to the way it did 
before. Not to say that it was ever great, but at least I can search 
as well as I did prior to the search changes.

Its only when you're looking at the message list pages that the 
search is buggered.

Re: Twisted trio?

Roy J. Tellason

#9526

On Saturday 10 April 2004 07:23 pm, upand_at_them wrote:
I've read that there's a benefit to using twisted pair wire for
carrying signals when the distance isn't small.

But what do you do when you have 3 lines (Vsupply, Ground, and
Vout)?  Should I braid them all together?...Or wrap the third around
the twisted pair?The benefit to twisted pair is that noise induced into one wire will also be 
induced into the other one at pretty much the same amplitude,  and the wires 
will typically be balanced,  and out of phase with each other.  Phone lines 
work like that -- no shielding,  and they can run for miles with really low 
level signals and not pick much up.  Balanced microphone lines that run all 
over in broadcast and recording studio setups also work this way.

What kind of signal are you running,  and how is it interfaced at each end? 
How long of a run are you talking about?

Re: Yahoo seriously messed up

[email protected]

#9529

开云体育

In a message dated 4/10/2004 2:57:48 AM Central Standard Time, stefan_trethan@... writes:

didn't you notice that in the last days there was way more chaos than
normal?

Yep.

Twisted trio?

#9525

I've read that there's a benefit to using twisted pair wire for 
carrying signals when the distance isn't small.

But what do you do when you have 3 lines (Vsupply, Ground, and 
Vout)?  Should I braid them all together?...Or wrap the third around 
the twisted pair?

Mike

Re: Yahoo seriously messed up

Stefan Trethan

#9524

I agree, the online search is useless.
However i have all messages stored in the email software.
(only since i joined, which is not long in this group)
I do like the search function of the mail software (opera) much more than any
online search.

There is also some software which allows you to download the whole archive and store
it locally, one would assume it has a search feature (hopefully more than a "on the package feature").
There was no free software when i last checked (maybe 6 months or a year ago) but there mey be
now, or you might even be prepared to pay for it.

ST

Show quoted text

On Sat, 10 Apr 2004 17:39:44 -0000, Phil <phil1960us@...> wrote:

Sorry, danger, We will just have to disagree that the search function
is ok.

Re: Yahoo seriously messed up

#9523

Sorry, danger, We will just have to disagree that the search function 
is ok.  

Having to hit next,next,next,next,next,next... to get through a large 
message base is enough to make me only use it when I've completely 
given up on other avenues.  In that sense, they have succeeded.  I 
dont know of another search engine that makes you do that.  suppose 
google did that?  They would dry up and blow away.

Its really a shame that they felt the need to put a barrier up to 
finding information.  AV science's forum SW has a much smarter way to 
reducing search overhead - they make you select the "depth" of 
search.  You can search the whole enchilada but you have to select 
it.  Default is a "light" search.  Other search engines use search 
ranges (like dates) to limit search load.  It doesn't bother me to 
have to select search parameters at the beginning but I shouldn't 
have to mother the search along.  I just seems to be an artificial 
and contrived way to minimize use while being able to claim the 
feature.

--- In Electronics_101@..., "manifold" <manifold_1@y...> 
wrote:

On one hand, I'm starting to scare myself at how radical I'msounding.  But
on the other hand...

<Channelling Braveheart:--"FREEEEEEDOOOOOMMMMM!!!!">

Oops.  I seem to have misplaced my blue facepaint.

If anything I have said is flameworthy, flame away.

-DM

----- Original Message ----- Without the blue face paint it's The Patriot; same soundtrack too,
Uhg!, ack!, splurt!, die, die, die.

A delay of a few hours is fine by me. I like reading and replying to
the list on the web. I do not even have an email client on my machine. 

The search function still works fine, I just tried and it did great.
You do have to hit 'Next' to make it through the whole archive. It's
not terrible. Just start your search from 'Home' and not 'Messages'.
From 'Home' it starts the search over the entire archive, from
'Messages' it only searches the ones visible. At least I think that's
the way it was working.

Re: Yahoo seriously messed up

Stefan Trethan

#9522

On Fri, 9 Apr 2004 19:26:45 EDT, <JanRwl@...> wrote:


If you post something and it doesn't show up within a few minutesTo WHOM???I think that were my words - not sure, so i will answer.

I guess you mean he is on te other side of the world and it does not matter.
what matters is that you can not see wich answers were written between the time of
posting the question and the question arriving you. that leads to people answering
multiple times (which is a waste of time) but also worse to answers with wrong assumptions
that should long have been corrected etc.
If one wants to correct anoter answer or adds details this gets even more compicated
and slow. it is like playing chess over snail mail. i wouldn't have the patience.

didn't you notice that in the last days there was way more chaos than normal?

ST

Re: Yahoo seriously messed up

#9521

On one hand, I'm starting to scare myself at how radical I'msounding.  But
on the other hand...

<Channelling Braveheart:--"FREEEEEEDOOOOOMMMMM!!!!">

Oops.  I seem to have misplaced my blue facepaint.

If anything I have said is flameworthy, flame away.

-DM

----- Original Message ----- Without the blue face paint it's The Patriot; same soundtrack too,
Uhg!, ack!, splurt!, die, die, die.

A delay of a few hours is fine by me. I like reading and replying to
the list on the web. I do not even have an email client on my machine. 

The search function still works fine, I just tried and it did great.
You do have to hit 'Next' to make it through the whole archive. It's
not terrible. Just start your search from 'Home' and not 'Messages'.
From 'Home' it starts the search over the entire archive, from
'Messages' it only searches the ones visible. At least I think that's
the way it was working.

Re: Flyback transformer test

John Johnson

#9519

You really need a glass or plastic tube to put around your ladder.
That way, the hot air from the arc rises, carrying the arc with it.

Regards,
  JJ

Show quoted text

On Friday, Apr 9, 2004, at 07:37 US/Eastern, rsnyder187 wrote:

Steve,

I took apart (sawed and pryed etc) the flyback just to see how is is
constucted.

I purchased another old $2 monitor.  I removed the CRT and made a
Jacobs Ladder.  The idea came from this website


My next step will be to remove the flyback from this old Radioshack
color montior.  It has what I think is a seperate Hv rectifier -
square cube about 1"x1"x1" that is located after the flyback and
before the ctr.

Bob




--- In Electronics_101@..., "Steve" <alienrelics@y...>
wrote:
--- In Electronics_101@..., "rsnyder187"<rsnyder187@y...>
wrote:
Alien Steve

The flyback has a ferrite core going down the middle of thewindings
and extending outside to form a large 0.  This large 0 is madewith a
split which is held together by a large U shaped spring clamp. Isthe
external portion where to wrap these new primary windings around?Yes.

The crack (from falling form the workbench) is the ferrite and isall
the way through.  The large U clamp keeps it still in one piece.Do
do think it would be ruined?Probably fine for your purpose. I would not put it back in a TV or
monitor and expect it to work, but for experimenting with highvoltage
you won't be running it at anywhere near its full power so it will
probably be OK.

Alien Steve

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Yahoo! Groups Links

Re: Yahoo seriously messed up

Matt

#9515

--- In Electronics_101@..., "dangermouse" 
<dangermouse1956@g...> wrote:
Actually, you beat me to the punch of suggesting a web-forum solution such
as VBulletin, which I thought of (typically) AFTER hitting the <send>
button.  I belong to two of those, although NOT in any sort of
administrative capacity.  But both you and ST have good points:  webforums
are everywhere, and NNTP--Usenet--has been around for thousands of years.
Hundreds, anyway.  And it's as simple as a text file.  Why reinvent the
wheel?  Because we've all forgotten how to drive a stick?  (Forgive the bad
analogy!)

If I may be so bold as to be, well, bold <ahem>, perhaps we have all (myself
generously included) grown too accustomed to being patronized by entities
such as Yahoo.  We have an interest in keeping things simple, with an
"automatic transmission," and they have an interest in keeping us captive
audience to their ads.  How convenient.  Riiiight.

Maybe it's time to think differently.  Do any of you guys remember the
original eGroups, just a few years ago, when things really seemed to run
well?  For that matter, (to strain an already overtaxed analogy) did any of
us ever used to tune up our own cars?

On one hand, I'm starting to scare myself at how radical I'm sounding.  But
on the other hand...

<Channelling Braveheart:--"FREEEEEEDOOOOOMMMMM!!!!">

Oops.  I seem to have misplaced my blue facepaint.

If anything I have said is flameworthy, flame away.

-DM

I think I could write a flat threaded forum with the mailing list 
type feature, and make it pretty much the same style as yahoo groups, 
but a different site design of course, and not all the ads.

Matt