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my comments were about power plug costing more (~80+ usd/node) than
X10. TCP/IP isn't lightweight and so could not be done with a cheap
uC. Also powerplug uses a pile of signal processing to get more bits
over the powerline than X10's "600 baud".


--- In Electronics_101@..., "Gary Anderson (G)"
<andersg@t...> wrote:

Hi Richard..

I thought of this but sunlight seems to play a problem. I have a

pair

which I use for the TV's around the house but if direct sunlight

they

seem to not work..

I like the idea of using the POWER plugs. I have seen an intercom
system which works this way and pretty well and simple..If I could
modulate the signal and demodulate on the other end that would

surely

work. Like two modems..

Phil you mention TCP/IP and being expensive. What is expensive??

More

than buying the RX and TX modules mentioned by Stehan??


Thks
Gary

Gary
I was just looking through a book that had video projects, and

one

was

an IR video rx/tx setup that claimed about 300 meters range. All

else

being the same, he used two 4"x4" fresnel lenses to collimate the

IR

beam and then to focus it at the rx photo diode. He aligned the

two

systems to make it work, but if you are stationary, it shouldn't

be

an

issue. That could give you an IRDA link. I guess another think

would

be to set up a two node 11b/g network, hooked to 2 sat-TV dishes

to

make

it point to point and give you the extra distance. DON'T FORGET

TO

SECURE/ENCRYPT THE NETWORK!!! Both field expedients, but that's

part

of

the fun!
Richard

Some comments:

(1) A Sallen-Key filter is not generally the best filter topology.
Leakage feed through limits its ultimate stop band rejection to
perhaps 60 dB, maximum. For a given application, an MFB filter
provides better stop band rejection - about 80 dB.

(2) Varying only two resistors (one for frequency and the other for
offset) is a very optimal solution already. You may not be able to
do better.

(3) Using FET's is possible, but non-linearities, parameter drift,
lot variations, and support components may make you wish you could
change back to the programmable pots.

Send me your filter requirements - type, adjustment range, etc. and
I will see what I can do for you.

Bruce Carter

Hi All,
I am trying to search for a better way to design a programmable

analog

filter. I implemented a 2nd order Sallen&key filter with DC adjust

a while

back using AD8400 digital potentiometers.
I am looking for ideas to use a FET as a variable resistor.

I am uploading the existing design "Filter with DC adjust.jpg" in

group

files.

Any suggestions or ideas..............


Regards,

Syed Rizvi

hi
try looking at the rfpics. only problem with them is the receiver side is surfacemount, other wize it is a very good thing to use. it works in the range of 400mhz

I am using them for a robot controller.

edd


This email was scanned by ICL's anti-virus solution at

--- In Electronics_101@..., "Don Kinzer"
wrote:
> I have an Intel Flash device that is marked N28F001 that I'd like
to
> be able to program with my home-built Flash burner.? However, I
can't
> seem to find any specifications for it that would tell what the
> programming sequence is.

Finally!? I found some documentation here:

---

: 6MB, m???s protecci???n contra el spam ???gratis!

On Wednesday 14 April 2004 09:37 am, upand_at_them wrote:

the part number sounds like an EEPROM.
Those aren't the same as flash, are they?

They're not? I thought they were.

Are they? I dunno at this point...

For some reason I'm rather fuzzy about where things went when this stuff came
out. I guess it's connected somewhat to me being cut off for a while from a
lot of the sources of info I used to use...

On Wednesday 14 April 2004 02:09 am, Don Kinzer wrote:

--- In Electronics_101@..., "Don Kinzer" <dkinzer@e...>
wrote:

Finally! I found some documentation here:

Thanks for the link, I've added that to the "pile of stuff" here...

I am a bit fuzzy on some of these parts, I guess.

the part number sounds like an EEPROM.
Those aren't the same as flash, are they?

They're not? I thought they were.

Mike

Hi Sudeep,
Yes U can use AM/FM transmitter-Receiver of same
frequency. If U are interested U can email me on my
email ID seperately. Ill provide consultancy.
I am dip engr. Tell me abt Ur project details.

--- writetosudeep <sudeepnayak@...> wrote: >
Hi All..

I need to Transfer data between two data lines (~5V)
.
Is there any such circuit that I could build, with
both transmitter
and receiver? IF so, any WEB address would be nice.

Sudeep.




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--- In Electronics_101@..., "Don Kinzer" <dkinzer@e...>
wrote:

I have an Intel Flash device that is marked N28F001 that I'd like

to

be able to program with my home-built Flash burner. However, I

can't

seem to find any specifications for it that would tell what the
programming sequence is.

Finally! I found some documentation here:

--- In Electronics_101@..., "Roy J. Tellason"
<rtellason@b...> wrote:

On Tuesday 13 April 2004 11:28 pm, Don Kinzer wrote:

I have an Intel Flash device that is marked N28F001 ...

...the part number sounds like an EEPROM. Those aren't the same
as flash, are they?

The part says Flash right on it. I assumed that that meant it is a
flash device.

By changing the timing (adding delays), I can get different results.
They're not right yet, though.

On Tuesday 13 April 2004 11:28 pm, Don Kinzer wrote:

I have an Intel Flash device that is marked N28F001 that I'd like to
be able to program with my home-built Flash burner. However, I can't
seem to find any specifications for it that would tell what the
programming sequence is. I tried using the same sequence as I do
successfully for the SST 39SF122 but it didn't work. It erased OK
but it doesn't program.

Does anyone have any information on this device?

I'm not as up on that stuff as I'd like to be, but the part number sounds
like an EEPROM. Those aren't the same as flash, are they?

On Tuesday 13 April 2004 08:45 pm, manifold wrote:

--- In Electronics_101@..., "Roy J. Tellason"

<...>

I did forget to add you will need a RC network across the triac to
protect it from possible high voltages.

That network is to prevent the device from triggering when the
voltage across it rises too rapidly, if I'm remembering right.

Yes, a fast dv dt across the anode and cathode terminals will cause a
SRC or TRIAC to trigger without any gate signal applied.

That's the expression I was reaching for and couldn't quite recall, dv/dt!

The voltage does not need to be particularly high so the RC network is not
there to protect against high voltages, it is there to slow things down a
bit.

This meshes with my understanding as well.

No, A DC gate signal will not 'turn on the TRIAC' it will only rectify
the current to the load if the power source is from the AC mains. A
TRIAC is the same as two reverse parallel SCRs. If a DC gate signal is
applied, only one of the 'SCR halves' will ever turn on.

Oh?

A DC signal should work fine for a photo-coupled TRIAC.I have driven
small motors and lights directly from an optocoupled triac using a DC
signal; it worked fine.

Yes, TRIACs almost always fail closed. Most light dimmers that go bad
stop dimming but the light will still go full on as long as the switch
works. Don't forget that relays can also weld their contacts together
and fail short. Look for a more positive way to shut off the circuit
if there is a failure like remove all power, short the motor and blow
the fuse, etc.

Yes, I was thinking that fuses were good to have in there. As well as way
over-spec'ing the triacs, as I sure haven't seen many fail.

I have an Intel Flash device that is marked N28F001 that I'd like to
be able to program with my home-built Flash burner. However, I can't
seem to find any specifications for it that would tell what the
programming sequence is. I tried using the same sequence as I do
successfully for the SST 39SF122 but it didn't work. It erased OK
but it doesn't program.

Does anyone have any information on this device?

Thanks.

--- In Electronics_101@..., "Roy J. Tellason"
<rtellason@b...> wrote:

On Tuesday 13 April 2004 11:30 am, Stefan Trethan wrote:

On Tue, 13 Apr 2004 11:05:53 -0400, Roy J. Tellason

<rtellason@b...> wrote:

On Tuesday 13 April 2004 10:58 am, Stefan Trethan wrote:

I'm not entirely sure if the pulse can be both polarities or

only the

one in which the current should flow, the datasheet can tell i

hope.

(please answer if someone knows).
Tomi Engdahl has told me it can be both polarities, no matter which
polarity the main current has but i am not sure about this.

This is correct. However a triac _will_ have different

sensitivity in

different "quadrants" (the term that the datasheet will used to

refer to

the different combinations of gate polarity and other polarity).

that means if you apply a dc current to the gate (higher than trigger
current in all quadrants)
the triac will be on all the time, throughout the full sine wave?

I would think so, yeah.

in which magnitude should one expect the difference between the

quadrants?

I guess the answer to that one would be on some data sheets. I

don't remember

offhand, just that there were differences.

I did forget to add you will need a RC network across the triac to

protect

it from possible high voltages.

That network is to prevent the device from triggering when the

voltage across

it rises too rapidly, if I'm remembering right.

Yes, a fast dv dt across the anode and cathode terminals will cause a
SRC or TRIAC to trigger without any gate signal applied. The voltage
does not need to be particularly high so the RC network is not there
to protect against high voltages, it is there to slow things down a bit.

No, A DC gate signal will not 'turn on the TRIAC' it will only rectify
the current to the load if the power source is from the AC mains. A
TRIAC is the same as two reverse parallel SCRs. If a DC gate signal is
applied, only one of the 'SCR halves' will ever turn on.

A DC signal should work fine for a photo-coupled TRIAC.I have driven
small motors and lights directly from an optocoupled triac using a DC
signal; it worked fine.

Yes, TRIACs almost always fail closed. Most light dimmers that go bad
stop dimming but the light will still go full on as long as the switch
works. Don't forget that relays can also weld their contacts together
and fail short. Look for a more positive way to shut off the circuit
if there is a failure like remove all power, short the motor and blow
the fuse, etc.

Good luck!

On Tuesday 13 April 2004 11:30 am, Stefan Trethan wrote:

On Tue, 13 Apr 2004 11:05:53 -0400, Roy J. Tellason

<rtellason@...> wrote:

On Tuesday 13 April 2004 10:58 am, Stefan Trethan wrote:

I'm not entirely sure if the pulse can be both polarities or only the
one in which the current should flow, the datasheet can tell i hope.
(please answer if someone knows).
Tomi Engdahl has told me it can be both polarities, no matter which
polarity the main current has but i am not sure about this.

This is correct. However a triac _will_ have different sensitivity in
different "quadrants" (the term that the datasheet will used to refer to
the different combinations of gate polarity and other polarity).

that means if you apply a dc current to the gate (higher than trigger
current in all quadrants)
the triac will be on all the time, throughout the full sine wave?

I would think so, yeah.

in which magnitude should one expect the difference between the quadrants?

I guess the answer to that one would be on some data sheets. I don't remember
offhand, just that there were differences.

I did forget to add you will need a RC network across the triac to protect
it from possible high voltages.

That network is to prevent the device from triggering when the voltage across
it rises too rapidly, if I'm remembering right.

--- In Electronics_101@..., "Mariss Freimanis"
<mariss92705@y...> wrote:

I enthusiasticaly second Dave's recommendation. Advanced Circuits
does all of our boards and I couldn't be happier with them. Their
prices are low, their quality is excellent and they ship on time,
every time.

When they do screw up, (everyone does eventually) they make good on
it and they do it quickly at no charge. They do not argue to say

it's

your fault or some other lame excuse. They have redone 1,000 4-

layer

boards for us in 2 days.

Check out their $33 proto board deal (actually $100 because there

is

a 3 board minimum).

Just a very satisfied customer.

Mariss
Geckodrive Inc.

Yes, but you have the pick-and-place machine to do the assembly.

I can get the boards made, but am looking for someone to assemble the
boards with chips and solder them.

Dave

--- In Electronics_101@..., James Liddle

<jliddle31@y...>

wrote:

Hi Dave -

I have a friend who owns a mid-sized business - he uses and

recommends

Jim

Dave Mucha <dave_mucha@y...> wrote:
Hi all,

I have a small board with a couple 8 pin uSOC chips on it that I

am

starting to sell.

I am looking for an assembly board house that can assemble these

for

me.

The boards are pretty small and the two chips are not too hard as

the

board is single sided.

I have been looking for a board house but cannot sort thru the

huge

quantity of google hits.

Anyway, can anyone offer any ideas ?

Dave





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--- In Electronics_101@..., Stefan Trethan
<stefan_trethan@g...> wrote:

Nearly all triac failures will be shorts.

Doh, oh well. Back to relays for this application. I'll check
epanorama though, good to know these things!

Thanks again.

Why not just use wireless networking modules? Two Radio Control
TX/RX's have got to be a lot more money than just two wireless network
cards.

Plus using RC sets or garage door openers this way is just as illegal
as using a CB radio channel. Most printers require two way communication.

Range should not be a problem, but even if it is, I have a ton of
links in the Links area on 2.4GHz antennas.

Alien Steve

First, we did not lose the search function. I keep seeing this
repeated. You do have to keep hitting "next".

Second, I like having most of the lists I'm on, in one place. I'm on
other lists on other systems, and I rarely go to them -because- they
are elsewhere.

And how will people find it to join?

What about another established list site, like Delphiforums?


Alien Steve