PRC as a amplifier in GPS question.

[Phil Allison]

"Adam the ASD Fucked Ass "

OK, well, its good to see that my GENUINE question

** It was a stinking TROLL


- you vile PILE of SHIT !!!





........ Phil

 

[Terryc]

David L. Jones wrote:

Don't buy a house under or near big power lines.
Regardless of whether or not there is any real health risk, your resale
value will SUCK.

How are those houses for "free" electricity?

 

[Phil Allison]

<ralphy@thefreesite.com> wrote in message
news:1165302983.873421.119620@n67g2000cwd.googlegroups.com...


** Dangerous groper alert !

Here in the USA, about half of the power cords on household things have
3 prongs, and the others have 2 prongs.

** Wot - no single prong ?

I was looking for some New Zealand / Austrailian power cords for
something I am building. Seems like 99% of the sites selling cords for
that area have only 3 prongers. Is 3-prong the standard for NZ & Aus
plugs?

** No.

Do all electrical appliances there have an earthground?

** All the ones that need to be earthed for safety are.

The rest can have two pin plugs or 3 pin with no connection to the earth
pin.




....... Phil

 

[Kevin Martin]

ralphy@thefreesite.com wrote:

Here in the USA, about half of the power cords on household things have
3 prongs, and the others have 2 prongs.

I was looking for some New Zealand / Austrailian power cords for
something I am building. Seems like 99% of the sites selling cords for
that area have only 3 prongers. Is 3-prong the standard for NZ & Aus
plugs? Do all electrical appliances there have an earthground?

Try http://www.accesscomms.com.au/catalogcurrent/powercord.pdf

For various power cords etc. You do realise we use 240 Volt at 50 Hz
here? Not trying to be clever, but many Americans do not know this.

--
Regards

Kevin Martin

To reply - delete what is "not required" (Abbrev) from my address.

 

Kevin - Thanks for the catalog page.

Yes, I do know about 240V/50Hz difference, but I appreciate your "just
in case" reminder.

I was further thrown by finding an "Austrailian version" knock-off from
a competitor that has a 3-prong plug. (The original USA version they
copied is not grounded.) When I opened it up, the ground wire was cut
off and went nowhere.

// Ralph

Kevin Martin wrote:
<snip> You do realise we use 240 Volt at 50 Hz
> here? Not trying to be clever, but many Americans do not know this.

 

[Phil Allison]

<ralphy@thefreesite.com>.

Yes, I do know about 240V/50Hz difference, but I appreciate your "just
in case" reminder.

** Here is another reminder - DO NOT TOP POST !!!

I was further thrown by finding an "Austrailian version" knock-off from
a competitor that has a 3-prong plug. (The original USA version they
copied is not grounded.) When I opened it up, the ground wire was cut
off and went nowhere.

** It is common to see 3 pin plugs on items that have only two core AC
leads here in Australia.

Firstly and unlike in the US, an Aussie AC supply plug has to be finger
touch safe when partially installed in the outlet.

Secondly, AC supply plugs are more stable when all 3 pins are inserted -
this is particularly true with plug packs ( or wall warts as you Yanks like
to call them).




....... Phil

 

[gcd]

"Geoff C" <notinterestedin@spam.com> wrote in message
news:Xns98917293ACC7Dtestnospamcom@61.8.0.29...

I have recently had a lot of troubles with 2 PCB assy's which had been
working in products for 10 years or more, but about a year ago started
having problems. The symptom appeared to be leakage in the preamp, as
these
boards have high gain and also modulated input signals of a few dozen Hz.
The problems began when we started using different suppliers, such as a
popular low-cost one in Queensland. I could not pin down a correlation
with
a particular supplier, but all the bad boards used Chinese blanks.
However,
we had also used Chinese boards for some years without problems. That is
what made it hard to simply blame chinese suppliers.

Circumstantial evidence points to US origin FR4 material being much better
than the Chinese. Perhaps Chinese makers were importing US FR4 for some
time but now make their own, but that is conjecture. When we switched to a
ceramic fibreglass composite by a particular maker, the problem
disappeared. Also, as a test, we tried some PCB's from a large reputable
(but pricey) Melbourne PCB maker. They were good too, but if Chinese FR4
is
a problem and they start to use it, then we would still have a problem.

I can't say what the nature of leakage is, but the ceramic PCB's do work,
with a few $ extra per board. I will say that we have about 150 other
board
types with no problems with Chinese suppliers, but they are not so
sensitive to leakage or dielectric variation.

BTW, we tried baking, guard rings etc.

Hi ,
are you sure you should be pointing to the PCB material?

Did you analyse the nature of the failures being observed and try to
determine the root cause? Sounds perhaps that the root cause was not
determined.

Could it be a variation in component tolerances which was not accounted for
in the circuit design? Perhaps a pole or zero moving, bias changes, etc as a
result? Or perhaps components out of tolerance and no inwards goods
inspection?

Were all the test articles made from the same batch code components as the
problem units?

Were some of the components lead free and the problem a result of whiskers?,
not all manufacturers can guarantee you don't have lead free parts (yet).

In your last comment you indicate that you know the circuit is sensitive to
dielectric variation, isn't that saying you've not designed a robust cct or
have not defined the minimum requirements of the substrate to be used?

If it is the material then that is easy fixed, specify on your purchase
orders the material to be used, or supply it FIA.


Greg
(deja vu or have i actually read this or a very similar post in the recent
past?)

 

[jasen]

On 2006-12-05, ralphy@thefreesite.com <ralphy@thefreesite.com> wrote:

Kevin - Thanks for the catalog page.

Yes, I do know about 240V/50Hz difference, but I appreciate your "just
in case" reminder.

I was further thrown by finding an "Austrailian version" knock-off from
a competitor that has a 3-prong plug. (The original USA version they
copied is not grounded.) When I opened it up, the ground wire was cut
off and went nowhere.

posslbly the manufacturer got a good deal on grounded power leads, or was
over stocked.

I've also seen three pin-plugs on two-counductor leads (Makita does this)

It helps keep the plug and the extension lead together.


--

Bye.
Jasen

 

[Geoff]

Mr.T wrote:

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:4tmk5kF13llp2U1@mid.individual.net...
Secondly, AC supply plugs are more stable when all 3 pins are
inserted - this is particularly true with plug packs ( or wall
warts as you Yanks like to call them).

Which is true, but funny considering how many plug packs have only 2
pins. (lots of mine are)
With a large amount of mains equipment using IEC leads though, you
don't see many with 2 pin plugs, even if the ground is not connected.
There are exceptions in both cases of course.

The danger is when non-double-insulated appliances get used with a
2-conductor power lead on the strength of there being 3 pins.

Not that 'double-insulated' means much any more anyway ....

geoff

 

[Geoff C]

"gcd" <gcd.deletemelbnospam@melbnospam.iimetro.com.au> wrote in
news:12ncqjiep131166@corp.supernews.com:

"Geoff C" <notinterestedin@spam.com> wrote in message
news:Xns98917293ACC7Dtestnospamcom@61.8.0.29...
I have recently had a lot of troubles with 2 PCB assy's which had been
working in products for 10 years or more, but about a year ago
started having problems. The symptom appeared to be leakage in the
preamp, as these
boards have high gain and also modulated input signals of a few dozen
Hz. The problems began when we started using different suppliers,
such as a popular low-cost one in Queensland. I could not pin down a
correlation with
a particular supplier, but all the bad boards used Chinese blanks.
However,
we had also used Chinese boards for some years without problems. That
is what made it hard to simply blame chinese suppliers.

Circumstantial evidence points to US origin FR4 material being much
better than the Chinese. Perhaps Chinese makers were importing US FR4
for some time but now make their own, but that is conjecture. When we
switched to a ceramic fibreglass composite by a particular maker, the
problem disappeared. Also, as a test, we tried some PCB's from a
large reputable (but pricey) Melbourne PCB maker. They were good too,
but if Chinese FR4 is
a problem and they start to use it, then we would still have a
problem.

I can't say what the nature of leakage is, but the ceramic PCB's do
work, with a few $ extra per board. I will say that we have about 150
other board
types with no problems with Chinese suppliers, but they are not so
sensitive to leakage or dielectric variation.

BTW, we tried baking, guard rings etc.

Hi ,
are you sure you should be pointing to the PCB material?

Yep.

Did you analyse the nature of the failures being observed and try to
determine the root cause? Sounds perhaps that the root cause was not
determined.

Yes, heaps of analysis. The one thing that always worked was wiring the
components connected to the opamp input node in the air without touching
the PCB.

Could it be a variation in component tolerances which was not
accounted for in the circuit design? Perhaps a pole or zero moving,
bias changes, etc as a result? Or perhaps components out of tolerance
and no inwards goods inspection?

Circuit is tolerant of component cganges as the gain is servoed.

Were all the test articles made from the same batch code components as
the problem units?

Not sure, the bare boards were in stock for some time. Incoming QC is
minimal. You know, costs and all that.

Were some of the components lead free and the problem a result of
whiskers?, not all manufacturers can guarantee you don't have lead
free parts (yet).

Whiskers would create larger currents than the few nA I've observed.

In your last comment you indicate that you know the circuit is
sensitive to dielectric variation, isn't that saying you've not
designed a robust cct or have not defined the minimum requirements of
the substrate to be used?

Well, I commented on dielectric constant but I don't really think it's an
issue, just something that a lot of people here suggest since it is more
of a problem on RF baords when trying to control stripline impedances
etc. It's true that if you take the worst case for FR4 into account, the
circuit could conceivably not work. FR4 specs are really not that great
but the typical performance is much better. That is a correct assertion
you've made. However, when the cct was first used, and for about 10 years
since, it has worked fine. Under these conditions, it would be not
desirable to use lower leakage PCB's since it FR4 is cheap.

If it is the material then that is easy fixed, specify on your
purchase orders the material to be used, or supply it FIA.

That is the solution proposed at present.

Greg
(deja vu or have i actually read this or a very similar post in the
recent past?)

I mentioned this some months ago before the buildup of circumstantial
evidence pointing to the bare boards.

 

[Phil Allison]

"Geoff" <geoff@nospam-paf.co.nz>

The danger is when non-double-insulated appliances get used with a
2-conductor power lead on the strength of there being 3 pins.

** How can this happen ?

The leads are made to be physically incompatible.

Not that 'double-insulated' means much any more anyway ....

** As you have the slightest clue about the topic.



....... Phil

 

[Geoff]

Phil Allison wrote:

"Geoff" <geoff@nospam-paf.co.nz


The danger is when non-double-insulated appliances get used with a
2-conductor power lead on the strength of there being 3 pins.


** How can this happen ?

The leads are made to be physically incompatible.

Are we not talking about the power PLUG end here. And a 3-pin moulded plug
with a 2 conductor cable, and a standard IEC 3-hole female socket on the
equipment end . You've never seem one ?

Not that 'double-insulated' means much any more anyway ....


** As you have the slightest clue about the topic.

I do , actually. I have the misfortune to ork on such gear every day. You
find unearthed equipment with bare conductive components at mains potential
centimetres away from a relatively flimsy metal chassis satisfactory ?
That's what most consumer gear is like these days.

geoff

 

[Geoff]

Phil Allison wrote:

"Geoff" <geoff@nospam-paf.co.nz


The danger is when non-double-insulated appliances get used with a
2-conductor power lead on the strength of there being 3 pins.


** How can this happen ?

The leads are made to be physically incompatible.

Are we not talking about the power PLUG end here. And a 3-pin
moulded plug with a 2 conductor cable, and a standard IEC 3-hole female
socket on the equipment end . You've never seem one ?


** Such leads are NOT on sale anywhere.

So you've seen everywhere.

All IEC leads are " prescribed items " and must be type approved.

Should be.

You are an ASS.

And you are an ARSE.

I do , actually. I have the misfortune to work on such gear every
day. You find unearthed equipment with bare conductive components at
mains potential centimetres away from a relatively flimsy metal
chassis satisfactory ?


** If you have a point to make about Class 2 safety, then make it.

Cleary you DON'T .

Dont call me cleary.

If you don't find the above to be a point, then that's your problem. My
understanding of Class 2 safety of devices is that there should be two
insulating layers on all parts of the circuit at mains potential and
external metalic parts, and between HV and LV sides of a cct. The devices I
describe fail that miserably, and probably only exist through creative
interpretation of the wording of whatever legislation.

Go sit on a DVD player....

geoff
..

 

[Geoff C]

"Alf Katz" <alfkatz@iremove.the.bloody.obvious.ieee.org> wrote in
news:45780960$0$19406$afc38c87@news.optusnet.com.au:

Hey Geoff,
Haven't had any problems ourselves, lots of boards from China,
but
nothing nanoampish.
Have you megged out the bare boards at all?
Other possibilities besides the FR4 material, if you haven't
already
considered them could be:
Solder resist (if any).
Residue from whatever is used to adhere the Cu to the board.
Residue from etchant and/or whatever is used to clean after
etching
(possibly under the solder resist - if any).
Moisture trapped under the solder resist.

Most of these could be eliminated with careful use of a dremel
between
tracks.

Cheers,
Alf

Hi Alf,

yep, megged boards with Keithley electrometer but measured >200 gigohm.
Have considered all of above. Moisture under the resist or some other leaky
substance is possible, but we can't control that. Baking overnight at 60
deg had no measurable effect. We need something manufacturable that
requires no intervention.

The boards that work use Rogers 4003 material, and this stuff is not too
bad in cost, about $13 for DS PT and 70x80mm.

 

[Bob Parker]

On 25/11/2006 01:00 rowan194 wrote:

Bob Parker wrote:
I can tell you for sure that Energizer 2.5AH AA NiMH cells rapidly
go weaker even if you don't use them. Their rate of self discharge is
amazingly high compared to others I've used, especially in this warmer
weather.

Good, it's nice to know I'm not going crazy. I use those for my camera
flash unit, and if I charge them fully then leave them for a week they
are virtually useless...

We aren't alone in having Energizer 2.5AH NiMH cells (supposedly
made by Sanyo) self discharging at an absurd rate. Check out a
discussion on the subject at:

http://www.stevesforums.com/forums/view_topic.php?id=92856&forum_id=51&page=2

Quote from preceding: "Conclusion: Self discharge of these
Energizers is in the order of 25% per day...totally useless. Could be a
bad batch, but once bitten twice shy.".

I entirely agree.


Bob

 

[Poxy]

"Bob Parker" <bobp.deletethis@bluebottle.com> wrote in message
news:45790888$0$855$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

On 25/11/2006 01:00 rowan194 wrote:
Bob Parker wrote:
I can tell you for sure that Energizer 2.5AH AA NiMH cells rapidly
go weaker even if you don't use them. Their rate of self discharge is
amazingly high compared to others I've used, especially in this warmer
weather.

Good, it's nice to know I'm not going crazy. I use those for my camera
flash unit, and if I charge them fully then leave them for a week they
are virtually useless...


We aren't alone in having Energizer 2.5AH NiMH cells (supposedly
made by Sanyo) self discharging at an absurd rate. Check out a
discussion on the subject at:


http://www.stevesforums.com/forums/view_topic.php?id=92856&forum_id=51&page=2

Quote from preceding: "Conclusion: Self discharge of these
Energizers is in the order of 25% per day...totally useless. Could be a
bad batch, but once bitten twice shy.".

I've been using 2 sets of them in a large Metz flash unit and they seem to
have plenty of charge, even after sitting around for a month, but it's hard
to judge it gets used at widely different power settings.

If I get a chance I'll do a discharge cycle and see how much power they
deliver.

 

[Alf Katz]

"Geoff C" <notinterestedin@spam.com> wroteWe need something manufacturable
that

requires no intervention.

LOL. The dremel suggestion was intended to eliminate surface effects as a

culprit on known bad board, not as a manufacturing technique. At least that
will confirm the material is the cause.

Anyhow, good luck with it. Sounds like at those sort of current levels, any
excuse to use a better material is a good one.

Cheers,
Alf

 

[Bob Parker]

On 8/12/2006 21:09 Poxy wrote:

I've been using 2 sets of them in a large Metz flash unit and they seem to
have plenty of charge, even after sitting around for a month, but it's hard
to judge it gets used at widely different power settings.

If I get a chance I'll do a discharge cycle and see how much power they
deliver.

The ones I'm having trouble with are 15 months old and were OK until
a few months ago. I've got a few other sets of them I bought 12 months
and less ago, and they're still holding charge for weeks.
It could be that these bad ones were from a defective batch.

 

[The Real Andy]

On Sat, 16 Dec 2006 07:36:32 +1100, Ray <zathrasAT@netspaceDOTnet.au>
wrote:

In article <pc05o2p1qvnpq0kehmp0phfbimqaa2bkjt@4ax.com>,
will_get_back_to_you_on_This@b.c says...
On Fri, 15 Dec 2006 17:24:50 +1100, Clifford Heath
no@spam.please.net> wrote:

Aldo wrote:
The kit uses a USB to SERIAL module from Elexol.

Oh, cool, even easier. Just need an RS232 T circuit that
feeds each end's transmissions into separate RS232 input
lines (e.g. two wired RS232 ports), and a simple program to
log the RS232 traffic.

I don't have one of the ECG units, as you can tell, but it
doesn't seem like it'd be hard to work out .

I just did a similar job. Why wont SC release the source code?


Because they are not really interested in educating their readers, but
more lining the pockets of their kit supplier mates.

The projects are trivial toys but the source code is treated like the be
all and end all of some magnificent highly engineered device.

Oh for the good ol days of the ETI 660 and Dream computers when these
magazine types were overflowing with source code.

I sent an unacknowledged letter to Leo Simpson many years ago bemoaning
the "security" device embedded into one of their $10 projects, a
temperature sensor from memory. For Christs sake, a toy but you were
expected to pay royalties to some author for some software that was
probably lifted from the application notes.

Ray

I just installed the app, no wonder they dont release source code.
Once can usually judge the quality of the code behind the application
simply by looking at the design itself. The app is absoloute rubbish.
They couldn't even change the installer directory from the default
"Project 1" name. The icon is the default MS VB icon..

Looking at the native code looks like the had the brains to change the
naming of the objects to something usefull though. The application is
quite small, so it should be easy to reverse..

 

[kreed]

On Dec 25, 1:53 pm, "Art M - Artfromny" <artga...@nycap.rr.com> wrote:

Too bad I didnt know you when I got in a mess of IBM reel-reel drives -
refrigerator sized - went with whatever was the commercial version of the
7090 (7080?)
Next time I get a few pallets of vintage mainframe stuff in I will spam your
newsgroup and if you pay shipping you can have it all - cheaper for me than
trashing it.
Then again if youre talking Tandy and Commodore and Apple you probably arent
into the mainframe stuff . . .

Truce? You give up jumping on my posts (remember the First Amendment) and I
will stop jumping on your answers.


The "first amendment" isn't worth shit in Australia. (appears worthless

in USA as well, with things like political correctness being standard
practice there)

For that matter Civil rights - especially freedom of speech, and are
just "optional" in this country and routinely trashed by governments.