PRC as a amplifier in GPS question.

[Phil Allison]

"Mark van der Eynden" <mvandere@iprimus.com.au> wrote in message
news:48ed3358.0308271435.496a7003@posting.google.com...

The Silicon Chip Editorial for September has some comments about
aus.electronics and aus.hifi that could not be described as 'kind'.

Whilst I agree with much of what Leo has to say I do not agree with
his right to say it (Especially as an editorial in SC).

** Editors have a "divine right" to adopt postures and pontificate -
didn't you know that ;- )

One of THE major rules of Usenet, as I understand it, is "If you don't
contribute, you can't criticise".

** But one can "tut tut" to your their heart's content.

I presume the opposite is also true and this is perhaps why the most
unkind posts here also come from the people who make the most helpful
posts.

** I would say more often the opposite is true.

So Leo, come on down, stop lurking and contribute! And please some
contributions from other SC staff as well, take note from EPE staff
who contribute to their forum.

** Be assured the Angels at SC and Jaycar are *watching* - in case
their interests are ever affected.

And as someone once said 'If we get more quality posters, the noise
makers will fade to insignificance (be it a better SN ratio)'

** Then why ever did you ask for Leo ??




.............. Phil

 

[Dom]

The 2 items have been sold.

Thanks, Dom



Dom <simoco@gmx.net> wrote:

Hi
I have a Motorola Speaker/Mic to suit the MTX8000, MTX838, MT/S2000,
GP900, HT1000, XTS3000 etc.

It is in Mint condition. $60 includes Aust-wide express post.

I also have a Security covert kit terminating with a 3.5mm stereo plug
for use with a speaker/mic or audio adaptor. The kit consists of an
earphone and a PTT switch with a mic in it (For the sleeve).

It is in very good condition. $30 includes Aust-wide express post.

You can have both for $80 including express post (aust-wide).

Thanks, Dom
all prices AU$
simoco@gmx.net

 

[PčéJäy]

"Trevor Matthews" <suetrevm@ozemail.com.au> wrote in message
news:3F4D7B76.FD6F6C8B@ozemail.com.au...

does anyone out there who subscribes to SC have their September copy yet?

I am continually finding that my copy arrives at least >1wk later than
copies in newstands. While people criticise the projects, I usually find
parts of each issue interesting (even if I just cannabilise one part of a
circuit to suit something I'm working on). Although my frustration with
the lateness is increasing.

Am I alone, or is this widespread?

I got mine today at 2pm

Trev

Mark van der Eynden wrote:

The Silicon Chip Editorial for September has some comments about
aus.electronics and aus.hifi that could not be described as 'kind'.

Whilst I agree with much of what Leo has to say I do not agree with
his right to say it (Especially as an editorial in SC).

One of THE major rules of Usenet, as I understand it, is "If you don't
contribute, you can't criticise".

I presume the opposite is also true and this is perhaps why the most
unkind posts here also come from the people who make the most helpful
posts.

So Leo, come on down, stop lurking and contribute! And please some
contributions from other SC staff as well, take note from EPE staff
who contribute to their forum.

And as someone once said 'If we get more quality posters, the noise
makers will fade to insignificance (be it a better SN ratio)'

Cheers,

Mark

P.S. this did not get cross posted to aus.hifi as the news reader I am
using at the moment is not up to it.

 

bemw wrote:

I have hundreds of tubes of ICs in a box, and everytime I need a particular
IC, I have to sort through them all to find the tube I need. Can anyone
suggest a simple storage method for the tubes that will make finding the
right part simpler.

About 10 years ago, I designed and had Gawler Industries make up a cabinet
and drawers for exactly this purpose. It's height matched the height of their
6 drawer rack, the width was a bit over 3 x the width of the racks, and the depth
was about 300mm, as I remember. They may still have the design, if they're still
in business.

--

David

 

[Lizard Blizzard]

Mark Fergerson wrote:

Duane C. Johnson wrote:

snip

I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif


This is a newer version of a ckt you previously posted using LEDs as
PV cells to get the +5V, yes? I saw the older one some time ago and lost
your name and the URL or I'd have asked you sooner; can you please
provide a description of the ckt's operation?

I'm interested because I have a sh*tload of LEDs lying around unused
and would like to fiddle with the ckt because I think it's more amenable
to miniaturization than other (vaguely) similar ckts I've seen, and the
limited lifetine of standard Si PV cells (I want to try a bunch of red
LEDs for the low V supply part instead of a Si PV). BTW, any data on the
lifetime and efficiency of LEDs used in this manner?

In my experience the LEDs can generate only sub-microamp currents.
After all, it takes square inches of solar cell to generate milliamps,
and you have a LED with a chip that's no bigger than a millimeter on a
side.

Mark L. Fergerson

 

[Lizard Blizzard]

William P.N. Smith wrote:

Mark Fergerson <mfergerson1@cox.net> wrote:

Duane C. Johnson wrote:

I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif


can you please provide a description of
the ckt's operation?


Gee, that's easy, and it's not even my circuit:

U1{A,B,C} make up an oscillator, coupled to U1{D,E,F}, which provide a
driver to the two FETs.

Q1 drives a simple step-up through D1 to provide 5V to drive U1, the
two LEDs provide a shunt to keep the voltage from rising too high.

Q2, T1, D3 provide a step-up with a transformer boost to charge the
battery. D2 provides overcharge protection and bootstraps U1.

The two LEDs can apparently also provide some bootstrap via their PV
action.


and the limited lifetine
of standard Si PV cells


Decades aren't enough?

Yeah, I agree. I see no point in messing with .5V single cells. I
bought some SPL-60 solar cells for $3.50 from All Electronics, have the
solderable contacts etc. They're good for 3V at 40 mA. For more info,
see
http://www.allelectronics.com/cgi-bin/category.cgi?category=565&type=store

@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@
@

 

[Lizard Blizzard]

Mark Fergerson wrote:

[snip]

Decades aren't enough?

Nope, I'm thinking about an application similar to Watt Sun's "forever
flashers", but I want to charge a supercap instead of a NiCd, which is
why I mentioned stacked green LEDs.

Next question is how many red LEDs I'll need to equal the Iout of a
small PV cell.

Lessee... A LED chip is about a square mm. The 'small PV cell' is
maybe an inch square, say 25 mm on a side. So it would take about 625
LEDs to give you the same area. And that's assuming the LEDs put out
the same current per square mm as the solar cells, which they don't. So
why don't you try for an even thousand.... )

So now you'll have to sign your name:

> Mark L. "Honey, I just used up all my spare LEDs" Fergerson

 

[Spehro Pefhany]

On Thu, 28 Aug 2003 08:07:38 -0700, the renowned Lizard Blizzard
<NOSPAM@rsccd.org> wrote:

Mark Fergerson wrote:

[snip]

Decades aren't enough?

Nope, I'm thinking about an application similar to Watt Sun's "forever
flashers", but I want to charge a supercap instead of a NiCd, which is
why I mentioned stacked green LEDs.

Next question is how many red LEDs I'll need to equal the Iout of a
small PV cell.

Lessee... A LED chip is about a square mm.

You're being too kind by more than 10:1 there. We use special LED dice
that are larger (and more expensive, and brighter) in some of our
displays so I know the die sizes.

Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Rob Judd]

Mark van der Eynden wrote:

The Silicon Chip Editorial for September has some comments about
aus.electronics and aus.hifi that could not be described as 'kind'.

Whilst I agree with much of what Leo has to say I do not agree with
his right to say it (Especially as an editorial in SC).

One of THE major rules of Usenet, as I understand it, is "If you don't
contribute, you can't criticise".

I presume the opposite is also true and this is perhaps why the most
unkind posts here also come from the people who make the most helpful
posts.

So Leo, come on down, stop lurking and contribute! And please some
contributions from other SC staff as well, take note from EPE staff
who contribute to their forum.

And as someone once said 'If we get more quality posters, the noise
makers will fade to insignificance (be it a better SN ratio)'

Cheers,

Mark

P.S. this did not get cross posted to aus.hifi as the news reader I am
using at the moment is not up to it.

I'm impressed he's even heard of us. When Leo flew me up for an
interview a couple of years ago they didn't even have an internet
connection in the office. Good thing the place had a comprehensive
library otherwise I'm blowed if I know how they would have conducted any
research.

Rob

 

[Mark Fergerson]

Spehro Pefhany wrote:

On Thu, 28 Aug 2003 08:07:38 -0700, the renowned Lizard Blizzard
NOSPAM@rsccd.org> wrote:


Mark Fergerson wrote:

[snip]

Next question is how many red LEDs I'll need to equal the Iout of a
small PV cell.

Lessee... A LED chip is about a square mm.


You're being too kind by more than 10:1 there. We use special LED dice
that are larger (and more expensive, and brighter) in some of our
displays so I know the die sizes.

When I said "a sh*tload" I meant it; I have lots of
assorted display board from dead VCRs and like that, many of
which contain SMT LEDs which I planned to use to approach
the equivalent surface area of a PV. Yeah, I know, lots of
persnickety hand-soldering.

OTOH it doesn't look all that good efficiency-wise. Guess
I'll bite the bullet and go with a Si PV.

Mark L. Fergerson

 

[Mark Fergerson]

Lizard Blizzard wrote:

William P.N. Smith wrote:

Mark Fergerson <mfergerson1@cox.net> wrote:

<bitching about>

the limited lifetine of standard Si PV cells

Decades aren't enough?


Yeah, I agree. I see no point in messing with .5V single cells. I
bought some SPL-60 solar cells for $3.50 from All Electronics, have the
solderable contacts etc. They're good for 3V at 40 mA. For more info,
see
http://www.allelectronics.com/cgi-bin/category.cgi?category=565&type=store

So, how long are they good for?

Mark L. Fergerson

 

[Rod Speed]

eug k <removethis@optushome.com.au> wrote in
message news:bileup$6sj$1@bunyip.cc.uq.edu.au...

#HISH <spamme@will.haha> wrote:

Is there any way to use commercially available
pagers for a private short distance local paging?

Nope, not unless you subscribe to a paging service
which may or may not work in your area etc.

I live in a rural area and the kids tend to wander so when
tea-time comes around and the kids are out of earshot its
a pain in the arse to trek around looking for them.

The simplest approach is invididual cages.

Individual cages so they cant savage each other in a group cage.

I had the idea of using a 'paging' car alarm as a standalone
paging system that is capable of 3+ K's but thought there may
be a cheaper way using outdated commercially available pagers.

It aint gunna be cheap to do the transmitter end, and illegal anyway.

I dont need to send text, just some kind
of tone or signal to say "get your arse home".

One of those remote alarm things might well be viable.
Really depends on how far the kids roam tho.

Anyone here with experience in this area?

can't help you with the pagers, but why not UHF CB?
You'd be able to talk to them as well.

Unlikely to survive for long.

 

[Duane C. Johnson]

Hi Lizard;

Lizard Blizzard <NOSPAM@rsccd.org> wrote:

William P.N. Smith wrote:
Mark Fergerson <mfergerson1@cox.net> wrote:
Duane C. Johnson <redrok@redrok.com> wrote:

I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif

can you please provide a description of
the ckt's operation?

Gee, that's easy, and it's not even my circuit:

U1{A,B,C} make up an oscillator, coupled to U1{D,E,F},
which provide a driver to the two FETs.

Q1 drives a simple step-up through D1 to provide 5V to
drive U1, the two LEDs provide a shunt to keep the voltage
from rising too high.

Q2, T1, D3 provide a step-up with a transformer boost to
charge the battery. D2 provides overcharge protection
and bootstraps U1.

The two LEDs can apparently also provide some bootstrap
via their PV action.

and the limited lifetine
of standard Si PV cells

Decades aren't enough?

Yeah, I agree. I see no point in messing with .5V single
cells. I bought some SPL-60 solar cells for $3.50 from
All Electronics, have the solderable contacts etc.
They're good for 3V at 40 mA. For more info, see
http://www.allelectronics.com/cgi-bin/category.cgi?category=565&type=store

Actually there is a lot of merit to the solar battery
that you found for small applications.
(I say battery because it is composed of a number
of cells strung in series.) I like simplicity.
For very low powered applications this would work well.

However, for more power hungry applications this
small solar battery doesn't make it.:
1. The absolute power is low at 0.12W.
2. The efficiency is pretty low at about 3%.
Or the specific power is about 3W/ft^2.
OK, this just means that I need 5 of these to equal the
efficiency of a quality .5V PV cell at 15% efficiency.
3. The specific cost is about $29/W. And heck it's not
even mounted yet.

I found some 4" round PV cells about a year ago
or about $10, 1.3W, .5V, 2.6A, 15%, 15W/ft^2, @ $8/W.
There are probably better buys out there.

Much better buy if the low voltage can be inverted
to something useful.

The reason for pursuing the inverter technology was to
reduce the size and cost of small PV systems.
It doesn't take a lot to improve on $20/W to $50/W
with a little electronics.

Next step is to concentrate on single cells, maybe
5X to 10X, with a common grounded rear contact.
The idea is to have a power MOSFET and transformer
winding associated with each cell.

Duane

--
Home of the $35 Solar Tracker Receiver
http://www.redrok.com/electron.htm#led3X [*]
Powered by \ \ \ //|
Thermonuclear Solar Energy from the Sun / |
Energy (the SUN) \ \ \ / / |
Red Rock Energy \ \ / / |
Duane C. Johnson Designer \ \ / \ / |
1825 Florence St Heliostat,Control,& Mounts |
White Bear Lake, Minnesota === \ / \ |
USA 55110-3364 === \ |
(651)426-4766 use Courier New Font \ |
redrok@redrok.com (my email: address) \ |
http://www.redrok.com (Web site) ===

 

[Duane C. Johnson]

Hi Andre;

Andre <testing_h@yahoo.com> wrote:

Lizard Blizzard <NOSPAM@rsccd.org> wrote:

In my experience the LEDs can generate only sub-microamp
currents. After all, it takes square inches of solar
cell to generate milliamps, and you have a LED with a
chip that's no bigger than a millimeter on a side.

Interesting - I have heard that the superbright 10mm LEDs
can go up to a milliamp.

The green 10mm Lumex LEDs I use can generate up to
200uA or so if I carefully aim at the sun.

Seems that the best results can be had from infra-red LEDs
(lower barrier voltage, so higher output under load).

Not exactly. Yes the lower band gap voltage can have
higher currents because there are more suitably energetic
photons to get lots of electrons. That's the good part.

That's also the bad part. Since the voltage is low the
trade off is lower power.

I think the best single band gap color is in the green
range. This is because the sun is brightest in the green
and the voltage is fairly high.

This is all good for light sensors as the voltage is
about 1.7V per cell.

Cost is another thing. Gallium Indium Phosphide is
very expensive. To expensive for PV panels.
Nice for generating medium cost light as the amount
of material is small.

-A

Duane

--
Home of the $35 Solar Tracker Receiver
http://www.redrok.com/electron.htm#led3X [*]
Powered by \ \ \ //|
Thermonuclear Solar Energy from the Sun / |
Energy (the SUN) \ \ \ / / |
Red Rock Energy \ \ / / |
Duane C. Johnson Designer \ \ / \ / |
1825 Florence St Heliostat,Control,& Mounts |
White Bear Lake, Minnesota === \ / \ |
USA 55110-3364 === \ |
(651)426-4766 use Courier New Font \ |
redrok@redrok.com (my email: address) \ |
http://www.redrok.com (Web site) ===

 

[Duane C. Johnson]

Hi René;

René <rjz@xs4all.nl> wrote:

"Duane C. Johnson" <redrok@redrok.com> wrote:
Anyway, I have made an inverter that works on single
PV cells. See:
http://www.redrok.com/images/pvcellinv01.gif

Just curious: (for my education)

How does C5 (150 pF) carry enough signal to the driver
gates while R3 pulls the voltage towards Vcc and the
much larger C6 (100nF) loads C5 into a virtual
AC short (C1)?

I don't know. Its been about a year since I worked on
it and reused the plug board. Possibly I made a mistake
on the value. Trust me, it did work though.
Maybe C6 was 100pF.

C6 helped to hold off driving the BS107 when voltage was
low. At very low voltage the oscillator out does not
swing from rail to rail as it does at higher voltages.
C6 and R3 bias the input high.

OK here is the tricky part. There is an unseen protection
diode on CMOS inputs to VCC. Depending on how much voltage
swing the output from the oscillator has the average
voltage gets lower. The protection diode clamps the
oscillator swing on the high side bringing the low
swing low enough to switch the gate.

The result is very low current draw from VCC until the
things can get started.

There isn't any regulation in this circuit.
The 2.2M resisters holds the fet driver input high
when starting. This allows the 2 LEDs to get VCC
up to the point the oscillator will start. At this point
the small fet can just start to invert the .5V PV power
to raise VCC.

Once VCC gets higher the oscillator drives harder
bringing the power MOSFET into the picture.

BTW, don't substitute other CMOS gates for the CD4069.
The CD4069 is an un-buffered gate.

What stops the oscillation if there is no light?

- René

Duane

--
Home of the $35 Solar Tracker Receiver
http://www.redrok.com/electron.htm#led3X [*]
Powered by \ \ \ //|
Thermonuclear Solar Energy from the Sun / |
Energy (the SUN) \ \ \ / / |
Red Rock Energy \ \ / / |
Duane C. Johnson Designer \ \ / \ / |
1825 Florence St Heliostat,Control,& Mounts |
White Bear Lake, Minnesota === \ / \ |
USA 55110-3364 === \ |
(651)426-4766 use Courier New Font \ |
redrok@redrok.com (my email: address) \ |
http://www.redrok.com (Web site) ===

 

[Rob Judd]

Rob Judd wrote:

Mark van der Eynden wrote:

The Silicon Chip Editorial for September has some comments about
aus.electronics and aus.hifi that could not be described as 'kind'.

Whilst I agree with much of what Leo has to say I do not agree with
his right to say it (Especially as an editorial in SC).

One of THE major rules of Usenet, as I understand it, is "If you don't
contribute, you can't criticise".

I presume the opposite is also true and this is perhaps why the most
unkind posts here also come from the people who make the most helpful
posts.

So Leo, come on down, stop lurking and contribute! And please some
contributions from other SC staff as well, take note from EPE staff
who contribute to their forum.

And as someone once said 'If we get more quality posters, the noise
makers will fade to insignificance (be it a better SN ratio)'

Cheers,

Mark

P.S. this did not get cross posted to aus.hifi as the news reader I am
using at the moment is not up to it.

I'm impressed he's even heard of us. When Leo flew me up for an
interview a couple of years ago they didn't even have an internet
connection in the office. Good thing the place had a comprehensive
library otherwise I'm blowed if I know how they would have conducted any
research.

It has been pointed out to me that in fact this interview took place
more than "a couple of years ago" and in fact on checking my old emails,
the correct date was probably sometime in mid-1999. Strange, I thought
it was after I came back from working in Belgium, so I must be getting
forgetful. Time does indeed get by when one is having fun.

At the time I was told that the office didn't have a web connection, but
an advertised email address has been available at SC since 1998.

At least I know who the lurker is now.

Rob

 

[Jon]

MSI have a board for less than $120 with network 5.1 audio sd ram/DDR mem.
Video card built in and upgrading is no pain. They make good board too. Asus
my first choice, MSI second or Gigabyte third.
"Noah" <noah@susie.linux.au> wrote in message
newsan.2003.08.22.13.58.15.778333@susie.linux.au...

On Fri, 22 Aug 2003 12:00:04 +1000, Mike Harding wrote:

Going to buy a new motherboard and CPU to upgrade my PC
on Sunday from a swap meet. Can anyone advise what are the
current buzz words to look out for in the motherboard world.
ie. what should I buy in the 1.5GHz(ish) area?

Thanks in advance
Mike Harding

An Athlon 1800+ will compare to the Intels 1.8Ghz and it runs at 1.53Ghz.
You should be able to pick one up for around $100.
As for the motherboard. An Asus A7V8X or something is reasonably priced
or a Gigabyte 7VA is also a good choice at around $100. If I was buying a
board, I'd get a Gigabyte 7VA.

--

Noah

 

[The real Andy]

"Rod Speed" <rod_speed@yahoo.com> wrote in message
news:bilhpu$atpbd$1@ID-69072.news.uni-berlin.de...

eug k <removethis@optushome.com.au> wrote in
message news:bileup$6sj$1@bunyip.cc.uq.edu.au...
#HISH <spamme@will.haha> wrote:

Is there any way to use commercially available
pagers for a private short distance local paging?

Nope, not unless you subscribe to a paging service
which may or may not work in your area etc.

Once again speed, you are wrong. Once again, we can forgive you for your
incompetence.

It is possible, maybe not that cheap unless you are willing to construct the
encoder and pager programmer yourself. Visit Commtech wireless website for
details on non-commercial paging systems using commercially available
pagers.

 

[Tony Pearce]

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3f4ec508$0$28121$afc38c87@news.optusnet.com.au...

All his posts are *both* unhelpful and pig ignorant.

Nobody holds a candle to you in that area Phil.

TonyP.

 

[Watson A.Name - 'Watt Sun]

In article <3F4E3B34.8010603@cox.net>, mfergerson1@cox.net
mentioned...

Lizard Blizzard wrote:
William P.N. Smith wrote:

Mark Fergerson <mfergerson1@cox.net> wrote:

bitching about

the limited lifetine of standard Si PV cells

Decades aren't enough?


Yeah, I agree. I see no point in messing with .5V single cells. I
bought some SPL-60 solar cells for $3.50 from All Electronics, have the
solderable contacts etc. They're good for 3V at 40 mA. For more info,
see
http://www.allelectronics.com/cgi-bin/category.cgi?category=565&type=store

So, how long are they good for?

We had a discussion on these recently here. These are coated with
epoxy, and someone said that they fail if you coat the PV cells with
epoxy because of the diff in thermal expansion, I believe. But they
said they came out of some equipment so I would think that they would
not have a problem for years if the mfgr wanted to stay in business.

Mark L. Fergerson

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@