PRC as a amplifier in GPS question.

Jan,

I can give you a little help along your way, but since you've already
formulated an answer then my explanation can help you validate your
work.

Expressing sinusoidal signals (such as AC RMS) with the same frequency
(in this case 50Hz) as phasors is useful for consolidating by addition
the signals into a signal formula. The key to phasors is that this can
be done when the frequency is the same, but the amplitudes and phases
differ. For example,

N
Sum of A(k) cos(W(0) * t + Phi(k)) = A cos(W * t + Phi)
k=1

Note that on the left hand of the equation, I have written in ASCII
text as follows:

"W(0)" is short hand for writing W subscript 0 and represents the
radian measure of angle,
"Phi(k)" is short for Phi subscript k,
"t" is used as the classic symbol representing time.

This equation states that the sum of N cosine signals of differing
amplitudes and phase shifts, but with the same frequency, can always be
reduced to a single cosine signal of the same frequency. [Excerpted
from text "DSP First, A multimedia approach", by McClellan, et al. pp
31]. We know that this is only one half of the fun. Euler provided us
with complete fun by showing us that we could express cosine signals as
the real part of e^(W*t + Phi) * j. His brilliance helps us in one way
because it saves us from having to write annoying trigonometric
identities all over the place, and reduces the math to addition in the
exponents. Thus,

e^(Omega * j) = cos(Omega) + j * sin (Omega)

Real{ e^(Omega * j) } = cos(Omega)
Imaginary{ e^(Omega * j) } = sin(Omega)

Notes:

Omega is the English literal translation of the Greek symbol O,
j represents the imaginary symbol representing square root of -1.

Hence,

N
Sum of A(k) cos(W(0) * t + Phi(k))
k=1
= Sum of A(k) Re{ e^(W(0) * t + Phi(k)) * j }
= Sum of A(k) Re{ e^(W(0) * t) * j + e^(Phi(k)) * j }
= Re { e^(W(0) * t) * j } * Sum of A(k) * Re { e^(Phi(k)) * j }

So much for phasors. From your problem statement we have,

W(0) = 50 Hz
V = 240 Vrms

We know that, "Peak Voltage: Peak voltage tells you how far the voltage
swings, either positive or negative, from the point of reference... The
RMS voltage of a pure‡ sine wave is approximately .707*peak voltage."
[http://www.bcae1.com/voltages.htm]


V = I*R [Ohms law]

Thus,

I = 240 Vrms/ 1 Ohm.
= 240rms cos(2*pi*50*t + Phi)
= 240/0.707 Peak Current * cos(2*pi*50*t + Phi)

a) Forty 50 watts incandescent lamps with unity power factor

Power = Watts = V * I

40 * 50 W = 240/0.707 Peak Voltage * cos(2*pi*50*t + 0) * I,
I = (40 * 50 W) / (240 / 0.707) Peak Current * cos(2*pi*50*t + 0)
= (40 * 50 W) / (240 / 0.707) * Re { e^(2*pi*50*t)*j }

b) Thirty-five 40 watts fluorescent lamps with a lagging power factor
of 0.9

35 * 40 W = 240/0.707 Peak Voltage * cos(2*pi*50*t + 2*pi*0.9) * I
I = (35 * 40 W) / (240 / 0.707) Peak Current * cos(2*pi*50*t +
2*pi*0.9)
= (35 * 40 W) / (240 / 0.707) Peak Current * Re { e^(2*pi*50*t +
2*pi*0.9)*j }
= (35 * 40 W) / (240 / 0.707) Peak Current * Re { e^(2*pi*50*t)*j *
e^(2*pi*0.9)*j }

c) One 2400 watts air conditioning system with a lagging power factor
of
0.65.

1 * 2400 W = 240/0.707 Peak Voltage * cos(2*pi*50*t + 2*pi*0.65) * I
I = (1 * 2400 W) / (240 / 0.707) Peak Current * cos(2*pi*50*t +
2*pi*0.65)
= ...

Etcetera, etcetera.... Now see if you can do the rest.
You're Welcome,
-Beagle

 

[Gordon W]

I wrote on the 20may05

I need help with fault finding a car alarm key fob transmitter and its
receiver.
For some time the operating range has been decreasing and my fix was to
adjust the tuning capacitor in the Tx.
At short range I can see the code being received on a CRO and the voltages
around both ccts seem ok using a DMM.
Question 1. How do I determine which cct is at fault ?

Since then, with some help, I put more distance between the Tx and Rx and
found one of the amplifier stages of the Rx (a 741 opamp) not pulling its
weight. Replacement, fixed.

I've learned my tuning of the Tx was only fine tuning, and I needed to
increase the distance between the Tx and Rx until the fault became obvious.

Hope this helps someone in the future and thanks again everyone for your
help.

Gordon

ps: now WE'RE happy SHE'S got her 'beeper' back.

 

[Jim]

"Gordon W" <welch@hypermax.net.au> wrote in message
news:1117064958.569888@nntp0.iseek.com.au...

I wrote on the 20may05

I need help with fault finding a car alarm key fob transmitter and its
receiver.
For some time the operating range has been decreasing and my fix was to
adjust the tuning capacitor in the Tx.
At short range I can see the code being received on a CRO and the voltages
around both ccts seem ok using a DMM.
Question 1. How do I determine which cct is at fault ?

Since then, with some help, I put more distance between the Tx and Rx and
found one of the amplifier stages of the Rx (a 741 opamp) not pulling its
weight. Replacement, fixed.

I've learned my tuning of the Tx was only fine tuning, and I needed to
increase the distance between the Tx and Rx until the fault became
obvious.

Hope this helps someone in the future and thanks again everyone for your
help.

Gordon

ps: now WE'RE happy SHE'S got her 'beeper' back.

Well done. How did I know that there was a SWMBO in there somewhere? By the

desperate tone of the post ))

Cheers
Jim

 

[swanny]

Ed- wrote:

next question:
how can i get the electric meter to turn backwards by using some caps?

You can make it stop simply by turning off the main switch.

 

[b]

Franc Zabkar wrote:

Here are some excerpts from the instruction manual for a Legend LSD2
digital set top box.

snip)

try www.engrish.com !!! some real classics there.

Ben

 

[John_H]

Neo wrote:

<cross post deleted>

I am about to purchase a temperature controlled soldering station.

Seems that the Hakko936 are very well known.

As are Weller.

However, I have been unable to find any feedback on Goot stations.

These are sold in Australia by Jaycar.

Wonder what they'll be selling next week!

https://secure2.vivid-design.com.au...x=&SUBCATID=627

Link doesn't work, but last time I looked they were selling something
called Durateck and Hakko

Anybody tried these?

Most of us wouldn't bother.

How do they measure up to Hakko's?

Unless their backup is similar they almost certainly won't.

Hakko and Weller both have good backup with good availability of
spares, which you'll need sooner or later no matter what you buy.

Hakko have variable temperature (which isn't necessarily an advantage)
and a light that goes out when it reaches temperature. Downside is
it's easy to accidentally bump the temperature control, and more
likely to be accidentally left switched on (which you can easily avoid
by having your soldering iron on on the same switch as your work
light).

Weller have a better range of tips, both genuine and aftermarket.
They also have a power on light (which makes it easy to see when it's
switched on), but you've gotta listen for the click (or hold it in
your hand) to know when it reaches temperature.

I've currently got 2 Wellers and a Hakko, with no serious complaints
against either brand, and a very slight preference for Weller (due to
the better range of tips). It might also be worth comparing the
price and availability of SMD removal tips if you have a need for
them.

Avoid wet sponges like the plague and you'll get a lot better run out
of whatever you decide to buy.

--
John H

 

[Phil Allison]

"John_H"
Neo

How do they measure up to Hakko's?

Unless their backup is similar they almost certainly won't.

Hakko and Weller both have good backup with good availability of
spares, which you'll need sooner or later no matter what you buy.

** That is certainly true of the Weller WTCPT mechanically switched
rons - you will need **lots of spares** and often.

Hakko have variable temperature (which isn't necessarily an advantage)

** Huh ?

Continuously variable temp with a knob is not an advantage ??

and a light that goes out when it reaches temperature.

** What a weird way to explain a LED that cycles with the iron's heater.

Downside is
it's easy to accidentally bump the temperature control,

** Huh ??

and more
likely to be accidentally left switched on

** Huh ??????

(which you can easily avoid
by having your soldering iron on on the same switch as your work
light).

** Applies to any iron.

Weller have a better range of tips, both genuine and aftermarket.

** Hakko have a very good range too - yet another non issue.

They also have a power on light (which makes it easy to see when it's
switched on), but you've gotta listen for the click (or hold it in
your hand) to know when it reaches temperature.

** The mechanical switch in the Weller WTCPT is piece of garbage that
constantly fails - and so does that fragile heater unit too.

This is very annoying, time wasting PLUS ***damn*** expensive.

OTOH - Hakko irons seem to go on for ever with no repairs.

Avoid wet sponges like the plague ....

** Please explain ???




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

 

[John_H]

Phil Allison wrote:

"John_H"

Avoid wet sponges like the plague ....


** Please explain ???

A dry tip cleaner, such as Hakko 599B, extends tip life enormously.
Nor have I replaced a heating element since I stopped using wet
sponges -- reduced thermal shock maybe.

FWIW I've _never_ had to replace a thermal switch in my own WT's, the
oldest of which I've been using for over twenty years. I've always
suspected that those who do have problems (and I'm well aware of
plenty that do) destroy the switches by bumping the iron to remove
excess solder.... As used to be common practice in the days before
solder stations.

--
John H

 

[Phil Allison]

"John_H"

Phil Allison wrote:

Avoid wet sponges like the plague ....


** Please explain ???

A dry tip cleaner, such as Hakko 599B, extends tip life enormously.

** Why ? That sounds like pure BS to me.

Nor have I replaced a heating element since I stopped using wet
sponges -- reduced thermal shock maybe.

** Now, that IS pure BS.

FWIW I've _never_ had to replace a thermal switch in my own WT's, the
oldest of which I've been using for over twenty years.

** You oughta donate it to the Smithsonian - put it alongside that 40
watt ES bulb that has been in the same outdoor dunny for 60 years !!!!

I've always
suspected that those who do have problems (and I'm well aware of
plenty that do) destroy the switches by bumping the iron to remove
excess solder....

** Drivel.

As used to be common practice in the days before
solder stations.

** 240 volt irons have much finer wire in the heater than 24 or 48 volt
ones.

The Birkos were long lasters - Adcolas were not, both were way better
than Weller crap.



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

 

[Phil Allison]

"Terry Given" <my_name@ieee.org> wrote in message
news:iN8pe.5672$U4.797746@news.xtra.co.nz...


** Piss OFF - you evil, cross posting Sheep Shagging arsehole !!!





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

 

[Alan Rutlidge]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3gkebgFcvcmiU1@individual.net...

"John_H"
Neo

How do they measure up to Hakko's?

Unless their backup is similar they almost certainly won't.

Hakko and Weller both have good backup with good availability of
spares, which you'll need sooner or later no matter what you buy.


** That is certainly true of the Weller WTCPT mechanically switched
rons - you will need **lots of spares** and often.


Hakko have variable temperature (which isn't necessarily an advantage)


** Huh ?

Continuously variable temp with a knob is not an advantage ??


and a light that goes out when it reaches temperature.


** What a weird way to explain a LED that cycles with the iron's heater.


Downside is
it's easy to accidentally bump the temperature control,


** Huh ??


and more
likely to be accidentally left switched on


** Huh ??????


(which you can easily avoid
by having your soldering iron on on the same switch as your work
light).


** Applies to any iron.


Weller have a better range of tips, both genuine and aftermarket.


** Hakko have a very good range too - yet another non issue.


They also have a power on light (which makes it easy to see when it's
switched on), but you've gotta listen for the click (or hold it in
your hand) to know when it reaches temperature.


** The mechanical switch in the Weller WTCPT is piece of garbage that
constantly fails - and so does that fragile heater unit too.

This is very annoying, time wasting PLUS ***damn*** expensive.

There is nothing funadmentally wrong with the design of the Weller WTCP
series irons.

Most element failures on these irons are due to idiots who seem to think
they have to constantly tap the barrel of the iron to flick excess solder
from the tip, rather than using a dampened sponge to wipe off excess solder
on the tip as recommended by the manufacturer. It's amazing just how long
tools can last when they are used correctly and in accordance with the
maker's instructions.

Admittely having to change tips to change operating temperature is a PITA,
but if you are using the same solder there is no need to. Even with the
electronic temperature controlled irons you still have to change tips to
suit the job you are doing, so no real advantage here.

I still have an old W-TCP-D (more than 30 y.o.) and it's still going strong
on its original element and switch. It isn't on 24/7, but in its earlier
life it sure had its fair share of work where it was used every working day
and left on for up to almost 9 hours at a time. I've also got a later model
Weller (TC-202-D power unit + TCP-1 iron) and likewise have had absolutely
no problem with it either. Even in a training college environment where we
had hundreds of soldering irons, the Weller TCP series were the least
troublesome of the lot. Not bad considering trainee techs are usually the
last to RTFM.

I guess some (like Phil) may have had less than an impressive run with the
Weller TCP series, but I can't say I've experienced the same failures.

Cheers,
Alan

OTOH - Hakko irons seem to go on for ever with no repairs.



Avoid wet sponges like the plague ....


** Please explain ???




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

 

[sommes]

could anyone please kindly explain this for me.
"when the code from the receiver matches with the code from the satellite,
the signal is loud compared to background noise (amplified)"

 

[Phil Allison]

"Alan Rutlidge"
"Arny Krueger"

It takes significant distances for audio electrical signals to
demonstrate things like reflections and standing waves. For most
practical purposes, they never happen because by the time the audio goes
that far in the modern world, its probably already been digitized.


Digitising an audio signal does not eliminate propagation delay if the
signal is transmitted over a long distance. To demonstrate this in
combination with the problem of impedance mismatch - make an international
telephone call to a third world country like India. The echo you hear is
usually 100% attributable to poor impedance mismatch at the other end of
the line. And guess what? It's all occurring at audio frequencies (300Hz
to 3400Hz).

** ROTFLMAO !!!!

Does this Rutmaniac, fucking idiot actually teach such monumental
**BULLSHIT** to IT industry trainees ????

Only the dullest teenagers would fall for such utter shite !!!


FYI

Telecommunications data is digital ( not audio) and travels to places like
India via optical fibre and geo-stationery satellites - not thousands of
miles of bloody co-ax !!

What a complete MORON !!!!



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

 

[PhiI AIIison]

MESSAGE BY PHIL (LUNATIC, VULGAR, TROLL) ALLISON
RE-POSTED TO APPROPRIATE NEWSGROUP


On Thu, 1 Sep 2005 17:25:01 +1000, "Phil Allison"
<philallison@tpg.com.au> wrote:

"Alan Rutlidge"
"Arny Krueger"


It takes significant distances for audio electrical signals to
demonstrate things like reflections and standing waves. For most
practical purposes, they never happen because by the time the audio goes
that far in the modern world, its probably already been digitized.


Digitising an audio signal does not eliminate propagation delay if the
signal is transmitted over a long distance. To demonstrate this in
combination with the problem of impedance mismatch - make an international
telephone call to a third world country like India. The echo you hear is
usually 100% attributable to poor impedance mismatch at the other end of
the line. And guess what? It's all occurring at audio frequencies (300Hz
to 3400Hz).


** ROTFLMAO !!!!

Does this Rutmaniac, fucking idiot actually teach such monumental
**BULLSHIT** to IT industry trainees ????

Only the dullest teenagers would fall for such utter shite !!!


FYI

Telecommunications data is digital ( not audio) and travels to places like
India via optical fibre and geo-stationery satellites - not thousands of
miles of bloody co-ax !!

What a complete MORON !!!!



.......... Phil

 

[Phil Allison]

"Don Pearce"


** Snip fucking idiot questions.

Only only planet Phil does the world work this way.

** Err - the way the Don said.





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

 

[Phil Allison]

"Alan Rutlidge"
Phil Allison

** ROTFLMAO !!!!

Does this Rutmaniac, fucking idiot actually teach such monumental
**BULLSHIT** to IT industry trainees ????

Only the dullest teenagers would fall for such utter shite !!!

Oh, and it looks as if I've been elevated from wire tugging status to
Information Technologist virtually overnight.

** A fuckwit, wire tugger is all you are - Arse Bandit.

Falsely impersonating an IT instructor is what you do.

Chasing under aged boys around Thailand notwithstanding.

You know, one of these days he's actually gonna get something right about
me.

** Been doing just that for a very long time.

No surprise that a congenital LAIR & a criminal Arse Bandit would never
agree.





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

 

[Phil Allison]

"Nh"


** Who are you ??

Some maggot that lives in an outdoor dunny ?




.......... Phil

 

On Thu, 15 Sep 2005 17:43:53 +1000, Phil Allison
<philallison@tpg.com.au> wrote:

On Thu, 15 Sep 2005 15:54:34 +1000, aaa wrote:





http://cgi.ebay.com.au/1923-Diseases-Of-The-Rectum-Anus-and-Colon-3-Volumes_W0QQitemZ6560815167QQcategoryZ29223QQrdZ1QQcmdZViewItem


** Modesty might stay some hands, but there is a story to tell.

These books contain 1128 illustrations on 1085 figures, with 10
insert in colour (or color, as you please).

*I* am the subject of each illustration/insert. They are all head
and shoulder shots of *me*, showing various states of diseases of the
rectum, anus and colon.

Who said that I had no claim to world fame?




........ Phil

LOL.

 

[Saxology]

*I* am the subject of each illustration/insert. They are all head
and shoulder shots of *me*, showing various states of diseases of the
rectum, anus and colon.

Who said that I had no claim to world fame?




........ Phil

Diseases are important to people, Phil is not. I believe that Phil
Allishole is just trying to be important, when in actuallity he is just a
useless, pathetic, simple, asshole. Sorry he didn't make it into the book,
just wasn't worth the paper.
-Sax

 

On Thu, 15 Sep 2005 17:43:53 +1000, Phil Allison
<philallison@tpg.com.au> wrote:







http://cgi.ebay.com.au/1923-Diseases-Of-The-Rectum-Anus-and-Colon-3-Volumes_W0QQitemZ6560815167QQcategoryZ29223QQrdZ1QQcmdZViewItem

** Modesty might stay some hands, but there is a story to tell.

These books contain 1128 illustrations on 1085 figures, with >10 inserts in colour (or color, as you please).

*I* am the subject of each illustration/insert. They are all head
and shoulder shots of *me*, showing various states of diseases of the
rectum, anus and colon.

Who said that I had no claim to world fame?




........ Phil

LOL.