magnetic field

[CWatters]

"Lorraine" <lorrainewinters80@yahoo.com> wrote in message
news:1116888210.590810.20720@f14g2000cwb.googlegroups.com...
Hi Lorraine.

Keep asking those questions! We won't always have the time or the ability to
answer (we aren't all professional teachers) but how else can one learn. You
planning to study electronics at college or? My first electronics text book
was published by Ladybird. Sadly I don't think it's printed anymore.

Voltage is said to be the difference between the electric
potential between two poles of a battery.

Not just two poles of a battery. Any two points...

http://www.answers.com/topic/voltage

What is the
relationship between electric field and electric
potential at the poles. Is there a difference in the
electric field between the two poles?

Well an Electric field exists _between_ the poles. I mean in the space
between them physically.

http://whatis.techtarget.com/definition/0,,sid9_gci752086,00.html

Imagine two large sheets of metal seperated by 1 meter. Connect each plate
to one terminal of a 9V battery. The field in the gap between the plates
would be 9 Volts per Meter. If both plates are the same shape then the field
near one plate will be similar to the field near to the other.

 

[CWatters]

"Lorraine" <lorrainewinters80@yahoo.com> wrote in message
news:1116888639.722597.298790@g49g2000cwa.googlegroups.com...

I'm asking this because I plan to use a DC regulated power supply
and make the signal vibrate at 1 Mhz and direct it to the antennae
to experiment with em radiation.

Ok now call me suspicious but you are starting to sound like a troll.

 

[Dr Engelbert Buxbaum]

siliconmike wrote:

I just bought a new TV and found

1. it had no earthing pin in its power cable (only Phase and Neutral
were there)

That's very common in Audio/Video equipment to prevent ground loops when
devices are connected (which result in huming at mains frequency)

2. its audio GND (accessible from RCA connector) showed me presence of
voltage when I touched a screw-driver-cum-mains-tester to it.

Not unheared of either. I had a satelite receiver that carried 80 V on
its case compared to ground. It actually gave a tingling sensation when
touched. No problems at all, if your house has a residual current device
(RCD). If the current becomes so high as to be dangerous, the RCD flips
and that's that.

Can I safely connect my PC audio output to TV audio input ?

Yes, the voltage should have so high an internal resistance that little
current will flow. If you are worried, use an audio transformer.

What if I manually earthed the TV GND ?

You would get a ground loop with any grounded equipment connected to it.

 

[Ken Taylor]

"siliconmike" <siliconmike@yahoo.com> wrote in message
news:1116924454.569777.127980@g47g2000cwa.googlegroups.com...

Gotta spread them around further.

Oddly enough when I used Samsung's site search engine I didn't find
that
model, but when I used Google it popped up. Hmmm, maybe they are a
bit
ashamed.....


Well I'm not sure who should be ashamed of surfing abilities, but here
are the specs on Samsung's website found in less than a minute.

http://www.samsung.com/in/products/tv/flattv/regularflattv/cs_29t10pa.asp

Yep, I found it straight away when I Googled but for some reason Samsung's
home page didn't bring it up. I wonder if they don't necessarily search all
their global sites, although I don't recall seeing that option. Not sure why
I said the bit about ashamed now, something was trolling through my tiny
mind. No offence meant to you, it was being directed towards Samsung's site.

Cheers.

Ken

 

[Mark VB]

cheian07@yahoo.com wrote:

good day!

i have a problem with my cyrix 586 mainboard. When i turn it on, it
sounds one beep, displaying BIOS logo, running memory count, but when
it begins searching for OS or maybe turning to that phase, it now
hangs. just there forever w/ a blinking cursor. i tried to swap the
BIOS but just the same. i like to restore this computer because its
wonderful to learn new things & if it is fixed, it can still be useful
because i do encoding only most of the time. pls anyone on the web can
give me ideas and suggestions on how to save this computer. helps would
be so greatly appreciated.

ian (phil.)

If you have Video and no BIOS-errors, there's no problem with the
MotherBoard. I suppose you didn't flash your BIOS just before the
problem came up, so it sounds like the MBR of your harddisk is damaged.
Are you still able to boot with a floppy disk ?

First check if your HD is still recognized by the BIOS and try restoring
the MBR. But if that doesn't work, you'll have to reformat (possibly
repartition) the harddisk. I don't think the HD will be defective,
because in that case, you should get an error-message from BIOS.


HTH,
Mark Van Borm

 

[N:dlzc D:aol T:com (dlzc)]

Dear Pat Flannery:

"Pat Flannery" <flanner@daktel.com> wrote in message
news:1196icu1shkmue3@corp.supernews.com...

N:dlzc D:aol T:com (dlzc) wrote:

I'm not sure you understand, so...
As the corona inception voltage goes down,
so does the average velocity of the ions
leaving. If the velocity goes down, the thrust
goes down by the square of the velocity.
Altogether a bad thing, epecially when
rarefied air presents a good opportunity to reduce drag.

Yeah I got your point; there's something else
to take into consideration here- what happens
when the Lifter hits the ozonosphere?

*Ionosphere*.

Isn't ozone electrically conductive, and won't that short
the whole works out?

No, it is no more conductive than oxygen. In fact, since it is
polar, it will actually increase the energy required to start
"coronation".

David A. Smith

 

[John Fields]

On 24 May 2005 21:35:49 -0700, "isaac" <ssamlove79@naver.com> wrote:

I really want to find datasheet 'HVD355B'

where can I find this datasheet and

please recommend a site where I can find a lot of datasheets.

---
Do your own legwork.
You can find it in about 15 seconds if you search for it on Google.
I did.
--
John Fields
Professional Circuit Designer

 

[Joe Soap]

In response to what <administrator@datasheetarchive.com> posted in
news:1117022012.799684.242510@g43g2000cwa.googlegroups.com:

Our site has it.

www.datasheetarchive.com

That site demands payment.

--
Joe Soap.
JUNK is stuff that you keep for 20 years,
then throw away a week before you need it.

 

[Bill]

"Peter Bennett" <peterbb@somewhere.invalid> wrote in message
news:0it49190uqesq3c06fisd9hfa6plpt2fn9@news.supernews.com...

On 23 May 2005 13:49:45 -0700, "Lorraine"
lorrainewinters80@yahoo.com> wrote:

Hi,

I wanna convert the 12 volts DC in my car to AC 110 volts
60 Hz so I can use my appliance inside the car, what's the
simplest circuit lying around in the net where I can build
one? Pls. mention some sites and schematics as well as the
IC. All I know is the 555 timer ic, but it doesn't up
the voltage from 12 to 110 volts.

You can buy a suitable inverter much cheaper than you can build one,
particularly given the level of electronics knowledge your questions
indicate.

To select an appropriate inverter, you will need to determine the
power required by your appliance.


To make the circuit simpler, can I just use 30 Hz, I
guess my appliance would still run at this frequency
right? For electric fan, would it run slower at 30 Hz
versus 60 Hz or the same? How about light bulb. Would
it flicker at this lower frequency?

Most devices designed for 60 Hz will not operate correctly (or maybe
at all) at 30 Hz, and an incandescent light bulb would probably have a
noticeable flicker.

I agree with the other suggestions. Also, you can probably find a small
inverter from $25 to $40. You did not mention what the appliance was, but if
you try to run something that requires a lot of power from the cigarette
lighter you will probably blow a fuse. And you may lose something like 20% of
the power through the inverter.

Bill

 

[Don Bowey]

On 5/25/05 2:48 PM, in article
1117057734.982070.293720@z14g2000cwz.googlegroups.com, "Lory"
<lorrainewinters80@yahoo.com> wrote:

Hi,

The sine waves in my XR2206 IC function generator started
at 3 volts and varied from there to 5 volts and 1 volt.

In ordinary function generator equipment. Is the
sine wave at 0 volts and rising/falling from it or
does it also start at higher voltage as base?

My function generator allows me to offset the signal by a variable amount,
both pos. & neg. I think it may be based on the XR2206, but I'm not
certain.

Don

 

[John Fields]

On 25 May 2005 12:37:05 GMT, Joe Soap <me@privacy.net> wrote:

In response to what <administrator@datasheetarchive.com> posted in
news:1117022012.799684.242510@g43g2000cwa.googlegroups.com:

Our site has it.

www.datasheetarchive.com

That site demands payment.

---
No, it doesn't. That's where I found it. No registration, no payment
required. Decent.

--
John Fields
Professional Circuit Designer

 

[Ken Taylor]

"Lory" <lorrainewinters80@yahoo.com> wrote in message
news:1117057734.982070.293720@z14g2000cwz.googlegroups.com...

Hi,

The sine waves in my XR2206 IC function generator started
at 3 volts and varied from there to 5 volts and 1 volt.

In ordinary function generator equipment. Is the
sine wave at 0 volts and rising/falling from it or
does it also start at higher voltage as base?

Lory

It depends on whether the designer made it one or the other. If the output
is couple with a capacitor there is no DC offset, so the sine wave varies
around 0V. If a DC offset is superimposed then the output will vary around
that.

Ken

 

[Ken Taylor]

"Lory" <lorrainewinters80@yahoo.com> wrote in message
news:1117057383.218111.145300@o13g2000cwo.googlegroups.com...

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

I build a function generator using the IC XR2206. It's
current is so low I can't even drive a bulb of light
with it. So I plan to boost the voltage and current
by plugging it to a power amplifier. I need a voltage
10V or above. I wonder what is the average voltage
rating of a power amplifier. Is it dependent on the
wattage or power rating? How do I know its respective
voltage and current?

Thanks.

Lory

Do you actually want to vary a light bulb's intensity or are you using that
as an example? Since you built the generator you may like to look up some of
the amplifier IC's that are available, such as the LM386.

Ken

 

[Tomi Holger Engdahl]

"Lory" <lorrainewinters80@yahoo.com> writes:

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

The power to a load can be calculated with voltage
and resitance values with equation

power = (U * U) / R

Where U is the voltage and R is the resistance

This becomes U = sqrt( power * R)
In this case the voltage with 750W @ 4 ohm load would
be around 54.8 V. That's the RMS voltage.
The peaks go to around +-77V.

I build a function generator using the IC XR2206. It's
current is so low I can't even drive a bulb of light
with it. So I plan to boost the voltage and current
by plugging it to a power amplifier.

That's a good idea. A normal audio amplifier works well
with function generator as long as you work within the
frequency response of the amplifier.

I need a voltage 10V or above.

The amplifier you have can definately give that.

I wonder what is the average voltage
rating of a power amplifier. Is it dependent on the
wattage or power rating? How do I know its respective
voltage and current?

I answered those in the example above.

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

 

[Joe Soap]

In response to what siliconmike <siliconmike@yahoo.com> posted in
news:1117102395.853037.197110@z14g2000cwz.googlegroups.com:

I would appreciate if anyone can advise as to how to make magnets. I
have an electronic engineering background, but have never done this
before. I want to make tiny magnets, say size of 4mm x 4mm or 6mm x
6mm, of the power of 4000 to 5000 Gauss (higher the better)..

What material should I use ?
What coating should I do on that material for corrosion protection ?
What would be the thickness of the coating ?
Should I do coating before / after magnetizing ?
What would be the coil / dc power setup ?
How do I measure the strength afterwards ?

Search ebay for neodymium

--
Joe Soap.
JUNK is stuff that you keep for 20 years,
then throw away a week before you need it.

 

[John Fields]

On 26 May 2005 11:14:22 +0300, Tomi Holger Engdahl
<then@solarflare.cs.hut.fi> wrote:

"Lory" <lorrainewinters80@yahoo.com> writes:

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

The power to a load can be calculated with voltage
and resitance values with equation

power = (U * U) / R

Where U is the voltage and R is the resistance

---
Since when is voltage "U"?

--
John Fields
Professional Circuit Designer

 

[Ken Taylor]

"Lory" <lorrainewinters80@yahoo.com> wrote in message
news:1117146922.950761.147240@f14g2000cwb.googlegroups.com...

Hi,

Does ordinary DC power supply produce ripples? What is the
usual frequency and waveform shape (sine, square) of
the ripples supposed the source is 60 hz. What
circuit component (capacitor, ics, etc) can eliminate
all ripples? How come the dc power supply didn't use
this eliminator, is it expensive? Tnx.

Lory

Hi Lory.

Take a look at: http://www.oldradioz.com/electronic_course/ch3.htm
It uses valves, which give me a warm rosy glow; you can substitute
semiconductor diodes and the theory doesn't change. This page gives a fairly
extensive explanation of what's going on which isn't the case with a lot of
them.

You should go out and buy a copy of The ARRL Handbook (Amazon or any
half-decent bookstore, even in the Antipodes). It will answer a lot of your
questions and give you insights into what's going on. It is not at the
engineering level but is excellent grounding.

Cheers.

Ken

 

[Boris Mohar]

On Thu, 26 May 2005 19:27:22 -0500, John Fields
<jfields@austininstruments.com> wrote:

On 26 May 2005 11:14:22 +0300, Tomi Holger Engdahl
then@solarflare.cs.hut.fi> wrote:

"Lory" <lorrainewinters80@yahoo.com> writes:

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

The power to a load can be calculated with voltage
and resitance values with equation

power = (U * U) / R

Where U is the voltage and R is the resistance

---
Since when is voltage "U"?

Since Urope started using it. Pretty soon all electrical products shipped to
Urope will have to Uoltage ratings specified.

--

Boris Mohar

 

[Ken Taylor]

"Boris Mohar" <borism_-void-_@sympatico.ca> wrote in message
news9tc91t9m27tqfdpik7u4chehe1po5b3ck@4ax.com...

On Thu, 26 May 2005 19:27:22 -0500, John Fields
jfields@austininstruments.com> wrote:

On 26 May 2005 11:14:22 +0300, Tomi Holger Engdahl
then@solarflare.cs.hut.fi> wrote:

"Lory" <lorrainewinters80@yahoo.com> writes:

Hi,

How do you calculate the output voltage of a particular power
amplifier model? They are most rated in watts such as
750W @ 4 ohm load.

The power to a load can be calculated with voltage
and resitance values with equation

power = (U * U) / R

Where U is the voltage and R is the resistance

---
Since when is voltage "U"?

Since Urope started using it. Pretty soon all electrical products shipped
to
Urope will have to Uoltage ratings specified.

--

Boris Mohar


V haue to be kidding!

Ken

 

[R. Steve Walz]

Vidar Lřkken wrote:

Lorraine wrote:

Voltage is said to be the difference between the electric
potential between two poles of a battery. What is the
relationship between electric field and electric
potential at the poles. Is there a difference in the
electric field between the two poles?

This might sound harsh, but this group is here to _discuss_ electronics,
not to teachs you the basic of electronics.
------------------------

You're full of shit, Vidar. YOU just don't know the answer so
you're posturing, a common ploy to try to gain stature illicitly
on a group for a newbie like you.

--
The generalized factor-label difference between potential and field
should be understood basically thus:

Force between charges is expressed as K*Q1*Q2 / R^2, where K is
a constant having a factor label required to make Q^2/R^2 have
the units of force in Newtons, where K's value is 9 x10^9 N*m^2/C^2.

Electric field is defined as Force per charge applied to a tiny
test charge Q2 so that E-Field F/Q2 = E = K*Q1 / R*2

So Field is a way of specifying the force per charge a field
produces.

Now, another useful expression about a Field is the energy per
charge, and that is called potential.

And just like the energy between to charges is given by
PE = K*Q1*Q2 / R , so also can the potential, the energy per charge
offered by this field be written: PE/Q1 = V = K*Q1 / R .

So, since:
E-Field = Force(Newtons)/Charge(Coulombs),
And Potential (Volts) = Energy(Joules)/Charge(Coulombs),
Then since Force(Newtons) * Distance(Meters) = Energy(Joules),
Then E-Field(Newtons/Coulomb) * Distance(Meters) = Potential(Volts)
And KineticEnergy(Joules) = Potential(Volts) * Charge(Coulombs)

Electric Field vs Potential then can be described by saying that
Potential(Volts) between battery terminals implies an E-Field
that depends on the distance traveled in a conductor between
them, so that EField = Potential/Distance and the EField can
be expressed in Volts/Meter.
--
-Steve

--
-Steve Walz rstevew@armory.com ftp://ftp.armory.com/pub/user/rstevew
Electronics Site!! 1000's of Files and Dirs!! With Schematics Galore!!
http://www.armory.com/~rstevew or http://www.armory.com/~rstevew/Public