magnetic field

Jim Thompson · Jul 4, 2005

On 4 Jul 2005 11:32:25 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 4 Jul 2005 10:58:57 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 3 Jul 2005 19:07:57 -0700, "cnctut" <cnctutwiler@wmconnect.com
wrote:

Try google for "charge pump"--a variation of the normal doubler circuit
that can be staged as you suggest. Output of Vinsin(wt) input would be
the multiplier x Vin (DC voltage of course.) The limitation to the
idea is poor voltage regulation and low-current capability.

Good luck

Tut

See, for example...

Newsgroups: alt.binaries.schematics.electronic
Subject: Charge Pump (from S.E.D) - ChargePump-4X-Example.pdf
Message-ID: <c6oic11k134gr5u9c70re5r9ebu35iklk4@4ax.com

...Jim Thompson

Google didn't pull that one up, since Google doesn't archive binaries.

Use a good news server. Doesn't your ISP have a news server?

Do you have another source for that?

I designed it ;-) It's now on the S.E.D/Schematics page of my
website.

Bob Clark

How many times does it multiply the input voltage?

Bob Clark

"ChargePump-4X-Example.pdf" 4X ?

480)460-2350 | |
| E-mail Address at Website Fax

John Larkin · Jul 4, 2005

On 4 Jul 2005 11:32:25 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 4 Jul 2005 10:58:57 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 3 Jul 2005 19:07:57 -0700, "cnctut" <cnctutwiler@wmconnect.com
wrote:

Try google for "charge pump"--a variation of the normal doubler circuit
that can be staged as you suggest. Output of Vinsin(wt) input would be
the multiplier x Vin (DC voltage of course.) The limitation to the
idea is poor voltage regulation and low-current capability.

Good luck

Tut

See, for example...

Newsgroups: alt.binaries.schematics.electronic
Subject: Charge Pump (from S.E.D) - ChargePump-4X-Example.pdf
Message-ID: <c6oic11k134gr5u9c70re5r9ebu35iklk4@4ax.com

...Jim Thompson

Google didn't pull that one up, since Google doesn't archive binaries.

Use a good news server. Doesn't your ISP have a news server?

Do you have another source for that?

I designed it ;-) It's now on the S.E.D/Schematics page of my
website.

Bob Clark

How many times does it multiply the input voltage?

Bob Clark

This thread is setting some sort of record for "least coherent."

John

Nick Kennedy · Jul 4, 2005

It's a bad idea. The added external inductance would be equivalent to
what's called *leakage* inductance, which is generally the bad kind. The
other kind is *mutual* inductance, which is what causes transformer action.
The mutual inductance is generally also what is seen as *magnetizing*
inductance in a transformer.

Leakage inductance causes a voltage drop proportional to load and so causes
the transformer's output voltage to deviate from the ideal transformation
ratio.

A simple but fairly good model of a transformer consists of a leakage
inductance term in series with the source, a magnetizing inductance term
after that, in paralle, and an "ideal" transformer following that. If the
leakage inductance approaches zero and the magnetizing inductance becomes
very high, then the model approaches an ideal transformer, which is usually
what you want.

Not sure why you can't measure your inductance. It might be relatively high
and so may be off scale for the inductance meter built in to your DVM.

Regards,

Nick

"Manny" <cktmanny@yahoo.com> wrote in message
news:1120459472.271393.242940@o13g2000cwo.googlegroups.com...

Two questions.

Can I just add an inductor in series to a transformer
primary and secondary to increase the inductive reactance
of both (rather than adding more turns)? Will this affect the voltage??
I wonder if adding an inductor and adding more
turns would produce similar behavior in the circuit. What
do you think.

I tried using my multi-meter to measure the inductance
of a transfomer. How come I can't measure any, as if there
is open connections. What's the proper procedure. Thanks.

Manny

Si Ballenger · Jul 4, 2005

On 4 Jul 2005 10:54:44 -0700, "dAN" <dan.lavoie@gmail.com> wrote:

Does someone have ordering something from http://www.futurlec.com/ . I
have read on differents newsgroups that they have some problems with
the shipping.

Does it ok now?

I'm interested by their valuepack.

Thanks.
DL

I've ordered in the past and it seemed to take 2-3 weeks for my
order to arrive. Everything was as ordered, but just took a long
time to get it compared to the usual electronic suppliers.

BFoelsch · Jul 4, 2005

"John Larkin" <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote in message
news:5h1jc1t3jkvn7lt2j20da1ejg6p53pt6m1@4ax.com...

On 4 Jul 2005 11:32:25 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 4 Jul 2005 10:58:57 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 3 Jul 2005 19:07:57 -0700, "cnctut" <cnctutwiler@wmconnect.com
wrote:

Try google for "charge pump"--a variation of the normal doubler
circuit
that can be staged as you suggest. Output of Vinsin(wt) input would
be
the multiplier x Vin (DC voltage of course.) The limitation to the
idea is poor voltage regulation and low-current capability.

Good luck

Tut

See, for example...

Newsgroups: alt.binaries.schematics.electronic
Subject: Charge Pump (from S.E.D) - ChargePump-4X-Example.pdf
Message-ID: <c6oic11k134gr5u9c70re5r9ebu35iklk4@4ax.com

...Jim Thompson

Google didn't pull that one up, since Google doesn't archive binaries.

Use a good news server. Doesn't your ISP have a news server?

Do you have another source for that?

I designed it ;-) It's now on the S.E.D/Schematics page of my
website.

Bob Clark

How many times does it multiply the input voltage?

Bob Clark

This thread is setting some sort of record for "least coherent."

John

This is true. Rational people could explain the OP's issue using the terms
"AC" and "DC," but we can't use those terms here
anymore..............................

Winfield Hill · Jul 4, 2005

rgregoryclark@yahoo.com wrote...

jmorriss@idirect.com wrote:
So, did it go from V to 2V 'cause you added V, or multiplied
by 2? When you add stages, will you add V or multiply by 2?

Correction: with the usual circuit adding another stage takes it
from 2V to 3V, not 4V.

What's the puzzle? The ac swing you have available to work with
and stack up, is always V, that's not doubled, or tripled, etc.,
at any point. That'd be nice, but how would it be?

--
Thanks,
- Win

Jamie · Jul 5, 2005

Guy Macon wrote:

Jamie wrote:

lets see, our RDI vaults produce a little over 1 M volts
using a CW multiplier in an insulated pressured gas sourcing

from a 3000 Kv OSC via pie RF transformers.

i can tell you that we don't have a mile rectifier stacks
in there.

That's roughly 333 stages. The breakdown voltage in air is
roughly 25kV to 75kV per inch (depending on electrode shape,
humidity, etc) so lets give each stage an an inch to be really
sure. That's a bit under 40 feet total, which will fit in your
garage with sepentine construction.

As for the output, here is a fellow making 4-foot sparks in air:
[ http://homepage.ntlworld.com/electricstuff/marxthree.html ]
So I can see why one would want to have an insulator better
than air.

well i meant to say 3000 V not 3000 Kv or should have said 3Kv

on the input. and that is on the input side of the pie xformer.
the output of the pie is around 12k..18k volts.
one of the vessels is around some where in the neighborhood of
40 or so feet long.

--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Jamie · Jul 5, 2005

Chip Anderson wrote:

Guy Macon <http://www.guymacon.com/> wrote in
news:11chho723iuj50@corp.supernews.com:

Jamie wrote:

lets see, our RDI vaults produce a little over 1 M volts
using a CW multiplier in an insulated pressured gas sourcing

from a 3000 Kv OSC via pie RF transformers.

i can tell you that we don't have a mile rectifier stacks
in there.

That's roughly 333 stages. The breakdown voltage in air is
roughly 25kV to 75kV per inch (depending on electrode shape,
humidity, etc) so lets give each stage an an inch to be really
sure. That's a bit under 40 feet total, which will fit in your
garage with sepentine construction.

As for the output, here is a fellow making 4-foot sparks in air:
[ http://homepage.ntlworld.com/electricstuff/marxthree.html ]
So I can see why one would want to have an insulator better
than air.

This fellow is going to accidentally kill himself one day.

from what i have seen in here from some, it may not be an

accident!

--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

CWatters · Jul 5, 2005

<cheian07@yahoo.com> wrote in message
news:1120526346.472915.24640@g43g2000cwa.googlegroups.com...

tnx, because as a beginner, i just want to see my network stations to
see each other even the router is off.( just discovering, learning). by
the way, i can see the ip adresses of each computer when i type
ipconfig. but i dont know how to view the ip address of the router.

To configure the router you normally have to surf to a special web page
built into the router itself. The instruction manual for the router will
tell you how to do this.

and
also how to change its ip address.

same as above.

please give me the concept of
operation of a router.
thanks in advance!!!

Skip the sections you know..
http://computer.howstuffworks.com/router.htm

CWatters · Jul 5, 2005

<cheian07@yahoo.com> wrote in message
news:1120527300.373467.292260@g47g2000cwa.googlegroups.com...

Thank you. by the way how can i turn off the DCHP
thnks in advance!!!

See the instruction manual for the router.

Jim Thompson · Jul 5, 2005

On 5 Jul 2005 04:43:03 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 4 Jul 2005 11:32:25 -0700, rgregoryclark@yahoo.com wrote:

How many times does it multiply the input voltage?

Bob Clark

"ChargePump-4X-Example.pdf" 4X ?

...Jim Thompson

Cockroft-Walker multipliers with fewer components can multiply voltage
8 times:

Cockroft Walton Voltage Multipliers
http://home.earthlink.net/~jimlux/hv/cw1.htm

Read more carefully, it multiplies 8X the PEAK, or 4X the
Peak-to-Peak; mine does the same, just in a fashion that allows
monolithic implementation without forward biasing wells and creating
latch-up, etc.

Diodes can't be implemented in monolithic form, as in your example,
because all kinds of bad parasitic things happen.

Are saying your circuit has the advantage of being able to be staged
to *multiply* by 4 each time?

Bob Clark

You've got a hair up your butt about "staged".

"Staged" doesn't happen. The output is DC. The only way would be to
add a switching device at the end of a 4X and you have no power to run
it.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice

480)460-2350 | |
| E-mail Address at Website Fax

Guy Macon · Jul 5, 2005

rgregoryclark@yahoo.com wrote:

"Charge pump" is a catch-all term that is also applied to
Cockroft-Walton multipliers. Are you sure the type you're thinking of
can be staged to *multiply* by the same factor at each stage?

The circuit that I described as a theoretical possibility that isn't
used, only to discover that someone was using it, actuall does multiply.

Consider a bog-standard Cockroft-Walton voltage multiplier that has
a DC-to-AC inverter on the front end, and enough levels to get a nice
10X increase from the DC in to the DC out.

10X increase from start to finish.

Now take that 10X DC out and use it to feed another bog-standard
Cockroft-Walton voltage multiplier that has a DC-to-AC inverter
on the front end, and enough levels to get a nice 10X increase
from the DC in to the DC out.

100X increase from start to finish. Add another, it's 1000X
increase from start to finish.

The downside is that doing this throws away the main advantage
of the Cockroft-Walton configuration; that no component is
subjected to more than a small fraction of the output voltage.
A regular Cockroft-Walton can go as high as you want.

(I am still amazed that anyone would do it that way given the
many alternative topologies that seem, on the face of things,
to be better choices.)

Jim Thompson · Jul 5, 2005

On 5 Jul 2005 09:09:20 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 5 Jul 2005 04:43:03 -0700, rgregoryclark@yahoo.com wrote:

Jim Thompson wrote:
On 4 Jul 2005 11:32:25 -0700, rgregoryclark@yahoo.com wrote:

How many times does it multiply the input voltage?

Bob Clark

"ChargePump-4X-Example.pdf" 4X ?

...Jim Thompson

Cockroft-Walker multipliers with fewer components can multiply voltage
8 times:

Cockroft Walton Voltage Multipliers
http://home.earthlink.net/~jimlux/hv/cw1.htm

Read more carefully, it multiplies 8X the PEAK, or 4X the
Peak-to-Peak; mine does the same, just in a fashion that allows
monolithic implementation without forward biasing wells and creating
latch-up, etc.

You can't read what is not there. You ONLY said it multiplies "4
times". The Cockroft-Walton circuit page specifically says 8 times
peak.
You're post is also misleading in that it was in response to the post
by "cnctut" who suggested "charge pumps" could multiply at each
additional stage.
I don't know if this is accurate or not.

Bob Clark

480)460-2350 | |
| E-mail Address at Website Fax

Jim Thompson · Jul 5, 2005

On 5 Jul 2005 09:34:42 -0700, rgregoryclark@yahoo.com wrote:

Guy Macon wrote:
rgregoryclark@yahoo.com wrote:

"Charge pump" is a catch-all term that is also applied to
Cockroft-Walton multipliers. Are you sure the type you're thinking of
can be staged to *multiply* by the same factor at each stage?

The circuit that I described as a theoretical possibility that isn't
used, only to discover that someone was using it, actuall does multiply.

Consider a bog-standard Cockroft-Walton voltage multiplier that has
a DC-to-AC inverter on the front end, and enough levels to get a nice
10X increase from the DC in to the DC out.

10X increase from start to finish.

Now take that 10X DC out and use it to feed another bog-standard
Cockroft-Walton voltage multiplier that has a DC-to-AC inverter
on the front end, and enough levels to get a nice 10X increase
from the DC in to the DC out.

100X increase from start to finish. Add another, it's 1000X
increase from start to finish.

The downside is that doing this throws away the main advantage
of the Cockroft-Walton configuration; that no component is
subjected to more than a small fraction of the output voltage.
A regular Cockroft-Walton can go as high as you want.

(I am still amazed that anyone would do it that way given the
many alternative topologies that seem, on the face of things,
to be better choices.)

I still haven't seen an example where this is actually done.
In my application, I need a high voltage power supply in the kilovolt
range that is portable (lightweight) and can run off DC batteries in
the 30V range AND at the same time can put out hundreds of watts.
The usual way of getting high voltage is to use a transformer and then
perhaps use a CW doubler or tripler to ramp up the voltage. The problem
is that transformer usually has a ferrite core and that makes it heavy.
Ideally, I would want the power supply (exclusive of the battery) to
weigh less than 1 gm for every 1 watt generated while producing
kilovolts.
I wanted to eliminate the transformer to save weight. So I thought I
could use *many* stages in a CW alone to get the high voltage. However,
the usual CW circuit is additive. So if I wanted 30,000V from 30V I
would need 1,000 capacitors and associated diodes. Even using those
flat disc capacitors, this would probably weigh more than just using a
transformer.
Therefore my question arose, is it possible instead to feed one CW
multiplier into another *multiplying* the voltage with each repetition?

Bob Clark

(1) Guy Macon couldn't locate his asshole with both hands and a
flashlight. His 2-3 year job cycles prove that ;-)

(2) It is NOT possible to feed one CW into another.

(3) "hundreds of watts" forces you to use a transformer.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice

480)460-2350 | |
| E-mail Address at Website Fax

Zak · Jul 5, 2005

Jim Thompson wrote:

"Staged" doesn't happen. The output is DC. The only way would be to
add a switching device at the end of a 4X and you have no power to run
it.

What about a spark gap?

Thomas

Jim Thompson · Jul 5, 2005

On Tue, 05 Jul 2005 18:58:09 +0200, Zak <jute@zak.invalid> wrote:

Jim Thompson wrote:

"Staged" doesn't happen. The output is DC. The only way would be to
add a switching device at the end of a 4X and you have no power to run
it.

What about a spark gap?

Thomas

480)460-2350 | |
| E-mail Address at Website Fax

Guy Macon · Jul 5, 2005

rgregoryclark@yahoo.com wrote:

Guy Macon wrote:

rgregoryclark@yahoo.com wrote:

"Charge pump" is a catch-all term that is also applied to
Cockroft-Walton multipliers. Are you sure the type you're thinking of
can be staged to *multiply* by the same factor at each stage?

The circuit that I described as a theoretical possibility that isn't
used, only to discover that someone was using it, actually does multiply.

Consider a bog-standard Cockroft-Walton voltage multiplier that has
a DC-to-AC inverter on the front end, and enough levels to get a nice
10X increase from the DC in to the DC out.

10X increase from start to finish.

Now take that 10X DC out and use it to feed another bog-standard
Cockroft-Walton voltage multiplier that has a DC-to-AC inverter
on the front end, and enough levels to get a nice 10X increase
from the DC in to the DC out.

100X increase from start to finish. Add another, it's 1000X
increase from start to finish.

The downside is that doing this throws away the main advantage
of the Cockroft-Walton configuration; that no component is
subjected to more than a small fraction of the output voltage.
A regular Cockroft-Walton can go as high as you want.

(I am still amazed that anyone would do it that way given the
many alternative topologies that seem, on the face of things,
to be better choices.)

I still haven't seen an example where this is actually done.
In my application, I need a high voltage power supply in the kilovolt
range that is portable (lightweight) and can run off DC batteries in
the 30V range AND at the same time can put out hundreds of watts.
The usual way of getting high voltage is to use a transformer and then
perhaps use a CW doubler or tripler to ramp up the voltage. The problem
is that transformer usually has a ferrite core and that makes it heavy.
Ideally, I would want the power supply (exclusive of the battery) to
weigh less than 1 gm for every 1 watt generated while producing
kilovolts.

I wanted to eliminate the transformer to save weight. So I thought I
could use *many* stages in a CW alone to get the high voltage. However,
the usual CW circuit is additive. So if I wanted 30,000V from 30V I
would need 1,000 capacitors and associated diodes.

You are off by a factor of two. The nominal output voltage (no load)
assuming perfect parts is *twice* the peak input voltage multiplied
by the number of stages.

Even using those flat disc capacitors, this would probably weigh
more than just using a transformer.

Therefore my question arose, is it possible instead to feed one CW
multiplier into another *multiplying* the voltage with each repetition?

I have never seen the topology I described above either, but Winfield
says that he uses it, so obviously my experience isn't broad enough
to have ran into it in practice or read any literature on it. It does
indeed multiply, so from a voltage standpoint you can use three copies
of a Cockroft-Walton voltage multiplier with a DC-to-AC inverter on
the front end, and enough stages to get a nice 10X increase from
each copy. That's 30 to 40 capacitors and associated diodes, plus
whatever parts you need to make the 3 DC-AC inverters.

That "hundreds of watts" specification concerns me. Cockroft-Walton
voltage multipliers aren't all that good at putting out current.
Here is how to figure your currentL

Let's look at a single Cockroft-Walton voltage multiplier that with a
DC-to-AC inverter on the front end.

Start with the oversimplified model of the nominal output voltage
being twice the peak input voltage multiplied by the number of stages,

Now reduce it by the number of diode drops you have.

Now figure the voltage drop;

Edrop = I1oad /(f*C)*(2/3*n^3+n^2/2-n/6)

Edrop = voltage drop
Iload = load current
f = frequency
C = capacitance
n = number of stages.

Now figure the ripple;

Assume all capacitances are equal.

Eripple = Iload/(f*C)*n*(n+1)/2

You can reduce the ripple by making the capacitors smaller at
the top and larger at the bottom: C1,C2=10*C C3,C4=9C, etc.
This gives you;

Eripple = Iload/(f*C)

As you can see, you want to keep that frequency as high as
you can before the switching losses start kicking in. I have
had good results with starting at a low frequency and ramping
the frequency up - sort of a poor man's soft start.

(Disclaimer: I am away from my reference books and I don't have
the above equations memorized, so I snagged them off the web.
Make sure they are right before actually building anything.)

--
Guy Macon <http://www.guymacon.com/>

Rich The Newsgroup Wacko · Jul 5, 2005

On Mon, 04 Jul 2005 14:09:53 -0700, Winfield Hill wrote:

rgregoryclark@yahoo.com wrote...

jmorriss@idirect.com wrote:
So, did it go from V to 2V 'cause you added V, or multiplied
by 2? When you add stages, will you add V or multiply by 2?

Correction: with the usual circuit adding another stage takes it
from 2V to 3V, not 4V.

What's the puzzle? The ac swing you have available to work with
and stack up, is always V, that's not doubled, or tripled, etc.,
at any point. That'd be nice, but how would it be?

With that damn transformer, of course. ;-D

--
Cheers!
Rich
------
"Look out for yourself -- or they'll pee on your grave."
-- Louis B. Mayer
"The reason so many people showed up at Louis B. Mayer's funeral was
because they wanted to make sure he was dead."
-- Samuel Goldwyn

Winfield Hill · Jul 5, 2005

Jim Thompson wrote...

rgregoryclark@yahoo.com wrote:

In my application, I need a high voltage power supply in the kilovolt
range that is portable (lightweight) and can run off DC batteries in
the 30V range AND at the same time can put out hundreds of watts.
The usual way of getting high voltage is to use a transformer and then
perhaps use a CW doubler or tripler to ramp up the voltage. The problem
is that transformer usually has a ferrite core and that makes it heavy.
Ideally, I would want the power supply (exclusive of the battery) to
weigh less than 1 gm for every 1 watt generated while producing
kilovolts. I wanted to eliminate the transformer to save weight.

(3) "hundreds of watts" forces you to use a transformer.

I agree completely. Fortunately, with sufficient skill, you can run
a small, light resonant transformer at a high frequency and do far
better than any C-W circuit. I suggest you look into that approach.

For how long a time period do you need to continuously supply 100s of
watts of these kVs, and with what duty cycle? More detail, please.

--
Thanks,
- Win

John Larkin · Jul 5, 2005

On Tue, 05 Jul 2005 18:58:09 +0200, Zak <jute@zak.invalid> wrote:

Jim Thompson wrote:

"Staged" doesn't happen. The output is DC. The only way would be to
add a switching device at the end of a 4X and you have no power to run
it.

What about a spark gap?

Thomas

Marx generators usually use spark gaps, but they're still additive per
stage. There's a neat megavolt Marx out at Livermore that uses
laser-triggered spark gaps and water-filled clear plastic tubes as the
charging resistors.

John

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