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printed inductors
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Tom Del Rosso
May 13, 2013, 10:34:01 PM5/13/13
to
When an inductor is printed on a PCB in the shape of a 'square wave' or
square zigzag, each time it zags the trace doubles back on itself. Doesn't
this cancel the magnetic field to an extent? How much does the coil
structure matter to a coiled inductor, or would the straight wire have the
same inductance?
--
Reply in group, but if emailing remove the last word.
brent
May 13, 2013, 10:45:36 PM5/13/13
to
On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
wrote:
perhaps it is a high frequency inductor which is more like a
distributed transmission line inductor?
wrote:
distributed transmission line inductor?
Tim Wescott
May 13, 2013, 11:41:20 PM5/13/13
to
On Mon, 13 May 2013 22:34:01 -0400, Tom Del Rosso wrote:
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself.
> Doesn't this cancel the magnetic field to an extent? How much does the
> coil structure matter to a coiled inductor, or would the straight wire
> have the same inductance?
When it doubles back it'll reinforce the magnetic field, and only
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself.
> Doesn't this cancel the magnetic field to an extent? How much does the
> coil structure matter to a coiled inductor, or would the straight wire
> have the same inductance?
destructively interfere on the next line over (with the current going the
same way).
But I have no clue how much difference it makes, or how much it acts like
a straight wire of the same length.
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
John Larkin
May 14, 2013, 12:26:46 AM5/14/13
to
On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
<tom...@verizon.net.invalid> wrote:
>
>When an inductor is printed on a PCB in the shape of a 'square wave' or
>square zigzag, each time it zags the trace doubles back on itself. Doesn't
>this cancel the magnetic field to an extent? How much does the coil
>structure matter to a coiled inductor, or would the straight wire have the
>same inductance?
The ones you see on PC boards may be delay lines. When you route a differential
>
>When an inductor is printed on a PCB in the shape of a 'square wave' or
>square zigzag, each time it zags the trace doubles back on itself. Doesn't
>this cancel the magnetic field to an extent? How much does the coil
>structure matter to a coiled inductor, or would the straight wire have the
>same inductance?
pair and turn a corner or something, one trace gets longer than the other. So
some people wigwag the shorter one to make the electrical lengths equal.
Like this:
https://dl.dropboxusercontent.com/u/53724080/PCBs/T165_zigzag.jpg
I doubt that a tight wigwag has a time delay that exactly corresponds to the
geometric trace length that the PCB layout software reports.
Real RF inductors are usually proper spirals.
--
John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators
Phil Allison
May 14, 2013, 2:49:14 AM5/14/13
to
"Tim Wescott"
>> When an inductor is printed on a PCB in the shape of a 'square wave' or
>> square zigzag, each time it zags the trace doubles back on itself.
>> Doesn't this cancel the magnetic field to an extent? How much does the
>> coil structure matter to a coiled inductor, or would the straight wire
>> have the same inductance?
>
> When it doubles back it'll reinforce the magnetic field, and only
> destructively interfere on the next line over (with the current going the
> same way).
.... Phil
George Herold
May 14, 2013, 9:02:29 AM5/14/13
to
On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
wrote:
wrote:
I'm not sure what you mean by zig-zagging back... maybe a picture?
Re: a coil versus a length of wire. You get more inductance from the
coil. I think if you have a fixed length of wire and wanted to make
the largest inductance then you'd wind it as one big single turn
coil. (hopefully someone will correct me if that is wrong.)
George H.
Baron
May 14, 2013, 9:05:24 AM5/14/13
to
George Herold Inscribed thus:
I suspect the OP is refering to the meander lines on a pcb used to match
signal timing over varying trace lengths.
--
Best Regards:
Baron.
signal timing over varying trace lengths.
--
Best Regards:
Baron.
Ian Field
May 14, 2013, 10:13:21 AM5/14/13
to
"Tom Del Rosso" <tom...@verizon.net.invalid> wrote in message
news:kms7un$4bl$1...@dont-email.me...
>
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself.
> Doesn't this cancel the magnetic field to an extent? How much does the
> coil structure matter to a coiled inductor, or would the straight wire
> have the same inductance?
The only zig-zag inductors' I've seen, were tacho generators in "pancake"
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself.
> Doesn't this cancel the magnetic field to an extent? How much does the
> coil structure matter to a coiled inductor, or would the straight wire
> have the same inductance?
motors such as the spindle drive in a disk drive or similar.
Maybe a service manual for that kind of kit would throw some light.
Vladimir Vassilevsky
May 14, 2013, 11:01:44 AM5/14/13
to
On 5/14/2013 8:02 AM, George Herold wrote:
> We make spiral coils on PCB to 'shim' magnetic fields.
PCB inductors appear to have poor Q.
> We make spiral coils on PCB to 'shim' magnetic fields.
They are convenient to make, but lacking performance.
> I'm not sure what you mean by zig-zagging back... maybe a picture?
>
> Re: a coil versus a length of wire. You get more inductance from the
> coil. I think if you have a fixed length of wire and wanted to make
> the largest inductance then you'd wind it as one big single turn
> coil. (hopefully someone will correct me if that is wrong.)
with max. number of turns.
Vladimir Vassilevsky
DSP and Mixed Signal Designs
www.abvolt.com
Tom Del Rosso
May 14, 2013, 11:31:33 AM5/14/13
to
John Larkin wrote:
> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
> <tom...@verizon.net.invalid> wrote:
>
> >
> > When an inductor is printed on a PCB in the shape of a 'square
> > wave' or square zigzag, each time it zags the trace doubles back on
> > itself. Doesn't this cancel the magnetic field to an extent? How
> > much does the coil structure matter to a coiled inductor, or would
> > the straight wire have the same inductance?
>
> The ones you see on PC boards may be delay lines. When you route a
> differential pair and turn a corner or something, one trace gets
> longer than the other. So some people wigwag the shorter one to make
> the electrical lengths equal.
connected to the power trace on a 4GHz board.
Tim Wescott
May 14, 2013, 12:12:15 PM5/14/13
to
And have you taken your meds today?
John Larkin
May 14, 2013, 12:25:50 PM5/14/13
to
On Tue, 14 May 2013 11:31:33 -0400, "Tom Del Rosso"
lossy, high-impedance transmission line, which it is in the sense that it has
some limiting Zo at high frequencies, and reflections. Chop out some ground
plane to increase Zo.
I did a zigzag choke like that recently:
https://dl.dropboxusercontent.com/u/53724080/PCBs/T160_wiggles.JPG
It maybe wasn't absolutely necessary, but I had the room and it was sort of fun.
Hey, engineers are easily amused.
If you know the operating frequency, you can optimize the length for max
impedance. RF stuff.
<tom...@verizon.net.invalid> wrote:
>
>John Larkin wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>> >
>> > When an inductor is printed on a PCB in the shape of a 'square
>> > wave' or square zigzag, each time it zags the trace doubles back on
>> > itself. Doesn't this cancel the magnetic field to an extent? How
>> > much does the coil structure matter to a coiled inductor, or would
>> > the straight wire have the same inductance?
>>
>> The ones you see on PC boards may be delay lines. When you route a
>> differential pair and turn a corner or something, one trace gets
>> longer than the other. So some people wigwag the shorter one to make
>> the electrical lengths equal.
>
>I should have said that this definitely is an inductor. It's a choke
>connected to the power trace on a 4GHz board.
Oh yeah, you can make a choke. You can think of it as an inductor, or as a long,
>
>John Larkin wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>> >
>> > When an inductor is printed on a PCB in the shape of a 'square
>> > wave' or square zigzag, each time it zags the trace doubles back on
>> > itself. Doesn't this cancel the magnetic field to an extent? How
>> > much does the coil structure matter to a coiled inductor, or would
>> > the straight wire have the same inductance?
>>
>> The ones you see on PC boards may be delay lines. When you route a
>> differential pair and turn a corner or something, one trace gets
>> longer than the other. So some people wigwag the shorter one to make
>> the electrical lengths equal.
>
>I should have said that this definitely is an inductor. It's a choke
>connected to the power trace on a 4GHz board.
lossy, high-impedance transmission line, which it is in the sense that it has
some limiting Zo at high frequencies, and reflections. Chop out some ground
plane to increase Zo.
I did a zigzag choke like that recently:
https://dl.dropboxusercontent.com/u/53724080/PCBs/T160_wiggles.JPG
It maybe wasn't absolutely necessary, but I had the room and it was sort of fun.
Hey, engineers are easily amused.
If you know the operating frequency, you can optimize the length for max
impedance. RF stuff.
John Larkin
May 14, 2013, 12:28:09 PM5/14/13
to
On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <ghe...@teachspin.com>
wrote:
>On May 13, 10:34�pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
>wrote:
>> When an inductor is printed on a PCB in the shape of a 'square wave' or
>> square zigzag, each time it zags the trace doubles back on itself. �Doesn't
>> this cancel the magnetic field to an extent? �How much does the coil
>> structure matter to a coiled inductor, or would the straight wire have the
>> same inductance?
>>
>> --
>>
>> Reply in group, but if emailing remove the last word.
>
>We make spiral coils on PCB to 'shim' magnetic fields.
How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
>I'm not sure what you mean by zig-zagging back... maybe a picture?
>
>Re: a coil versus a length of wire. You get more inductance from the
>coil. I think if you have a fixed length of wire and wanted to make
>the largest inductance then you'd wind it as one big single turn
>coil. (hopefully someone will correct me if that is wrong.)
There is a solution for that somewhere. Turns out to be a stubby solenoid.
wrote:
>On May 13, 10:34�pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
>wrote:
>> When an inductor is printed on a PCB in the shape of a 'square wave' or
>> square zigzag, each time it zags the trace doubles back on itself. �Doesn't
>> this cancel the magnetic field to an extent? �How much does the coil
>> structure matter to a coiled inductor, or would the straight wire have the
>> same inductance?
>>
>> --
>>
>> Reply in group, but if emailing remove the last word.
>
>We make spiral coils on PCB to 'shim' magnetic fields.
>I'm not sure what you mean by zig-zagging back... maybe a picture?
>
>Re: a coil versus a length of wire. You get more inductance from the
>coil. I think if you have a fixed length of wire and wanted to make
>the largest inductance then you'd wind it as one big single turn
>coil. (hopefully someone will correct me if that is wrong.)
George Herold
May 14, 2013, 2:11:14 PM5/14/13
to
On May 14, 11:01 am, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
> On 5/14/2013 8:02 AM, George Herold wrote:
>
> > We make spiral coils on PCB to 'shim' magnetic fields.
>
> PCB inductors appear to have poor Q.
> They are convenient to make, but lacking performance.
>
Yeah just DC coils.
> On 5/14/2013 8:02 AM, George Herold wrote:
>
> > We make spiral coils on PCB to 'shim' magnetic fields.
>
> PCB inductors appear to have poor Q.
> They are convenient to make, but lacking performance.
>
> > I'm not sure what you mean by zig-zagging back... maybe a picture?
> >
> > Re: a coil versus a length of wire. You get more inductance from the
> > coil. I think if you have a fixed length of wire and wanted to make
> > the largest inductance then you'd wind it as one big single turn
> > coil. (hopefully someone will correct me if that is wrong.)
>
> That is incorrect. Using same piece of wire, max. inductance is achieved
> with max. number of turns.
George H.
George Herold
May 14, 2013, 2:15:05 PM5/14/13
to
On May 14, 12:28 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <gher...@teachspin.com>
and Z gradient and then a Z^2 gradient. (Z is the diectron of the
static field.)
George H
>
> --
>
> John Larkin Highland Technology Incwww.highlandtechnology.com jlarkin at highlandtechnology dot com
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <gher...@teachspin.com>
> wrote:
>
> >On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
> >wrote:
> >> When an inductor is printed on a PCB in the shape of a 'square wave' or
> >> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> >> this cancel the magnetic field to an extent? How much does the coil
> >> structure matter to a coiled inductor, or would the straight wire have the
> >> same inductance?
>
> >> --
>
> >> Reply in group, but if emailing remove the last word.
>
> >We make spiral coils on PCB to 'shim' magnetic fields.
>
> How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
Hard to tune... I bet. This has just 4 coils, one each for the X, Y
>
> >On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
> >wrote:
> >> When an inductor is printed on a PCB in the shape of a 'square wave' or
> >> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> >> this cancel the magnetic field to an extent? How much does the coil
> >> structure matter to a coiled inductor, or would the straight wire have the
> >> same inductance?
>
> >> --
>
> >> Reply in group, but if emailing remove the last word.
>
> >We make spiral coils on PCB to 'shim' magnetic fields.
>
> How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
and Z gradient and then a Z^2 gradient. (Z is the diectron of the
static field.)
>
> >I'm not sure what you mean by zig-zagging back... maybe a picture?
>
> >Re: a coil versus a length of wire. You get more inductance from the
> >coil. I think if you have a fixed length of wire and wanted to make
> >the largest inductance then you'd wind it as one big single turn
> >coil. (hopefully someone will correct me if that is wrong.)
>
> There is a solution for that somewhere. Turns out to be a stubby solenoid.
OK I'll have to check... gotta run
> >I'm not sure what you mean by zig-zagging back... maybe a picture?
>
> >Re: a coil versus a length of wire. You get more inductance from the
> >coil. I think if you have a fixed length of wire and wanted to make
> >the largest inductance then you'd wind it as one big single turn
> >coil. (hopefully someone will correct me if that is wrong.)
>
> There is a solution for that somewhere. Turns out to be a stubby solenoid.
George H
>
> --
>
> John Larkin Highland Technology Incwww.highlandtechnology.com jlarkin at highlandtechnology dot com
Tom Del Rosso
May 14, 2013, 2:19:12 PM5/14/13
to
Its operation depends on its magnetic field, so what is the effect of having
each segment of conductor nearest to segments conducting in the opposite
direction?
Spehro Pefhany
May 14, 2013, 3:02:58 PM5/14/13
to
On Tue, 14 May 2013 09:28:09 -0700, John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <ghe...@teachspin.com>
>wrote:
>
>>On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
>>wrote:
>>> When an inductor is printed on a PCB in the shape of a 'square wave' or
>>> square zigzag, each time it zags the trace doubles back on itself. Doesn't
>>> this cancel the magnetic field to an extent? How much does the coil
>>> structure matter to a coiled inductor, or would the straight wire have the
>>> same inductance?
>>>
>>> --
>>>
>>> Reply in group, but if emailing remove the last word.
>>
>>We make spiral coils on PCB to 'shim' magnetic fields.
>
>How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
>
>
>>I'm not sure what you mean by zig-zagging back... maybe a picture?
>>
>>Re: a coil versus a length of wire. You get more inductance from the
>>coil. I think if you have a fixed length of wire and wanted to make
>>the largest inductance then you'd wind it as one big single turn
>>coil. (hopefully someone will correct me if that is wrong.)
>
>There is a solution for that somewhere. Turns out to be a stubby solenoid.
Optimal coil length is a bit less than the coil radius.
<jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <ghe...@teachspin.com>
>wrote:
>
>>On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
>>wrote:
>>> When an inductor is printed on a PCB in the shape of a 'square wave' or
>>> square zigzag, each time it zags the trace doubles back on itself. Doesn't
>>> this cancel the magnetic field to an extent? How much does the coil
>>> structure matter to a coiled inductor, or would the straight wire have the
>>> same inductance?
>>>
>>> --
>>>
>>> Reply in group, but if emailing remove the last word.
>>
>>We make spiral coils on PCB to 'shim' magnetic fields.
>
>How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
>
>
>>I'm not sure what you mean by zig-zagging back... maybe a picture?
>>
>>Re: a coil versus a length of wire. You get more inductance from the
>>coil. I think if you have a fixed length of wire and wanted to make
>>the largest inductance then you'd wind it as one big single turn
>>coil. (hopefully someone will correct me if that is wrong.)
>
>There is a solution for that somewhere. Turns out to be a stubby solenoid.
http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
A Brooks coil is pretty close to optimal.
amdx
May 14, 2013, 4:20:15 PM5/14/13
to
Mikek
Tom Del Rosso
May 14, 2013, 4:51:30 PM5/14/13
to
a different length.
petrus bitbyter
May 14, 2013, 5:41:27 PM5/14/13
to
"Tom Del Rosso" <tom...@verizon.net.invalid> schreef in bericht
news:kmu8nm$ouv$1...@dont-email.me...
an important parameter.
petrus bitbyter
George Herold
May 14, 2013, 5:59:24 PM5/14/13
to
On May 14, 3:02 pm, Spehro Pefhany <speffS...@interlogDOTyou.knowwhat>
wrote:
> >On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <gher...@teachspin.com>
>
> A Brooks coil is pretty close to optimal.- Hide quoted text -
>
> - Show quoted text -
What about a toroid? (I always want to put to r's in torroid)
Or do you get more B field by spraying it everywhere?
George H.
(I love SED, say something stupid and learn something new, thanks)
wrote:
> On Tue, 14 May 2013 09:28:09 -0700, John Larkin
>
>
>
>
>
> <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>
>
>
>
>
> >On Tue, 14 May 2013 06:02:29 -0700 (PDT), George Herold <gher...@teachspin.com>
> >wrote:
>
> >>On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
> >>wrote:
> >>> When an inductor is printed on a PCB in the shape of a 'square wave' or
> >>> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> >>> this cancel the magnetic field to an extent? How much does the coil
> >>> structure matter to a coiled inductor, or would the straight wire have the
> >>> same inductance?
>
> >>> --
>
> >>> Reply in group, but if emailing remove the last word.
>
> >>We make spiral coils on PCB to 'shim' magnetic fields.
>
> >How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
>
> >>I'm not sure what you mean by zig-zagging back... maybe a picture?
>
> >>Re: a coil versus a length of wire. You get more inductance from the
> >>coil. I think if you have a fixed length of wire and wanted to make
> >>the largest inductance then you'd wind it as one big single turn
> >>coil. (hopefully someone will correct me if that is wrong.)
>
> >There is a solution for that somewhere. Turns out to be a stubby solenoid.
>
> Optimal coil length is a bit less than the coil radius.http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>
> >>On May 13, 10:34 pm, "Tom Del Rosso" <tomd...@verizon.net.invalid>
> >>wrote:
> >>> When an inductor is printed on a PCB in the shape of a 'square wave' or
> >>> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> >>> this cancel the magnetic field to an extent? How much does the coil
> >>> structure matter to a coiled inductor, or would the straight wire have the
> >>> same inductance?
>
> >>> --
>
> >>> Reply in group, but if emailing remove the last word.
>
> >>We make spiral coils on PCB to 'shim' magnetic fields.
>
> >How many channels? I saw a 40-channel NMR shim system once. It was hard to tune.
>
> >>I'm not sure what you mean by zig-zagging back... maybe a picture?
>
> >>Re: a coil versus a length of wire. You get more inductance from the
> >>coil. I think if you have a fixed length of wire and wanted to make
> >>the largest inductance then you'd wind it as one big single turn
> >>coil. (hopefully someone will correct me if that is wrong.)
>
> >There is a solution for that somewhere. Turns out to be a stubby solenoid.
>
>
> A Brooks coil is pretty close to optimal.- Hide quoted text -
>
> - Show quoted text -
What about a toroid? (I always want to put to r's in torroid)
Or do you get more B field by spraying it everywhere?
George H.
(I love SED, say something stupid and learn something new, thanks)
Tim Williams
May 14, 2013, 6:55:23 PM5/14/13
to
"George Herold" <ghe...@teachspin.com> wrote in message
news:46b559a0-f837-432d...@y5g2000yqy.googlegroups.com...
usually give you more inductance -- it takes a lot of work to make B,
because B is energy density (in fact, e ~ B^2).
Dunno about the length required for an air-core toroid. Should be easy to
find from the thin, infinite-turns toroid formulas though.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com
news:46b559a0-f837-432d...@y5g2000yqy.googlegroups.com...
>> Optimal coil length is a bit less than the coil
>> radius.http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>>
>> A Brooks coil is pretty close to optimal.- Hide quoted text -
>>
>
>> radius.http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>>
>> A Brooks coil is pretty close to optimal.- Hide quoted text -
>>
>
>What about a toroid? (I always want to put to r's in torroid)
>Or do you get more B field by spraying it everywhere?
You get more B by focusing it into a smaller space, but that doesn't
>Or do you get more B field by spraying it everywhere?
usually give you more inductance -- it takes a lot of work to make B,
because B is energy density (in fact, e ~ B^2).
Dunno about the length required for an air-core toroid. Should be easy to
find from the thin, infinite-turns toroid formulas though.
Tim
--
Deep Friar: a very philosophical monk.
Website: http://seventransistorlabs.com
George Herold
May 14, 2013, 8:16:08 PM5/14/13
to
On May 14, 6:55 pm, "Tim Williams" <tmoran...@charter.net> wrote:
> "George Herold" <gher...@teachspin.com> wrote in message
spread out is a win. (In other ways toroids seem like a nice inductor
shape.)
George H.
> "George Herold" <gher...@teachspin.com> wrote in message
>
> news:46b559a0-f837-432d...@y5g2000yqy.googlegroups.com...
>
> >> Optimal coil length is a bit less than the coil
> >> radius.http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>
> >> A Brooks coil is pretty close to optimal.- Hide quoted text -
>
> >What about a toroid? (I always want to put to r's in torroid)
> >Or do you get more B field by spraying it everywhere?
>
> You get more B by focusing it into a smaller space, but that doesn't
> usually give you more inductance -- it takes a lot of work to make B,
> because B is energy density (in fact, e ~ B^2).
Yeah, I get to integrate the B field over all space so letting it
> news:46b559a0-f837-432d...@y5g2000yqy.googlegroups.com...
>
> >> Optimal coil length is a bit less than the coil
> >> radius.http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>
> >> A Brooks coil is pretty close to optimal.- Hide quoted text -
>
> >What about a toroid? (I always want to put to r's in torroid)
> >Or do you get more B field by spraying it everywhere?
>
> You get more B by focusing it into a smaller space, but that doesn't
> usually give you more inductance -- it takes a lot of work to make B,
> because B is energy density (in fact, e ~ B^2).
spread out is a win. (In other ways toroids seem like a nice inductor
shape.)
George H.
John Larkin
May 14, 2013, 9:13:15 PM5/14/13
to
On Tue, 14 May 2013 14:19:12 -0400, "Tom Del Rosso"
I'd call it an inductor if I use it as one.
>
>Its operation depends on its magnetic field, so what is the effect of having
>each segment of conductor nearest to segments conducting in the opposite
>direction?
Even a straight wire has inductance that increases with length. A PCB
trace will, too.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
>
>Its operation depends on its magnetic field, so what is the effect of having
>each segment of conductor nearest to segments conducting in the opposite
>direction?
trace will, too.
--
John Larkin Highland Technology, Inc
jlarkin at highlandtechnology dot com
Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation
Phil Allison
May 14, 2013, 10:55:34 PM5/14/13
to
"Spehro Pefhany"
>>
>>>Re: a coil versus a length of wire. You get more inductance from the
>>>coil. I think if you have a fixed length of wire and wanted to make
>>>the largest inductance then you'd wind it as one big single turn
>>>coil. (hopefully someone will correct me if that is wrong.)
>>
>>There is a solution for that somewhere. Turns out to be a stubby solenoid.
>
> Optimal coil length is a bit less than the coil radius.
> http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>
> A Brooks coil is pretty close to optimal.
>
** You have just linked a page from a Kiwi radio ham ??
>>>Re: a coil versus a length of wire. You get more inductance from the
>>>coil. I think if you have a fixed length of wire and wanted to make
>>>the largest inductance then you'd wind it as one big single turn
>>>coil. (hopefully someone will correct me if that is wrong.)
>>
>>There is a solution for that somewhere. Turns out to be a stubby solenoid.
>
> Optimal coil length is a bit less than the coil radius.
> http://www.qsl.net/zl1an/Downloads/Inductance_Problem.pdf
>
> A Brooks coil is pretty close to optimal.
>
WTF ??
The wanker does NOT even mention that his question is restricted to single
layer coils.
With any number of layers permitted, the solution is more like a sphere with
a hollow centre.
Coils made for loudspeaker crossovers were sometimes wound like a ball of
wool in a "beehive" shape for maximum utilisation of the wire used.
.... Phil
Robert Baer
May 15, 2013, 4:15:20 AM5/15/13
to
Tom Del Rosso wrote:
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> this cancel the magnetic field to an extent? How much does the coil
> structure matter to a coiled inductor, or would the straight wire have the
> same inductance?
>
>
The only geometries i saw were spiral in nature on one side (shaped
> When an inductor is printed on a PCB in the shape of a 'square wave' or
> square zigzag, each time it zags the trace doubles back on itself. Doesn't
> this cancel the magnetic field to an extent? How much does the coil
> structure matter to a coiled inductor, or would the straight wire have the
> same inductance?
>
>
either circular or square); inner end of spiral to via withstraight exit
to outside of area.
josephkk
May 17, 2013, 11:55:18 PM5/17/13
to
On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
<tom...@verizon.net.invalid> wrote:
>
>When an inductor is printed on a PCB in the shape of a 'square wave' or
>square zigzag, each time it zags the trace doubles back on itself. Doesn't
>this cancel the magnetic field to an extent? How much does the coil
>structure matter to a coiled inductor, or would the straight wire have the
>same inductance?
That is not an inductor, that is a delay line (transmission line type).
>
>When an inductor is printed on a PCB in the shape of a 'square wave' or
>square zigzag, each time it zags the trace doubles back on itself. Doesn't
>this cancel the magnetic field to an extent? How much does the coil
>structure matter to a coiled inductor, or would the straight wire have the
>same inductance?
?-)
josephkk
May 18, 2013, 12:01:08 AM5/18/13
to
On Tue, 14 May 2013 14:19:12 -0400, "Tom Del Rosso"
At 4GHz it is not so clear. If you really want to know the tools are
expensive (in part to really encourage you to buy platform enough). Like
serious 3D EM solvers. Ask Dr. Hobbs.
?-)
expensive (in part to really encourage you to buy platform enough). Like
serious 3D EM solvers. Ask Dr. Hobbs.
?-)
josephkk
May 18, 2013, 12:07:07 AM5/18/13
to
transverse to its axis) and n (number of turns) is not that clean. Crank
the formulas and see for your self where the first and second order terms
are.
Uncle Steve
May 18, 2013, 9:53:09 AM5/18/13
to
each line, for no obvious reason. Keyboard row/column scanning can't
be time-sensitive that way.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
Fred Bartoli
May 18, 2013, 3:02:31 PM5/18/13
to
Le Sat, 18 May 2013 09:53:09 -0400, Uncle Steve a écrit:
> On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>>
>> >When an inductor is printed on a PCB in the shape of a 'square wave'
>> >or square zigzag, each time it zags the trace doubles back on itself.
>> >Doesn't this cancel the magnetic field to an extent? How much does
>> >the coil structure matter to a coiled inductor, or would the straight
>> >wire have the same inductance?
>>
>> That is not an inductor, that is a delay line (transmission line type).
>
> I've seen them on the plastic PCB used in a laptop keyboard. One on
> each line, for no obvious reason. Keyboard row/column scanning can't be
> time-sensitive that way.
>
>
Then you have more room to improve your typing skills and speed...
> On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>>
>> >When an inductor is printed on a PCB in the shape of a 'square wave'
>> >or square zigzag, each time it zags the trace doubles back on itself.
>> >Doesn't this cancel the magnetic field to an extent? How much does
>> >the coil structure matter to a coiled inductor, or would the straight
>> >wire have the same inductance?
>>
>> That is not an inductor, that is a delay line (transmission line type).
>
> I've seen them on the plastic PCB used in a laptop keyboard. One on
> each line, for no obvious reason. Keyboard row/column scanning can't be
> time-sensitive that way.
>
>
--
Thanks,
Fred.
Uncle Steve
May 18, 2013, 3:14:46 PM5/18/13
to
Jamie
May 18, 2013, 5:22:18 PM5/18/13
to
Jamie
josephkk
May 18, 2013, 10:47:59 PM5/18/13
to
On Sat, 18 May 2013 09:53:09 -0400, Uncle Steve <stev...@gmail.com>
wrote:
>On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>> >
>> >When an inductor is printed on a PCB in the shape of a 'square wave' or
>> >square zigzag, each time it zags the trace doubles back on itself. Doesn't
>> >this cancel the magnetic field to an extent? How much does the coil
>> >structure matter to a coiled inductor, or would the straight wire have the
>> >same inductance?
>>
>> That is not an inductor, that is a delay line (transmission line type).
>
>I've seen them on the plastic PCB used in a laptop keyboard. One on
>each line, for no obvious reason. Keyboard row/column scanning can't
>be time-sensitive that way.
>
>
>Regards,
>
>Uncle Steve
It could well be that the person that did the keyboard layout thought it
looked "cool" and had no idea about its functional aspects.
?-)
wrote:
>On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> <tom...@verizon.net.invalid> wrote:
>>
>> >
>> >When an inductor is printed on a PCB in the shape of a 'square wave' or
>> >square zigzag, each time it zags the trace doubles back on itself. Doesn't
>> >this cancel the magnetic field to an extent? How much does the coil
>> >structure matter to a coiled inductor, or would the straight wire have the
>> >same inductance?
>>
>> That is not an inductor, that is a delay line (transmission line type).
>
>I've seen them on the plastic PCB used in a laptop keyboard. One on
>each line, for no obvious reason. Keyboard row/column scanning can't
>be time-sensitive that way.
>
>
>Regards,
>
>Uncle Steve
looked "cool" and had no idea about its functional aspects.
?-)
Uncle Steve
May 18, 2013, 11:38:07 PM5/18/13
to
John Devereux
May 19, 2013, 4:26:39 AM5/19/13
to
Uncle Steve <stev...@gmail.com> writes:
> On Sat, May 18, 2013 at 07:47:59PM -0700, josephkk wrote:
>> On Sat, 18 May 2013 09:53:09 -0400, Uncle Steve <stev...@gmail.com>
>> wrote:
>>
>> >On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> >> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> >> <tom...@verizon.net.invalid> wrote:
>> >>
>> >> >
>> >> >When an inductor is printed on a PCB in the shape of a 'square wave' or
>> >> >square zigzag, each time it zags the trace doubles back on itself. Doesn't
>> >> >this cancel the magnetic field to an extent? How much does the coil
>> >> >structure matter to a coiled inductor, or would the straight wire have the
>> >> >same inductance?
>> >>
>> >> That is not an inductor, that is a delay line (transmission line type).
>> >
>> >I've seen them on the plastic PCB used in a laptop keyboard. One on
>> >each line, for no obvious reason. Keyboard row/column scanning can't
>> >be time-sensitive that way.
>> >
>> >
>> >Regards,
>> >
>> >Uncle Steve
>>
>> It could well be that the person that did the keyboard layout thought it
>> looked "cool" and had no idea about its functional aspects.
>
> FK, I dunno. As far as I could tell they were redundant.
I wonder, could they possibly limit ESD current? A (very) poor mans
> On Sat, May 18, 2013 at 07:47:59PM -0700, josephkk wrote:
>> On Sat, 18 May 2013 09:53:09 -0400, Uncle Steve <stev...@gmail.com>
>> wrote:
>>
>> >On Fri, May 17, 2013 at 08:55:18PM -0700, josephkk wrote:
>> >> On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
>> >> <tom...@verizon.net.invalid> wrote:
>> >>
>> >> >
>> >> >When an inductor is printed on a PCB in the shape of a 'square wave' or
>> >> >square zigzag, each time it zags the trace doubles back on itself. Doesn't
>> >> >this cancel the magnetic field to an extent? How much does the coil
>> >> >structure matter to a coiled inductor, or would the straight wire have the
>> >> >same inductance?
>> >>
>> >> That is not an inductor, that is a delay line (transmission line type).
>> >
>> >I've seen them on the plastic PCB used in a laptop keyboard. One on
>> >each line, for no obvious reason. Keyboard row/column scanning can't
>> >be time-sensitive that way.
>> >
>> >
>> >Regards,
>> >
>> >Uncle Steve
>>
>> It could well be that the person that did the keyboard layout thought it
>> looked "cool" and had no idea about its functional aspects.
>
> FK, I dunno. As far as I could tell they were redundant.
ferrite bead?
You see all sorts of interesting structures on mass-market boards, like
spark gaps on power supplies or a telecoms interface.
--
John Devereux
Tom Del Rosso
May 19, 2013, 11:26:43 AM5/19/13
to
particular type of inductor, used as a choke. They do exist.
Tom Del Rosso
May 19, 2013, 11:27:04 AM5/19/13
to
Jamie
May 19, 2013, 12:54:03 PM5/19/13
to
We use square zing lanes for two reasons...
Delay and reduction of e-line propagation of near by fields.
Have it your way, but that is how I've understood and used them for years.
Now of they were circular in a square location, then that would
constitute an inductor.
You can argue all you want about it. It won't change anything.
Jamie
Tom Del Rosso
May 19, 2013, 5:14:38 PM5/19/13
to
Jamie wrote:
> Tom Del Rosso wrote:
>
> > Jamie wrote:
> >
> > > josephkk wrote:
> > >
> > > > On Mon, 13 May 2013 22:34:01 -0400, "Tom Del Rosso"
> > > > <tom...@verizon.net.invalid> wrote:
> > > >
> > > >
> > > >
> > > > > When an inductor is printed on a PCB in the shape of a 'square
> > > > > wave' or square zigzag, each time it zags the trace doubles
> > > > > back on itself. Doesn't this cancel the magnetic field to an
> > > > > extent? How much does the coil structure matter to a coiled
> > > > > inductor, or would the straight wire have the same inductance?
> > > >
> > > >
> > > > That is not an inductor, that is a delay line (transmission line
> > > > type). ?-)
> > >
> > > Exactly... :)
> >
> >
> > Not.
> >
> >
> Sorry, but it's true...
talking about it's a choke. It's conncted to the power supply. You do not
connect to power through a delay line.
Fred Bartoli
May 19, 2013, 8:56:11 PM5/19/13
to
--
Thanks,
Fred.
Tom Del Rosso
May 19, 2013, 11:24:00 PM5/19/13
to
Fred Bartoli wrote:
> Le Sun, 19 May 2013 17:14:38 -0400, Tom Del Rosso a �crit:
>
> > No it's true that delay lines are ALSO made that way, but on the
> > board I'm talking about it's a choke. It's conncted to the power
> > supply. You do not connect to power through a delay line.
>
>
> Sure you can. Just make it lambda/4.
You can use a delay line to connect power? What are you delaying?
> > No it's true that delay lines are ALSO made that way, but on the
> > board I'm talking about it's a choke. It's conncted to the power
> > supply. You do not connect to power through a delay line.
>
>
> Sure you can. Just make it lambda/4.
Rodwell
May 20, 2013, 2:33:00 AM5/20/13
to
feature. Are they?
Fred Bartoli
May 20, 2013, 5:35:49 AM5/20/13
to
Le Sun, 19 May 2013 23:24:00 -0400, Tom Del Rosso a écrit:
> Fred Bartoli wrote:
> Fred Bartoli wrote:
>> Le Sun, 19 May 2013 17:14:38 -0400, Tom Del Rosso a écrit:
>>
>> > No it's true that delay lines are ALSO made that way, but on the
>> > board I'm talking about it's a choke. It's conncted to the power
>> > supply. You do not connect to power through a delay line.
>>
>>
>> Sure you can. Just make it lambda/4.
>
> You can use a delay line to connect power? What are you delaying?
Transmission lines transform impedances they have on one side (ZL) to
>>
>> > No it's true that delay lines are ALSO made that way, but on the
>> > board I'm talking about it's a choke. It's conncted to the power
>> > supply. You do not connect to power through a delay line.
>>
>>
>> Sure you can. Just make it lambda/4.
>
> You can use a delay line to connect power? What are you delaying?
another impedance on the other side (Zin).
For a lossless line:
Zin=Zc (ZL + Zc Tan(Lr))/(Zc + ZL Tan(Lr))
with Lr=2 pi len/lambda (Lr is the reduced length in radian and len the
line length)
At lambda/4 a shorted line gives Zin= Zc Tan(Lr) with Lr->pi/2 and
transforms the s/c into an open circuit.
Obviously, at DC it's no more lambda/4 and Zin=ZL=0.
This obviously doesn't hold for wideband signals.
--
Thanks,
Fred.
Tim Williams
May 20, 2013, 6:30:45 PM5/20/13
to
"Fred Bartoli" <mynamewithA...@free.fr> wrote in message
news:5199ee75$0$2122$426a...@news.free.fr...
a... 20-some GHz satellite board, stubs and filters and amps all over.
Looks cool. They use thin 1/4 wave traces as bias tees all over (usually
with some additional LC bypass and filtering action, too).
news:5199ee75$0$2122$426a...@news.free.fr...
>>> Sure you can. Just make it lambda/4.
>>
>> You can use a delay line to connect power? What are you delaying?
>
...
>>
>> You can use a delay line to connect power? What are you delaying?
>
> At lambda/4 a shorted line gives Zin= Zc Tan(Lr) with Lr->pi/2 and
> transforms the s/c into an open circuit.
>
> Obviously, at DC it's no more lambda/4 and Zin=ZL=0.
>
> This obviously doesn't hold for wideband signals.
^^ You see it all the time on microwave stuff. Wikipedia has a picture of
> transforms the s/c into an open circuit.
>
> Obviously, at DC it's no more lambda/4 and Zin=ZL=0.
>
> This obviously doesn't hold for wideband signals.
a... 20-some GHz satellite board, stubs and filters and amps all over.
Looks cool. They use thin 1/4 wave traces as bias tees all over (usually
with some additional LC bypass and filtering action, too).
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