Does a coil also have a capaciotance?

[Bill Sloman]

On May 14, 1:13 am, "Phil Allison" <phi...@tpg.com.au> wrote:

"BillSloman= Lying Cunt"
 "Phil Allison"

"Uwe Hercksen"

** Hey Uwe,

Billis Dutch and a colossal pedant.

Actually I'm Australian

** Like hell.

You are a Dutch pig and massively autistic.

Phil's got his opinion, and the Australian government has another.

But you sound like an much bigger, German one.

Show the old fool who is boss.

Go for it - boy.

Getting a Ph.D. is the kind of thing that instills pedantic habits

** Being a massive autistic fuckwit is the real reason.

According to the ever-reliable Phil.

--
Bill Sloman, Nijmegen

 

[Michael A. Terrell]

Jamie wrote:

Joe Snodgrass wrote:
It seems to go against everything they taught us in class, but the
various turns are closely spaced conductors, separated by a dielectric
layer, just like the plates of a capacitor. TIA.
Yes they do..

this is where Self resonance frequency (SRF) comes into play. The
coil will actually resonate at a freq with out any help from external
caps.

Coil designers have to keep this in mind.

Maynard

It's actually called: "Self Resonant Frequency (SRF)"


--
You can't fix stupid. You can't even put a Band-Aid™ on it, because it's
Teflon coated.

 

[Phil Allison]

"Bill Sloman= Lying Dutch Cunt"

Actually I'm Australian

** Like hell.

You are a Dutch pig and massively autistic.

Phil's got his opinion,

**Bill Sloman is living in Nijmegen with all his rellies around and
waiting
for him to die.

In fact most of my relatives live in Sydney. I'm going to be there for
most of June, July and August.

Phil's address in Sydney has been published on the web. I should print
out a few of his more entertaining subject headings in large print and
glue them to his front door ... taking care to bring along my large ex-
Rugby-playing lawyer nephew in case Phil feels upset by bad language
on his front door.


** That is 100% a criminal threat - Bill.

Not the first one you have made either.

You show up and I will call the police and have you put in jail.

Send anyone to do your dirty work and I will put them in the ground.



.... Phil

 

[Bill Sloman]

On May 14, 3:23 am, "Phil Allison" <phi...@tpg.com.au> wrote:

 "BillSloman= Lying Dutch Cunt"

"Phil Allison"

"Uwe Hercksen"

** Hey Uwe,

Bill is Dutch and a colossal pedant.

Actually I'm Australian

** Like hell.

You are a Dutch pig and massively autistic.

Phil's got his opinion,

**Bill Sloman is living in Nijmegen with all his rellies around and waiting
for him to die.

In fact most of my relatives live in Sydney. I'm going to be there for
most of June, July and August. If my relatives are "waiting for me to
die" they aren't exactly sitting on their edge of their seats. My
mother has appreciably more money than I do and has made it to 93 so
far ....

Phil's address in Sydney has been published on the web. I should print
out a few of his more entertaining subject headings in large print and
glue them to his front door ... taking care to bring along my large ex-
Rugby-playing lawyer nephew in case Phil feels upset by bad language
on his front door.

Getting a Ph.D. is the kind of thing that instills pedantic habits

** Being a massive autistic fuckwit is the real reason.

According to the ever-reliable Phil.

Bill Sloman, Nijmegen

** See.

Phil doesn't see much - does he - and remembers less.

--
Bill Sloman, Nijmegen

 

[Okkim Atnarivik]

In sci.electronics.design Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:
: On Fri, 13 May 2011 12:04:32 -0700 (PDT), the renowned Bill Sloman
: <bill.sloman@gmail.com> wrote:
: >No. Did have an interesting conversation with a couple of guys at an
: >Analog Devices presentation earlier in the week - they are developing
: >an infra-red sensing array which basically runs on the edge of super-
: >conduction, with super-conducting quantum interference devices to
: >amplify the sensor output. The whole thing is going into a satellite
: >with a closed-circuit liquid helium refrigeration system.

: Some nasty vibrations from that cryocooler, I'll bet.

Sounds like the SAFARI instrument for the SPICA mission. Actually,
EMI causes more headache than mechanical vibrations, currently.

Regards,
Mikko

 

[Robert Baer]

Joe Snodgrass wrote:

It seems to go against everything they taught us in class, but the
various turns are closely spaced conductors, separated by a dielectric
layer, just like the plates of a capacitor. TIA.
I have a few class Qs 4 U:

1) Does a capacitor have inductance?
2) Does a 40 inch square, one inch long wire have capacitance? Inductance?
3) Does a sheet of glass have capacitance?
4) Explain your answers to all of the quesions above.

 

[Okkim Atnarivik]

In sci.electronics.design Okkim Atnarivik <Okkim.Atnarivik@twenrtyfour.fi.invalid> wrote:
: In sci.electronics.design Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:
: : On Fri, 13 May 2011 12:04:32 -0700 (PDT), the renowned Bill Sloman
: : <bill.sloman@gmail.com> wrote:
: : >No. Did have an interesting conversation with a couple of guys at an
: : >Analog Devices presentation earlier in the week - they are developing
: : >an infra-red sensing array which basically runs on the edge of super-
: : >conduction, with super-conducting quantum interference devices to
: : >amplify the sensor output. The whole thing is going into a satellite
: : >with a closed-circuit liquid helium refrigeration system.

: : Some nasty vibrations from that cryocooler, I'll bet.

: Sounds like the SAFARI instrument for the SPICA mission. Actually,
: EMI causes more headache than mechanical vibrations, currently.

To elaborate a bit: the final SQUID stage at 4K must drive several metres
of cable before there is the first location in the spacecraft with enough
cooling power to accommodate a decent semiconductor based amplifier. The 4K
cooling budget does not allow very much signal power to be generated there,
hence fighting to get enough SNR for the cable stretch with the presence of
EMI is indeed a headache. I have been considering a 4K amplifier operating
more deeply in D-class, or something with higher efficiency than a standard
SQUID anyway. An intersting twitch is that the standard SQUID in a way
*does* resemble the D-class amplifiers: the signal is effectively pulse
width modulated Josephson oscillation.

However, the schedule is so tight that there is not much opportunity to
develop anything novel or unproven, so perhaps we'll go by the brute force
and just shave the margins where-ever possible. A D-class CMOS amplifier
*might* do the job, but the handful off-the-shelf micropower CMOS comparators
I tried failed a quick test at 4K. A test would require a full custom chip
design it seems.

Regards,
Mikko

 

[Spehro Pefhany]

On Tue, 17 May 2011 15:56:04 +0300 (EEST), the renowned Okkim
Atnarivik <Okkim.Atnarivik@twentyfour.fi.invalid> wrote:

In sci.electronics.design Okkim Atnarivik <Okkim.Atnarivik@twenrtyfour.fi.invalid> wrote:
: In sci.electronics.design Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:
: : On Fri, 13 May 2011 12:04:32 -0700 (PDT), the renowned Bill Sloman
: : <bill.sloman@gmail.com> wrote:
: : >No. Did have an interesting conversation with a couple of guys at an
: : >Analog Devices presentation earlier in the week - they are developing
: : >an infra-red sensing array which basically runs on the edge of super-
: : >conduction, with super-conducting quantum interference devices to
: : >amplify the sensor output. The whole thing is going into a satellite
: : >with a closed-circuit liquid helium refrigeration system.

: : Some nasty vibrations from that cryocooler, I'll bet.

: Sounds like the SAFARI instrument for the SPICA mission. Actually,
: EMI causes more headache than mechanical vibrations, currently.

To elaborate a bit: the final SQUID stage at 4K must drive several metres
of cable before there is the first location in the spacecraft with enough
cooling power to accommodate a decent semiconductor based amplifier. The 4K
cooling budget does not allow very much signal power to be generated there,
hence fighting to get enough SNR for the cable stretch with the presence of
EMI is indeed a headache. I have been considering a 4K amplifier operating
more deeply in D-class, or something with higher efficiency than a standard
SQUID anyway. An intersting twitch is that the standard SQUID in a way
*does* resemble the D-class amplifiers: the signal is effectively pulse
width modulated Josephson oscillation.

However, the schedule is so tight that there is not much opportunity to
develop anything novel or unproven, so perhaps we'll go by the brute force
and just shave the margins where-ever possible. A D-class CMOS amplifier
*might* do the job, but the handful off-the-shelf micropower CMOS comparators
I tried failed a quick test at 4K. A test would require a full custom chip
design it seems.

Regards,
Mikko

Did you end up using the SiGe option?



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

 

[Paul Hovnanian P.E.]

John Larkin wrote:

[snip]

That was comedy?

Yes. In the fine tradition going all the way back to Sophocles.

--
Paul Hovnanian mailtoaul@Hovnanian.com
------------------------------------------------------------------
Human beings were created by water to transport it uphill.

 

[George Herold]

On May 17, 8:56 am, Okkim Atnarivik
<Okkim.Atnari...@twentyfour.fi.invalid> wrote:

In sci.electronics.design Okkim Atnarivik <Okkim.Atnari...@twenrtyfour.fi..invalid> wrote:
: In sci.electronics.design Spehro Pefhany <speffS...@interlogdotyou.knowwhat> wrote:
: : On Fri, 13 May 2011 12:04:32 -0700 (PDT), the renowned Bill Sloman: : <bill.slo...@gmail.com> wrote:

: : >No. Did have an interesting conversation with a couple of guys at an
: : >Analog Devices presentation earlier in the week - they are developing
: : >an infra-red sensing array which basically runs on the edge of super-
: : >conduction, with super-conducting quantum interference devices to
: : >amplify the sensor output. The whole thing is going into a satellite
: : >with a closed-circuit liquid helium refrigeration system.

: : Some nasty vibrations from that cryocooler, I'll bet.

:   Sounds like the SAFARI instrument for the SPICA mission. Actually,
: EMI causes more headache than mechanical vibrations, currently.

  To elaborate a bit: the final SQUID stage at 4K must drive several metres
of cable before there is the first location in the spacecraft with enough
cooling power to accommodate a decent semiconductor based amplifier. The 4K
cooling budget does not allow very much signal power to be generated there,
hence fighting to get enough SNR for the cable stretch with the presence of
EMI is indeed a headache. I have been considering a 4K amplifier operating
more deeply in D-class, or something with higher efficiency than a standard
SQUID anyway. An intersting twitch is that the standard SQUID in a way
*does* resemble the D-class amplifiers: the signal is effectively pulse
width modulated Josephson oscillation.

By EMI I assume you are talking about 'cr@p' leaking in through the
cable shield.
This is probably silly, but could an active shield driven from the
high temperature end help with EMI? I was playing around with a
driven shield last year to help get the signal out. (reduce cable
capacitance) So shield was driven by the signal. To shield from EMI
can you drive the shield with a signal from the outside? Some sort of
antenna? SQUIDS are pretty high frequency though, I was only doing
1MHz stuff.

George H.

  However, the schedule is so tight that there is not much opportunity to
develop anything novel or unproven, so perhaps we'll go by the brute force
and just shave the margins where-ever possible. A D-class CMOS amplifier
*might* do the job, but the handful off-the-shelf micropower CMOS comparators
I tried failed a quick test at 4K. A test would require a full custom chip
design it seems.

     Regards,
               Mikko

 

[Okkim Atnarivik]

In sci.electronics.design Spehro Pefhany <speffSNIP@interlogdotyou.knowwhat> wrote:
: Did you end up using the SiGe option?

SiGe is the obvious choice for the cryogenic LNA at the 'warm' 110K
end of the cable, but its efficiency when operated class-A causes too
much dissipation at 4K. Making a class-B or class-D amplifier out
of packaged SiGe discretes is probably too tedious, especially dealing
with the stability issues and the dissipation budget when there are many
active devices per an amp. Custom transistors or an ASIC would be
conceivable, e.g. SiGe devices from the AMS SiGe BiCMOS process (available
via MOSIS or Europractice) are known to function at 4K. Weinreb and his
colleagues have recently fabbed cryogenic SiGe amps for the SKA using
(I think) IBM SiGe process. A SiGe ASIC is probably a slow
path, however, which is likely to take several design iterations. We
have a superconducting foundry in-house, hence I'd prefer to keep the
control in our own hands and try to manage with SQUID-related devices.

Regards,
Mikko

 

[Okkim Atnarivik]

In sci.electronics.design George Herold <gherold@teachspin.com> wrote:
: By EMI I assume you are talking about 'cr@p' leaking in through the
: cable shield.
: This is probably silly, but could an active shield driven from the
: high temperature end help with EMI? I was playing around with a
: driven shield last year to help get the signal out. (reduce cable
: capacitance) So shield was driven by the signal. To shield from EMI

We did consider guarding, but that becomes tough at high frequencies
where the cable represents a (small) fraction of the wavelengths. Already a
small phase shift between the EMI and the guard signal would cause
untolerably strong coupling.

Regards,
Mikko