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Groups > sci.electronics.design > #518255 > unrolled thread
| Started by | John Larkin <jjlarkin@highland_snip_technology.com> |
|---|---|
| First post | 2018-10-03 15:03 -0700 |
| Last post | 2018-10-05 10:44 -0400 |
| Articles | 20 on this page of 96 — 26 participants |
Back to article view | Back to sci.electronics.design
really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-03 15:03 -0700
Re: really fast buffers Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-03 15:23 -0700
Re: really fast buffers Andy Bennet <andyb@andy.com> - 2018-10-04 08:20 +0100
Re: really fast buffers Lasse Langwadt Christensen <langwadt@fonz.dk> - 2018-10-04 08:45 -0700
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-03 15:52 -0700
Re: really fast buffers George Herold <gherold@teachspin.com> - 2018-10-03 18:08 -0700
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-03 20:02 -0700
Re: really fast buffers bitrex <user@example.net> - 2018-10-03 21:54 -0400
Re: really fast buffers Steve Wilson <9fe142ac@gmail.com> - 2018-10-03 20:10 -0700
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-03 20:40 -0700
Re: really fast buffers pcdhobbs@gmail.com - 2018-10-04 05:00 -0700
Re: really fast buffers Steve Wilson <9fe142ac@gmail.com> - 2018-10-04 08:39 -0700
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-04 12:38 -0400
Re: really fast buffers Steve Wilson <9fe142ac@gmail.com> - 2018-10-04 14:35 -0700
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-04 18:27 -0400
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-05 03:21 +0000
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-05 10:38 -0400
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-04 11:50 -0700
Re: really fast buffers Clifford Heath <no.spam@please.net> - 2018-10-05 09:26 +1000
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-04 17:09 -0700
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-05 03:12 +0000
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-05 14:18 -0700
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-05 23:42 +0000
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-06 14:41 -0400
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-05 03:09 +0000
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-05 10:40 -0400
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-05 11:06 -0400
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-05 19:16 -0700
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-05 14:26 -0700
Re: really fast buffers George Herold <gherold@teachspin.com> - 2018-10-05 18:36 -0700
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-05 19:22 -0700
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-06 02:28 +0000
Re: really fast buffers <698839253X6D445TD@nospam.org> - 2018-10-06 06:03 +0000
Re: really fast buffers Steve Wilson <9fe142ac@gmail.com> - 2018-10-05 23:41 -0700
Re: really fast buffers <698839253X6D445TD@nospam.org> - 2018-10-06 08:12 +0000
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-06 14:46 -0400
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-06 19:03 +0000
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-06 15:32 -0400
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-06 20:08 +0000
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-06 22:19 +0200
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-06 21:02 +0000
Re: really fast buffers tabbypurr@gmail.com - 2018-10-06 16:57 -0700
Re: really fast buffers krw@notreal.com - 2018-10-06 22:30 -0400
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-07 04:30 +0200
Re: really fast buffers <698839253X6D445TD@nospam.org> - 2018-10-07 07:15 +0000
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-07 08:24 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-07 18:51 -0700
Re: really fast buffers tabbypurr@gmail.com - 2018-10-08 08:16 -0700
Re: really fast buffers Winfield Hill <hill@rowland.harvard.edu> - 2018-10-07 07:19 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-10 00:38 -0700
Re: really fast buffers tabbypurr@gmail.com - 2018-10-10 03:02 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-10 04:07 -0700
Re: really fast buffers DecadentLinuxUserNumeroUno@decadence.org - 2018-10-10 11:28 +0000
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-11 22:06 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-12 00:08 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-13 22:29 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-14 00:30 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-15 19:38 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-15 20:55 -0700
Re: really fast buffers tabbypurr@gmail.com - 2018-10-14 04:31 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-14 07:29 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-15 19:42 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-15 20:57 -0700
Re: really fast buffers tabbypurr@gmail.com - 2018-10-16 08:41 -0700
Re: really fast buffers krw@notreal.com - 2018-10-16 17:38 -0400
Re: really fast buffers bill.sloman@ieee.org - 2018-10-16 19:37 -0700
Re: really fast buffers bill.sloman@ieee.org - 2018-10-16 19:40 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-15 19:40 -0700
Re: really fast buffers Robert Baer <robertbaer@localnet.com> - 2018-10-11 22:04 -0700
Re: really fast buffers tabbypurr@gmail.com - 2018-10-12 08:02 -0700
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-10 14:06 +0200
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-10 08:31 -0700
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-11 01:49 +0200
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-10 17:41 -0700
Re: really fast buffers "John Miles, KE5FX" <jmiles@gmail.com> - 2018-10-10 20:53 -0700
Re: really fast buffers Jasen Betts <jasen@xnet.co.nz> - 2018-10-11 05:47 +0000
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-11 12:35 +0200
Re: really fast buffers George Herold <gherold@teachspin.com> - 2018-10-06 12:39 -0700
Re: really fast buffers Steve Wilson <no@spam.com> - 2018-10-06 20:11 +0000
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-08 20:26 -0700
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-06 14:45 -0400
Re: really fast buffers George Herold <gherold@teachspin.com> - 2018-10-06 12:46 -0700
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-08 21:00 -0700
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-09 07:11 +0200
Re: really fast buffers Chris Jones <lugnut808@spam.yahoo.com> - 2018-10-09 23:20 +1100
Re: really fast buffers Jeroen Belleman <jeroen@nospam.please> - 2018-10-09 15:17 +0200
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-04 09:18 -0700
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-04 12:39 -0400
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-04 11:51 -0700
Re: really fast buffers Piotr Wyderski <peter.pan@neverland.mil> - 2018-10-08 13:19 +0200
Re: really fast buffers John Larkin <jjlarkin@highlandtechnology.com> - 2018-10-08 08:52 -0700
Re: really fast buffers whit3rd <whit3rd@gmail.com> - 2018-10-04 11:57 -0700
Re: really fast buffers David Nadlinger <david@klickverbot.at> - 2018-10-04 23:05 +0100
Re: really fast buffers John Larkin <jjlarkin@highland_snip_technology.com> - 2018-10-04 17:23 -0700
Re: really fast buffers Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> - 2018-10-05 11:26 +0200
Re: really fast buffers Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2018-10-05 10:44 -0400
Page 3 of 5 — ← Prev page 1 2 [3] 4 5 Next page →
| From | Steve Wilson <no@spam.com> |
|---|---|
| Date | 2018-10-06 21:02 +0000 |
| Message-ID | <XnsA973AD4CC2A18idtokenpost@69.16.179.23> |
| In reply to | #518582 |
Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote:
> Am 06.10.2018 um 21:03 schrieb Steve Wilson:
>> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>> On 10/5/18 10:28 PM, Steve Wilson wrote:
>>>> George Herold <gherold@teachspin.com> wrote:
>>>>> It oscillates because of a slow edge and no hysteresis?
>>>> It oscillates because of inductance in the base lead. Along with the
>>>> base- emitter capacitance and capacitance from the emitter to ground,
>>>> this forms a Colpitts oscillator, which is one of the most vigorous
>>>> oscillators known. It can accept an extremely wide range of
>>>> parameters and still oscillate.
>>>> The purpose of the resistor in the base lead is to dampen the Q of
>>>> the tank so oscillations are no longer possible.
>>>>> Is it similar to cap. multiplier oscillations?
>>>> Could be. Any place where you have some inductance in the base and
>>>> capacitance from the emitter to ground could form a Colpitts,
>>>> especially where you have some inductance in the emitter lead.
>>> The key ingredient is negative input resistance.
>> That term always bothered me. Negative input resistance to what? If you
>> look a the base input impedance, it is always positive. When the
>> oscillations get going, the transistor is cut off most of the time.
>> Where is the negative input impedance then?
> Negative input impedance from base/gate to GND. It is not positive and
> it sustains the oscillation. And it can be measured.
> https://www.flickr.com/photos/137684711@N07/34701106245/in/album-72157682
> 404684680/
> This is S11 of a baseband amplifier with absurdly high gm to enforce
> low voltage noise with IF3602 JFETs. Everything that is outside the
> circle that goes through X=0 has a negative real part of the input
> impedance. The exact values at the 3 cursors are given in the picture.
> The green line is outside of that circle for most of the intended
> frequency range, until the amplifier runs out of steam.
> BTW I have found no way to cure that without compensating it with a
> positive resistance in the input or cutting the feedback. None of this
> is attractive in a low noise measurement amplifier. :-( :-( :-(
> Those network analyzers are so unforgiving. If you just ignore it,
> you can happily measure around in circuits that have enough source
> resistance. Just sometimes, it won't work. There are lots of
> low noise amplifiers that share its fate.
> BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier from
> AOE3. The non-differential version, since my source is never centered
> around 0 Vdc. Works as promised. :-)
> Yes, it could use even more 'lytics, but that was a test balloon for
> a chopper amplifier. At 500 KHz the caps are no more that critical.
> https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662
> 535945536/
> cheers,
> Gerhard
Gerhard, I have the utmost appreciation for your accomplishements and your
skill in electronics.
However, a simple Colpitts oscillator in LTspice shows the input impedance
at the base is positive. The emitter current is also in phase with the base
current.
Another example is a simple 74HC04 Pierce oscillator with an LC tank as
feedback.
The input impedance of the 74HC04 is capacitive. The impedance is
Xc = 1 / (2piFC)
There is no negative input resistance.
A further example is "A General Theory of Phase Noise in Electrical
Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee,
Member, IEEE"
https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf
"Consider as one example the Colpitts oscillator of Fig. 5(a).
The collector voltage and the collector current of the transistor
are shown in Fig. 13. Note that the collector current consists
of a short period of large current followed by a quiet interval.
The surge of current occurs at the minimum of the voltage
across the tank where the ISF is small."
Clearly the collector current is a function of the base current, and is in
phase with the base current. The input impedance at the base is positive,
therefore there is no negative resistance term available.
Oscillators work on positive feedback. If the loop gain is positive and in
phase, oscillations ensue.
[toc] | [prev] | [next] | [standalone]
| From | tabbypurr@gmail.com |
|---|---|
| Date | 2018-10-06 16:57 -0700 |
| Message-ID | <3215103f-12af-4f51-b6c7-3b16d29a2929@googlegroups.com> |
| In reply to | #518587 |
On Saturday, 6 October 2018 22:02:14 UTC+1, Steve Wilson wrote: > Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote: > > > Am 06.10.2018 um 21:03 schrieb Steve Wilson: > >> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > > >>> On 10/5/18 10:28 PM, Steve Wilson wrote: > >>>> George Herold <gherold@teachspin.com> wrote: > > >>>>> It oscillates because of a slow edge and no hysteresis? > > >>>> It oscillates because of inductance in the base lead. Along with the > >>>> base- emitter capacitance and capacitance from the emitter to ground, > >>>> this forms a Colpitts oscillator, which is one of the most vigorous > >>>> oscillators known. It can accept an extremely wide range of > >>>> parameters and still oscillate. > > >>>> The purpose of the resistor in the base lead is to dampen the Q of > >>>> the tank so oscillations are no longer possible. > > >>>>> Is it similar to cap. multiplier oscillations? > > >>>> Could be. Any place where you have some inductance in the base and > >>>> capacitance from the emitter to ground could form a Colpitts, > >>>> especially where you have some inductance in the emitter lead. > > >>> The key ingredient is negative input resistance. > > >> That term always bothered me. Negative input resistance to what? If you > >> look a the base input impedance, it is always positive. When the > >> oscillations get going, the transistor is cut off most of the time. > >> Where is the negative input impedance then? > > > Negative input impedance from base/gate to GND. It is not positive and > > it sustains the oscillation. And it can be measured. > > > https://www.flickr.com/photos/137684711@N07/34701106245/in/album-72157682 > > 404684680/ > > > This is S11 of a baseband amplifier with absurdly high gm to enforce > > low voltage noise with IF3602 JFETs. Everything that is outside the > > circle that goes through X=0 has a negative real part of the input > > impedance. The exact values at the 3 cursors are given in the picture. > > > The green line is outside of that circle for most of the intended > > frequency range, until the amplifier runs out of steam. > > > > BTW I have found no way to cure that without compensating it with a > > positive resistance in the input or cutting the feedback. None of this > > is attractive in a low noise measurement amplifier. :-( :-( :-( > > > Those network analyzers are so unforgiving. If you just ignore it, > > you can happily measure around in circuits that have enough source > > resistance. Just sometimes, it won't work. There are lots of > > low noise amplifiers that share its fate. > > > BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier from > > AOE3. The non-differential version, since my source is never centered > > around 0 Vdc. Works as promised. :-) > > > Yes, it could use even more 'lytics, but that was a test balloon for > > a chopper amplifier. At 500 KHz the caps are no more that critical. > > > https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662 > > 535945536/ > > > cheers, > > Gerhard > > Gerhard, I have the utmost appreciation for your accomplishements and your > skill in electronics. > > However, a simple Colpitts oscillator in LTspice shows the input impedance > at the base is positive. The emitter current is also in phase with the base > current. > > Another example is a simple 74HC04 Pierce oscillator with an LC tank as > feedback. > > The input impedance of the 74HC04 is capacitive. The impedance is > > Xc = 1 / (2piFC) > > There is no negative input resistance. > > A further example is "A General Theory of Phase Noise in Electrical > Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee, > Member, IEEE" > > https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf > > "Consider as one example the Colpitts oscillator of Fig. 5(a). > The collector voltage and the collector current of the transistor > are shown in Fig. 13. Note that the collector current consists > of a short period of large current followed by a quiet interval. > The surge of current occurs at the minimum of the voltage > across the tank where the ISF is small." > > Clearly the collector current is a function of the base current, and is in > phase with the base current. The input impedance at the base is positive, > therefore there is no negative resistance term available. > > Oscillators work on positive feedback. If the loop gain is positive and in > phase, oscillations ensue. FWIW it's not hard to demonstrate the existence of oscillators that rely purely on negative resistance. L, C, carbon arc. The v/i plot of the carbon arc shows positive large signal dc resistance, negative small signal ac resistance over a limited v swing. NT
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| From | krw@notreal.com |
|---|---|
| Date | 2018-10-06 22:30 -0400 |
| Message-ID | <rsrirdhi2qm89pa1uokihp2j9ocdv0iaef@4ax.com> |
| In reply to | #518596 |
On Sat, 6 Oct 2018 16:57:16 -0700 (PDT), tabbypurr@gmail.com wrote: >On Saturday, 6 October 2018 22:02:14 UTC+1, Steve Wilson wrote: >> Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote: >> >> > Am 06.10.2018 um 21:03 schrieb Steve Wilson: >> >> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >> >> >>> On 10/5/18 10:28 PM, Steve Wilson wrote: >> >>>> George Herold <gherold@teachspin.com> wrote: >> >> >>>>> It oscillates because of a slow edge and no hysteresis? >> >> >>>> It oscillates because of inductance in the base lead. Along with the >> >>>> base- emitter capacitance and capacitance from the emitter to ground, >> >>>> this forms a Colpitts oscillator, which is one of the most vigorous >> >>>> oscillators known. It can accept an extremely wide range of >> >>>> parameters and still oscillate. >> >> >>>> The purpose of the resistor in the base lead is to dampen the Q of >> >>>> the tank so oscillations are no longer possible. >> >> >>>>> Is it similar to cap. multiplier oscillations? >> >> >>>> Could be. Any place where you have some inductance in the base and >> >>>> capacitance from the emitter to ground could form a Colpitts, >> >>>> especially where you have some inductance in the emitter lead. >> >> >>> The key ingredient is negative input resistance. >> >> >> That term always bothered me. Negative input resistance to what? If you >> >> look a the base input impedance, it is always positive. When the >> >> oscillations get going, the transistor is cut off most of the time. >> >> Where is the negative input impedance then? >> >> > Negative input impedance from base/gate to GND. It is not positive and >> > it sustains the oscillation. And it can be measured. >> >> > https://www.flickr.com/photos/137684711@N07/34701106245/in/album-72157682 >> > 404684680/ >> >> > This is S11 of a baseband amplifier with absurdly high gm to enforce >> > low voltage noise with IF3602 JFETs. Everything that is outside the >> > circle that goes through X=0 has a negative real part of the input >> > impedance. The exact values at the 3 cursors are given in the picture. >> >> > The green line is outside of that circle for most of the intended >> > frequency range, until the amplifier runs out of steam. >> >> >> > BTW I have found no way to cure that without compensating it with a >> > positive resistance in the input or cutting the feedback. None of this >> > is attractive in a low noise measurement amplifier. :-( :-( :-( >> >> > Those network analyzers are so unforgiving. If you just ignore it, >> > you can happily measure around in circuits that have enough source >> > resistance. Just sometimes, it won't work. There are lots of >> > low noise amplifiers that share its fate. >> >> > BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier from >> > AOE3. The non-differential version, since my source is never centered >> > around 0 Vdc. Works as promised. :-) >> >> > Yes, it could use even more 'lytics, but that was a test balloon for >> > a chopper amplifier. At 500 KHz the caps are no more that critical. >> >> > https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662 >> > 535945536/ >> >> > cheers, >> > Gerhard >> >> Gerhard, I have the utmost appreciation for your accomplishements and your >> skill in electronics. >> >> However, a simple Colpitts oscillator in LTspice shows the input impedance >> at the base is positive. The emitter current is also in phase with the base >> current. >> >> Another example is a simple 74HC04 Pierce oscillator with an LC tank as >> feedback. >> >> The input impedance of the 74HC04 is capacitive. The impedance is >> >> Xc = 1 / (2piFC) >> >> There is no negative input resistance. >> >> A further example is "A General Theory of Phase Noise in Electrical >> Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee, >> Member, IEEE" >> >> https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf >> >> "Consider as one example the Colpitts oscillator of Fig. 5(a). >> The collector voltage and the collector current of the transistor >> are shown in Fig. 13. Note that the collector current consists >> of a short period of large current followed by a quiet interval. >> The surge of current occurs at the minimum of the voltage >> across the tank where the ISF is small." >> >> Clearly the collector current is a function of the base current, and is in >> phase with the base current. The input impedance at the base is positive, >> therefore there is no negative resistance term available. >> >> Oscillators work on positive feedback. If the loop gain is positive and in >> phase, oscillations ensue. > > >FWIW it's not hard to demonstrate the existence of oscillators that rely purely on negative resistance. L, C, carbon arc. The v/i plot of the carbon arc shows positive large signal dc resistance, negative small signal ac resistance over a limited v swing. > Tunnel diodes
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| From | Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> |
|---|---|
| Date | 2018-10-07 04:30 +0200 |
| Message-ID | <g1t9erFjdq1U1@mid.individual.net> |
| In reply to | #518587 |
Am 06.10.2018 um 23:02 schrieb Steve Wilson:
> Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote:
Some pages of Randall W. Rhea: Discrete oscillator Design.
That won't stay there for long, but for the discussion,
methinks it is fair use. The book is worth every penny.
<
https://www.flickr.com/photos/137684711@N07/44424328234/in/album-72157672050645837/
>
Sorry for the quick & dirty repro. 04:30 am here.
Have a good night.
Gerhard
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| From | <698839253X6D445TD@nospam.org> |
|---|---|
| Date | 2018-10-07 07:15 +0000 |
| Message-ID | <ppcbro$vq1$1@gioia.aioe.org> |
| In reply to | #518587 |
Steve Wilson >Another example is a simple 74HC04 Pierce oscillator with an LC tank as >feedback. > >The input impedance of the 74HC04 is capacitive. The impedance is > >Xc = 1 / (2piFC) > >There is no negative input resistance. > >A further example is "A General Theory of Phase Noise in Electrical >Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee, >Member, IEEE" > >https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf > >"Consider as one example the Colpitts oscillator of Fig. 5(a). >The collector voltage and the collector current of the transistor >are shown in Fig. 13. Note that the collector current consists >of a short period of large current followed by a quiet interval. >The surge of current occurs at the minimum of the voltage >across the tank where the ISF is small." > >Clearly the collector current is a function of the base current, and is in >phase with the base current. The input impedance at the base is positive, >therefore there is no negative resistance term available. > >Oscillators work on positive feedback. If the loop gain is positive and in >phase, oscillations ensue. Steve I completely agree with your viewpoint. Just saying 'input has negative impedance' does not explain a thing, and then adding a resistor to make it positive again is fake close to string theory. Better is to understand the Cbe - CeGND step up, and that can be compensated for in many ways and is of no significance when driving the base with some circuits. I have had exactly one case of an oscillating emitter follower in my life, and that was in a missile tracking system, replacing the transistor fixed it, not all trannies are the same ... I do not use base resistors in my RF amps, that just decreases performance. And no those do not oscillate. You oscillators are doing something basically wrong, layout? ;-) hehe ;-)
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| From | John Larkin <jjlarkin@highlandtechnology.com> |
|---|---|
| Date | 2018-10-07 08:24 -0700 |
| Message-ID | <b89krd9b36df7tlspmenem6ihpjatht424@4ax.com> |
| In reply to | #518587 |
On Sat, 06 Oct 2018 21:02:09 GMT, Steve Wilson <no@spam.com> wrote: >Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote: > >> Am 06.10.2018 um 21:03 schrieb Steve Wilson: >>> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > >>>> On 10/5/18 10:28 PM, Steve Wilson wrote: >>>>> George Herold <gherold@teachspin.com> wrote: > >>>>>> It oscillates because of a slow edge and no hysteresis? > >>>>> It oscillates because of inductance in the base lead. Along with the >>>>> base- emitter capacitance and capacitance from the emitter to ground, >>>>> this forms a Colpitts oscillator, which is one of the most vigorous >>>>> oscillators known. It can accept an extremely wide range of >>>>> parameters and still oscillate. > >>>>> The purpose of the resistor in the base lead is to dampen the Q of >>>>> the tank so oscillations are no longer possible. > >>>>>> Is it similar to cap. multiplier oscillations? > >>>>> Could be. Any place where you have some inductance in the base and >>>>> capacitance from the emitter to ground could form a Colpitts, >>>>> especially where you have some inductance in the emitter lead. > >>>> The key ingredient is negative input resistance. > >>> That term always bothered me. Negative input resistance to what? If you >>> look a the base input impedance, it is always positive. When the >>> oscillations get going, the transistor is cut off most of the time. >>> Where is the negative input impedance then? > >> Negative input impedance from base/gate to GND. It is not positive and >> it sustains the oscillation. And it can be measured. > >> https://www.flickr.com/photos/137684711@N07/34701106245/in/album-72157682 >> 404684680/ > >> This is S11 of a baseband amplifier with absurdly high gm to enforce >> low voltage noise with IF3602 JFETs. Everything that is outside the >> circle that goes through X=0 has a negative real part of the input >> impedance. The exact values at the 3 cursors are given in the picture. > >> The green line is outside of that circle for most of the intended >> frequency range, until the amplifier runs out of steam. > > >> BTW I have found no way to cure that without compensating it with a >> positive resistance in the input or cutting the feedback. None of this >> is attractive in a low noise measurement amplifier. :-( :-( :-( > >> Those network analyzers are so unforgiving. If you just ignore it, >> you can happily measure around in circuits that have enough source >> resistance. Just sometimes, it won't work. There are lots of >> low noise amplifiers that share its fate. > >> BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier from >> AOE3. The non-differential version, since my source is never centered >> around 0 Vdc. Works as promised. :-) > >> Yes, it could use even more 'lytics, but that was a test balloon for >> a chopper amplifier. At 500 KHz the caps are no more that critical. > >> https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662 >> 535945536/ > >> cheers, >> Gerhard > >Gerhard, I have the utmost appreciation for your accomplishements and your >skill in electronics. > >However, a simple Colpitts oscillator in LTspice shows the input impedance >at the base is positive. The emitter current is also in phase with the base >current. > >Another example is a simple 74HC04 Pierce oscillator with an LC tank as >feedback. > >The input impedance of the 74HC04 is capacitive. The impedance is > >Xc = 1 / (2piFC) > >There is no negative input resistance. > >A further example is "A General Theory of Phase Noise in Electrical >Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee, >Member, IEEE" > >https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf > >"Consider as one example the Colpitts oscillator of Fig. 5(a). >The collector voltage and the collector current of the transistor >are shown in Fig. 13. Note that the collector current consists >of a short period of large current followed by a quiet interval. >The surge of current occurs at the minimum of the voltage >across the tank where the ISF is small." > >Clearly the collector current is a function of the base current, and is in >phase with the base current. The input impedance at the base is positive, >therefore there is no negative resistance term available. > >Oscillators work on positive feedback. If the loop gain is positive and in >phase, oscillations ensue. Not always. Most positive feedback loops just latch in one state. -- John Larkin Highland Technology, Inc lunatic fringe electronics
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| From | bill.sloman@ieee.org |
|---|---|
| Date | 2018-10-07 18:51 -0700 |
| Message-ID | <87e0de3f-5858-4465-90e6-db81019ce8c6@googlegroups.com> |
| In reply to | #518640 |
On Monday, October 8, 2018 at 2:24:45 AM UTC+11, John Larkin wrote: > On Sat, 06 Oct 2018 21:02:09 GMT, Steve Wilson <no@spam.com> wrote: > > >Gerhard Hoffmann <ghf@hoffmann-hochfrequenz.de> wrote: > > > >> Am 06.10.2018 um 21:03 schrieb Steve Wilson: > >>> Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: > > > >>>> On 10/5/18 10:28 PM, Steve Wilson wrote: > >>>>> George Herold <gherold@teachspin.com> wrote: > > > >>>>>> It oscillates because of a slow edge and no hysteresis? > > > >>>>> It oscillates because of inductance in the base lead. Along with the > >>>>> base- emitter capacitance and capacitance from the emitter to ground, > >>>>> this forms a Colpitts oscillator, which is one of the most vigorous > >>>>> oscillators known. It can accept an extremely wide range of > >>>>> parameters and still oscillate. > > > >>>>> The purpose of the resistor in the base lead is to dampen the Q of > >>>>> the tank so oscillations are no longer possible. > > > >>>>>> Is it similar to cap. multiplier oscillations? > > > >>>>> Could be. Any place where you have some inductance in the base and > >>>>> capacitance from the emitter to ground could form a Colpitts, > >>>>> especially where you have some inductance in the emitter lead. > > > >>>> The key ingredient is negative input resistance. > > > >>> That term always bothered me. Negative input resistance to what? If you > >>> look a the base input impedance, it is always positive. When the > >>> oscillations get going, the transistor is cut off most of the time. > >>> Where is the negative input impedance then? > > > >> Negative input impedance from base/gate to GND. It is not positive and > >> it sustains the oscillation. And it can be measured. > > > >> https://www.flickr.com/photos/137684711@N07/34701106245/in/album-72157682 > >> 404684680/ > > > >> This is S11 of a baseband amplifier with absurdly high gm to enforce > >> low voltage noise with IF3602 JFETs. Everything that is outside the > >> circle that goes through X=0 has a negative real part of the input > >> impedance. The exact values at the 3 cursors are given in the picture. > > > >> The green line is outside of that circle for most of the intended > >> frequency range, until the amplifier runs out of steam. > > > > > >> BTW I have found no way to cure that without compensating it with a > >> positive resistance in the input or cutting the feedback. None of this > >> is attractive in a low noise measurement amplifier. :-( :-( :-( > > > >> Those network analyzers are so unforgiving. If you just ignore it, > >> you can happily measure around in circuits that have enough source > >> resistance. Just sometimes, it won't work. There are lots of > >> low noise amplifiers that share its fate. > > > >> BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier from > >> AOE3. The non-differential version, since my source is never centered > >> around 0 Vdc. Works as promised. :-) > > > >> Yes, it could use even more 'lytics, but that was a test balloon for > >> a chopper amplifier. At 500 KHz the caps are no more that critical. > > > >> https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662 > >> 535945536/ > > > >> cheers, > >> Gerhard > > > >Gerhard, I have the utmost appreciation for your accomplishements and your > >skill in electronics. > > > >However, a simple Colpitts oscillator in LTspice shows the input impedance > >at the base is positive. The emitter current is also in phase with the base > >current. > > > >Another example is a simple 74HC04 Pierce oscillator with an LC tank as > >feedback. > > > >The input impedance of the 74HC04 is capacitive. The impedance is > > > >Xc = 1 / (2piFC) > > > >There is no negative input resistance. > > > >A further example is "A General Theory of Phase Noise in Electrical > >Oscillators, by Ali Hajimiri, Student Member, IEEE, and Thomas H. Lee, > >Member, IEEE" > > > >https://authors.library.caltech.edu/4917/1/HAJieeejssc98.pdf > > > >"Consider as one example the Colpitts oscillator of Fig. 5(a). > >The collector voltage and the collector current of the transistor > >are shown in Fig. 13. Note that the collector current consists > >of a short period of large current followed by a quiet interval. > >The surge of current occurs at the minimum of the voltage > >across the tank where the ISF is small." > > > >Clearly the collector current is a function of the base current, and is in > >phase with the base current. The input impedance at the base is positive, > >therefore there is no negative resistance term available. > > > >Oscillators work on positive feedback. If the loop gain is positive and in > >phase, oscillations ensue. > > Not always. Most positive feedback loops just latch in one state. An over-general claim. If the positive gain is between 1.0 and 2.0 it isn't even unstable and won't latch. Back in 1979, I put a positive gain of 1.003 into a circuit to raise the current through a platinum resistive sensor as it got hotter, to compensate for the decline in the temperature coefficient of resistance with increasing temperature. The clown that took over the circuit claimed that this would make the circuit "unstable", and replaced it with a diode-break linear approximation. Someone at Honeywell seems to have invented the same circuit as I had at much the same time, and it worked fine in the field. Positive feedback loops can be designed for all sorts of jobs, and - if they are designed by people who know what they are doing - they won't latch up. -- Bill Sloman, Sydney
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| From | tabbypurr@gmail.com |
|---|---|
| Date | 2018-10-08 08:16 -0700 |
| Message-ID | <f55ae6a7-4883-4663-a059-5dbcb210b691@googlegroups.com> |
| In reply to | #518640 |
On Sunday, 7 October 2018 16:24:45 UTC+1, John Larkin wrote: > On Sat, 06 Oct 2018 21:02:09 GMT, Steve Wilson <no@spam.com> wrote: > >Oscillators work on positive feedback. If the loop gain is positive and in > >phase, oscillations ensue. > > Not always. Most positive feedback loops just latch in one state. And at the other end of the scale some can produce a gain of far over 1,000 and be somewhat stable. That isn't the once round loop gain of course, it's V_out over V_in. NT
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| From | Winfield Hill <hill@rowland.harvard.edu> |
|---|---|
| Date | 2018-10-07 07:19 -0700 |
| Message-ID | <ppd4lu01sfe@drn.newsguy.com> |
| In reply to | #518582 |
Gerhard Hoffmann wrote...
>
> BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier
> from AoE3. The non-differential version, since my source is
> never centered around 0 Vdc. Works as promised. :-)
>
> Yes, it could use even more 'lytics, but that was a test balloon for
> a chopper amplifier. At 500 kHz the caps are no more that critical.
>
>https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662535945536/
Nice! Please post your complete schematic. We only show a
common-emitter amplifying stage, with millions of paralleled
transistors, and our measurements, pages 506-509.
--
Thanks,
- Win
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2018-10-10 00:38 -0700 |
| Message-ID | <C%hvD.145878$wV2.45096@fx01.iad> |
| In reply to | #518631 |
Winfield Hill wrote: > Gerhard Hoffmann wrote... >> >> BTW, I have built a variation of Winfield's 70 pV/rtHz amplifier >> from AoE3. The non-differential version, since my source is >> never centered around 0 Vdc. Works as promised. :-) >> >> Yes, it could use even more 'lytics, but that was a test balloon for >> a chopper amplifier. At 500 kHz the caps are no more that critical. >> >> https://www.flickr.com/photos/137684711@N07/45141749941/in/album-72157662535945536/ > > Nice! Please post your complete schematic. We only show a > common-emitter amplifying stage, with millions of paralleled > transistors, and our measurements, pages 506-509. > > In certain cases, one can achieve what LOOKS like negative time delay. Input pulse has a (relatively) slow rise time, and feeds a fast op-amp set to sense low threshold of the rise...output pops up beyond logic threshold BEFORE input.
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| From | tabbypurr@gmail.com |
|---|---|
| Date | 2018-10-10 03:02 -0700 |
| Message-ID | <7dc2dbc0-33cf-454a-8867-3e66b214fecd@googlegroups.com> |
| In reply to | #518862 |
On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > In certain cases, one can achieve what LOOKS like negative time delay. > Input pulse has a (relatively) slow rise time, and feeds a fast > op-amp set to sense low threshold of the rise...output pops up beyond > logic threshold BEFORE input. What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) NT
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| From | bill.sloman@ieee.org |
|---|---|
| Date | 2018-10-10 04:07 -0700 |
| Message-ID | <a0b18e12-9cc1-4749-b06b-58cc1318e166@googlegroups.com> |
| In reply to | #518866 |
On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: > On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > > > In certain cases, one can achieve what LOOKS like negative time delay. > > Input pulse has a (relatively) slow rise time, and feeds a fast > > op-amp set to sense low threshold of the rise...output pops up beyond > > logic threshold BEFORE input. > > What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) https://en.wikipedia.org/wiki/Thiotimoline Isaac Asimov invented it in 1947, and published his first paper on it in 1948. -- Bill Sloman, Sydney
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| From | DecadentLinuxUserNumeroUno@decadence.org |
|---|---|
| Date | 2018-10-10 11:28 +0000 |
| Message-ID | <ppknop$u9p$1@gioia.aioe.org> |
| In reply to | #518867 |
bill.sloman@ieee.org wrote in news:a0b18e12-9cc1-4749-b06b-58cc1318e166@googlegroups.com: > On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com > wrote: >> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: >> >> > In certain cases, one can achieve what LOOKS like negative time >> > dela > y. >> > Input pulse has a (relatively) slow rise time, and feeds a fast >> > op-amp set to sense low threshold of the rise...output pops up >> > beyond > >> > logic threshold BEFORE input. >> >> What would happen if a computer were built of negative time delay >> gates? > The output would appear before the input occurred. Since the input > would sometimes be undecided when the output occurred, the output > would determine the input. So take a standard computer, swap labels on > inputs & outputs, and there you have it, a faster than light future > predicting computer. In fact the slower it is, the faster it is :) > > https://en.wikipedia.org/wiki/Thiotimoline > > Isaac Asimov invented it in 1947, and published his first paper on it > in 1948. > Take a pair of scissors that span between the Earth and the Moon. It has straight cutting edges open at the moon and just beginning to shear at the Earth end. As the scissors close, the shear point travels up the pair faster than light as the angle closes the Moon ends together. Of course, the depends on how fast the blades close. But the point of shear moves really fast. Shear press for sheet metal works on this principle. The entire sheet gets cut in a single blade drop action, but the shear point is mobile allowing the event to occur with less shock and less force. For thick steel, the shear angle is not needed, but a cherry hot ingot may be.
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2018-10-11 22:06 -0700 |
| Message-ID | <tZVvD.102548$9O2.3250@fx03.iad> |
| In reply to | #518867 |
bill.sloman@ieee.org wrote: > On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: >> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: >> >>> In certain cases, one can achieve what LOOKS like negative time delay. >>> Input pulse has a (relatively) slow rise time, and feeds a fast >>> op-amp set to sense low threshold of the rise...output pops up beyond >>> logic threshold BEFORE input. >> >> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) > > https://en.wikipedia.org/wiki/Thiotimoline > > Isaac Asimov invented it in 1947, and published his first paper on it in 1948. > Yes, i remember the book. He takes all of the credit in Science FICTION. I am talking about science FACT. Remember, "what LOOKS like negative time delay".
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| From | bill.sloman@ieee.org |
|---|---|
| Date | 2018-10-12 00:08 -0700 |
| Message-ID | <0b56107b-ad0c-4888-8849-5870897f7764@googlegroups.com> |
| In reply to | #519027 |
On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: > bill.sloman@ieee.org wrote: > > On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: > >> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > >> > >>> In certain cases, one can achieve what LOOKS like negative time delay. > >>> Input pulse has a (relatively) slow rise time, and feeds a fast > >>> op-amp set to sense low threshold of the rise...output pops up beyond > >>> logic threshold BEFORE input. > >> > >> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) > > > > https://en.wikipedia.org/wiki/Thiotimoline > > > > Isaac Asimov invented it in 1947, and published his first paper on it in 1948. > > > Yes, I remember the book. You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact > He takes all of the credit in Science FICTION. > I am talking about science FACT. That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. > Remember, "what LOOKS like negative time delay". He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. -- Bill Sloman, Sydney
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2018-10-13 22:29 -0700 |
| Message-ID | <_uAwD.214074$MK2.44673@fx35.iad> |
| In reply to | #519033 |
bill.sloman@ieee.org wrote: > On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: >> bill.sloman@ieee.org wrote: >>> On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: >>>> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: >>>> >>>>> In certain cases, one can achieve what LOOKS like negative time delay. >>>>> Input pulse has a (relatively) slow rise time, and feeds a fast >>>>> op-amp set to sense low threshold of the rise...output pops up beyond >>>>> logic threshold BEFORE input. >>>> >>>> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) >>> >>> https://en.wikipedia.org/wiki/Thiotimoline >>> >>> Isaac Asimov invented it in 1947, and published his first paper on it in 1948. >>> >> Yes, I remember the book. > > You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" * And THEN it was published and printed in a BOOK. > > https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact > >> He takes all of the credit in Science FICTION. >> I am talking about science FACT. > > That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. > >> Remember, "what LOOKS like negative time delay". > > He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. * I guess you cannot READ; NO back-tracking, that is exactly what said. Perhaps you think i said there was a negative time delay. Build the circuit as described, and see for yourself..an apparent negative time delay. >
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| From | bill.sloman@ieee.org |
|---|---|
| Date | 2018-10-14 00:30 -0700 |
| Message-ID | <4dc237f7-a0ea-427b-a628-9a410f8bfcce@googlegroups.com> |
| In reply to | #519231 |
On Sunday, October 14, 2018 at 4:29:36 PM UTC+11, Robert Baer wrote: > bill.sloman@ieee.org wrote: > > On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: > >> bill.sloman@ieee.org wrote: > >>> On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: > >>>> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > >>>> > >>>>> In certain cases, one can achieve what LOOKS like negative time delay. > >>>>> Input pulse has a (relatively) slow rise time, and feeds a fast > >>>>> op-amp set to sense low threshold of the rise...output pops up beyond > >>>>> logic threshold BEFORE input. > >>>> > >>>> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) > >>> > >>> https://en.wikipedia.org/wiki/Thiotimoline > >>> > >>> Isaac Asimov invented it in 1947, and published his first paper on it in 1948. > >>> > >> Yes, I remember the book. > > > > You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" > * And THEN it was published and printed in a BOOK. > > > > > https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact > > > >> He takes all of the credit in Science FICTION. > >> I am talking about science FACT. > > > > That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. > > > >> Remember, "what LOOKS like negative time delay". > > > > He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. > > * I guess you cannot READ; NO back-tracking, that is exactly what said. Reading is one thing. Comprehending the non-thinking going on is another. > Perhaps you think i said there was a negative time delay. > Build the circuit as described, and see for yourself..an apparent > negative time delay. Only if you have absolutely no insight into what is going on. Read up on "constant fraction discriminators" sometime. -- Bill Sloman, Sydney
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2018-10-15 19:38 -0700 |
| Message-ID | <4bcxD.64920$UI2.1399@fx18.iad> |
| In reply to | #519240 |
bill.sloman@ieee.org wrote: > On Sunday, October 14, 2018 at 4:29:36 PM UTC+11, Robert Baer wrote: >> bill.sloman@ieee.org wrote: >>> On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: >>>> bill.sloman@ieee.org wrote: >>>>> On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: >>>>>> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: >>>>>> >>>>>>> In certain cases, one can achieve what LOOKS like negative time delay. >>>>>>> Input pulse has a (relatively) slow rise time, and feeds a fast >>>>>>> op-amp set to sense low threshold of the rise...output pops up beyond >>>>>>> logic threshold BEFORE input. >>>>>> >>>>>> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) >>>>> >>>>> https://en.wikipedia.org/wiki/Thiotimoline >>>>> >>>>> Isaac Asimov invented it in 1947, and published his first paper on it in 1948. >>>>> >>>> Yes, I remember the book. >>> >>> You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" >> * And THEN it was published and printed in a BOOK. >> >>> >>> https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact >>> >>>> He takes all of the credit in Science FICTION. >>>> I am talking about science FACT. >>> >>> That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. >>> >>>> Remember, "what LOOKS like negative time delay". >>> >>> He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. >> >> * I guess you cannot READ; NO back-tracking, that is exactly what said. > > Reading is one thing. Comprehending the non-thinking going on is another. > >> Perhaps you think i said there was a negative time delay. >> Build the circuit as described, and see for yourself..an apparent >> negative time delay. > > Only if you have absolutely no insight into what is going on. * I know exactly what happens and why. > > Read up on "constant fraction discriminators" sometime. * Has nothing to with "my" circuit. >
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| From | bill.sloman@ieee.org |
|---|---|
| Date | 2018-10-15 20:55 -0700 |
| Message-ID | <35cb38d2-0bbe-4b51-96cd-18e93c92a7dc@googlegroups.com> |
| In reply to | #519432 |
On Tuesday, October 16, 2018 at 1:39:00 PM UTC+11, Robert Baer wrote: > bill.sloman@ieee.org wrote: > > On Sunday, October 14, 2018 at 4:29:36 PM UTC+11, Robert Baer wrote: > >> bill.sloman@ieee.org wrote: > >>> On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: > >>>> bill.sloman@ieee.org wrote: > >>>>> On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabb...@gmail.com wrote: > >>>>>> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > >>>>>> > >>>>>>> In certain cases, one can achieve what LOOKS like negative time delay. > >>>>>>> Input pulse has a (relatively) slow rise time, and feeds a fast > >>>>>>> op-amp set to sense low threshold of the rise...output pops up beyond > >>>>>>> logic threshold BEFORE input. > >>>>>> > >>>>>> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) > >>>>> > >>>>> https://en.wikipedia.org/wiki/Thiotimoline > >>>>> > >>>>> Isaac Asimov invented it in 1947, and published his first paper on it in 1948. > >>>>> > >>>> Yes, I remember the book. > >>> > >>> You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" > >> * And THEN it was published and printed in a BOOK. > >> > >>> > >>> https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact > >>> > >>>> He takes all of the credit in Science FICTION. > >>>> I am talking about science FACT. > >>> > >>> That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. > >>> > >>>> Remember, "what LOOKS like negative time delay". > >>> > >>> He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. > >> > >> * I guess you cannot READ; NO back-tracking, that is exactly what said. > > > > Reading is one thing. Comprehending the non-thinking going on is another. > > > >> Perhaps you think i said there was a negative time delay. > >> Build the circuit as described, and see for yourself..an apparent > >> negative time delay. > > > > Only if you have absolutely no insight into what is going on. > > * I know exactly what happens and why. You may think you do. Your confidence about your grasp of your misconceptions is just another misconception. > > Read up on "constant fraction discriminators" sometime. > * Has nothing to with "my" circuit. Since your circuit was a moronic thought experiment, who cares? -- Bill Sloman, Sydney
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| From | tabbypurr@gmail.com |
|---|---|
| Date | 2018-10-14 04:31 -0700 |
| Message-ID | <eda49bcc-2999-46d8-99c3-743fcfd03c4f@googlegroups.com> |
| In reply to | #519231 |
On Sunday, 14 October 2018 06:29:36 UTC+1, Robert Baer wrote: > bill.sloman@ieee.org wrote: > > On Friday, October 12, 2018 at 4:06:38 PM UTC+11, Robert Baer wrote: > >> bill.sloman@ieee.org wrote: > >>> On Wednesday, October 10, 2018 at 9:03:01 PM UTC+11, tabby wrote: > >>>> On Wednesday, 10 October 2018 08:38:16 UTC+1, Robert Baer wrote: > >>>> > >>>>> In certain cases, one can achieve what LOOKS like negative time delay. > >>>>> Input pulse has a (relatively) slow rise time, and feeds a fast > >>>>> op-amp set to sense low threshold of the rise...output pops up beyond > >>>>> logic threshold BEFORE input. > >>>> > >>>> What would happen if a computer were built of negative time delay gates? The output would appear before the input occurred. Since the input would sometimes be undecided when the output occurred, the output would determine the input. So take a standard computer, swap labels on inputs & outputs, and there you have it, a faster than light future predicting computer. In fact the slower it is, the faster it is :) > >>> > >>> https://en.wikipedia.org/wiki/Thiotimoline > >>> > >>> Isaac Asimov invented it in 1947, and published his first paper on it in 1948. > >>> > >> Yes, I remember the book. > > > > You don't. All three items were originally published in "Astounding Science Fiction" which is a periodical (now called "Analog Science Fact and Fiction" > * And THEN it was published and printed in a BOOK. > > > > > https://en.wikipedia.org/wiki/Analog_Science_Fiction_and_Fact > > > >> He takes all of the credit in Science FICTION. > >> I am talking about science FACT. > > > > That is Robert Baer's deluded opinion. He is about a reliable at distinguishing fact from fiction as Cursitor Doom, and what he knows about science could be written on the head of pin in large letters. > > > >> Remember, "what LOOKS like negative time delay". > > > > He can't even back-track gracefully. It was a moronic interjection, and he's silly enough not to realise this. > * I guess you cannot READ; NO back-tracking, that is exactly what said. > Perhaps you think i said there was a negative time delay. > Build the circuit as described, and see for yourself..an apparent > negative time delay. Save yourself the time. He'll never get real. NT
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