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Old 20th January 2013, 04:33 PM   #51
sreten is offline sreten  United Kingdom
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Hi,

There is nothing unconstructive about saying "somebody has reinvented
the wheel", in this case "bootstrapping", if the circuit works as claimed,
or they don't have anything if it doesn't work as claimed.

The claims about distortion appear to be
"guilding the lily" and don't make any sense.

The only way to lower the high pass frequency is to make the apparent
input impedance higher, and to do that you need to modulate the other
side of the input resistor with a signal similar to the input signal. This
is a doddle with a unity gain stage, with a bootstrap capacitor from the
output. If you have gain then the unity gain point is the inverting input,
and you bootstrap from that point, noting it has higher source impedance
than directly from the output.

What is unconstructive is the obfuscation about something that either
works and is very old, or its "new" and it doesn't work as claimed.

There is a phenomenal arrogance in stating you have come up with
a "new" simple circuit topology when that likelihood is very near zero.

rgds, sreten.

Unity gain bootstrap for a low low pass with a small capacitor :

Click the image to open in full size.

How to modify the original circuit should be obvious.
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Last edited by sreten; 20th January 2013 at 04:53 PM.
 
Old 20th January 2013, 05:08 PM   #52
sreten is offline sreten  United Kingdom
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Hi,

Should read :

Unity gain bootstrap for a low high pass with a small capacitor :

rgds, sreten.
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There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
 
Old 20th January 2013, 05:46 PM   #53
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sreten:

My circuit does not look anything like what you have presented.

There are many more variants. Not everything always leads to this bootstrapping technique (which may serve to increase the impedance seen by the signal source) ...

Do you think that this bootstrapping technique is the only way to reach the goal?. The technical horizon is wider than you think.

As an example: Mooly uploaded a proposal that does not necessarily use the bootstrapping technique (and was very close to the targets).

Anyway, thanks for your effort (that's more positive for the whole forum).

regards
 
Old 20th January 2013, 06:09 PM   #54
Mooly is offline Mooly  United Kingdom
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So we have to think outside the box

I am still intrigued
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Old 20th January 2013, 06:12 PM   #55
sreten is offline sreten  United Kingdom
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Hi,

The level of pretension here is out of control.

Put up or shut up. Not many people get to redefine
how circuits should be designed and you don't
remotely strike me as someone that could.

rgds, sreten.
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There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow

Last edited by sreten; 20th January 2013 at 06:22 PM.
 
Old 21st January 2013, 12:49 PM   #56
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sreten:

Here there is no pretense of anything: I have invited you to try to get a particular result in a given circuit, given certain conditions.

Anyone who wants to participate, explains his idea and then we can discuss it. This is very simple.

Also, I do not pretend to redefine the way each of you design their circuits: I only expose the pros and cons of each alternative (uploaded by forum users) when compared with the option that I use, to arrive at the desired results.

If someone finds out what I'm using, congratulations.

If not discovered, also serves: you can always salvage something positive.

regards
 
Old 21st January 2013, 02:45 PM   #57
GoatGuy is offline GoatGuy  United States
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SRETEN, I simply don't think that DiegoMJ has any idea how ivory-tower pretentious he's being. I've noted this in other forums, and with people in daily life. They have extraordinary faith in their magnificent achievement, and through scheming and obfuscation, through come-along and super-authoritarian pseudo-mentorship, challenge all those whom they get in audience, to invent or recreate something they barely have the ability to concretely describe. DiegoMJ is such a character, it is clear. Has probably desired his entire life to be so inscrutably superior that all people around him are not peers but subjects.

Paraphrasing his pretention: "I have done it! I challenge you to take this simple looking thing, and using no other components, improve upon it hugely. The results you come up with, I will grade for their authenticity, and I'll keep providing feedback while y'all with my blindfolds on, keep searching with your hands out. Its fun! Its educational! Keep at it me hearties! You're so close to the bucket 'o' gold. (Moves the bucket again...)"

Yes, pretention, stultifying self-absorbed ego, and if anyone unhappy with this analysis cares to remember: No damned diagram Its patent-pending, you know.

Your analysis of impedance-lifting is exactly correct. There are no other solutions that don't topologically rearrange to impedance multiplication if the frequency-response of an input (or other signal-path) capacitor is to be mitigated. Period.

GoatGuy
 
Old 21st January 2013, 03:20 PM   #58
Mooly is offline Mooly  United Kingdom
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I have a question

The circuit in post 1 could be duplicated (i.e. two built) and then be fed from a "normal" source such as a CD player etc. Both circuits would in that case operate independently of course.

Can your "new" circuit like-wise be duplicated in the same way and two the "channels" operate independently when fed from a "common" source.

Just a wonderin
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Old 21st January 2013, 06:19 PM   #59
magdrop is offline magdrop  United States
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This is a great challenge; it's very easy to understand yet very difficult to solve.

Obviously, some folks don't respond well to being presented with a challenge. This turns out to be much more entertaining than the puzzle itself.

Great thread, and great OP!
 
Old 21st January 2013, 07:30 PM   #60
sreten is offline sreten  United Kingdom
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Quote:
Originally Posted by magdrop View Post
This is a great challenge; it's very easy to understand yet very difficult to solve.

Hi,

Really ? How do you know that ? You'd have to know the supposed
solution and your stuff to be any judge of the merits of this thread.

rgds, sreten.

I've already posted how you usually would do it, and it works.
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There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow

Last edited by sreten; 21st January 2013 at 07:39 PM.
 

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