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Old 11th October 2011, 06:24 PM   #21
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I was afraid it might be the Cathermin tube with inindium complex of +4, which would be really bad
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Old 11th October 2011, 09:47 PM   #22
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Sorry out of town, so i dont have ability to add sketch. Looking at your article, Michael, the first schematic where you introduced the mosfets and bias resistors. Even though the load is on the drain, it is functioning as a transconductance amp, correct, providing only current gain. Flip the fet and make it common drain, you have a buffer who's cuurent is determined by bias. Either way, you have only current gain.
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Old 11th October 2011, 10:22 PM   #23
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Here's an old drawing I did. Would we expect these two circuits to behave the same?
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Old 12th October 2011, 02:00 AM   #24
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In second schematic with no ground there re two paths for the signal, one thru fet and other thru voltage source of opposite side. Left side drain will see inverted signal while right side will see non inverted signal
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Old 12th October 2011, 12:30 PM   #25
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Hello, Buzz

I believe you were asking if the standalone circlotron stage has current gain, voltage gain, or both. Were you not?
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Old 12th October 2011, 03:24 PM   #26
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Are you saying the reference to ground makes V gain possible?
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Old 12th October 2011, 07:01 PM   #27
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No.

I'm suggesting the lower diagram has both. You may recognize it conceptually as the output stage of The Amazing FET Circlotron.

Last edited by Michael Rothacher; 12th October 2011 at 07:20 PM.
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Old 12th October 2011, 08:13 PM   #28
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How does the lack of ground reference change things?
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Old 12th October 2011, 08:55 PM   #29
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Quote:
Originally Posted by buzzforb View Post
How does the lack of ground reference change things?
Who says it does?

Let's go at this from another angle for the moment:

Quote:
Originally Posted by buzzforb View Post
Couple surface observations or questions, whichever. Single stage circlotron, operated as source followwer is basically power buffer with current output determined by bias choice. Operated as common source, it is transconductance amplifier(quasi buffer), with gain of fet determining current to load. In both cases, it is just supplying current to load, thus the need for second stage. For V gain
Why do you assert that the latter has no voltage gain?
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Old 12th October 2011, 11:52 PM   #30
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Does the speaker serve as a load resistor? If it does, isn't the fet just feeding current to the load. Isn't the source seeing the same load as the drain with the exception of passing through the "battery"?

Last edited by buzzforb; 12th October 2011 at 11:56 PM.
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