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Old 21st November 2006, 01:52 PM   #1
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Default 10W JFET/MOSFET SE Class A, no Feed Back

This is my new project:
Click the image to open in full size.
1st stage - common source (2SJ103BL), 2nd - source follower (2SK170BL), power stage - common source with current source load (2SK159 & 2SJ200), no feedback, no input or output caps...
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Old 21st November 2006, 01:59 PM   #2
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Thumbs up Nice!

Nice widowmaker!

Good to see you posting a project again.
They are usually very interesting, to me.


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Old 21st November 2006, 02:01 PM   #3
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10x, Lineup!
More info about this project will coming soon
AgTa cap is russian military production, 1000uF/6V. I think thas is better choice than Black Gate cap...
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Old 24th November 2006, 01:25 PM   #4
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I made some changes on this project.
The schematic bocomes more simplified...
Now the servo has only opamp and few caps and resistors.
bypassing (by quality cap) the source resistor on first stage is good enough to eliminate noises from opamp...
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Old 25th November 2006, 01:27 AM   #5
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Nice to see another minimalist MOSFET amp.
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Old 25th November 2006, 06:35 AM   #6
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interesting, have you built a prototype? what kind of PS would be ideal? i have always wanted to try a capacitance multiplier.
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Old 25th November 2006, 03:05 PM   #7
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I think that PS with CLC filters (one for each rail) is good enough.
for example:
47mF/3mH(3.5A, iron core)/47-100mF
New, modified schematic coming soon
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Old 25th November 2006, 08:38 PM   #8
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i have always been interested in CLC filters but i can't ever find any Ls of the right type for a price i would remotely consider paying....what about just lots of capacitance, Krell style? or full on regulation? i have read that regulators introduce a triangular waveform into the rail while capacitance multipliers come very close to full regulation while avoiding the triangular waveform. is this true, or of consequence?
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Old 26th November 2006, 12:46 PM   #9
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Another great construction from Widowmaker
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Old 26th November 2006, 01:00 PM   #10
lineup is offline lineup  Sweden
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Quote:
Originally posted by widowmaker
I think that PS with CLC filters (one for each rail) is good enough.
for example:
47mF/3mH(3.5A, iron core)/47-100mF
New, modified schematic coming soon

Quote:
Originally posted by bikehorn
i have always been interested in CLC filters but i can't ever find any Ls of the right type for a price i would remotely consider paying....what about just lots of capacitance, Krell style? or full on regulation? i have read that regulators introduce a triangular waveform into the rail while capacitance multipliers come very close to full regulation while avoiding the triangular waveform. is this true, or of consequence?

Attachment
Have a look at my effective C-R-C-R-C-R-C.

This time I used resistors:
0.10 - 0.22 - 0.33 Ohm
and capacitors:
4700 - 4700 - 10.000 - 10.000 uF

Result:
Very Good effective Power Supply filtering.
Almost no ripple for 2 A constant current.
In Multisim.

The drop of 1.3 Volt I can live with, because
so much easier to find some power resistors 0.10 - 0.33 Ohm
than winding your coils or try to find and buy such

----------------------------------
Have a setup of 0.10 - 0.47 Ohm (2-5 Watt) resistors at home
as well as a supply of 4.700uF / 10.000uF supply caps
.. and you will put together a nice low ripple power supply very quickly
whenever you get an idea you want to try.
---------------------------------.

lineup

See my Very Clean Supply in Attachment
here
Attached Images
File Type: png classa21194-2a.png (12.5 KB, 450 views)
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