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Old 7th May 2010, 08:36 AM   #121
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Location: Serbia
Quote:
Originally Posted by kenpeter View Post
Creative??? I guess thats one polite way to describe it...
I steal a load of ideas then implement them incorrectly?

---

My earlier problem with limiters:
Any attempt to shunt an offending
gate toward cutoff (toward center),
had nasty side-effect to also shunt
the opposing gate into a complete
hard cutoff (much closer to cutoff
to begin with). And pull the drive
signal itself toward the offending
rail!

The correction circuit can only
pull inward, so had no power to
enforce common sense over this
inward pulling madness! Worse,
just fooled correction circuit
transistors to shut down too...

So thats why I have it all turned
inside out for the moment... Shunt
either gate toward cutoff (toward
rail), has side effect to turn ON
the opposing MOSFET. An inward
pull correction circuit can sucessfully
fight against this orientation of
unwanted error (through the mirror).
Also preventing unwanted shutdown
of the correction circuit. And pull
drive away from the rail too. (half
baked theory)

Is there is a better way to do all
this turned rightside-out? I havn't
figured anything that works yet...

---

Loftin White circuit is out of tune
now... You can graph +/-15mA in the
470uF bypass cap! I suspect the Mu
Follwer Gyro's self-centering resistor
R10 is too small value for plate load?
I measure big AC current leak here.
Inductor I had goten rid of earlier
might want to come back...

Or maybe I'll take another crack at
a real servo??? I suspect it didn't
work before for same reason as the
limiters. Maybe no problem anymore?
I have very positive impressions with your work and ideas.
Regards
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Old 22nd May 2010, 01:06 AM   #122
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I've stumbled upon the cause and possibly a solution to why the
crossing correction circuit hates any kind of soft or hard limiting.

Limiting actually works well if the driver isn't too low impedance.
A series resistor allows the limiter to work its magic. Of course
this is an unfortunate conflict with a drive of low impedance to
handle Miller when VDS<VGS...

I'm thinking to throw the limiter feedback direct to the plate.
So that its not fighting low impedance of the Triodlington's
emitter, nor confusing the crossing correction to shut down.
And lets us drive with low impedance, but feed back into a
higher one...

This is negative feedback, and may be outside the design
rule. But definitely not a linearizing feedback, nor feedback
that runs full time... Kicks in only to compress peaks in the
extreme situation.

I'll draw it up this weekend and see if it plays...
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Old 7th September 2010, 02:02 AM   #123
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ECC82 can be use for HT100.
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Old 31st October 2010, 09:41 PM   #124
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With quasi BJT output stage amp can be simple like this from 'Elektor'
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File Type: jpg mugencircuit.jpg (68.1 KB, 1099 views)
File Type: jpg mugendriver_360.jpg (21.6 KB, 1041 views)
File Type: jpg mugenpowerciruit_360.jpg (21.3 KB, 947 views)
File Type: jpg mugenprotooverview_360.jpg (25.7 KB, 922 views)

Last edited by apexaudio; 31st October 2010 at 09:49 PM.
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Old 2nd November 2010, 04:36 PM   #125
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Preamp for Tube/Mosfet amp

Part list:
R1,R2-12k 2W
R3,R4-220R
R5,R6-680R
R7,R8-100R
R9,R10,R13-1M
R11,R12-3M9
R14,R15-10k
R16,R17-1k
R18,R19-10R
R20-680k
R21-470R

C1,C2,C3,C4-1uF400V MKP
C5,C6,C8-22uF/350V
C7-47uF/16V
C9,C10,C11,C12-47uF/350V
C13,C14-1000uF/16V
C15-47nF/100V MKS
C16-220nF/150V MKS
C17-100nF/63V MKS

D1,D2-ZF10V
D3,D4,D5-1N4148
D6,D7,D8,D9,D10,D11,D12,D13,D14-1N4007

V1-ECC88

Q1,Q2-BC546
Q3-IRF830

IC1-NE555
IC2-7805

LD1-RED
LD2-GREEN

RE1-5V2X1A

AC1-120VAC 100mA
AC2-9VAC 1A
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File Type: jpg APEX TUBE PREAMP.jpg (403.0 KB, 660 views)
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Old 2nd November 2010, 05:13 PM   #126
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Preamp can be use for drive output stage with high input impedance.
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Old 22nd April 2011, 04:04 AM   #127
radio is offline radio  Macedonia
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Thumbs up Schematic for preamplifier?

Quote:
Originally Posted by apexaudio View Post
Preamp can be use for drive output stage with high input impedance.
Hello!
Show the Schematic of this preamplifier!
Best regards

Здраво Миле!
Ако си у могукности прикажи шему овог претпојачавача?!
Или кде може да се надје комплетни пројекат на интернрту?!
Унапред хвала!

Last edited by radio; 22nd April 2011 at 04:12 AM.
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Old 22nd April 2011, 04:36 AM   #128
radio is offline radio  Macedonia
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Quote:
Originally Posted by radio View Post
Hello!
Show the Schematic of this preamplifier!
Best regards

Здраво Миле!
Ако си у могукности прикажи шему овог претпојачавача?!
Или кде може се наки комплетни пројекат на интернрту?!
Унапред хвала!
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Old 22nd April 2011, 04:03 PM   #129
MiiB is offline MiiB  Denmark
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The schematics is as I see it in post 125...
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Old 22nd April 2011, 07:53 PM   #130
bra is offline bra
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it is my version off Jeff Macauley's MOSCODE
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