Can somebody take a peek at this circuit for me?

[Michael Noone]

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?

https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.

The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp. Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)

Thanks for your help,

-Michael J. Noone

 

[Genome]

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would
come
even close to working?

https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.

The idea is that VSS will be 400V - so the voltage divider will
divide the
output by forty, thus providing negative feedback to the op-amp.
Oh - by
the way the MOSFET part number is entirely random (just found a part
with
what I thought was the right symbol) - and I don't plan on using a
741 op-
amp either - (I haven't chosen one yet - I just used that as it is
the
"classic" op amp)

Thanks for your help,

-Michael J. Noone

Look Micheal, I'll do you a deal.

You fuck off and I won't report you.

If you are associated with the uni you get fucked.

If you are spoofing then they don't try and sue your ass.

They have a department with people in white coats and access to compfy
cells.

DNA

 

[Michael Noone]

"Genome" <ilike_spam@yahoo.co.uk> wrote in news:XyO%d.37188$3A6.10057
@newsfe1-gui.ntli.net:

Look Micheal, I'll do you a deal.

You fuck off and I won't report you.

If you are associated with the uni you get fucked.

If you are spoofing then they don't try and sue your ass.

They have a department with people in white coats and access to compfy
cells.

DNA

Huh?

Best regards,

-M. Noone

 

[xray]

On Tue, 22 Mar 2005 00:20:36 -0600, Michael Noone
<mnoone.uiuc.edu@127.0.0.1> wrote:

"Genome" <ilike_spam@yahoo.co.uk> wrote in news:XyO%d.37188$3A6.10057
@newsfe1-gui.ntli.net:

Look Micheal, I'll do you a deal.

You fuck off and I won't report you.

If you are associated with the uni you get fucked.

If you are spoofing then they don't try and sue your ass.

They have a department with people in white coats and access to compfy
cells.

DNA

Huh?

Best regards,

-M. Noone

OK. Missed something? Maybe this will help...
"

LOOK MICHEAL, I'LL DO YOU A DEAL.

YOU FUCK OFF AND I WON'T REPORT YOU.

IF YOU ARE ASSOCIATED WITH THE UNI YOU GET FUCKED.

IF YOU ARE SPOOFING THEN THEY DON'T TRY AND SUE YOUR ASS.

THEY HAVE A DEPARTMENT WITH PEOPLE IN WHITE COATS AND ACCESS TO COMPFY
CELLS.

dna"

Any better?

 

[Michael Noone]

xray <notreally@hotmail.invalid> wrote in
news:inev311tn8ucreeq4fg71m0hktjek74q7s@4ax.com:

Any better?

Nope.

-Michael

 

[Paul Burke]

Michael Noone wrote:

Huh?

I think that Mr. Genome is suggesting that the circuit is trivial: if
you don't KNOW whether it will work or not, you should get one of the
electronic department's technicians to look at it for you and swap wages
with him. I think he might be rather afraid that you are one of the
teaching staff of some academic institution.

Paul Burke

 

[Michael Noone]

Paul Burke <paul@scazon.com> wrote in news:3aa449F675aq5U2@individual.net:

Michael Noone wrote:


Huh?

I think that Mr. Genome is suggesting that the circuit is trivial: if
you don't KNOW whether it will work or not, you should get one of the
electronic department's technicians to look at it for you and swap wages
with him. I think he might be rather afraid that you are one of the
teaching staff of some academic institution.

Paul Burke

Well - it's a very foreign idea to me. So far in school (I'm a second year
EE) all I've been taught with FETs is how to use them as switches.

So this will work?

Regards,

-M. Noone

 

[Larry Brasfield]

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?

You should learn to say what a circuit has to do in
terms of performance, preferably quantifiable. I
could say your circuit will "work", because you
have not really specified what that means.

https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.

I suggest you learn to use a simulator rather than presenting
stuff that just cannot work. By using it to examine currents
and voltages for specific branches and nodes, you should be
able to discover elementary errors for yourself.

The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp.

The supply value belongs on your schematic.

There is no value on the shunt leg of your divider.
So, my prediction is it will divide by "unknown".

Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)

When you simulate your circuit, you will find that the
MOSFET is always on. I leave it to you to figure out
why. A "simulation" done with your mind would be
a good way to start. That is a skill you will need no
matter how good computer based simulation become.

Unless there is a load, and it is connected to a more
positive level than the VSS supply, I would expect no
output like what you probably hope for.

Another issue with your circuit, (and boost stages
added to op-amps generally), is that it may not
be stable. Depending on your load, your circuit
could easily oscillate (once you get the MOSFET
to not be always on).

Thanks for your help,

Sure. Be sure to ignore the crap that gets thrown
around here. It reflects nothing upon you. You
may want to take basic questions like this to
alt.electronics.basics
where there is a little more tolerance.

That said, more care inspecting your schematics
before they leave your desk would be good.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Fred Bloggs]

Larry Brasfield wrote:

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?


You should learn to say what a circuit has to do in
terms of performance, preferably quantifiable.

Why should he quantify anything?- You sure as hell never do.

I
could say your circuit will "work", because you
have not really specified what that means.

You "could" say it "will" work because he has "not" specified what that
means? If that is not confused gibberish I don't know what is. You have
almost certainly have severe brain damage.

https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.


I suggest you learn to use a simulator rather than presenting
stuff that just cannot work. By using it to examine currents
and voltages for specific branches and nodes, you should be
able to discover elementary errors for yourself.

That is a totally wrong and ass-backwards approach. SPICE is not to be
used to "discover" anything- it used to confirm the details of an
overall circuit operation that is understood beforehand. But I guess you
know better than the original founders and expert practitioners of SPICE
simulation- don't you, PIT (pseudo-intellectual trash)?

The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp.


The supply value belongs on your schematic.

There is no value on the shunt leg of your divider.
So, my prediction is it will divide by "unknown".

Oh real smart observation- it's just incredible how you can zoom in on
the irrelevant- what a p.o.s. and PIT-bag.

Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)



When you simulate your circuit, you will find that the
MOSFET is always on.

Is that what call "always on"- a MOSFET blown to hell by 400V of applied
VGS?

I leave it to you to figure out
why. A "simulation" done with your mind would be
a good way to start. That is a skill you will need no
matter how good computer based simulation become.

What a bucket of piss...

Unless there is a load, and it is connected to a more
positive level than the VSS supply, I would expect no
output like what you probably hope for.

Another issue with your circuit, (and boost stages
added to op-amps generally), is that it may not
be stable. Depending on your load, your circuit
could easily oscillate (once you get the MOSFET
to not be always on).

No kidding ? Really?

Thanks for your help,


Sure. Be sure to ignore the crap that gets thrown
around here.

You mean killfile pseudo-intellectual trash like yourself....

 

[Larry Brasfield]

Derf transform applied.

"Fred Bloggs" <nospam@nospam.com> wrote in message
news:423FFCAF.9070507@nospam.com...

Larry Brasfield wrote:
"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...
[derf]
When you simulate your circuit, you will find that the
MOSFET is always on.

Is that what call "always on"- a MOSFET blown to hell by 400V of applied VGS?

That would be one way to put it.

A great many SPICE models for MOSFETs do not have
any provision for modeling the rupture of the gate oxide.
In fact, I know of no exceptions. My prediction stands.

For purposes of helping the OP learn what he needs
to learn, "always on" does the job just fine. That was
enough for me, and still is. He can learn about smoke
when he starts building real circuits.

[derf]
--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Fred Bloggs]

Larry Brasfield wrote:

Derf transform applied.

Re-inserted snipped material:

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?


You should learn to say what a circuit has to do in
terms of performance, preferably quantifiable.

Why should he quantify anything?- You sure as hell never do.

I
could say your circuit will "work", because you
have not really specified what that means.

You "could" say it "will" work because he has "not" specified what that means? If that is not confused gibberish I don't know what is. You have almost certainly have severe brain damage.



https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.


I suggest you learn to use a simulator rather than presenting
stuff that just cannot work. By using it to examine currents
and voltages for specific branches and nodes, you should be
able to discover elementary errors for yourself.

That is a totally wrong and ass-backwards approach. SPICE is not to be used to "discover" anything- it used to confirm the details of an overall circuit operation that is understood beforehand. But I guess you know better than the original founders and expert practitioners of SPICE simulation- don't you, PIT (pseudo-intellectual trash)?



The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp.


The supply value belongs on your schematic.

There is no value on the shunt leg of your divider.
So, my prediction is it will divide by "unknown".

Oh real smart observation- it's just incredible how you can zoom in on the irrelevant- what a p.o.s. and PIT-bag.



Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)



When you simulate your circuit, you will find that the
MOSFET is always on.

Is that what call "always on"- a MOSFET blown to hell by 400V of applied VGS?

I leave it to you to figure out
why. A "simulation" done with your mind would be
a good way to start. That is a skill you will need no
matter how good computer based simulation become.

What a bucket of piss...


Unless there is a load, and it is connected to a more
positive level than the VSS supply, I would expect no
output like what you probably hope for.

Another issue with your circuit, (and boost stages
added to op-amps generally), is that it may not
be stable. Depending on your load, your circuit
could easily oscillate (once you get the MOSFET
to not be always on).

No kidding ? Really?



Thanks for your help,


Sure. Be sure to ignore the crap that gets thrown
around here.

You mean killfile pseudo-intellectual trash like yourself....

 

[Fred Bloggs]

Larry Brasfield wrote:

Derf transform applied.

Snipped material re-inserted:

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?


You should learn to say what a circuit has to do in
terms of performance, preferably quantifiable.

Why should he quantify anything?- You sure as hell never do.

I
could say your circuit will "work", because you
have not really specified what that means.

You "could" say it "will" work because he has "not" specified what that means? If that is not confused gibberish I don't know what is. You have almost certainly have severe brain damage.



https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.


I suggest you learn to use a simulator rather than presenting
stuff that just cannot work. By using it to examine currents
and voltages for specific branches and nodes, you should be
able to discover elementary errors for yourself.

That is a totally wrong and ass-backwards approach. SPICE is not to be used to "discover" anything- it used to confirm the details of an overall circuit operation that is understood beforehand. But I guess you know better than the original founders and expert practitioners of SPICE simulation- don't you, PIT (pseudo-intellectual trash)?



The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp.


The supply value belongs on your schematic.

There is no value on the shunt leg of your divider.
So, my prediction is it will divide by "unknown".

Oh real smart observation- it's just incredible how you can zoom in on the irrelevant- what a p.o.s. and PIT-bag.



Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)



When you simulate your circuit, you will find that the
MOSFET is always on.

Is that what call "always on"- a MOSFET blown to hell by 400V of applied VGS?

I leave it to you to figure out
why. A "simulation" done with your mind would be
a good way to start. That is a skill you will need no
matter how good computer based simulation become.

What a bucket of piss...


Unless there is a load, and it is connected to a more
positive level than the VSS supply, I would expect no
output like what you probably hope for.

Another issue with your circuit, (and boost stages
added to op-amps generally), is that it may not
be stable. Depending on your load, your circuit
could easily oscillate (once you get the MOSFET
to not be always on).

No kidding ? Really?



Thanks for your help,


Sure. Be sure to ignore the crap that gets thrown
around here.

You mean killfile pseudo-intellectual trash like yourself....

 

[Fred Bloggs]

Larry Brasfield wrote:

Derf transform applied.

Snipped material re-inserted:

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9620F289F46Emnooneuiucedu127001@216.196.97.136...

Hi - can somebody tell me if this circuit would work, or if it would come
even close to working?


You should learn to say what a circuit has to do in
terms of performance, preferably quantifiable.

Why should he quantify anything?- You sure as hell never do.

I
could say your circuit will "work", because you
have not really specified what that means.

You "could" say it "will" work because he has "not" specified what that means? If that is not confused gibberish I don't know what is. You have almost certainly have severe brain damage.



https://netfiles.uiuc.edu/mnoone/www/Linearamplifierwithfet.jpg

The circuit is supposed to amplify a 0-10V signal to 0-400V.


I suggest you learn to use a simulator rather than presenting
stuff that just cannot work. By using it to examine currents
and voltages for specific branches and nodes, you should be
able to discover elementary errors for yourself.

That is a totally wrong and ass-backwards approach. SPICE is not to be used to "discover" anything- it used to confirm the details of an overall circuit operation that is understood beforehand. But I guess you know better than the original founders and expert practitioners of SPICE simulation- don't you, PIT (pseudo-intellectual trash)?



The idea is that VSS will be 400V - so the voltage divider will divide the
output by forty, thus providing negative feedback to the op-amp.


The supply value belongs on your schematic.

There is no value on the shunt leg of your divider.
So, my prediction is it will divide by "unknown".

Oh real smart observation- it's just incredible how you can zoom in on the irrelevant- what a p.o.s. and PIT-bag.



Oh - by
the way the MOSFET part number is entirely random (just found a part with
what I thought was the right symbol) - and I don't plan on using a 741 op-
amp either - (I haven't chosen one yet - I just used that as it is the
"classic" op amp)



When you simulate your circuit, you will find that the
MOSFET is always on.

Is that what call "always on"- a MOSFET blown to hell by 400V of applied VGS?

I leave it to you to figure out
why. A "simulation" done with your mind would be
a good way to start. That is a skill you will need no
matter how good computer based simulation become.

What a bucket of piss...


Unless there is a load, and it is connected to a more
positive level than the VSS supply, I would expect no
output like what you probably hope for.

Another issue with your circuit, (and boost stages
added to op-amps generally), is that it may not
be stable. Depending on your load, your circuit
could easily oscillate (once you get the MOSFET
to not be always on).

No kidding ? Really?



Thanks for your help,


Sure. Be sure to ignore the crap that gets thrown
around here.

You mean killfile pseudo-intellectual trash like yourself....

 

[Larry Brasfield]

Derf transform applied.

"Fred Bloggs" <nospam@nospam.com> wrote in
message news:42400231.4050308@nospam.com...

You seem to be repeating yourself, Fred. It may
be time for a system checkup and/or reformat.

By the way, I apply the Derf transform for clarity when you
actually have something to say that is worth responding to.
What survives the filter is related to that purpose, not your
desire to post some spew every time I post anything.

When nothing except article references and sigs gets thru
the Dreck-Extraneousness-Redundancy-Frivolity filter,
I will not be responding at all. So you can rest assured
that most of your contributions will go unanswered.

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

[Fred Bloggs]

Larry Brasfield wrote:

Derf transform applied.

Shut the hell up, PIT- until you learn how to format a proper response.

[...snip your trash without taking *any* time to read it...]

 

[John Larkin]

On Tue, 22 Mar 2005 03:13:09 -0600, Michael Noone
<mnoone.uiuc.edu@127.0.0.1> wrote:

Paul Burke <paul@scazon.com> wrote in news:3aa449F675aq5U2@individual.net:

Michael Noone wrote:


Huh?

I think that Mr. Genome is suggesting that the circuit is trivial: if
you don't KNOW whether it will work or not, you should get one of the
electronic department's technicians to look at it for you and swap wages
with him. I think he might be rather afraid that you are one of the
teaching staff of some academic institution.

Paul Burke

Well - it's a very foreign idea to me. So far in school (I'm a second year
EE) all I've been taught with FETs is how to use them as switches.

So this will work?

Regards,

-M. Noone

Looks to me, as I understand the stated voltages, that you have 400
volts gate-to-source on this fet. That will kill it.

John

 

[John Fields]

On Tue, 22 Mar 2005 03:44:59 -0800, "Larry Brasfield"
<donotspam_larry_brasfield@hotmail.com> wrote:

Derf transform applied.

"Fred Bloggs" <nospam@nospam.com> wrote in
message news:42400231.4050308@nospam.com...

You seem to be repeating yourself, Fred. It may
be time for a system checkup and/or reformat.

By the way, I apply the Derf transform for clarity when you
actually have something to say that is worth responding to.
What survives the filter is related to that purpose, not your
desire to post some spew every time I post anything.

When nothing except article references and sigs gets thru
the Dreck-Extraneousness-Redundancy-Frivolity filter,
I will not be responding at all. So you can rest assured
that most of your contributions will go unanswered.

---
Would that that last sentence were true!

Sadly though, you preach silence while practicing noise, all in the
same bray.

--
John Fields

 

[Michael Noone]

John Larkin <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
news:8ig041puudk80v93lqk5i64dcqbn8m5h1j@4ax.com:

On Tue, 22 Mar 2005 03:13:09 -0600, Michael Noone
mnoone.uiuc.edu@127.0.0.1> wrote:

Paul Burke <paul@scazon.com> wrote in
news:3aa449F675aq5U2@individual.net:

Michael Noone wrote:


Huh?

I think that Mr. Genome is suggesting that the circuit is trivial:
if you don't KNOW whether it will work or not, you should get one of
the electronic department's technicians to look at it for you and
swap wages with him. I think he might be rather afraid that you are
one of the teaching staff of some academic institution.

Paul Burke

Well - it's a very foreign idea to me. So far in school (I'm a second
year EE) all I've been taught with FETs is how to use them as
switches.

So this will work?

Regards,

-M. Noone

Looks to me, as I understand the stated voltages, that you have 400
volts gate-to-source on this fet. That will kill it.

John

I was planning on using a high voltage FET. I was thinking something
along the lines of this: http://www.irf.com/product-
info/datasheets/data/irfb17n50l.pdf - it's designed to switch 500V...
Why would it get killed? Thanks,

-M. Noone

 

[Michael Noone]

"Leon Heller" <leon_heller@hotmail.com> wrote in
news:423ff4d4$0$10937$cc9e4d1f@news-text.dial.pipex.com:

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns962120B4371BDmnooneuiucedu127001@216.196.97.136...
Paul Burke <paul@scazon.com> wrote in
news:3aa449F675aq5U2@individual.net:

Michael Noone wrote:


Huh?

I think that Mr. Genome is suggesting that the circuit is trivial:
if you don't KNOW whether it will work or not, you should get one of
the electronic department's technicians to look at it for you and
swap wages with him. I think he might be rather afraid that you are
one of the teaching staff of some academic institution.

Paul Burke

Well - it's a very foreign idea to me. So far in school (I'm a second
year EE) all I've been taught with FETs is how to use them as
switches.

So this will work?

Why not simulate it? If it simulates OK you can actually build it and
see what happens.

Leon

I don't have the slightest idea how to simulate a circuit, or even where
to begin to try, Could you point me towards possibly an introduction to
circuit simulation? Thanks,

-M. Noone

 

[Larry Brasfield]

"Michael Noone" <mnoone.uiuc.edu@127.0.0.1> wrote in message
news:Xns9621752B7559Bmnooneuiucedu127001@216.196.97.136...

John Larkin <jjSNIPlarkin@highTHISlandPLEASEtechnology.XXX> wrote in
news:8ig041puudk80v93lqk5i64dcqbn8m5h1j@4ax.com:
....
Looks to me, as I understand the stated voltages, that you have 400
volts gate-to-source on this fet. That will kill it.

John


I was planning on using a high voltage FET. I was thinking something
along the lines of this: http://www.irf.com/product-
info/datasheets/data/irfb17n50l.pdf - it's designed to switch 500V...
Why would it get killed? Thanks,

You need to consider:

1. What range of output voltage (with respect to ground)
can the op-amp output cover given its connections?
2. Given the FET source connection, how does answer
to 1 affect the gate-to-source voltage applied to the FET?
3. What is the rated gate-to-source voltage of the FET?

When you have answers to those questions, you will have
the answer to "Why would it get killed?"

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.