opamp sine wave oscillator

[Inventor]

Hi, hope I'm posting to the right place. I created a nifty little
sine wave oscillator. I have no plans to patent it just want to tell
the world about it cause I think it's pretty cool. You can download
the pdf file here:

http://www.freedomodds.com/osc/

I like it for lots of reasons, but what's more important is peer
review. So what do you think of my nifty little oscillator?

 

[Jim Thompson]

Hi, hope I'm posting to the right place. I created a nifty little
sine wave oscillator. I have no plans to patent it just want to tell
the world about it cause I think it's pretty cool. You can download
the pdf file here:

http://www.freedomodds.com/osc/

I like it for lots of reasons, but what's more important is peer
review. So what do you think of my nifty little oscillator?

WHERE is the invention ?

...Jim Thompson

 

[Inventor]

WHERE is the invention ?

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

It is in the pdf file linked to by the first sentence on the page.
The page says:

The Oscillator.pdf file contains a description of my new oscillator.
Enjoy.

That Oscillator.pdf is the like to it. Guess I should make that more
obvious, huh?

 

[Jim Thompson]

It is in the pdf file linked to by the first sentence on the page.
The page says:

The Oscillator.pdf file contains a description of my new oscillator.
Enjoy.

That Oscillator.pdf is the like to it. Guess I should make that more
obvious, huh?

I read the PDF. I fail to observe any invention. Please describe the
improvement.

...Jim Thompson

 

[Inventor]

I read the PDF. I fail to observe any invention. Please describe the
improvement.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

Well, there are a few. For one, it is a single-opamp oscillator. It
does not have multiple opamps, transistor feedback stages, light
bulbs, or other such stuff to make it work. For another, it is
amplitude stabilized by the supply rail, which is nice. Plus it can
operate as an amplitude modulator. It is also a class of circuits,
not just a single circuit, based on some design principles. Those are
some of the improvements.

 

[Don Klipstein]

Well, there are a few. For one, it is a single-opamp oscillator. It
does not have multiple opamps, transistor feedback stages, light
bulbs, or other such stuff to make it work. For another, it is
amplitude stabilized by the supply rail, which is nice. Plus it can
operate as an amplitude modulator. It is also a class of circuits,
not just a single circuit, based on some design principles. Those are
some of the improvements.

Wien bridge oscillators with one opamp and no other semiconductors have
been around already.

http://www.ti.com/sc/docs/apps/msp/journal/aug2000/aug_07.pdf

And I saw in your pdf the oscilloscope trace. It appears to me that
your supply rail amplitude stabilization involves some clipping. Did you
try listening to it through an amplifier and a loudspeaker? I have heard
what a sine wave looking like that one sounds like, and I would not mind
one little bit using an incandescent lamp to fix that.

- Don Klipstein ([email protected])

 

[Jim Thompson]

Well, there are a few. For one, it is a single-opamp oscillator. It
does not have multiple opamps, transistor feedback stages, light
bulbs, or other such stuff to make it work. For another, it is
amplitude stabilized by the supply rail, which is nice. Plus it can
operate as an amplitude modulator. It is also a class of circuits,
not just a single circuit, based on some design principles. Those are
some of the improvements.

With clipping distortion what's the value?

People who rave about what they've done with a single OpAmp are in the
same class as those who make a single-transistor LED flasher ;-)

Come back when you have a sine-wave oscillator with better than 0.01%
THD.

...Jim Thompson

 

[Inventor]

With clipping distortion what's the value?

People who rave about what they've done with a single OpAmp are in the
same class as those who make a single-transistor LED flasher ;-)

Come back when you have a sine-wave oscillator with better than 0.01%
THD.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

The solution to that is to use the non-inverting tap, which has much
lower harmonic content (see the other photo).

 

[John Larkin]

Hi, hope I'm posting to the right place. I created a nifty little
sine wave oscillator. I have no plans to patent it just want to tell
the world about it cause I think it's pretty cool. You can download
the pdf file here:

http://www.freedomodds.com/osc/

I like it for lots of reasons, but what's more important is peer
review. So what do you think of my nifty little oscillator?

The pseudo-scientific-paper format is interesting, but the style and
syntax are jarring in that context.

The oscillator itself is trivial. Hewlett did a better job in 1938.

John

 

[Winfield]

With clipping distortion what's the value?

People who rave about what they've done with a single OpAmp are in the
same class as those who make a single-transistor LED flasher ;-)

Come back when you have a sine-wave oscillator with better than 0.01%
THD.

Our new 2-opamp "AoE oscillator" (a modified
Wien bridge made with two inverting opamps and
G=2) has about 0.0002% (2ppm) distortion, IIRC.

 

[Jim Thompson]

The pseudo-scientific-paper format is interesting, but the style and
syntax are jarring in that context.

The oscillator itself is trivial. Hewlett did a better job in 1938.

John

But just wait until you see the "Inventor" PhD dissertation.

Bwahahahahahahaha ha ;-)

...Jim Thompson

 

[MooseFET]

Hi, hope I'm posting to the right place. I created a nifty little
sine wave oscillator. I have no plans to patent it just want to tell
the world about it cause I think it's pretty cool. You can download
the pdf file here:

http://www.freedomodds.com/osc/

I like it for lots of reasons, but what's more important is peer
review. So what do you think of my nifty little oscillator?

It has way too many parts in it.

10K
-------/\/\------------
! !
+-------!-\ LT1013 !
! ! >--------+---+----- Out
! GND--!+/ !
=== === 1.0u
! 0.1u !
GND GND

 

[John Popelish]

It has way too many parts in it.

10K
-------/\/\------------
! !
+-------!-\ LT1013 !
! ! >--------+---+----- Out
! GND--!+/ !
=== === 1.0u
! 0.1u !
GND GND

As opposed to not enough parts?

 

[John Larkin]

It has way too many parts in it.

10K
-------/\/\------------
! !
+-------!-\ LT1013 !
! ! >--------+---+----- Out
! GND--!+/ !
=== === 1.0u
! 0.1u !
GND GND

Your circuit has way too many parts.

-----------------------
! !
+-------!-\ AD840 !
! >------------+----- Out
GND--!+/

John

 

[Inventor]

Your circuit has way too many parts.


John

Thanks for your input, John. It does seem like a lot of parts, but
when you look at the alternatives, in most cases, it is fewer parts.
But yeah, four RC's for a single oscillator does seem like a lot. If
you want fewer parts try the LC oscillator described later in the
paper I guess.

 

[John Larkin]

Thanks for your input, John. It does seem like a lot of parts, but
when you look at the alternatives, in most cases, it is fewer parts.
But yeah, four RC's for a single oscillator does seem like a lot. If
you want fewer parts try the LC oscillator described later in the
paper I guess.

The "alternatives" have more parts for reasons. If you just let an RC
oscillator build up amplitude until it clips, you get a lot of
distortion. If you clip just a tiny bit, it's marginal to oscillate at
all.

Hewlett's lightbulb was a nonlinear element with a long gain time
constant that rolled off the gain to get stable amplitude with low
distortion.

An LC oscillator can be made with mimimal parts and low distortion,
but it's hard to tune over a wide range.

All this was understood 70 years ago.

John

 

[Eeyore]

With clipping distortion what's the value?

People who rave about what they've done with a single OpAmp are in the
same class as those who make a single-transistor LED flasher ;-)

Come back when you have a sine-wave oscillator with better than 0.01%
THD.

It'll need to be better than 0.001% to interest me !

I imagine that 'Inventor' isn't familiar with state of the art.

Graham

 

[Inventor]

It'll need to be better than 0.001% to interest me !

I imagine that 'Inventor' isn't familiar with state of the art.

Graham

Well, then maybe the circuit is not for you. You know, I am really
quite surprised at all the negativity in these responses. I figured
out something interesting, I wrote it up, and I posted it on the web
for you to enjoy. I'm not asking for anything from anyone other than
a plain, simple peer review and I've gotten some of that, thank you
very much. The circuit might prove very useful, it might not. I had
fun with the process of discovery so it was a pleasant, positive
experience for me. Why don't we all play nice for a change?
Thanks!

 

[John Devereux]

[...]

Well, then maybe the circuit is not for you. You know, I am really
quite surprised at all the negativity in these responses. I figured
out something interesting, I wrote it up, and I posted it on the web
for you to enjoy. I'm not asking for anything from anyone other than
a plain, simple peer review and I've gotten some of that, thank you
very much. The circuit might prove very useful, it might not. I had
fun with the process of discovery so it was a pleasant, positive
experience for me. Why don't we all play nice for a change?
Thanks!

I thought your article itself was quite interesting, nicely laid out
too. I think some people are having a problem with your perceived
claim to "inventing" something new. These circuit arrangements are no
doubt obvous and well known for decades, to those here more
experienced. And for the stated goal of a sine wave oscillator there
are better solutions.

 

[Inventor]

[...]

Well, then maybe the circuit is not for you. You know, I am really
quite surprised at all the negativity in these responses. I figured
out something interesting, I wrote it up, and I posted it on the web
for you to enjoy. I'm not asking for anything from anyone other than
a plain, simple peer review and I've gotten some of that, thank you
very much. The circuit might prove very useful, it might not. I had
fun with the process of discovery so it was a pleasant, positive
experience for me. Why don't we all play nice for a change?
Thanks!

I thought your article itself was quite interesting, nicely laid out
too. I think some people are having a problem with your perceived
claim to "inventing" something new. These circuit arrangements are no
doubt obvous and well known for decades, to those here more
experienced. And for the stated goal of a sine wave oscillator there
are better solutions.

Well, I can't really be certain, but I kind of thought there was
something new here, yes. I thought that stuff about using the inverse
dual voltage divider on opposite sides of the circuit was new, the
fact that it's a whole family of oscillators not just one was new, and
features like the amplitude stabilization and amplitude modulation
were new as well. I think people are reminded of familiar circuits by
the new circuit, and then they reply: "that's been done before!", but
at this point I'm still thinking there is novelty here. If it's an
old familiar circuit, would someone please post a reference, perhaps
an existing web link?