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:
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
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
America: Land of the Free, Because of the Brave
It is 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
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)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.
Wien bridge oscillators with one opamp and no other semiconductors have been around already.
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 ( snipped-for-privacy@misty.com)
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 Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)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).
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
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.
But just wait until you see the "Inventor" PhD dissertation.
Bwahahahahahahaha ha ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |
America: Land of the Free, Because of the Brave
It has way too many parts in it.
10K -------/\\/\\------------ ! ! +-------!-\\ LT1013 ! ! ! >--------+---+----- Out ! GND--!+/ ! === === 1.0u ! 0.1u ! GND GND
As opposed to not enough parts?
-- Regards, John Popelish
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.
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
I bow to your greatness :)
Try it. It doesn't wack against the rails and it does oscillate quite nicely.
Today an optically varied resistor or a JFET can used in place of the lightbulb.
An LED shining on a chunk on some strange sort of material that varies its resistance over the period of seconds works very well but it takes a long time to settle.
If you want to go with the JFET, you need one with a low gain so that the change in drain voltage doesn't effect the resistance much.
Phase sensitivity wrt normalized resonant frequency is 3.5x that of the conventional Wien, making it much more frequency stable, but that is stable at whatever frequency it settles on...
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