Richard,
Yes, you are completely correct too. Those are all good approaches and like you, I've had my invention log book for decades, sewn binding along with printed page numbers, etc, etc.
Nothing to be added additionally nor anything removed with out the log book showing signs of it. It's always a good back up along with witness signatures from those in the art.
Yes, my inventors log did pay off in a court dispute of a different matter and was favorable because I actually had the damn thing and it couldn't be disputed. It didn't matter that I chose not to apply for a patent, it still demonstrated the inventor's process with rigor resulting in certain related expenses, legal fees etc., which could be a deduction if one is reasonable and prudent.
Valuable in keeping a trade secret, non disclosure, etc. It is a valuable asset from that point of view. It wasn't my intent to say not to have the logs, data, etc. which are important, just that the USPTO changed the process which has a significan't affect.
It's always nice to answer the question, and how many patents do you have? in the affirmative.
And
As long as we are measuring when using the urinal, "oh this water is cold."
Answering: "and deep too."
Cheers,
Yes, you are completely correct too. Those are all good approaches and like you, I've had my invention log book for decades, sewn binding along with printed page numbers, etc, etc.
Nothing to be added additionally nor anything removed with out the log book showing signs of it. It's always a good back up along with witness signatures from those in the art.
Yes, my inventors log did pay off in a court dispute of a different matter and was favorable because I actually had the damn thing and it couldn't be disputed. It didn't matter that I chose not to apply for a patent, it still demonstrated the inventor's process with rigor resulting in certain related expenses, legal fees etc., which could be a deduction if one is reasonable and prudent.
Valuable in keeping a trade secret, non disclosure, etc. It is a valuable asset from that point of view. It wasn't my intent to say not to have the logs, data, etc. which are important, just that the USPTO changed the process which has a significan't affect.
It's always nice to answer the question, and how many patents do you have? in the affirmative.
And
As long as we are measuring when using the urinal, "oh this water is cold."
Answering: "and deep too."
Cheers,
@ Jan, yes, even if you are thinking of inventing or working with an attorney.
It will demonstrate an additional thing now...those invention marketing advertisers
on TV are no limited to the totally ignorant of patent law.
What you mean Linear Audio Bookzine didn't buy you that yacht to travel the world?
@Krisfr, you know that is actually a very good idea. Holy Cow...
@Jan? You too.
@Bob, do it before that other guy who publishes and writes does it before you.
Always something extra to show a publisher or massage the sales bonus structure
because you have a new feature to assit with sales and marketing.
@Richard, you too. Write a simple step by step book, a spiral printed note book
(it lays flat--required to work from) Do the headphone amp like that, offer
the book, kits, etc. If commercial, the post an area in the commercial sector.
Be forewarned. Some of the DIYAudio areas are limited to 1000 character posts only.
Like the community area where I started a NorthTexas DIY group.
So trying to post detailed information isn't so good.
I've got to figure out a way to get paid by the inch (writers).
But there is something to be said for that fifteen minutes (of fame).
Answering: "they didn't tie in to the sanitary elbow at the main properly, ouch!"
Cheers,
It will demonstrate an additional thing now...those invention marketing advertisers
on TV are no limited to the totally ignorant of patent law.
What you mean Linear Audio Bookzine didn't buy you that yacht to travel the world?
@Krisfr, you know that is actually a very good idea. Holy Cow...
@Jan? You too.
@Bob, do it before that other guy who publishes and writes does it before you.
Always something extra to show a publisher or massage the sales bonus structure
because you have a new feature to assit with sales and marketing.
@Richard, you too. Write a simple step by step book, a spiral printed note book
(it lays flat--required to work from) Do the headphone amp like that, offer
the book, kits, etc. If commercial, the post an area in the commercial sector.
Be forewarned. Some of the DIYAudio areas are limited to 1000 character posts only.
Like the community area where I started a NorthTexas DIY group.
So trying to post detailed information isn't so good.
I've got to figure out a way to get paid by the inch (writers).
But there is something to be said for that fifteen minutes (of fame).
Answering: "they didn't tie in to the sanitary elbow at the main properly, ouch!"
Cheers,
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From the same link:
"First, the best protection against loss of patent rights by academic publication under the new law is to file a patent application prior to any academic publication."
I use it partly for the non-switching behaviour.
But in its concept it is really refined for implementation on an IC and quite finicky to make happen discretely. The thermal tracking needs to be curated properly for the biasing structure to operate within reason, then also with a power amplifier half the trick is getting enough drive current into the output devices. The derived for CMOS variants typically don't cut it, and I guess that's why TI depict this stage as a magic triangle in their OPA16xx series diagrams.
Also if you actually attempt design it for rail to rail purposes all sorts of gremlins come out of the woodwork too. With some effort it can bring you quite a nice transfer function right in the centre 'first watt' region which was really what I was after.
Bob, I had a Eureka moment when thinking about your plan to measure transistor Early effect, by injecting a test current (AC) into the collector leg and measuring the resulting (AC) voltage.
Create a DC control loop which sets the bias current in the DUT by measuring the emitter current, and using that to frobbulate the base. For example a 1K resistor in series with the emitter will have 1 volt across it when there's 1mA flowing. An opamp compares the voltage across the sense resistor, against a 1.235V reference voltage from an LM385-1.2 bandgap chip. Opamp output drives the base.
Eureka! If we attach a whomping big capacitor across the emitter resistor, the emitter is at AC ground and the collector impedance is the native value (1/ro) without any increase from degeneration. The collector impedance will be (Vearly+Vce)/Ic . Measure collector impedance with a test current, extract Vearly.
Create a DC control loop which sets the bias current in the DUT by measuring the emitter current, and using that to frobbulate the base. For example a 1K resistor in series with the emitter will have 1 volt across it when there's 1mA flowing. An opamp compares the voltage across the sense resistor, against a 1.235V reference voltage from an LM385-1.2 bandgap chip. Opamp output drives the base.
Eureka! If we attach a whomping big capacitor across the emitter resistor, the emitter is at AC ground and the collector impedance is the native value (1/ro) without any increase from degeneration. The collector impedance will be (Vearly+Vce)/Ic . Measure collector impedance with a test current, extract Vearly.
Hi Mark,
This sounds like a good idea. One thing that I was fooling with a month or two ago was configuring the DUT transistor as the current source transistor of a feedback current source to establish its operating point. Then applying a fixed DC voltage to the collector and adding to that voltage a test signal. I seem to recall that measuring the error signal at the emitter of the DUT or at the base of the DUT allowed one to infer the Early voltage under that set of conditions.
I built it and fooled around with it awhile back, and think I got useful results, but stopped working on it before I was able to verify those results independently by another more conventional test method. The idea was that the signal voltage forced onto the collector forced there to be an error voltage at the base of the DUT to keep the collector current constant, that error voltage being developed by the feedback current source arrangement.
That error voltage was small, but definitely measurable. I tested the idea with a SPICE simulation and then built the circuit. The advantage of the technique was that it did not require any really high resistances and that the operating point of the DUT was easily established and controlled.
Cheers,
Bob
This sounds like a good idea. One thing that I was fooling with a month or two ago was configuring the DUT transistor as the current source transistor of a feedback current source to establish its operating point. Then applying a fixed DC voltage to the collector and adding to that voltage a test signal. I seem to recall that measuring the error signal at the emitter of the DUT or at the base of the DUT allowed one to infer the Early voltage under that set of conditions.
I built it and fooled around with it awhile back, and think I got useful results, but stopped working on it before I was able to verify those results independently by another more conventional test method. The idea was that the signal voltage forced onto the collector forced there to be an error voltage at the base of the DUT to keep the collector current constant, that error voltage being developed by the feedback current source arrangement.
That error voltage was small, but definitely measurable. I tested the idea with a SPICE simulation and then built the circuit. The advantage of the technique was that it did not require any really high resistances and that the operating point of the DUT was easily established and controlled.
Cheers,
Bob
Is this what you're referring to?
US4570128A - Class AB output circuit with large swing
- Google Patents
Bob, I just spent three weeks working on a project that arose from a single figure in your book! It was Figure 16.7 in the 1st edition (p.350): How on earth do I measure the ESL of my big whomper electrolytic capacitors like the ones in your figure? If I get Lesl wrong then my bypass damper will be tuned to the wrong frequency, and who wants that??
So I schemed a way to measure the Equivalent Series Inductance of big ole electrolytic capacitors, built me a PCBoard, and tried it out. Seems to work acceptably. {side note: one of the caps I measured, had an ESL of less than 16 nanohenrys. A lot smaller than the example in your book.}
But it cost more than 30 bucks to buy the parts and have a PCB fabbed. Plus the three weeks of hobby time that got hijacked over to this project! I gotta learn deep breathing and focus focus focus.
Here is a link to the measured results
By the way, the heart of the design is a semiconductor device sold by Linear Technology. The people who distribute the LTSPICE simulator. Hmmm, do you suppose...
So I schemed a way to measure the Equivalent Series Inductance of big ole electrolytic capacitors, built me a PCBoard, and tried it out. Seems to work acceptably. {side note: one of the caps I measured, had an ESL of less than 16 nanohenrys. A lot smaller than the example in your book.}
But it cost more than 30 bucks to buy the parts and have a PCB fabbed. Plus the three weeks of hobby time that got hijacked over to this project! I gotta learn deep breathing and focus focus focus.
Here is a link to the measured results
By the way, the heart of the design is a semiconductor device sold by Linear Technology. The people who distribute the LTSPICE simulator. Hmmm, do you suppose...
Hi Mark,
That's a neat test setup you built, and some good results. What I recall doing way back when was not nearly as sophisticated. I drove an AC current from a signal generator into the capacitor and measured the AC voltage across its terminals in Kelvin fashion with a sensitive AC meter that had a 1 mV FS scale. I don't remember if I drive the signal directly into the cap from the 50-ohm output of the audio generator or whether I also amplified it with a power amplifier and sent the signal to the cap through a resistor between 10-100 ohms. I may have just looked at the series resonance frequency of the capacitor and how low the impedance dipped. Don't recall exactly if I paralleled it with a film capacitor to create a parallel resonance at a higher frequency. My generator and AC meter setup was capable of 10 MHz (HP652A generator and HP400EL AC meter), so its possible I did that as well.
Cheers,
Bob
That's a neat test setup you built, and some good results. What I recall doing way back when was not nearly as sophisticated. I drove an AC current from a signal generator into the capacitor and measured the AC voltage across its terminals in Kelvin fashion with a sensitive AC meter that had a 1 mV FS scale. I don't remember if I drive the signal directly into the cap from the 50-ohm output of the audio generator or whether I also amplified it with a power amplifier and sent the signal to the cap through a resistor between 10-100 ohms. I may have just looked at the series resonance frequency of the capacitor and how low the impedance dipped. Don't recall exactly if I paralleled it with a film capacitor to create a parallel resonance at a higher frequency. My generator and AC meter setup was capable of 10 MHz (HP652A generator and HP400EL AC meter), so its possible I did that as well.
Cheers,
Bob
