Hi,
I found this site the other week, thought someone might find it usefull or at least get a kick out of it.
TI has a rather interesting patent for example, I've seen it mentioned before but now I understand the joke
http://www.acutechnology.com/ClassD/
Cheers
I found this site the other week, thought someone might find it usefull or at least get a kick out of it.
TI has a rather interesting patent for example, I've seen it mentioned before but now I understand the joke
http://www.acutechnology.com/ClassD/
Cheers
Thanks Chris for this VERY useful link,
Taking a very brief look at the listing, the first Patent would seem to proceed Brunos UCD patent!!! I believe it would be very hard to enforce UCD when this Patent exists!
Yes, I nearly fell of my chair when I first heard about TI trying to Patent Tri level (BD) modulation!!!
Once again this just reinforces how pointless Class D patents are – I’m sure you would 100% agree with me Jocko?
John
Taking a very brief look at the listing, the first Patent would seem to proceed Brunos UCD patent!!! I believe it would be very hard to enforce UCD when this Patent exists!
Yes, I nearly fell of my chair when I first heard about TI trying to Patent Tri level (BD) modulation!!!
Once again this just reinforces how pointless Class D patents are – I’m sure you would 100% agree with me Jocko?
John
Hi John,
My pleasure
Good to see you around again as well, I guess you've been busy?
TI has a number of wacky patents there:
Patent No: 5,994,954
"WOW In 1997, using a ramp and a comparator, TI patents the pulse width modulatorŠ"
I guess you can't blame them for trying, why they get awarded seems to be the real issue at hand, more money in their pockets huh, crooked sob's.
Cheers,
Chris
My pleasure
Good to see you around again as well, I guess you've been busy?
TI has a number of wacky patents there:
Patent No: 5,994,954
"WOW In 1997, using a ramp and a comparator, TI patents the pulse width modulatorŠ"
I guess you can't blame them for trying, why they get awarded seems to be the real issue at hand, more money in their pockets huh, crooked sob's.
Cheers,
Chris
Hi Chris,
I'm guessing TI lives in some kind of Time Warp!
I understand companies see Patents a method to improve the IP value of a company – you know its all just one big game, bankers now run our world – sell your stock options while you can!
Philips is just one example of a company which positively encourages its employees to apply for Patents with Cash rewards – not by accident then that it’s now the second biggest applier for Patents.
Yes, been designing away - starting my new Hi-Fi brand, lots of time spent in China, where Internet access to the outside world is very limited (read censured).
John
I'm guessing TI lives in some kind of Time Warp!
I understand companies see Patents a method to improve the IP value of a company – you know its all just one big game, bankers now run our world – sell your stock options while you can!
Philips is just one example of a company which positively encourages its employees to apply for Patents with Cash rewards – not by accident then that it’s now the second biggest applier for Patents.
Yes, been designing away - starting my new Hi-Fi brand, lots of time spent in China, where Internet access to the outside world is very limited (read censured).
John
Hi Jaka,
No link?
But no matter what might be said, I believe it would be near impossible to defend the differences in court – the diagrams say all – what is the difference between the two (at least from a diagram perspective) – ok maybe fight the clams, but then a patent must also be novel!
I believe many here share the same feelings towards patents, as I do – especially in the field of Class D.
When I first started working on my output stage error correction design more then 15 years ago, I worked pretty much in a vacuum, and even when I can across papers such as AES preprints – not being use to there terminology (why are scientific papers always published in such a complicated manner) I didn’t understand there significant.
Recently I was shown a patent from about 2002 that seem to show a similar method as I had developed - I was completely thrown – however soon afterwards I also found patents that had lapsed (due to age) that showed / claimed the same method!!! Yes a re-patent of a much older patent – which seems typical in the field of class D. So now at least the 2002 patent was void – and I could still use my designs without fear of IP issues. But even without the earlier patent I would not have had a hard time proving prior art – many of my designs float about Labs around the world…
Also after spending so long developing and understanding the Class D & OPS FB topologies, I have many different methods to “Crack the Egg”, if I run into Patent issues – I will just do it in another way.
To cut a long story short – no I will not be applying for a Patent for my technology; rather design into IC’s or under potted boards – only lawyers make money from patents. If you don’t have the funds to fight and protect a patent – then there’s no point in wasting your money in the first place.
Case in point, how many poor lawyers do you know, and try and balance this with how many poor engineers you know!
Likewise, how many engineers could become lawyers – and how many lawyers could become engineers!
Does this mean I will publish the circuit diagrams – maybe in due course, but only after my design and products have been released into the market place first.
I have been thinking of offering small potted modules for DIY / OEM use, but my battle with time is always lost…
Regards,
John
No link?
But no matter what might be said, I believe it would be near impossible to defend the differences in court – the diagrams say all – what is the difference between the two (at least from a diagram perspective) – ok maybe fight the clams, but then a patent must also be novel!
I believe many here share the same feelings towards patents, as I do – especially in the field of Class D.
When I first started working on my output stage error correction design more then 15 years ago, I worked pretty much in a vacuum, and even when I can across papers such as AES preprints – not being use to there terminology (why are scientific papers always published in such a complicated manner) I didn’t understand there significant.
Recently I was shown a patent from about 2002 that seem to show a similar method as I had developed - I was completely thrown – however soon afterwards I also found patents that had lapsed (due to age) that showed / claimed the same method!!! Yes a re-patent of a much older patent – which seems typical in the field of class D. So now at least the 2002 patent was void – and I could still use my designs without fear of IP issues. But even without the earlier patent I would not have had a hard time proving prior art – many of my designs float about Labs around the world…
Also after spending so long developing and understanding the Class D & OPS FB topologies, I have many different methods to “Crack the Egg”, if I run into Patent issues – I will just do it in another way.
To cut a long story short – no I will not be applying for a Patent for my technology; rather design into IC’s or under potted boards – only lawyers make money from patents. If you don’t have the funds to fight and protect a patent – then there’s no point in wasting your money in the first place.
Case in point, how many poor lawyers do you know, and try and balance this with how many poor engineers you know!
Likewise, how many engineers could become lawyers – and how many lawyers could become engineers!
Does this mean I will publish the circuit diagrams – maybe in due course, but only after my design and products have been released into the market place first.
I have been thinking of offering small potted modules for DIY / OEM use, but my battle with time is always lost…
Regards,
John
JohnW said:
Actually, most patent lawyers are engineers (or scientists, many with advanced degrees). It helps in writing and defending claims to understand the invention. Patent attorneys I know have to be careful to avoid becoming a co-inventor, as the engineer in them wants to tweak the invention to make it more novel or work better.
I don't know of any lawyers who became engineers, though.
You're right about the cost of defending a patent. It makes it really difficult for the little guy.
100% agreement, John.
A buddy from university has a job to review all the patent applications that the jet aircraft engine company where he works files. Mainly with an eye towards competition from European competitors.
Asked him once what his job qualifies him for when his job is downsized. Answer:
"Sell hardware at Home Depot."
Too bad he will find that they don't want guys like that there.............trust me.....a lot of us have already tried.
Back to the subject at hand............
Only TI could patent some silly marketing feature and be proud of it.
OK...........M$ probably would too, but they don't count.
Jocko
A buddy from university has a job to review all the patent applications that the jet aircraft engine company where he works files. Mainly with an eye towards competition from European competitors.
Asked him once what his job qualifies him for when his job is downsized. Answer:
"Sell hardware at Home Depot."
Too bad he will find that they don't want guys like that there.............trust me.....a lot of us have already tried.
Back to the subject at hand............
Only TI could patent some silly marketing feature and be proud of it.
OK...........M$ probably would too, but they don't count.
Jocko
Jocko Homo said:
Hardly. With experience like that he'd likely be snapped up as a patent agent by a law firm, assuming he has an engineering or science degree.
Contrary to popular belief, to become a patent agent, you don't need to have gone to law school. Admittance to the patent bar requires an engineering or science background.
Once he's been an agent for a number of years, most law firms will offer to pay to send a person to law school, which just enables them to offer legal opinions and litigate, but it's his choice. I know a couple very senior patent agents who have stuck to writing patents, because it's more satisfying for the engineering mind.
If your buddy isn't getting paid well, tell him to shop his resume around to IP firms.
Hi,
Regarding the UCD patent and Bruno's comments on it, linked to us here by Jaka Racman, is making use of a time delay simply not another form of hysteresis? Then you read the UCD patent and see "substantially free from hysteresis" which tells me it is still a part of it (at least a diode drop in the OR section of the comparator, which adds to the time delay).
If you read Bruno's reply which Jaka Racman linked to, and then his other reply to Analog Spiceman about using hysteresis with UCD:
"I know for certain that the UcD patent states the use of a comparator "substantially free from hysteresis", which means that applying hysteresis and modifying the feedback circuit in order to nullify the negative effects of this would not suffice to get from under the cover of the patent."
You'll find that in this thread http://www.diyaudio.com/forums/showthread/t-40502.html
So it would seem as I suspected, hysteresis is a part of the UCD patent as well. So I don't believe in one case you can use "substantially free from" to claim it has none, and therefore doesn't infringe, while in another case use "substantially free from" to claim that it does include it and therefore you can't get out from under it, surely it must be one or the other.
With the lack of common sense in courts though, and sometimes honesty, I sure as hell will not be the one to find out one way or the other, will you?$?
I think where UCD does deserve a patent in the rather elegant circuitry provided in it, but Takagishi should be listed as prior art and UCD as a simplification /improvement on the design.
It must be good though for everyone to loath its patent so much I don't see anyone debating TI's PWM modulator lol.
I feel the introductory paragraph of the link I posted originally in this thread really tells the story about patents though. It would seem anyone can get one if written properly, and anyone can contest it and win, if they have the money. It all comes down to who's got the green.
Regarding the UCD patent and Bruno's comments on it, linked to us here by Jaka Racman, is making use of a time delay simply not another form of hysteresis? Then you read the UCD patent and see "substantially free from hysteresis" which tells me it is still a part of it (at least a diode drop in the OR section of the comparator, which adds to the time delay).
If you read Bruno's reply which Jaka Racman linked to, and then his other reply to Analog Spiceman about using hysteresis with UCD:
"I know for certain that the UcD patent states the use of a comparator "substantially free from hysteresis", which means that applying hysteresis and modifying the feedback circuit in order to nullify the negative effects of this would not suffice to get from under the cover of the patent."
You'll find that in this thread http://www.diyaudio.com/forums/showthread/t-40502.html
So it would seem as I suspected, hysteresis is a part of the UCD patent as well. So I don't believe in one case you can use "substantially free from" to claim it has none, and therefore doesn't infringe, while in another case use "substantially free from" to claim that it does include it and therefore you can't get out from under it, surely it must be one or the other.
With the lack of common sense in courts though, and sometimes honesty, I sure as hell will not be the one to find out one way or the other, will you?$?
I think where UCD does deserve a patent in the rather elegant circuitry provided in it, but Takagishi should be listed as prior art and UCD as a simplification /improvement on the design.
It must be good though for everyone to loath its patent so much
I don't see anyone debating TI's PWM modulator lol.I feel the introductory paragraph of the link I posted originally in this thread really tells the story about patents though. It would seem anyone can get one if written properly, and anyone can contest it and win, if they have the money. It all comes down to who's got the green.
Yet another inventor from the hifi-forum.de seems to be the writer of this:
DE19838765A1 , a self oscillating design nearly same to this of Johan Soerensen.
Timo
DE19838765A1 , a self oscillating design nearly same to this of Johan Soerensen.
Timo
Hi,
Chris, your link is trully great. I have been searching class D patents since the days when IBM provided USPTO database sarch and I have a large pile of them, but I must say at least half of the listed patents were unknown to me. I am especially glad I have found Honeywell ampliverter (switching amplifier with HF transformer isolation) patent which predates Peavey for 10 years. I have recently found out that constructing transformers with coupling factor 0.99998 is possible and renewed interest in ampliverter design. But Peavey patent bothered me, as Bruno's patent bothered Subwo1 who also invented it, although a little later. Regarding Takagishi patent, I must give Bruno credit, he at least understands how the circuit works, while I am not sure if I can say the same for Takagishi.
John I must say I completly agree with you. If you have something new, the best way is to be quiet about it and produce it. If you must advertise it, then the best way is to take some insignificant part of your invention, invent some plausible marketing BS and throw sand into the eyes of your competition. For instance, you could advertise your excellent results are due to the superfine grain structure of the magnetic cores produced exclusively for you or something like that.
I would really like to know if any of the classD patents has been disputed in court and what were the results. It seems that today engineers need more and more legal education. I have found out that reading standards in a creative way (read: how to avoid them) is becoming more important than actual solid design work. Recently flicker standard was imposed on all medical equipment sold in EU. It affects all medical devices, also those that can not possibly operate without pulsed power consumption which would mean banning from the market. But with some twiddling with the boilerplate, standard can be avoided. What is the purpuse of this?
Best regards,
Jaka Racman
Chris, your link is trully great. I have been searching class D patents since the days when IBM provided USPTO database sarch and I have a large pile of them, but I must say at least half of the listed patents were unknown to me. I am especially glad I have found Honeywell ampliverter (switching amplifier with HF transformer isolation) patent which predates Peavey for 10 years. I have recently found out that constructing transformers with coupling factor 0.99998 is possible and renewed interest in ampliverter design. But Peavey patent bothered me, as Bruno's patent bothered Subwo1 who also invented it, although a little later. Regarding Takagishi patent, I must give Bruno credit, he at least understands how the circuit works, while I am not sure if I can say the same for Takagishi.
John I must say I completly agree with you. If you have something new, the best way is to be quiet about it and produce it. If you must advertise it, then the best way is to take some insignificant part of your invention, invent some plausible marketing BS and throw sand into the eyes of your competition. For instance, you could advertise your excellent results are due to the superfine grain structure of the magnetic cores produced exclusively for you or something like that.
I would really like to know if any of the classD patents has been disputed in court and what were the results. It seems that today engineers need more and more legal education. I have found out that reading standards in a creative way (read: how to avoid them) is becoming more important than actual solid design work. Recently flicker standard was imposed on all medical equipment sold in EU. It affects all medical devices, also those that can not possibly operate without pulsed power consumption which would mean banning from the market. But with some twiddling with the boilerplate, standard can be avoided. What is the purpuse of this?
Best regards,
Jaka Racman
Hi,
after some discussion in the German Hifi-Forum I tried to simulate the principle of the design, suggested in the patent two posts ago. I do not know, if this principle, feeding back the pre-filter output signal to the integrator _and_ to the comparator, was invented any time before 1998. The very simple addendum to the basic hysteretic modulator seems to be clever.
As I understand it, is the reason for that added resistor to compensate the influence of supply variations on the output signal by shifting the trip points of the comparator and therefore vary the resulting pulse width. This acts very fast, the next pulse will output the correct value.
Here are the schematic and the simulation data of the basic circuit, described in the patent.
In my opinion, the simulation results make this design worth a real world try. The post filter feedback may be added indeed, to improve the overall frequency behaviour and damping factor.
I would like to hear your opinion about this trick.
Regards, Timo
after some discussion in the German Hifi-Forum I tried to simulate the principle of the design, suggested in the patent two posts ago. I do not know, if this principle, feeding back the pre-filter output signal to the integrator _and_ to the comparator, was invented any time before 1998. The very simple addendum to the basic hysteretic modulator seems to be clever.
As I understand it, is the reason for that added resistor to compensate the influence of supply variations on the output signal by shifting the trip points of the comparator and therefore vary the resulting pulse width. This acts very fast, the next pulse will output the correct value.
Here are the schematic and the simulation data of the basic circuit, described in the patent.
In my opinion, the simulation results make this design worth a real world try. The post filter feedback may be added indeed, to improve the overall frequency behaviour and damping factor.
I would like to hear your opinion about this trick.
Regards, Timo
Hi Timo,
That strikes me as being very similar to Bruno's SODA amp.
http://www.diyaudio.com/forums/attachment.php?s=&postid=402801&stamp=1085661272
It was said to sound very good, but UCD made it obsolete.
Thanks for the schematic as I wasn't at all able to read that patent you linked to.
Hanging an EF pair as current booster off of the comparator to drive the output stage might be of some help.
Nice work!
Regards
Chris
That strikes me as being very similar to Bruno's SODA amp.
http://www.diyaudio.com/forums/attachment.php?s=&postid=402801&stamp=1085661272
It was said to sound very good, but UCD made it obsolete.
Thanks for the schematic as I wasn't at all able to read that patent you linked to.
Hanging an EF pair as current booster off of the comparator to drive the output stage might be of some help.
Nice work!
Regards
Chris
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