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How does one profit from a novel circuit idea?
T3sl4co1l:
I don't quite get all of that from a brief description, but it reminds me of a design I thought up a long time ago:
https://www.seventransistorlabs.com/Images/Power_OTA2_Sch.pdf
Operating principle is, everything's a CCS. With bootstrap or isolated power (note V1 and V4!) the MOSFETs can have local driver stages that convert an input current to a gate voltage, with source current feedback. A diff pair at the front starts everything off, steering a reference current (Q3) dependent on input voltage; hence, power OTA (operational transconductance amplifier).
Never did build it, but the simulation has some interesting traits. Bandwidth is high, like 10MHz. But phase shift is also high, so it's not stable closed-loop nearly as high -- I think like 800kHz, I forget. Possibly some improvement could be made in the current mirrors and drivers to pull that back, though I'm not sure how much bias current might have to be spent in the process. (A monolithic solution should be able to solve all those problems, likely reaching even higher frequencies; again, I suspect the problem is there's just not enough application for them to bother designing one.)
Heh, these days I wonder if I'd just apply RF amp techniques and put in coupling transformers or something. Gates take a lot of power to drive fast, they aren't all that capacitive up there -- not power MOSFETs at least. That would have to be some kind of split path design, where high frequencies are fed-forward through the transformers, and a typical feedback circuit handles low frequencies including DC. PITA to equalize split-band designs like that, but eh.
Tim
penfold:
--- Quote from: flowib on February 17, 2021, 10:10:01 pm ---I'm going through a rough time personally, the jobs i can get don't match my capabilities. And my capabilities don't match the jobs i really want.
--- End quote ---
This thread turned very dark and very dissuasive incredibly quickly! Don't be put off by that, its always worth building something testable and seeing how it compares with current products.
Even relatively slow HV amplifiers come up quite frequently in physics-ey sorts of areas, so it is well worth doing some research on target applications. Such companies do tend to be centred in quite specific locations of the world, so permanent jobs aren't abundant world-wide, but these companies are often open to freelance/contract workers - so that's something to consider especially if you have a few tested designs under your hat (they don't even necessarily need to be commercialised).
JohnnyMalaria:
Patents are weird things and writing them even more so, especially if you are used to writing scientific material.
The key to getting a patent is to act totally and utterly surprised that your idea worked. If you explain how you studied other people's work, figured out some theories etc, then you will be admitting it was obvious based on the information publicly available at the time.
In one of my patents with a previous employer, there is the classic phrase, "Surprisingly, we have discovered that..." rather than "I used my expertise in my scientific field to...". In other words, "We didn't have a clue what we were doing but bugger me if we didn't come up with this. Patent please!"
penfold:
--- Quote from: JohnnyMalaria on February 18, 2021, 02:24:20 am ---Patents are weird things and writing them even more so, especially if you are used to writing scientific material.
The key to getting a patent is to act totally and utterly surprised that your idea worked. If you explain how you studied other people's work, figured out some theories etc, then you will be admitting it was obvious based on the information publicly available at the time.
In one of my patents with a previous employer, there is the classic phrase, "Surprisingly, we have discovered that..." rather than "I used my expertise in my scientific field to...". In other words, "We didn't have a clue what we were doing but bugger me if we didn't come up with this. Patent please!"
--- End quote ---
I believe that's also they key to a Nobel prize... "I spilt this on a lab bench... look what happened"
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