Super small electronic variable resistor -- Exists?

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43 replies · 5K views
tech99 said:
But it does not have memory action.
Indeed. That is one of the properties that makes an optoisolator very close to a pure resistance element. From an analog engineer's perspective, that is ideal.
 
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How about a FET with a capacitor on the gate. FET behaves like a voltage controlled resistor and the capacitor keeps it working while the power is off (for a short period at least).
 
MeaningfromForm said:
I thought I had... okay let me try to explain better what I want to do logically
I want an input to be adjusted either up or down then into fed into a gate which has an activation potential, so that over a threshold current it will pass through, and under it will not pass through.

Further more, the component which amplifies or reduces the signal needs to be adjusted by the circuit itself, so the circuit needs to have some sort of feedback loop to the "adjuster".

This morning, after there was perhaps one reply to your original post, I started a post in which I was going to ask if you checked DigiKey, http://www.mouser.com/ , http://www.allelectronics.com/ or Fry's.

But Firefox crashed as it sometimes does on this PC, so I took the opportunity to upgrade packages. But I did something wrong and ended up with an incomplete upgrade which I've been fighting off and on all day. Finally, I got everything back to normal.

The other thing I'd say is what others almost mentioned. This sounds like an amplifier, which could be designed with almost any kind of transistor. Or you could us an opamp, which might be simpler.
 
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jim hardy said:
Base e arithmetic? I can't even count in base e.

I soon figured out "well sure, i guess one could use any number of voltage levels for his logic,
and analog computing is just the limit as that number approaches infinity."
I bought a book on irrational numbers planning to learn how to count in an irrational number base maybe √2 but it was way too abstract for my flea brain.

I don't want to appear to be pushing a product in my first post on this forum :nb) but given your interest, you may have already encountered this book - "Hacker's Delight" by Henry S Warren.
If you haven't, I would recommend it. There's a chapter on unusual bases that blew my rather closed mind when I first read it. There's a fun bit on base -1 +/- i, as well as a brief discussion on what base is "most efficient" from the point of view of cost. Standard binary is more costly than base e by a factor of 1.062 (According to the formula he used). This book might be useful for you, MeaningfromForm. :smile:
 
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MeaningfromForm said:
Nope it looks like what I wanted to create has already been invented so it's kind of pointless to continue, besides, I live in Edmonton Canada and I wouldn't be willing to share my idea with someone unless it was in person anyways...
Thank you everyone for the ideas, keywords to research and suggestions. Perhaps I will come back in the future and revisit this when I have a better understanding of the technical aspects.

It is one of the less peasant truths of the modern world. There are so many smart people on this planet, it is very difficult to have an idea that someone else didn't think of first. We who yearn to be original get frustrated by that.
 
MeaningfromForm said:
I believe its possible to design an analog neural network that can out perform a digital representation. Ofcourse if I can build it all, my first version won't out perform anything, but maybe after I build it, I can build it again, faster, with smaller components. Kind of like how vacuum tubes advanced.
Also I have an invention idea whoch requires a neural network that can be trained very fast, and very responsive.
The OP will not identify the conceptual model of the synapse or Neural Network that might use the component.

MeaningfromForm said:
Nope it looks like what I wanted to create has already been invented so it's kind of pointless to continue, besides, I live in Edmonton Canada and I wouldn't be willing to share my idea with someone unless it was in person anyways...
Thank you everyone for the ideas, keywords to research and suggestions. Perhaps I will come back in the future and revisit this when I have a better understanding of the technical aspects.
The OP also admits that someone else has already invented the idea. But it is still kept a secret to PF.

To the small inventor, a patent is financial death. It costs real money to establish, then any challenge will destroy the small inventor with the incredible cost of the legal defence. The invention will then be available to all, without licence.

Publication of the idea is the best solution for all. That way no one can patent the idea, while others design the solution. But here the OP has chosen obscurity.

It is interesting to observe that this thread is a bit like a UFO sighting. The less information the OP provides the more interpretations are possible and the longer the suggestions and discussion will continue.
 
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+1 what he said ^^^

and because of that I find these types of threads so pointless as everyone stumbles around in the dark
trying to outguess everyone else :rolleyes::rolleyes:
 
Baluncore said:
To the small inventor, a patent is financial death. It costs real money to establish,

I'll vouch for that.
Though US patent office now has reduced rates for small entities .
Still it'll probably cost at least ten grand , much of that to a patent lawyer to translate your writeup into patent office jargon . It's a pretty strange dialect .

US7177383 is my $15K 'vanity press' misadventure .. Never again.

Get it working, submit an article to a hobby magazine, have fun.

old jim
 
There's a huge problem with patents and consumer products. It makes them ineffective even if it's not a matter of money. A lot of the theft of IP occurs in China where US patents are not enforce-able. So you can spend all that time and money on a patent only for some Chinese outfit to copy your product and sell it for a tenth the cost. Granted the quality is almost always a lot better with an original product and that can count for a lot, but an inferior copy for a fraction of the cost deeply cuts into product sales for the original.

I've developed a couple consumer products myself and people often say to me, "you should get a patent on that." I don't bother to explain why it's a complete waste of time and money. The false paradigm in the US is that a patent actually provides some protection of IP to an individual. If an offending company does business in the US a patent is enforce-able, but still it's cost prohibitive. The only people that can benefit from the US patent system are the larger corporations that keep a team of lawyers on staff.
 
CraigHB said:
A lot of the theft of IP occurs in China where US patents are not enforce-able.
The problem of international asymmetry in patent law cuts both ways. For example, a US citizen could provide a signed statement, without proof or evidence to the US patent office that stated they were working on an invention before a foreign registered patent priority date. Preferred treatment to US citizens prevents some foreign patents in the USA.

If you patent your invention, the Chinese will have the information needed to copy it.

I did not patent my most profitable invention, but I hid the IP deep inside the product. Patents on other parts of the product expired in 1998. But the product then won UK trade awards in 2002 for “the most innovative product”. I manufacture ever increasing quantities of “the magic ingredient”.

There have been several failed attempts by others to clone the product, but without a patent they have no clue what a reliable solution entails, or how the hidden IP might overcome some quite surprising problems that I anticipated. After disappointing their customers in the first year, the clone manufacturers abandon the field to cut their losses.

My design has outlasted two eras of PCB manufacturing technology, so I am now completely replacing my PCB design software for the second time. I buy some electronic components from Britain and the USA, then manufacture in Australia. I also ship a finished electronics and interface kit back to British manufacturers for final assembly with steelwork. They export most of their finished product directly into Europe. China is not in the loop.

Originally, compliance with EU regulation was interesting. Now the thoughts of Brexit keep it interesting.
 
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