When I built the original a friend told me about Maplin and he also gave me a JLH circuit diagram, perhaps I have got mixed up between the Maplin amp and the JLH amp.
If this is true I have no idea who has copyright on the circuit.
On my own design pcb on ebay.
I think I might be right in saying I reverse engineered it then altered it for my own purposes.
Its not as if I stole the pcb layout then copied all the components.
I have changed every transistor, altered decoupling and modified slightly the LTP stage.
You have designed your own PCB
You have selected your own semiconductor components.
You have designed your own decoupling
You have designed your own LTP
You have designed your own passive component values
You have designed it to be different
Who's going to recognise it as being similar to some other very old product?
You have selected your own semiconductor components.
You have designed your own decoupling
You have designed your own LTP
You have designed your own passive component values
You have designed it to be different
Who's going to recognise it as being similar to some other very old product?
I tested it tonight with a square wave and it looks fine.
Just a slight droop due to input filter.
It sounds like you still feel uncomfortable with thinking of it as your own. I'm guessing that the one thing that hasn't really changed is the topology?
I know that when I saw a topology that I thought I had not seen used in a particular context being proposed without crediting me I was not pleased. Component values notwithstanding. It is true however, that particular configurations become part of a pallette of known good functions that we all draw on and consciously or unconsciously use and re-use, so there is nothing intrinsically sacrosanct about using somebody else's topology, it's just a risk assessment you have to make in a business sense. How likely is it really that you will be pursued?
Perhaps it might be sufficient to give a credit... 'After the style of the Maplin amplifier XXX'?
I know that when I saw a topology that I thought I had not seen used in a particular context being proposed without crediting me I was not pleased. Component values notwithstanding. It is true however, that particular configurations become part of a pallette of known good functions that we all draw on and consciously or unconsciously use and re-use, so there is nothing intrinsically sacrosanct about using somebody else's topology, it's just a risk assessment you have to make in a business sense. How likely is it really that you will be pursued?
Perhaps it might be sufficient to give a credit... 'After the style of the Maplin amplifier XXX'?
there is no business risk from using the circuit ideas, topology or even exact part types - circuits in publicly available magazine articles published over 20 years ago are Prior Art, Public Domain - have no legal protection whatsoever
the steady expansion of Prior Art is a natural part of "the advancement of the useful arts"
in most fields of engineering there isn't even much expectation of historical citation - good ideas just get used, when you look for the history many "inventions" in common use appear to have murky and often multiple origins - only some get patented and have limited protection - which expires
Copyright, Trademarks protect exact copies of Expressions of ideas, written works, art - not the ideas
the steady expansion of Prior Art is a natural part of "the advancement of the useful arts"
in most fields of engineering there isn't even much expectation of historical citation - good ideas just get used, when you look for the history many "inventions" in common use appear to have murky and often multiple origins - only some get patented and have limited protection - which expires
Copyright, Trademarks protect exact copies of Expressions of ideas, written works, art - not the ideas
IMO, that's the worst possible idea. "Maplin" is someone else's trademark and THAT is protected.
Yes Ed but those cookbook amps were meant to be copied - just so RCA could sell more transistors. That's not the case discussed here.
Jan
Hi
I think this is Maplins own specific design. Its not a JLH nor a Naim/RCA (which have quasi-complementary o/p stage). It has a specific design of o/p stage using sziklai pairs.
I think you would be on dodgy ground marketing an updated version of this without
Maplins consent which I doubt you will get. The actual topology is very common and
you could use it if you re-engineered it with for example a different gain structure
or say a degenerated LTP or different compensation ie something sufficient to prove
your specific design input.
I think this is Maplins own specific design. Its not a JLH nor a Naim/RCA (which have quasi-complementary o/p stage). It has a specific design of o/p stage using sziklai pairs.
I think you would be on dodgy ground marketing an updated version of this without
Maplins consent which I doubt you will get. The actual topology is very common and
you could use it if you re-engineered it with for example a different gain structure
or say a degenerated LTP or different compensation ie something sufficient to prove
your specific design input.
I wouldn't worry about Maplin's IP in this case as there's nothing particularly novel about the circuit anyway. The only slightly unusual (today) feature is the output stage with gain, but that was used e.g. in the Tiger amps way back in the seventies.
For example, have a look at the circuit shown here. Almost identical to the Maplin circuit, but published much earlier in a different magazine.
For example, have a look at the circuit shown here. Almost identical to the Maplin circuit, but published much earlier in a different magazine.
On what legal basis? No patent, copyright is irrelevant unless he's reproducing their collateral or artwork, and if he doesn't use their name, no trademark issue.
'over 20 years' is meaningless in the context of patent or copyright. Protection subsists for however long the legislation in the particular jurisdiction says it does, 70 years after the death of the author in the case of the UK, which is what we're discussing here.
The risk of a harassment suit is ever present regardless of its propriety, that is the nature of business.
The use of Maplin's name is not impossible with agreement, it is only amongst members here that agreement is impossible.
I am trying to find a way through for Nigel to exploit his work without guilt or exciting the disapprobation of his peers, is anybody else trying to do anything other than demonstrate the putative superiority of their intellect and education?
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yes some of us are stating facts verified over careers designing circuits in commercially sold products - in companies applying for, using and respecting or designing around valid patents
and using "Prior Art" circuit techniques from textbooks, manufacturer's app notes, professional and trade magazines
so while not lawyers there are many design engineers with substantial experience in what is and is not protected IP
Patent is the only method of protecting a circuit - and the US, UK, EU Harmonized Patent term is 20 years, with very small variation Term of patent - Wikipedia, the free encyclopedia
Copyright and Trademark Do Not apply to building circuits - only to specific drawings of circuits or a "artwork" - a redrawing of the same topology, even same part numbers is not covered by Copyright
DMCA, allowing Copyright for Software may have caused some confusion in those not clear on the distinction between hardware and software
and using "Prior Art" circuit techniques from textbooks, manufacturer's app notes, professional and trade magazines
so while not lawyers there are many design engineers with substantial experience in what is and is not protected IP
Patent is the only method of protecting a circuit - and the US, UK, EU Harmonized Patent term is 20 years, with very small variation Term of patent - Wikipedia, the free encyclopedia
Copyright and Trademark Do Not apply to building circuits - only to specific drawings of circuits or a "artwork" - a redrawing of the same topology, even same part numbers is not covered by Copyright
DMCA, allowing Copyright for Software may have caused some confusion in those not clear on the distinction between hardware and software
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