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| Authored by: Anonymous on Sunday, October 14 2012 @ 07:28 AM EDT |
"The use of PWM to control power to a device has been around many many years;
initially, I believe, in switch mode power supplies but latterly in DC motor
control and of course in lamp dimmers, a quick Googling brought this up ..
LED Dimmer
Circuit
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| Authored by: Gringo_ on Sunday, October 14 2012 @ 07:34 AM EDT |
I feel exactly as you. I was shocked when I read about
this patent for
something that is so common, and I was
surprised to learn that hardware patents
suffer from the same
"obvious" problem that software patents suffer. How could
anybody build any kind of electronic device with patents like
that around? It
would certainly stifle creativity if you
can't use all the tools in your tool
box. Like working with
one hand tied behind your back. [ Reply to This | Parent | # ]
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| Authored by: hairbear on Sunday, October 14 2012 @ 10:34 AM EDT |
PWM has been used to regulate the luminosity of LEDs for many years. I'm sure I
first came across it over 20 years ago. I have personally used it myself in a
manufactured product at least 6 years ago.
hairbear
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| Authored by: Anonymous on Sunday, October 14 2012 @ 11:05 AM EDT |
Even early SCR light dimmers used PWM. I had built one
based on a design published in a copy of Popular Electronics
back in the 1960's. Also, just about every switchmode
powersupply uses PWM for regulation. How on earth could
there be a non-expired patent on such a technique today?
Oh, I forgot, the USPTO grants patents by default, even if
the "invention" has already been in wide spread use for
decades.
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| Authored by: albert on Sunday, October 14 2012 @ 11:55 AM EDT |
I totally agree. I like to see Apple get a dose of its own medicine, but those
are bogo-patents. Using feedback to control _anything_ is as old as the hills.
The patents cited were issued in 2000, 2002, 2004, 2008. Feedback control of
photo strobes goes back to the 1960s, IIRC. There is nothing novel or unique
about ANY of the circuits shown. Pulse width modulation predates 2000. These
patents are merely collections of existing technology and should never have been
granted. I strongly suspect the 2000 was a trial balloon, and the remainder
filed after the first was granted.[ Reply to This | Parent | # ]
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| Authored by: Anonymous on Sunday, October 14 2012 @ 02:30 PM EDT |
The company is stated to have its place of business in Tyler TX.
Woohoo, does it actually do any business? So why is the suit
lodged in Delaware? Scrivener's error?
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- Jurisdiction? - Authored by: Anonymous on Sunday, October 14 2012 @ 02:35 PM EDT
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| Authored by: Anonymous on Monday, October 15 2012 @ 06:35 AM EDT |
I have given some consideration to the foolishness of patenting the same old
invention/implementation in a different context. While I generally fall in line
with the notion that "on the internet" or "in a mobile
device" does not a new patent make, I have also considered "what about
the roller skate?"
It's a wheel... placed on a shoe. The shoe is no longer a walking device as a
result of this modification. The patent on the wheel has probably expired by
now, but by putting it on a shoe, a whole new thing has been created.
I realize this isn't relevant to the specific instance of "regulating power
to an LED light using PWM." The use of PWM is a fairly general method
which answers the need to limit power draw and improve circuit simplicity. In
the sense that PWM has been a method used for quite a long time makes this
application of the method "obvious" and exceeds any notion of
novelty.
I guess the same is true of the roller skate as well... the installation of
wheels to help things move more easily and more quickly seems pretty obvious
too.
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| Authored by: artp on Monday, October 15 2012 @ 12:13 PM EDT |
Maybe not so latterly. :-)
It seems to me that I was seeing PWM motor control devices
in an energy management project that I was managing back in
1985.
It also makes me curious to take a look at the kind of
control that the early (1950's-1960's) digital control
minicomputers used when they ran DC electric motors in
processing plants. I had heard that one of their earliest
uses was in polyethylene letdown processes. Fisher Controls
had a special valve for use in that environment that had a
DC motor on it, if my memory isn't totally slagged out. That
was before my time, but I was able to see a few dinosaurs
that had survived.
---
Userfriendly on WGA server outage:
When you're chained to an oar you don't think you should go down when the galley
sinks ?[ Reply to This | Parent | # ]
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| Authored by: Anonymous on Tuesday, October 16 2012 @ 02:41 AM EDT |
I don't known when PWM have started to be use for the control of Electric
motors...
However, the Montreal subway train (MR-73) put in service for the 1976 Olympic
use a PWM controller (often call a Power Chopper). This is what give the
Montreal subway it characteristic sound signature when leaving a station (180,
240 and 360 Hz sound).
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