Driver to drive?

FPGAs are for fast computation, DSP for more moderate speeds, but the
line between "fast" and "moderate" keeps getting faster and faster.

Yes it could be done with a DSP, but my ADC/DAC sampling rate is up to
1MHz, (ie. 12bit resolution 20MHz+ SPI clock) and there are actually A
LOT of ADC's and DAC's as there is more than 1 SMPS circuit being
controlled, also the FPGA has nice predictable and fast response to the
overcurrent and overvoltage signals as well as good predictable gate
drive PWM. I am using upwards of 200 digital I/O on the FPGA, I might
put a soft CPU in the Cyclone 3 FPGA and try that approach, but I think
its hard to beat an FPGA for something like this, when you have a lot of
fast parallel tasks required.

Maybe if you explain more on how your circuit works others might provide
more elaborate insights ..?

What SMPS type do you use?

So far the only FPGA benefits I can see so far is the possibility to replace
many dedicated DSPs with one fpga in addition to the extra i/o.

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

Hitting the ground hard would hurt either way. But I imagine that,
for give masses M1 and M2 of two aircraft, not all mid-air collisions
would be equally catastrophic. Speed of each machine would matter
[which implies that super-slow flight would be possible], as well as
their individual structure. Also, for a given seat configuration,
structural strength to weight ratio would probably matter.

Yet more arm waving, babbling nonsense.

A mid air collision between two aircraft at any speed generally results
in the aircraft falling out of the sky due to either loss of
aerodynamics (the lift goes away) or controllability..


--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 4:25?pm, j...@specsol.spam.sux.com wrote:
Yet more arm waving, babbling nonsense.

A mid air collision between two aircraft at any speed generally results
in the aircraft falling out of the sky due to either loss of
aerodynamics (the lift goes away) or controllability..

Always?

I said generally, can't you read?

What if the aircraft are blimps?

What about it?

Blimps by their very nature are fragile, as can be verified by the families
of the 12 people who died when G-1 collided with L-1 on June 8, 1942.

--
Jim Pennino

Remove .spam.sux to reply.

 

[Kris Krieger]

mpm <mpmillard@aol.com> wrote in news:b4161056-6dd8-446d-a43a-140014c860f8
@w7g2000hsa.googlegroups.com:

On Sep 14, 9:05�pm, Jim Thompson <To-Email-Use-The-Envelope-I...@My-
Web-Site.com> wrote:
Just over a year ago I was on the 34th floor of the JP Morgan Chase
Tower in Houston, as expert witness on a patent matter.

Have you seen news shots of that building after Hurricane Ike?

Nasty way to lose very expensive furniture ;-)

I have some photos of Hurricanes Hugo & Andrew that make the Chase
Tower look like the Taj Mahal. Even some Wilma photos from Ft.
Lauderdale.

I wonder why someone doesn't engineer a temporary solution to retrofit
(protect) these high-rise windows from blowing out.? I mean, even if
you foamed them in place, it would still be less expensive cleanup?

There are "structural films" that can be applied to glass (commercial or
residential) which strengthen the glas sand, in the event of breakage, old ti
together to significantly reduce shattering. IIRC there are also additional
restraint ssytems, which may include special gaskets/seals that are flexible
(to accomidate shrinkage/expansion) and keep wind from working its way in-
between the glass panes.

You might ask in one of the Architecture groups; archtects and architectural
designers, esp. those who work in hurricane-prone areas, would be able to
answer your question re: various products/systems.

As to why they aren't used? Well, people play the odds. If a major storm
hits once every 20-25 years, people figure that they save more by using
standard systems, then they'll lose in a major storm. OTOH, if major storms
are becoming more frequent, that will change.

Oh, one more horror story: The Bank of America tower in downtown
Miami (at the time called Centrust Bank)... they had a major pipe
break on the top floor that fed their fire suppression system
(tanks). Whatever security did made the problem a lot worse. It
ended up literally drowning every floor of the building. Very, very
expensive and time-consuming cleanup.

Like, on the order of years.!
I would not want to be a Houston / Galvaston resident about now.
Be sure to make a donation to the Red Cross when you get to the office
tomorrow.
As stupid as some were for not heeding the evac orders, they still
need our help.

-mpm

Some waited too long, and some, I suppose, didn't believe the storm would be
as bad as it was. They're lucky it was not as bad as it could have been -
several factor combined to make it less severe than it very easily could have
been.


Tangential to your post, I just have to say that, long before FEMA started
"suggesting" that the Houston area power companies call upon out-of-state
workers, the Houston companies had already been on the ball, making
arrangements for extra personnel to come in. Meanwhile, for all of its
"suggesting", FEMA did *nothing* to help make sure that our First Responders
had water and food. OTOH, one local Representative actually *acted* by not
waiting around for FEMA and the State gov.t to get their act together, and
instead calling upon people who were in a stable situation to donate food and
water. We had surplusses (I always keep things well-stocked anyway, but had
socked away even more as it became certain that Ike would hit Houston), so we
brought them lots of non-perishable pop-top and packet foods, drinks, water,
toilet paper, and so on - and best of all, *MANY* of our fellow Houston-area
residents also generously heeded the call, responded to the need. It was
great to see all the people patiently lining up to drop off box after box of
supplies for our First Responders. FEMA didn't even *start* bringing trucks
of supplies in until last night - meanwhile, our local HEB and Kroger
groceries somehow managed to bring in truckload after truckload of
deliveries, trying to keep gettign supplies into stores with generators.

I know that there are some Scroodges in unaffected areas who will sit in
comfort and kvetch that "people shouldn't live in coastal areas", yet
hypocritically enjoy the benefits of Houston's port, the Houston area
refineries, and the Gulf drilling platforms - and all the people livng here
who man the ports, refiners, and platforms, and all of the service people who
sell them groceries, the physicians who take care of them and their families
- and on and on and on. THe focus usually goes to emgamillion vacation
homes, but the backbone of this city, like that of the nation, is its
everyday workers and their families. It doesn't make the news much, but I've
been seeing a lot of volunteerism, and neighbor helping neighbor, and
donations. FEMA or no FEMA, our local Coast Guard, First Responders, and
Mayor Bill White have also been going IMO a great job.

For every person who seems to be a doofus, and for every "mere vacationer who
just lost a boat", there are a great many people who are everyday people,
people who have been working the port and its docks, the refineries and
drilling rigs, that benefit a great amny Americans living far from here. And
any and all donations will, as you noted, be a great help

 

[Bob Eld]

"Fred" <frederick.brown@gmail.com> wrote in message
news:671f2cc6-9a2c-4200-9d7a-aa8505948291@l43g2000hsh.googlegroups.com...

On Sep 13, 3:22 pm, Eeyore <rabbitsfriendsandrelati...@hotmail.com
wrote:
Bob Eld wrote:
"Fred" <frederick.br...@gmail.com> wrote

I have an audio amp based on the LM3886. In order to get 50W out of
it I need to use a transformer who voltage rises too high for the
LM3886 to tolerate during no or light load times.

I have modeled a linear regulator for the amp, but is is very
wasteful, it dissipates over a hundred watts a channel. I had to
parallel four regulators on each rail in order to keep their
individual dissipations manageable.

I have started considering a switched mode power supply, and have
been
looking at chips such as the LM5116. Some time ago, I heard using
SMPSs in audio amplifers in problematic because of the difficulty in
filtering out the switching noise from the output.

Any suggestions would be appreciated.

I think you are putting the effort in the wrong place. Instead of
screwing
with regulators, switching supplies and the like, the effort should go
into
the amplifier(s) and not the power supply.

If it were me, I'd design an amplifier to replace the 3886 using
discrete
components that had sufficient head room for any voltage I desired,
unregulated. Plus and minus 20 volts, plus and minus 30 volts, plus
and
minus 40 volts, or more, whatever.

Designing a discrete amp to beat the LM3886 needs the kind of skills and
experience I have. It's NOT a hobby task.

The typical 'gainclone' circuit the OP is likely usung has PUNY
reservoir caps.
Around 1500uF IIRC. Make them 4700uF and use a larger transformer in
'under-rated mode' to get better supply regulation.

Remember a well designed amplifier does not need regulated power, it
is in
effect a high speed (regulator) on it's own, turning raw DC into
controlled
(regulated) audio voltage. adding additional regulation is redundant,
wasteful and can be noisy. Why do it? Put the effort into the
amplifier not
the power supply to fix a poor amplifier.

Since the LM3886 will sustain +/-47V (obviously allow for AC line
overvoltage
on top of this) where's his problem
?http://www.national.com/mpf/LM/LM3886.html

Graham

I think you mean +/-42V. And that is exactly what my PS was supplying
at no-load. It was under heavy load that two of the devices failed.
Nation said the only way to destroy the chips was wtih excessive
supply voltage combined with low load resistance.

Fred

Sounds like second breakdown to me. The solution: beg, borrow, steal, make,
purchase, design or whatever, a better amplifier. If these chips can't
handle their ratted current at even less than the rated voltage, they are no
damn good, period.

One caution, if the current voltage and power ratings are compromised in the
specs., what other specifications are in question? Likely much of the spec.
sheet is full of lies and half truths. Nothing can be trusted without
verification.

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 5:45?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:

On Sep 15, 4:25?pm, j...@specsol.spam.sux.com wrote:
Yet more arm waving, babbling nonsense.

A mid air collision between two aircraft at any speed generally results
in the aircraft falling out of the sky due to either loss of
aerodynamics (the lift goes away) or controllability..

Always?

I said generally, can't you read?

What if the aircraft are blimps?

What about it?

It would seem that there might be a correlation between degree-of-
catastrohpe and the nature of the construction, mass, velocity...of
the aircraft.

Duh.

M60 tank versus Toyota Prius head on, who wins?

Not much market for aircraft that fly less than 10 MPH.

IOW, a collision between two light-weight, slow-moving vehicles, which
no exposed moving parts (propeller, jet,..) might be, generally
speaking, less catastrophic than two heavy-weight, fast-moving
vehicles with props, especially if the prop itself participates in the
collision.

Let's see, two people, that's about 400 pounds to start with.

Add a structure, a real (not a Star Trek fantasy) engine, wheels, seats,
windscreen, fuel tanks, fuel, etc. and now you have better than a
thousand pounds.

And once again, there isn't much of a market for aircraft that fly less
than 10 MPH.

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?



--
Jim Pennino

Remove .spam.sux to reply.

 

[Phil Allison]

"Bob Too Elderly to Post Here"

Nation said the only way to destroy the chips was wtih excessive
supply voltage combined with low load resistance.

Fred

Sounds like second breakdown to me.

** Bet a dope like you has no idea what that even is.

Hint - it is not normally an issue with resistive loads.

Plus the LM3886 has very effective internal SOA protection (called SPIKE )
as well as thermal shut down if the chip reaches 165C.

Bet you have never even seen one on them.

It is one of the most popular audio power amp ICs ever made and found in
countless professional audio products.



..... Phil

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 6:55?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:





On Sep 15, 5:45?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:

On Sep 15, 4:25?pm, j...@specsol.spam.sux.com wrote:
Yet more arm waving, babbling nonsense.

A mid air collision between two aircraft at any speed generally results
in the aircraft falling out of the sky due to either loss of
aerodynamics (the lift goes away) or controllability..

Not much market for aircraft that fly less than 10 MPH.

IOW, a collision between two light-weight, slow-moving vehicles, which
no exposed moving parts (propeller, jet,..) might be, generally
speaking, less catastrophic than two heavy-weight, fast-moving
vehicles with props, especially if the prop itself participates in the
collision.

Let's see, two people, that's about 400 pounds to start with.

My OP said "one-seater".

OK, subtract about 200 pounds, you are still left with close to a
thousand pounds.

Add a structure, a real (not a Star Trek fantasy) engine, wheels, seats,
windscreen, fuel tanks, fuel, etc. and now you have better than a
thousand pounds.

If by "real", you mean ICE, that might be difference in opinion. You
are imagining something that looks more or less like a Cessna.

No, real means real and something that is obtainable as something
other than a Star Trek prop from a memorabilia dealer.

And once again, there isn't much of a market for aircraft that fly less
than 10 MPH.

Unless 10 mph is one of several ranges.

There are many reasons someone might like to momentarily fly 10 mph.

So there is only "momentarily" a chance of a mid air collision?

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?


--
Jim Pennino

Remove .spam.sux to reply.

 

[Kris Krieger]

bill.sloman@ieee.org wrote in news:78f4ddae-7ab3-4dbb-ad9a-
8e1f570945ef@s1g2000pra.googlegroups.com:

On Sep 13, 11:43 pm, "Michael A. Terrell" <mike.terr...@earthlink.net
wrote:
bill.slo...@ieee.org wrote:

alt.bigoted.right-wing.septic.tosspots

   Why don't you stay there and leave the decent people on thise grou
p
alone?

Not a request I've had from any of the decent people.

--
Bill Sloman, Nijmegen

First question:
What are the requirements for qualifying as "decent" in Terrell's world, and
what are the requireemnts for qualifying as "decent" in Bill's world?

Second question: What well-known figures best fit into each requiremnt set;
what are the characteristics shared by each group?

Third question: Who prefers to meet Terrell's requirements, and who prefers
to meet Bill's?

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 7:25?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
And once again, there isn't much of a market for aircraft that fly less
than 10 MPH.

Unless 10 mph is one of several ranges.

There are many reasons someone might like to momentarily fly 10 mph.

So there is only "momentarily" a chance of a mid air collision?

Momentarily meaning that sometimes 10 mph is desirable, and sometimes
100 mph is desirable, and sometimes speeds in between is desirable, so
an aircraft where entire range is accessible might be desirable.

And in your fantasy world aircraft are going to be spending the majority
of their time at less than 10 MPH?

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?



--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 8:35?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:

On Sep 15, 7:25?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
And once again, there isn't much of a market for aircraft that fly less
than 10 MPH.

Unless 10 mph is one of several ranges.

There are many reasons someone might like to momentarily fly 10 mph.

So there is only "momentarily" a chance of a mid air collision?

Momentarily meaning that sometimes 10 mph is desirable, and sometimes
100 mph is desirable, and sometimes speeds in between is desirable, so
an aircraft where entire range is accessible might be desirable.

And in your fantasy world aircraft are going to be spending the majority
of their time at less than 10 MPH?

Why do you say "majority of their time at less than 10 MPH?"?

Do you know what a "?" at the end of a sentence means?

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?

--
Jim Pennino

Remove .spam.sux to reply.

 

[Mike Monett]

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

[...]

No, the sampling head has a 50 input impedance.

The 40 dB pad resistors are 51.01, 2499.75, and 51.01.

John, a series resistor of 2499.75 ohms might be impractical for
this attenuator.

A stray capacitance of only 3.53E-15 F. between the ends would have
the same reactance as the series resistor at 18Ghz. This would
probably put the unit out of spec.

Also, a small amount of capacitance from the center of a long high
value resistor to the outside shield might have serious effects on
the bandwidth. For example, see Win's description of "High voltage
probe frequency response", at

http://www.repairfaq.org/REPAIR/F_hvprobe.html#HVPROBE_008

However, if the attenuator were split into three cascaded 10dB
sections, the resistors would be 96.25, 71.15, and 96.25 ohms. Ref:

http://www.random-science-tools.com/electronics/PI_attenuator.html

This would dramatically reduce the effects of stray capacitance.

This is getting tiresome.

Are you sure you are considering possibilities?

I find it stimulating, probably because I like to consider
possibilities

John

Mike Monett

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

It is hard to say without doing any simulations, but as I envision it,
a Cessna's
prop would cause much damage to my aircraft if my aircraft came in
contact with the prop. Otherwise, whether it could continue to fly
woulddepend much on the dynamics of the collision. Two of my aircraft
colliding with each other would cause very severe jolt, but would
probably leave the planes flyable. The "wings" on my aircraft would
be "atypical", so it would be harder to sheer them off during
collision. I would include a parachute with each airframe.

Wings don't usually sheer off in mid air collisions.

Typically the airplane gets "bent" enough that the aerodynamics are
destroyed and it becomes unflyable.

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?

You've said your airplane can fly at airpeeds between 10 MPH to 100
MPH (11.5 knots to 115 knots). There never has been an airplane that
can do that. Is your Nobel acceptance speech ready?

--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

On Sep 15, 11:05?pm, j...@specsol.spam.sux.com wrote:
In sci.physics Le Chaud Lapin <jaibudu...@gmail.com> wrote:
You've said your airplane can fly at airpeeds between 10 MPH to 100
MPH (11.5 knots to 115 knots). There never has been an airplane that
can do that. Is your Nobel acceptance speech ready?

Is there a Nobel Prize for flight?

There would be a Nobel in physics for discovering hitherto unknown
aerodynamics that would allow an airplane to fly over a range of
10 MPH to 100 MPH.

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?

You've said your airplane can fly at airpeeds between 10 MPH to 100
MPH (11.5 knots to 115 knots). There never has been an airplane that
can do that, so how are you going to do it?

--
Jim Pennino

Remove .spam.sux to reply.

 

In sci.physics Don Klipstein <don@manx.misty.com> wrote:

An aircraft staying airborne at 10 MPH sounds to me like:

* A lighter-than-air craft (tell me how it will achieve 100 MPH) - may
still have trouble weathering a 10 MPH collision

* something slow and fragile, towards the Gossamer Condor or the
Gossamer Albatross (tell me how this will survive a 10 MPH collission or
achieve 100 MPH)

* Helicopter or Osprey sort of a thing (with collisions involving rotor
contact usually being catastrophic)

He keeps saying airplane and lighter-than-air, helicopters, and the
Osprey are not airplanes.

Given his demonstrated lack of languages skills, it could well be he
doesn't know what the word "airplane" means.

I am not a pilot, I merely know one and know weather well, and I know
that airspeed is normally expressed in knots - nautical miles per hour.

Usually, though older airplanes, home builts, and LSA's often still
use MPH.

Also, an aircraft that is airborne at very slow airspeed still has to
deal with sharing airspace with fixed wing aircraft that need airspeeds
mostly near or over 40 knots to be airborne, unless the slow aircraft is
restricted to where Cessnas and Piper Cubs are prohibited but aircraft are
permitted (where?).

Nowhere. There are areas with maximum speed limits like 200 kts and
250 kts, but no minimums.

In the US, if an airplane has a N number, i.e. is registered, it flys
and there is no discrimination in the airspace.

Helicopters have some expectation of moving at speeds fairly usual for
fixed wing aircraft unless they are hovering - usually either close to the
ground or in urban areas usually within TCA areas below the TCA conical
area.
Ultralights are prohibited in urban areas - don't plan on much
utilization of ultralights (or much of anything else besides
news/traffic helicopters and police helicopters) where helicopters have
much use of hovering at 1,000 feet or whatever in urban areas. And
outside TCA areas, fixed wing aircraft are allowed at 1,000 and 2,000
feet!

Other than landing and taking off, airplanes must be operated 1000 feet
above the highest obstacle within 2000 in congested areas (cities, etc.)
and 500 feet in open water and sparsely populated areas (farm country, etc.).

There are LOTS of airplanes flying between 1500 and 3000 feet AGL on
short flights.

Also keep in mind that most smaller aircraft have pressure altimeters,

All airplanes are REQUIRED to have a pressure altimeters.

So tell us what your aircraft without an exposed propeller is. Does it
merely have the propeller within a tube and/or screens?

He has a good deal on Star Trek shuttle craft engines.


--
Jim Pennino

Remove .spam.sux to reply.

 

[Mike Monett]

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 16 Sep 2008 03:33:59 +0000, Mike Monett <None@here.adr> wrote:

John Larkin <jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

[...]

No, the sampling head has a 50 input impedance.

The 40 dB pad resistors are 51.01, 2499.75, and 51.01.

John, a series resistor of 2499.75 ohms might be impractical for
this attenuator.

A stray capacitance of only 3.53E-15 F. between the ends would have
the same reactance as the series resistor at 18Ghz. This would
probably put the unit out of spec.

Also, a small amount of capacitance from the center of a long high
value resistor to the outside shield might have serious effects on
the bandwidth. For example, see Win's description of "High voltage
probe frequency response", at

http://www.repairfaq.org/REPAIR/F_hvprobe.html#HVPROBE_008

However, if the attenuator were split into three cascaded 10dB
sections, the resistors would be 96.25, 71.15, and 96.25 ohms. Ref:

http://www.random-science-tools.com/electronics/PI_attenuator.html

This would dramatically reduce the effects of stray capacitance.

This is getting tiresome.

Are you sure you are considering possibilities?

I buy attenuators from Mini-Circuits. I don't know what's inside, but
the black-box equivalent is the pi network shown. I have seen
attenuators and terminators that are thinfilm sheets, not lumped
components at all.

You have discussed making a simple 20dB resistive attenuator probe for low
microwave frequencies in the past. I believe you recommended using a
Caddock resistor for the series element. This would work fine at low
microwave frequencies.

A thin film sheet might be also suitable for these frequencies, perhaps up
to 5GHz or so. But have you see it used in a 40dB attenuator for 18GHz?

The series resistor would have low stray capacity between the ends, but it
would still have capacity to the shield. Win's analysis shows this might
give problems at 18GHz. Also, depending on the length, the stray inductance
might become a problem at 18GHz.

So you want the length to be as short as possible to reduce the inductance,
but this increases the capacitance betwen the ends.

Alltogether, high values of resistance are difficult to use at these
frequencies.

And I might note that 3 times 10 dB is not 40 dB.

OK, put four 10dB sections in cascade. The resistors are cheap, and
the values remain the same.

John

Mike Monett

 

[Don Klipstein]

In <34n3q5-8ri.ln1@mail.specsol.com>, jimp@specsol.spam.sux.com wrote:

In sci.physics Don Klipstein <don@manx.misty.com> wrote:

An aircraft staying airborne at 10 MPH sounds to me like:

* A lighter-than-air craft (tell me how it will achieve 100 MPH) - may
still have trouble weathering a 10 MPH collision

* something slow and fragile, towards the Gossamer Condor or the
Gossamer Albatross (tell me how this will survive a 10 MPH collission or
achieve 100 MPH)

* Helicopter or Osprey sort of a thing (with collisions involving rotor
contact usually being catastrophic)

He keeps saying airplane and lighter-than-air, helicopters, and the
Osprey are not airplanes.

Given his demonstrated lack of languages skills, it could well be he
doesn't know what the word "airplane" means.

I am not a pilot, I merely know one and know weather well, and I know
that airspeed is normally expressed in knots - nautical miles per hour.

Usually, though older airplanes, home builts, and LSA's often still
use MPH.

Also, an aircraft that is airborne at very slow airspeed still has to
deal with sharing airspace with fixed wing aircraft that need airspeeds
mostly near or over 40 knots to be airborne, unless the slow aircraft is
restricted to where Cessnas and Piper Cubs are prohibited but aircraft are
permitted (where?).

Nowhere. There are areas with maximum speed limits like 200 kts and
250 kts, but no minimums.

In the US, if an airplane has a N number, i.e. is registered, it flys
and there is no discrimination in the airspace.

Oh, and as my father tells me, tell me if he is correct? Build an
experimental and have it fly 200 hours airborne with same pilot and same
owner without interruptions by airframe-damaging crashes? And if most or
even any of those need airspeed of 30 knots or more to maintain altitude
and controllability, then does that mean every cubic yard of airspace over
America require aircraft moving at airspeed 10 knots or slower to have to
worry about colliding with faster aircraft?

Helicopters have some expectation of moving at speeds fairly usual for
fixed wing aircraft unless they are hovering - usually either close to the
ground or in urban areas usually within TCA areas below the TCA conical
area.
Ultralights are prohibited in urban areas - don't plan on much
utilization of ultralights (or much of anything else besides
news/traffic helicopters and police helicopters) where helicopters have
much use of hovering at 1,000 feet or whatever in urban areas. And
outside TCA areas, fixed wing aircraft are allowed at 1,000 and 2,000
feet!

Other than landing and taking off, airplanes must be operated 1000 feet
above the highest obstacle within 2000 in congested areas (cities, etc.)
and 500 feet in open water and sparsely populated areas (farm country, etc.).

There are LOTS of airplanes flying between 1500 and 3000 feet AGL on
short flights.

Heck, I once rode a helicopter going about 140-150 miles only 1,000 feet
AGL (mostly with ground within 250 feet of sea level), mostly with
airspeed that I suspect is typical and not at all slow for fixed wing
aircraft used for GA use. As in about or a bit over 100 knots.

Also keep in mind that most smaller aircraft have pressure altimeters,

All airplanes are REQUIRED to have a pressure altimeters.

So tell us what your aircraft without an exposed propeller is. Does it
merely have the propeller within a tube and/or screens?

He has a good deal on Star Trek shuttle craft engines.

Oh, now I learn something - if an aircraft has GPS and/or radar
altimeter, does it also require a pressure one? If so, is that for
usefulness in areas where there is chance to interact with aircraft that
have pressure altimeters and no other altimeters?
Or is this so that all aircraft can clear mountains (and each other
at the same time?) based on controller instructions (or navigation
maps) that assume adjusted-to-current pressure altimeters, which also
assume that the pilots keep their pressure altimeter settings current then
and there?

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In <4en3q5-8ri.ln1@mail.specsol.com>, jimp@specsol.spam.sux.com wrote:

In sci.physics Le Chaud Lapin <jaibuduvin@gmail.com> wrote:

It is hard to say without doing any simulations, but as I envision it,
a Cessna's
prop would cause much damage to my aircraft if my aircraft came in
contact with the prop. Otherwise, whether it could continue to fly
woulddepend much on the dynamics of the collision. Two of my aircraft
colliding with each other would cause very severe jolt, but would
probably leave the planes flyable. The "wings" on my aircraft would
be "atypical", so it would be harder to sheer them off during
collision. I would include a parachute with each airframe.

Wings don't usually sheer off in mid air collisions.

Typically the airplane gets "bent" enough that the aerodynamics are
destroyed and it becomes unflyable.

What is it that your fly-by-wire home built will be able to do that any
modern airplane such as a Cirrus SR22 can't do?

What materials are you going to use to build the airframe of your home
built?

If you encounter significant turbulence, what is the first thing you do
and why?

You've said your airplane can fly at airpeeds between 10 MPH to 100
MPH (11.5 knots to 115 knots). There never has been an airplane that
can do that. Is your Nobel acceptance speech ready?

I would like to add that 10-100 knots is about 11.5-115 statute miles
per hour, not the other way around.

But I still have yet to hear of aircraft without rotor wings flying and
maintaining altitude and controllability at airspeed both 10 and 100 of
either!

If I had an aircraft other than helicopter/Osprey sort of thing that
flies controllably and maintains altitude at both 10 and 100 MPH, or both
10 and 100 knots, I would be working on a Nobel Prize acceptance speech!

- Don Klipstein (don@misty.com)

 

[MK]

"Jamie Morken" <jmorken@shaw.ca> wrote in message
news:5FIzk.170083$nD.46805@pd7urf1no...

Hi,

How long would it take a "good" engineer, say in the $150,000 a year
salary range to build this system and/or what would a fair value be for
the intellectual property of the system once complete, also what would the
prototyping fees be expected to be to reach a working prototype?

home energy system:

1. interface to solar panel (1000watt max)

2. interface to brushless DC wind turbine (3.6kW max)

3. interface to battery bank (charge/invert at 3.6kW max)

4. interface to electrical grid and offline loads, with 220VAC/240VAC
50Hz/60Hz splitphase truesine power output (3.6kW max output)


system notes:

1. can charge 12V to 48V battery banks from the grid, solar or turbine

2. can backfeed power into the grid from the solar, turbine or batteries,
to UL1741 specification

3. based completely on digital FPGA (Altera Cyclone3) based switch mode
power supply design with a typical operating frequency of 100kHz

4. wireless (nordic 2.4Ghz IC) and USB (ARM7 lpc2148) interface for
programming and status

5. modular so that PCB's can be removed if battery interface functionality
is not desired.

6. digital fan speed control with tach and temperature feedback

7. required size of enclosure with all functionality is 23"x13"x10"


cheers,
Jamie






Hello Jamie,

You have missed out some key parts of the spec.

How many will be built
What regulatory issues apply
In what countries will it be manufactured/sold

A 'ready for production' design for this is a big job >> 1 man year.

As a one off not so bad but much cheaper to buy a ready made system.

Michael Kellett

 

[me]

Jim Thompson <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote in
news:rcgvc4d549pa4oqs5t508cb85lh3moh99m@4ax.com:

On Tue, 16 Sep 2008 06:12:29 -0500, krw <krw@att.bizzzzzzzzzz> wrote:

In article <aebb07eb-b587-4751-a517-6509cc497fa3
@w7g2000hsa.googlegroups.com>, tmoranwms@gmail.com says...
On Sep 15, 9:09 am, mpm <mpmill...@aol.com> wrote:
In Jacksonville, FL all the lumber yards are on Beaver Street.
I wonder if anyone else finds that amusing?

It would be more amusing if the Red Light district coincided with said
street.

A few blocks from where I used to live in Poughkeepsie NY was the
intersection of Hooker Ave. and Cherry St.

General Hooker would be proud.

...Jim Thompson

Nebraska has a Hooker county...


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