Marriage is under fire!!

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[andy]

On Tue, 17 Aug 2004 17:02:15 -0500, John Fields wrote:

On Tue, 17 Aug 2004 20:24:22 +0100, andy
news4@earthsong.free-online.co.uk> wrote:


That's fair enough - but it's also part of the point that I'm trying to
make - that people trained in science are too ready to say that things
like chinese medicine cannot work, because they do not use the same
methods of proof and argument/theory as science does.

---
I don't think anyone's saying that Chinese medicine doesn't work, I
think what's being said is that the Chinese explanation for its
efficacy is painted with too broad a stoke for the reasons behind its
functioning to be more perfectly understood.

The way I see it is more to do with different ways of seeing and
understanding the world. In science, the methods of proof and argument are
more externalised and codified - you carry out an experiment using
tools of one sort or another, the results are recorded as numbers, graphs,
pictures or whatever, and then checked against theory using more or less
definable procedures - e.g. you make a calculation using standard
mathematical methods and see if the results add up right. So everything
has been brought more outside the human mind into the external world.
Whereas in chinese medicine, the theory exists more as a set of intuitive
associations between concepts like 'chi', 'the heart element', 'meridian'
etc, which are learnt through much more hands on, face to face methods of
diagnosis and treatment.

Which means it's hard to test the ideas of chinese medicine
scientifically, or associate those concepts with scientific ones in a
one-to-one way.

So no, it's not science in the way it's usually defined in the west, but
that isn't a good reason in itself to write it off as worthless.

Kind of like the difference between BASIC and assembler.

That is, write a line of .bas and you'll get something to happen, but
if you want to understand _why_ it happens you'll learn how to make it
happen by writing it in .asm

That doesn't seem quite right to me - it's assuming that every concept in
chinese medicine must be translatable into a set of equivalent concepts in
western medicine for it to be real. But as I was starting to say in my
second reply to you earlier, there are things which the
chinese medical language actually describes better than western medicine,
like patterns of association between emotions, body posture, tone of
voice, skin colour, and the characteristic illnesses associated with
these. Or the way different patterns of thought, action, and emotion
interact and play against each other.

I think that to make this argument properly, I would have to know a lot
more about both chinese and western medicine, so I'll leave it at that.

--
http://www.niftybits.ukfsn.org/

remove 'n-u-l-l' to email me. html mail or attachments will go in the spam
bin unless notified with

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[James Sweet]

"Greg" <xvreddog@yahoo.com> wrote in message
news:a13b52dc.0408181738.5ebba273@posting.google.com...

G'day from a long way away....

I am struggling with an argument about a couple of damaged home
computers and I was wondering if anyone can help????

The switchboard for a suburban house was replaced in November 2003.
Since February 03 various appliances in the house have failed,
including three pcs. The owners believe that lower than stat limits
voltage into the residence caused the failure. Since the switchboard
was replaced the problems have stopped.

Their electrician said that the switchboard was a 30 year old
porcelain-fused model and was burning out on the busbar and the
circuits on the board were overloaded with too many appliances.

My question to you, if you would be so kind...."What chance is there
that the slightly under supply of grid voltage would severely damage
pcs, or, is the pc damage more likely to be as a result of the arcing
at the switchboard?"

Greg,
Brisbane, Queensland, Australia

Either undervoltage or arcing can damage equipment.

 

[dude]

"Rich Grise" <null@example.net> wrote in message
news:lo7Vc.38804$SC1.3983@nwrddc03.gnilink.net...

blue wrote:

I am using flat ribbon IDE cables, 80 conductor / 40 pin. I understand
that the second connector is a ground, which should eliminate cable
crosstalk. But I do believe that my problem is actual RF or EMI
interference. I need to use longer cables because of the chassis
layout -
24" - 36". It would seem to be quite easy to shield the rounded cables
from EMI with some aluminum tape, I just don't really know what I need
to
consider. An EMI shield doesn't really make sense to me without a
ground.
And, is aluminum muffler tape the right stuff to use?

It would certainly work, as long as you're sure that you make a good
connection to it. You can't solder aluminum, you know - I'd seriously look
into some kind of contact that's designed to connect aluminum to copper.

Bad shielding could cause data transfer errors but could it really cause the
loss of the partition table? Assuming you are using FAT32 or something
similar I could see the FAT getting corrupted but the partition table? That
would require writes to sectors that shouldn't normally be written to.

are you sure something isn't erasing the drives themselves? like very strong
interference hitting the drives from the power supply?

Also, couldn't you put those round metal rings around the power cables to
stop some of the interference? not sure how much those help???

:{

And only ground it at one end.

It would also probably help to see to it that it's not a spiral-wound
inductor - be sure that there's contact from one strip to the next.

Or, get really wide aluminum tape and attach it lengthwise.

Good Luck!
Rich

 

[Tom Biasi]

"TrailRat" <Gadgetfreak_2000@hotmail.com> wrote in message
news:90322cbd.0408210219.e439a7c@posting.google.com...

I wish to build a solar powered water pump. I have in my junk pile a
working 12volt twin shaft motor onto which I will add the pumps,
modified from those you can get as a drill attachment. This will be
connected to a battery, like those from a motorbike (small and
compact). This is so I can make it portable, because where I plan to
use it is lacking in electricty. Now my only concern is he draining of
the battery before the job is completed, so I plan to add a solar
panel to charge the battery while its at rest or in use. Do I need any
circuitry, if so what and where can I find plans or products.

Thanks for any help given.


Gadget

We need some specs first. How much current will the motor draw under load?
What size battery will you have?
The solar panel needs a power output that can charge the battery in your
required time, and of course provide the proper voltage.
The 'portable' aspect of you setup may suffer a little when the panels start
to get large.

BTW: Those drill attachment pumps are not designed for drinking water just
in case you had that in mind.
Regards,
Tom

 

[Tom Biasi]

"~Dude17~" <dude17@sacbeemail.com> wrote in message
news:b959931f.0408210136.60aa899f@posting.google.com...

X-No-Archive: Yes

I've got an Invensys/Best 1000VA UPS that is drawing 26.7W constantly
with the battery fully charged and no load connected. This is an
offline design and the inverter is not in use when AC power is
available. All is trickle charging battery in standby. What takes so
much power?

This thing dissipates so much heat for what it is that internal fan
comes on every once in a while just idling. Everything runs properly,
so I don't think it's a malfunction.

There is no reason for it to take 27W of constant power to keep 36V
9Ah pack charged. With battery fully charged, I averaged the power
usage to be 0.64kWh/day or 230.6kWh/year. A Whirlpool EnergyStar
compliant 22 cu. ft freezer/refrigerator takes 472kWh/year. Anyone
else see a problem with an offline 1kVA UPS using half as much power
as a full size fridge just to keep its battery charged? This is 1999
or 2000 model.

What does the manufacturer say it should draw in standby?
Check your batteries too.

Tom

 

[Pete]

Thanks very much John. I will do just that. I received a post from Kim
off list also suggesting that i fried the transistor. I gave her some
additional information regarding the extra demands I was placing on the
circuit by trying to control the heat generated by a a number of
resistors in parallel. I've reposted seeking a more robust design under
"Need heater strip circuit" above because Kim reckons this design isn;t
going to work for that purpose.

--
Clear and dark skies!

Pete
------------------------------------------------
Home Page: http://www.users.bigpond.com/lansma/
Lat: 42° 53' S; Lon: 147° 19' E



John Fields wrote:

On Sat, 21 Aug 2004 15:05:21 GMT, "Pete" <lansma@bigpond.com> wrote:

Hi, I'm not sure whether anyone can help with this problem but I
though I would post on the of chance because I haven't a clue. I
have made a 12 V speed controller/light dimmer circuit that came in
kit form. It uses a LMC555/7555 CMOS timer and BUZ71A power mosfet
transistor. A 10K pot controls the motor speed. I was testing the
circuit tonight and it worked flawlessly then suddenly the pot
stopped controlling the speed. It now operates at full current
irrespective of where I set the pot. The pot seems to work alright
tested with a multimeter, so I'm anticipating the problem is
elsewhere. The transistor gets very hot (it has a heat sink
connected) as does a big 3A diode. There are no obvious signs that
anything has blown at all. Any clues?

---
Could be you've toasted the MOSFET or the diode. To find out,
disconnect the diode and measure its resistance in one direction and
then the other using your meter. If you don't have a DIODE TEST
function, then get 1.5V cell (battery) and a 100 ohm resistor and hook
everything up like this:


+--[-BAT+]---[100R]---[DUT]---[DMM (20mA)]--+
| |
+-------------------------------------------+

If the DUT (device under test) is OK, when you have it in the circuit
in one direction the meter will read about 8mA and when you reverse it
the meter should read zero milliamps. It might show a few microamps;
that's OK.

If you've popped the MOSFET, you can find out by connecting the gate
to the source and measuring the resistance between the source and the
drain. It should be very high with the drain connected to the +
output of the ohmmeter, and it should look like a diode with the
ohmmeter connected the other way around. If it reads like a low
resistance both ways, it's gone.

You can also test the 555 by disconnecting everything from its output,
setting your DMM to DC volts and measuring the output of the 555 as
you turn the pot. It should be low at one end of the pot's rotation
and high at the other.

Depending on your meter, though, you might have to do something like
this:


555OUT>----[1N4148>]--+------+ <--------+
| | |
[0.1ľF] [1K] [DC VOLTS]
| | |
------------------+------+ <--------+

 

[John Larkin]

On 21 Aug 2004 11:14:23 -0700, jwillsi1@tampabay.rr.com (jaydee)
wrote:

Since an electrical outlet might be used for any size appliance it
must contain a full/max current and then the appliance only uses what
it needs... right?

Does the appliance then reduce it? A simple lamp lightbulb uses very
little but doesn't contain any electronics that would do this. So how
does it use only a few watts and what happens to the rest?

Secondly, the electric meter and bill indicates watts used. How does
this work? This seems to imply that the current is always flowing in
and out like a two-way road and the meter measures the difference
(unlike all the water analogies that flow into a dead-end).

Thanks Jay.

To amplify JFs comments...

Think of the power coming into your house as a rotating shaft.
(Factories actually used to have one big rotating shaft from a water
wheel or steam engine, and it ran everything.) If it spins freely with
no load, no energy is taken and the power bill is zero. Any device can
be connected to the shaft (they used to use belts or gears) and it can
use all the horsepower it wants or needs. A mechanical device uses
torque, and the power it gobbles is torque times speed.

An electrical system has wires (== shaft), voltage (== rotation of
shaft), and loads take as much current (==torque) as they need. The
price you pay is voltage * current * time * some_dollar_factor,
because that quantity represents how much fuel the utility had to burn
to make that much energy.

A low resistance load is like a high-torque load. It may even pull the
line voltage down a bit, just like a big load might slow down the
drive shaft some.

I like that better than the water pressure analogy.

John

 

[andy]

On Sat, 21 Aug 2004 18:23:26 +0000, Michael Black wrote:

"viper" (viper@netcom.no) writes:
Hi.
Just wondering, is it possible to make incar dvd screen from a used pentium
svga laptopscreen.

Best regards
Viper



Well, you put a DVD drive in the laptop, and run software for viewing the
DVDs, and you've got your DVD player.

Or, get a card thatt has video in, and feed your external DVD player into
that. (I don't know if there are limitations in doing this).

The LCD display in a laptop is meant for integrated use in the laptop.
It's not like a VGA monitor that accepts VGA signals. It is interfaced
at a different level. Without the laptop, you'd be missing needed
electronics.

Every time a question like this comes up, the answer is pretty pessimistic.
There's not enough information available about the laptop displays, and
even if one had such information it would require work.

Michael

as far as I can tell,

http://www.hy-line.de/computer/frames/frame_display_kits.html

make separate lcd controller modules that might do this. The german only
site makes it hard to tell though.


--
http://www.niftybits.ukfsn.org/

remove 'n-u-l-l' to email me. html mail or attachments will go in the spam
bin unless notified with

 or [attachment] in the subject line.

 

[John Fields]

On Sat, 21 Aug 2004 12:02:07 -0700, John Larkin
<jjlarkin@highlandSNIPtechTHISnologyPLEASE.com> wrote:

To amplify JFs comments...

Think of the power coming into your house as a rotating shaft.
(Factories actually used to have one big rotating shaft from a water
wheel or steam engine, and it ran everything.) If it spins freely with
no load, no energy is taken and the power bill is zero. Any device can
be connected to the shaft (they used to use belts or gears) and it can
use all the horsepower it wants or needs. A mechanical device uses
torque, and the power it gobbles is torque times speed.

An electrical system has wires (== shaft), voltage (== rotation of
shaft), and loads take as much current (==torque) as they need. The
price you pay is voltage * current * time * some_dollar_factor,
because that quantity represents how much fuel the utility had to burn
to make that much energy.

A low resistance load is like a high-torque load. It may even pull the
line voltage down a bit, just like a big load might slow down the
drive shaft some.

I like that better than the water pressure analogy.

---
Yeah, me too.

The only thing that isn't taken care of is the oscillatory nature of
the AC, which would correspond to an oscillating shaft coming into
your house. For heaters and lamps it wouldn't matter, you just grab
the shaft and friction does the trick, no matter which way it's going,
but to get the unidirectional rotation you need to run compressors and
simulate motors you'd need some kind of a mechanical converter. Maybe
like those little manually propelled railroad cars with the push-pull
bars used?

--
John Fields

 

[Don Kelly]

If you are going to use a screwdriver motor -why not keep the gears that go
with it? If it is a series motor, you can limit current with a resistor. I
would suggest that as you are running at 3 times the voltage, use 2 times
the measured locked rotor resistance in series- rate the resistor on the
basis of the current under locked rotor conditions. This will limit the
current to what the motor normally takes in this condition and stall torque
to what it is normally. The speed will drop more under load than it would
normally.
A screwdriver motor is expected to stall so you could reduce the extra
resistance somewhat. Watch for arcing or sparking at the brushes- I think
the windings will take the overcurrent for the time under consideration but
the brushes may be a problem.


--
Don Kelly
dhky@peeshaw.ca
remove the urine to answer
"Emil Johnsen" <nospam.emil.johnsen@student.uib.no> wrote in message
news:cg3ehl$19uo$1@toralf.uib.no...

However, what is important is the current at startup in this operating
mode.
That will be higher than at normal load. In addition, the resistor while
cheap will not help at no load or light load- (speed will be high and
the
speed will change more rapidly under load.
Also- what kind of motor? shunt, permanent magnet, series? it makes a
difference.

I'm guessing series, because this motor comes from en electric screw
driver,
but I'm not 100% sure.

I'm going to use the motor as an actuator for a ball valve, obviously with
significant gear reduction. I will leave the motor on for <0.5sec, during
this time it will rotate the valve shaft 90deg and stall as it hits a
mechanical stop. The motor will not see particuarly light loads.

 

[John Fields]

On 22 Aug 2004 09:02:28 -0700, jwillsi1@tampabay.rr.com (jaydee)
wrote:

The light is getting brighter!

I just thought of another analogy... If you had a well connected to
your water heater... you would be paying to heat the water, but not
for the water itself.

My real objective was to understand enough to hook up a generator to
the breaker box and reduce my bill. Transfer switches do the opposite
of what I need... they work when the utility power is off and
disconnect when the power comes back on.

---
Actually, it's backwards from that in that when the utility power is
ON, that power actuates the switch and causes it to connect power to
the loads in your house. When the utility power goes off, the
transfer switch reverts to its de-energized position and a set of
normally closed contacts connect the alternate power source to the
loads in your house.
---

I've also read someplace that home generated power isn't pure (?)
enough to blend with the power company's.

---
I don't understand what you mean. Are you talking about selling
energy back to the power company or running some things on your house
on your own power at the same time you're running some others on power
company electricity, or connecting your power source in parallel with
the power company's so that you can run your house on both at the
same time?
---

If so my only alternatives
would be to use extension cords or a sub-panel for the few circuts I
could feed (yes/no).

---
Dunno... see above.

--
John Fields

 

[Peter Bennett]

On 22 Aug 2004 09:02:28 -0700, jwillsi1@tampabay.rr.com (jaydee)
wrote:

The light is getting brighter!

I just thought of another analogy... If you had a well connected to
your water heater... you would be paying to heat the water, but not
for the water itself.

My real objective was to understand enough to hook up a generator to
the breaker box and reduce my bill. Transfer switches do the opposite
of what I need... they work when the utility power is off and
disconnect when the power comes back on.

You MUST NOT connect your local generator in parallel with the power
company!!!

You will need a manual transfer switch to transfer those circuits you
want to power from your generator between the generator and power
company.

I've also read someplace that home generated power isn't pure (?)
enough to blend with the power company's. If so my only alternatives
would be to use extension cords or a sub-panel for the few circuts I
could feed (yes/no).

"purity" isn't the problem. AC power is continually varying in
voltage, so, if you want to connect two AC sources in parallel, you
must ensure that both sources are "in phase" (varying exactly in step
with each other) and of the same voltage.

Thanks for the education,
Jay

--
Peter Bennett, VE7CEI
peterbb4 (at) interchange.ubc.ca
new newsgroup users info : http://vancouver-webpages.com/nnq
GPS and NMEA info: http://vancouver-webpages.com/peter
Vancouver Power Squadron: http://vancouver.powersquadron.ca

 

[Rich Grise]

BretCahill wrote:

Could a solenoid be constructed to mimic
the proper valve position vs time curve of a
engine cam shaft? Maybe a circuit and/or
several coils in each solenoid?

It may be tricky or impossible to build such
a solenoid that works well over all rpms, but
if it could be built, it could be mass
produced very cheaply, maybe cheaper than
a cam system.

The other concerns such as force necessary to
accelerate valves (are solenoids orders of
magnitude more inefficient than cams?) and
mangled valves from electronic failure (like other
fail safe systems set the default of every valve
in a safe position) shouldn't be problems.

I brought this up some time ago in some mechanical group,

and they seemed to indicate that it's been tried a long
long time ago, and abandoned because it's noisy or
something. Actually, I still think it's a pretty cool
idea, when you consider how many HP a camshaft/rocker/
pushrod/lifter arrangement must consume.

And 100-amp semiconductors are common these days.

Anybody want to start hacking their cylinder head? ;-)

Cheers!
Rich

 

[Jonathan Kirwan]

On Sun, 22 Aug 2004 16:29:45 +0800, "Jacky Luk" <jl@knight.com> wrote:

Homework Question!

The early voltage is 60V in a common-emitter configuration for a npn bipolar
transistor. With Vbe = 0.65V and Vce = 1V collector current = 1.0mA, find
the collector current when Vbe = 0.67V and Vce = 9V

---

If i use the geometry thoery to calculate this,
I think i can approach to yielding the answer of this question. However when
Vbe's are different, the slope of these two curves are virtually different,
consider the
Slope of the device curve when Vbe = 0.65V
Vbe = 1mA / 60V + 1V where I would think of something similar to Vbe (when
0.67V) = Ic / 60V + 9V. Does the question offer too few or too many
parameters in solving the question?
but as stated in my book, using equation Ie = Ise * e ^ K * Vbe where K is
about 40V, I can yield the answer to be Ic = 1mA * Exp (40V -1 * 0.67V -
0.65V)
which is according to the first equation which states in my reference " it
shows that 10mV Increments correspond to increases in Ie and Ic by a factor
of exp (40V-1 * 0.01V) ".... then I feel the question is offering two many
parameters where some of them are not used???

You are very, very close, I can see.

For those not entirely clued in, here's the projection:

I(C)
|
|
| + -- V(BE)=0.67
| +
| + ^ . -- V(BE)=0.65
|+ . :
+ | . :
+ . | ^ :
+ . | : :
+ . | : :
<---+----------------------------0-------------------> V(CE)
60V 1V 9V
^
|
Early Voltage


Your computations are pretty much on the mark, I think. But keep in mind I'm a
hobbyist and have never taken a single class in electronics in my life. I read
and design small things, but that's all.

There are several ways to go at this, but one obvious factor is simply
projecting I(C) for V(CE)=9V, without dealing with the V(BE) change. That will
get you one piece of the way. Then, you need to deal with the impact of V(BE)
on that projected value. And you've got it almost right, there.

The projection is about the way I read you writing above. Namely, that the I(C)
at V(CE)=9V with V(BE)=0.65V would be a factor of ((60+9)/(60+1)) larger, based
only on the slope suggested by the Early voltage. Basic similar-triangle stuff,
as you suggest.

Next is that you need to deal with V(BE) and you can look at that from either a
e^(dV(BE)/V(t)) point of view (since V(BE) is large enough that the -1 can be
ignored) or else you can just remember that I(C) changes by a factor of 10 for
each 58.26mV (V(t)=q*T/k=25.3mV, variation ignoring the -1 is then V(t)*ln(10) =
58.2554mV or often shown as about 60mV) change in V(BE).

This is either:

change = e^(dV(BE)/25.3mV)

or,

change = 10^(dV(BE)/60mV)

Slight differences there, but your pick.

When you apply these together, the result is:

I(C)[@V(BE)=0.67V,V(CE)=9V] = 1mA * (VA+9)/(VA+1) * e^((0.67-0.65)/25.3mV)

Jon

 

[andy]

"IRR" <iotarhorho@REMOV3hotmail.com> wrote in message
news:3CwVc.5658$QJ3.1376@newssvr21.news.prodigy.com...
I've got one of these new portable cd players with a built-in FM
tun
and
used to keep it on my desk at work to listen to the radio all the time.
However, I've switched jobs and the radio reception at my new job really
stinks. I'm wondering if there's a way to augment the antenna strength on
this thing? There's no visible antenna on the player at all, and
I
read
(but not sure I believe) that the antenna is incorporated into

earphone
wiring or something like that.

My description seems a bit vague, so here's a picture of the thing (from
amazon.com):


http://www.amazon.com/exec/obidos/tg/detail/-/B000063574/002-5684509-4677659
?v=glance&s=electronics&me=ATVPDKIKX0DER&vi=pictures&img=14#more-pictures

Any ideas on how to boost the antenna's reception?


On
Sat, 21 Aug 2004 05:34:47 +0000, Dan Fraser wrote:

It is not easy. You have to open the unit, find where the internal antenna
connects, bring out a wire, run that wire outside, outside of the metal
shell of the building and erect a wire outside as an antenna.

Basically, when confronted with this kind of situation, find another station
that comes in better, buy a radio that might work better (you cannot tell
until you try it) or give up.

couldn't you just wire a hifi tuner type fm aerial to the appropriate
headphone lines, with maybe a passive high pass filter to keep the audio
signal out of the aerial?

e.g. wire up a jack plug and socket something like this:


1.5 nF
||
Left o--o---------------o-------||---------o
| | || |
| .-. |
| | | |
| | |1 kOhm |
| '-' |
| | |
Gnd o--|--o------------o------------------|----------------o
| | | |
| | .-. |
| | | | |
| | | |1 kOhm | Aerial
| | '-' |
| | | || |
Right o---|--|--o---------o-------||---------o----------------o
| | | ||
| | | 1.5 nF (3dB point = 100 KHz)
| | |
| | |
| | |
| | |
o o o
Left Gnd Right



I don't know if this would work though, or if it's the right way to do the
filter - it's a question not a solution.





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remove 'n-u-l-l' to email me. html mail or attachments will go in the spam
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[John Larkin]

On 23 Aug 2004 03:15:07 GMT, bretcahill@aol.com (BretCahill) wrote:

John Larkin jjlarkin@highlandSNIPtechTHISnologyPLEASE.com
Message-id: <f2uhi0pie2pgvadslflcqh85sq87uc48m4@4ax.com> writes:

. . .

Interesting: a cam (especially a roller cam) will return some of the
valve-spring energy to the camshaft when the valve closes, but a
solenoid won't.

I wouldn't be so sure.

A solenoid might be or has been built that
could recapture about as much wasted energy
as that by a cam. As the valve slowed it would
recharge the battery or power the next
cylinder's solenoid.

In any event your concern is valuable, even if
wrong.

Ooh, snotty!

Fast, powerful solenoids have a lot of copper loss, hence the cooling
problem. Not a lot of energy would be recovered.

I'd think that a roller cam could recover at least 60% of the energy
dumped into the valve spring. The exhaust valve does some real work
against pressure, but that's a different issue.

But it's not worth arguing about, or analyzing, because it doesn't
work.

I didn't think about it and I run energy
balances on everything.

I think about everything. That's more fun.

John

 

[BretCahill]

A lot of people seem worried about a computer
glitch causing the valves to get mangled, etc.
but the drivability of a motor vehicle drops to
zero anyway without the computer. For the
past 20 years automotive computer failure
hasn't been that big problem.

Besides there are various fail safe protections
that could be implemented.


Bret Cahill


Eric R Snow etpm@whidbey.com in

Message-id: <l47ki0lpbsbc3eed0i0st23qanrihdr7d3@4ax.com> writes:

On Mon, 23 Aug 2004 13:03:09 GMT, NoSpam@daqarta.com (Bob Masta)
wrote:

On 22 Aug 2004 17:25:01 GMT, bretcahill@aol.com (BretCahill) wrote:

Could a solenoid be constructed to mimic
the proper valve position vs time curve of a
engine cam shaft? Maybe a circuit and/or
several coils in each solenoid?

It may be tricky or impossible to build such
a solenoid that works well over all rpms, but
if it could be built, it could be mass
produced very cheaply, maybe cheaper than
a cam system.

The other concerns such as force necessary to
accelerate valves (are solenoids orders of
magnitude more inefficient than cams?) and
mangled valves from electronic failure (like other
fail safe systems set the default of every valve
in a safe position) shouldn't be problems.


I seem to recall reading in mags like EE Times about work
on "electronic valve timing" or words to that effect.
I had the impression that they were using solenoids,
and had similar concerns to yours.

The "all-electronic car" idea seems to be gaining momentum,
but it gives me the creeps, especially when they get to
electronic steering. Seems like they are just trying to make
everything electronic "because they can".

However, many years ago I worked for General Motors
Cadillac Division when electronic fuel injection was just
coming on board. For a while I was one of team that went
around the plant rescuing EFI cars that had died. At the
time it was a really fragile system. There were something like
32 wires to the EFI control box (which was mostly analog!), and
almost any of those could disrupt operation if it came out of
it's little connector. (We carried a supply of paper clips to poke
them back into their shells.) Worse yet, the early EFI system put
a massive amount of fuel into the chambers if you pumped the
pedal when cold-starting, as the drivers were used to doing on
carbureted cars. This would foul the plugs so badly that they
had to be replaced in order to start the car. (Simple manual
cleaning of plugs didn't help.)

I recall thinking that this was a terrible step backward for
overall reliability. There were tons of things that could
completely disable an EFI car, whereas almost nothing
bothered a carburetor short of somebody dismantling it an
throwing in a handful of dirt.

Nowadays, though, EFI is the norm and they certainly seem
to have gotten their act straight. Overall, seems far more
reliable than carburetors. So, maybe someday we'll feel that
way about electronic valve trains and steering. OK, so maybe
a few catastrophic failures in the learning curve to stimulate
new ideas.... <g


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Greetings Bob,
I used to shudder at the thought of "drive by wire" systems.
Mechanical systems just seemed so robust and forgiving when they do
fail, because often the failure isn't complete, but happens over time.
But, I had the left front suspension break and fold under a car I was
driving. In a parking lot going about 10 mph. There was no controlling
the car. Another time, I heard a squeak coming from the engine
compartment of an econline van I was driving. I turned on the turn
signal to change lanes over to the emergency lane. Before I got there
the shaft going throught the water pump let go and the fan screwed
itself through the radiator. These were sudden failures with no
warning ar just a second or two warning. But many electronic systems
are much less likely to fail. And they really don't wear out. My Dad's
company makes machines which check the probe cards which check the
finished wafers before they are sliced up into seperate dies. He's
been an electronic engineer for about 50 years. When I told him I had
a chip fail in a 20 year old machine he said that the chip was damaged
when new. He said it most likely was not damaged by age or run time.
And that the type of chip it is should function virtually forever. So
I'm waiting for the all electronic car.
ERS

 

[BretCahill]

NoSpam@daqarta.com (Bob Masta) in

Message-id: <4129e6f4.2009230@news.itd.umich.edu> writes:

On 22 Aug 2004 17:25:01 GMT, bretcahill@aol.com (BretCahill) wrote:

Could a solenoid be constructed to mimic
the proper valve position vs time curve of a
engine cam shaft? Maybe a circuit and/or
several coils in each solenoid?

It may be tricky or impossible to build such
a solenoid that works well over all rpms, but
if it could be built, it could be mass
produced very cheaply, maybe cheaper than
a cam system.

The other concerns such as force necessary to
accelerate valves (are solenoids orders of
magnitude more inefficient than cams?) and
mangled valves from electronic failure (like other
fail safe systems set the default of every valve
in a safe position) shouldn't be problems.

I seem to recall reading in mags like EE Times about work
on "electronic valve timing" or words to that effect.
I had the impression that they were using solenoids,
and had similar concerns to yours.

The "all-electronic car" idea seems to be gaining momentum,
but it gives me the creeps, especially when they get to
electronic steering. Seems like they are just trying to make
everything electronic "because they can".

I hate the way every microwave oven is
different. Just put a dial on the #@!&%! thing
and forget being cute with a lot of buttons.

However, many years ago I worked for General Motors
Cadillac Division when electronic fuel injection was just
coming on board. For a while I was one of team that went
around the plant rescuing EFI cars that had died. At the
time it was a really fragile system. There were something like
32 wires to the EFI control box (which was mostly analog!), and
almost any of those could disrupt operation if it came out of
it's little connector. (We carried a supply of paper clips to poke
them back into their shells.) Worse yet, the early EFI system put
a massive amount of fuel into the chambers if you pumped the
pedal when cold-starting, as the drivers were used to doing on
carbureted cars. This would foul the plugs so badly that they
had to be replaced in order to start the car. (Simple manual
cleaning of plugs didn't help.)

Good story.

I recall thinking that this was a terrible step backward for
overall reliability. There were tons of things that could
completely disable an EFI car, whereas almost nothing
bothered a carburetor short of somebody dismantling it an
throwing in a handful of dirt.

Nowadays, though, EFI is the norm and they certainly seem
to have gotten their act straight. Overall, seems far more
reliable than carburetors.

Maybe someone knew what he was doing.

So, maybe someday we'll feel that
way about electronic valve trains and steering. OK, so maybe
a few catastrophic failures in the learning curve to stimulate
new ideas.... <g

In politics we're talking trillions of dollars down
the drain.

An unreliable piece of electrical or mechanical
junk is positively charming in comparison.

Where do I sign up?

Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com

 

[Jim Rojas]

The porch light I have outside uses a replaceable 4 tube bulb with a built
in photoelectric sensor. I installed the fixture about 11 years ago. I have
only replaced the bulb once in all that time. This is totally
acceptable...It's the screw on type I am having a problem with. I don't
think they dissipate heat evenly enough, and may cause the glass to to
weaken, then fracture.

Jim Rojas

"Rich Grise" <null@example.net> wrote in message
news:WxxWc.948$HY.722@trnddc03...

Bennet Williams <> wrote:

I have had the same issues as you.
I was especially annoyed with the slow brightening of the bulbs.
I recently got some bulbs from Commercial Electric (at Home Depot).
They advertise "instant on".
They work great - they come on to full brightness immediately. I don't
know about the longevity yet.

I think it might be a turn-on-turn-off issue. In and apt. I lived in
a few years ago, they had one outside the door of each apartment,
like rows of porch lights in the hallway. In 5 years of living there,
I saw the maint. guy change one. But they're on 24/7. He seemed to
indicate that 5 years wasn't unusual at all.

Cheers!
Rich