FOAK: spinning backwards

It's the way the eye is meant to work - your eye is more sensitive to
flickering/movement in the peripheral vision so that you don't get
surprised by sabre-toothed tigers creeping up on you.

 

It was somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "TMack"

Bloody hell. VHF eyesight.

--

Dave

GS 850 x2 / SE 6a
SbS#6 DIAABTCOD#16 APOSTLE#6 FUB#3
FUB KotL OSOS#12? UKRMMA#19 COSOC#10

 

That should be *twice* the frequency.

 

It happens that Rexx formulated :

The problem was the florescent powder on the inside of the tubes dimmed
sufficiently between the 100Hz pulses of energy of the sine wave, to be
a problem.

Each phase is 120deg out by the other two, which means that the 100Hz
(50Hz) flashing will cancel each other out always assuming the three
banks of lights are in close enough proximity to each other.

It is not much of a problem these days if electronic ballasts are used,
as these work on a much higher frequency, independant of the mains
frequency.

Ordinary bulbs do not suffer the problem as the filaments are not able
to cool down to the point of dimming to produce a strobing effect.

 

*snip*

Gotcha - I wasn't sure if it was to prevent motors jamming or somesuch
either, by having coils on multiple phases - as you often get appliances
that only run on 3 phase, but of course, that could just be for the reason
above in that they're only for use in appropriate work environments.

 

Rexx formulated on Friday :

I understand the off centre parts (peripheral) of the eye are more
sensitive to motion (flicker), they are also more sensitive to light.
Night fighter pilots during the war were reported to be able to see
dimly lit targets much more easily with their peripheral vision.

 

After serious thinking Rexx wrote :

3ph supplies to motors is for several reasons....

They are more efficient, more compact, cheaper to build, can be built
in much bigger sizes than single phase ones and start much better
against a mechanical load. Generally, anything over a few HP would be a
3ph.

The electrical supply authorities also much prefer large loads to be
equally balanced on the 3phases as it is much more efficient for them.

In domestic environments, they generally aim to balance things out by
supplying each house with a different phase. No 1 would be on red
phase, No 2 on Yellow, No 3 on blue, No 4 on red and so on up the
street. The 'balance' wire, being the nuetral. If the single phase load
balancing has been done correctly, there will be little current flowing
down the nuetral core and out in the street this might well be half the
size of a phase core.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, Harry Bloomfield

They also have the endearing quality of being able to be
"plug-reversed". You can switch two of the phases over whilst the
thing's running and it'll stop dead and start to run backwards.

Bloody handy in a machine tool motor, is that.

 

And now you know why all cockpits were put on sideways after 1944.

 

Backpedalling a speciality of yours?

 

How I hate dim bulbs.

 

Beam me up, Harry!

 

Be still! and revere Phil Kyle Usenet Anti-Christ, who blessed us with their
presence on 22 Aug 2004...

LOL!

--
The Reverend Parson Peter Parsnip
VISIT ME ONLINE AT: http://peterparsnip.blogspot.com/

"Withhold not correction from the child: for if thou beatest him with
the rod, he shall not die." -- Proverbs 23:13 (AV)

 

I think one of the astronomers here said they (astronomers) are often
taught to try to observe stars with their peripheral vision, too.

 

That's where yer rods are, innit.

"Rods are designed for night vision and the detection of motion and
objects. They also provide peripheral vision, but they do not see as
acutely as cones. Rods are insensitive to color. When a person passes
from a brightly lit place to one that is dimly illuminated, such as
entering a movie theater during the day, the interior seems very dark.
After some minutes this impression passes and vision becomes more
distinct. In this period of adaptation to the dark the eye becomes
almost entirely dependent on the rods for vision, which operate best
at very low light levels. Since the rods do not distinguish color,
vision in dim light is almost colorless."

 

Don't point the finger at me, young Simian. Those quote marks, see -
the information was cut and pasted from the first approximate google
link. Near enough, I thought.

 

Take it up with Encarta.

 

go@fish (Vicar Peter Parsnip) wrote in

I suspect he is old and fat and possibly half Canadian.

 

When I was at the Uni of Kent @ Canterbury they 'upgraded one set of
squash courts. The Uni 'works' dept weren't allowed to put in the bright
lights they wanted because they were too expensive / used too much power
and others were chosen for them by the financial people there.

They put in mercury discharge lamps ( I think )

The effect for a large number of players including me was that I was
trying to hit, not a squash ball travelling across the court, but a
series of black 'dashes' with long gaps in between. Only a few people
used the courts until they put proper lights into them.

 

Eh!