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Posted by lwasserm on November 29, 2006, 10:54 pm
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>>>> Another great suggestion but probably will not help at my house.
>>>> My electricity can't make up it's mind. It changes directions
>>>> about 60 thousand times a second.
>>> Make that 120.
>> If you guys are getting all technical, wouldn't it only *change*
>> direction 119 times?
>Draw a graph of 60cps sine wave for 1 second. It will consist of 60
>cycles in the form of full sine waves. Each peak, top and bottom, is a
>change of direction. So: 120.
The direction of current flow changes when the graphed line crosses the
zero line, not at the peaks, but otherwise I agree.
the peak.
--
No dumb questions, just dumb answers.
Larry Wasserman - Baltimore, Maryland - lwasserm@charm.net
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Posted by Mark Lloyd on November 30, 2006, 2:17 pm
On Wed, 29 Nov 2006 21:54:56 -0600, lwasserm@fellspt.charm.net ()
wrote:
show/hide quoted text
>>>>> Another great suggestion but probably will not help at my house.
>>>>> My electricity can't make up it's mind. It changes directions
>>>>> about 60 thousand times a second.
>>>> Make that 120.
>>> If you guys are getting all technical, wouldn't it only *change*
>>> direction 119 times?
>>Draw a graph of 60cps sine wave for 1 second. It will consist of 60
>>cycles in the form of full sine waves. Each peak, top and bottom, is a
>>change of direction. So: 120.
>The direction of current flow changes when the graphed line crosses the
>zero line, not at the peaks, but otherwise I agree.
>the peak.
For 120VAC RMS, the peak voltage is 169V. That's the highest
hot-to-neutral voltage.
--
25 days until the winter solstice celebration
Mark Lloyd
http://notstupid.laughingsquid.com
"Unlike biological evolution. 'intelligent design' is
not a genuine scientific theory and, therefore, has
no place in the curriculum of our nation's public
school classes." -- Ted Kennedy
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Posted by Pat on November 30, 2006, 2:42 pm
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|<-- 3 cycles -->|
/\ /\ /\
--- 1 / 2 / 3 / 4 ------------ center line
\/ \/ \/
Starting at point 1, a complete cycle is achieved at point 2. The next
cycle is completed at point 2, the third cycle is point 4
You do not have a change of direction at point 1
Change of direction at point 2
Change of direction at point 3
You do not have a change of direction at point 4 (does not cross the
line, mere reaches it).
Therefore you only have 2 changes of direction. This = (cycles X 2) -
1 because your terminating point isn't a change of direction.
Therefore for 2 seconds, it would be 119 changes of direction (but 120
cycles)..
lwasserm@fellspt.charm.net wrote:
show/hide quoted text
> >>>> Another great suggestion but probably will not help at my house.
> >>>> My electricity can't make up it's mind. It changes directions
> >>>> about 60 thousand times a second.
> >>> Make that 120.
> >> If you guys are getting all technical, wouldn't it only *change*
> >> direction 119 times?
> >Draw a graph of 60cps sine wave for 1 second. It will consist of 60
> >cycles in the form of full sine waves. Each peak, top and bottom, is a
> >change of direction. So: 120.
> The direction of current flow changes when the graphed line crosses the
> zero line, not at the peaks, but otherwise I agree.
> the peak.
> --
> No dumb questions, just dumb answers.
>
> Larry Wasserman - Baltimore, Maryland - lwasserm@charm.net
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Posted by Goedjn on November 30, 2006, 3:20 pm
wrote:
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> |<-- 3 cycles -->|
> /\ /\ /\
>--- 1 / 2 / 3 / 4 ------------ center line
> \/ \/ \/
>Starting at point 1, a complete cycle is achieved at point 2. The next
>cycle is completed at point 2, the third cycle is point 4
>You do not have a change of direction at point 1
>Change of direction at point 2
>Change of direction at point 3
>You do not have a change of direction at point 4 (does not cross the
>line, mere reaches it).
Try that again, 1/4 cycle farther along the phase :-)
If the segment between 1 and 1.01 does not contain a zero-crossing,
than there must be a zero-crossing to the left of 1.
If that is true, and we have three complete cycles, then
there must also be a zero-crossing to the left of 4.
To demonstrate this, chop up your three-cycle diagram
into three separate 1-cycle diagrams.
If you have 1-2, 2-3, and 3-4, do the zero-crossings
at 2 and 3 just dissapear?
Do your diagram again for 6 cycles. How many
direction changes are there? Where did the
extra one come from?
--Goedjn
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Posted by Mark Lloyd on November 30, 2006, 2:27 pm
wrote:
show/hide quoted text
>Bert Byfield wrote:
>> > Another great suggestion but probably will not help at my house.
>> > My electricity can't make up it's mind. It changes directions
>> > about 60 thousand times a second.
>> Make that 120.
>If you guys are getting all technical, wouldn't it only *change*
>direction 119 times?
Consider that the current will VERY SELDOM be turned on at the exact
moment of zero-crossing, and left on for exactly 1 second.
--
25 days until the winter solstice celebration
Mark Lloyd
http://notstupid.laughingsquid.com
"Unlike biological evolution. 'intelligent design' is
not a genuine scientific theory and, therefore, has
no place in the curriculum of our nation's public
school classes." -- Ted Kennedy
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>>>> My electricity can't make up it's mind. It changes directions
>>>> about 60 thousand times a second.
>>> Make that 120.
>> If you guys are getting all technical, wouldn't it only *change*
>> direction 119 times?
>Draw a graph of 60cps sine wave for 1 second. It will consist of 60
>cycles in the form of full sine waves. Each peak, top and bottom, is a
>change of direction. So: 120.