Author Topic: Lots Of Nothing  (Read 33460 times)

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madlabs

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Re: Lots Of Nothing
« Reply #54 on: August 17, 2015, 11:18:36 AM »
Thanks Oz. Just checking...

JOnathan

DamonHD

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Re: Lots Of Nothing
« Reply #55 on: August 17, 2015, 02:28:03 PM »
I stand by my statement!  Watts are energy per unit time, ie power.

Rgds

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oztules

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Re: Lots Of Nothing
« Reply #56 on: August 17, 2015, 03:02:14 PM »
So I am having one of those days.....

Some how didn't read you correctly.

............oztules
Flinders Island Australia

bob g

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Re: Lots Of Nothing
« Reply #57 on: May 12, 2016, 05:11:16 PM »
hi there folks, been maybe a year since i checked in?

i always thought of a "watt" as being volt * amp, or rather 1 volt at 1amp = 1 watt,
i guess i never considered the "time" element!

so if i have 1 volt at 1 amp in a circuit, what unit of time do i have to have to consider the power in the circuit being 1 watt?

curious minds want to know and all that!
bob g
research and development of a S195 changfa based trigenerator, modified
large frame automotive alternators for high output/high efficiency project X alternator for 24, 48 and higher voltages, and related cogen components.
www.microcogen.info and a SOMRAD member

mab

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Re: Lots Of Nothing
« Reply #58 on: May 12, 2016, 05:39:25 PM »
watts (power) = joules (energy) per second
amps= coulombs (charge) per second

so:

1volt * 1 amp = 1volt * 1 coulomb/sec  = 1 joule/sec = 1 watt

clear as mud. :)


Mary B

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Re: Lots Of Nothing
« Reply #59 on: May 12, 2016, 05:43:09 PM »
Watts are an instantaneous measurement. Watt hours are a time measurement.

oztules

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Re: Lots Of Nothing
« Reply #60 on: May 12, 2016, 07:29:35 PM »
"i always thought of a "watt" as being volt * amp, or rather 1 volt at 1amp = 1 watt, "

Thats only always true if in a DC circuit....

In AC if  Pf=1...then yes...... otherwise, 1 volt x 1 amp = 1VA ( apparent power )

Watts equals real power..... or VA x Pf

So time does not count it is instantaneous measurement..... only if your trying to unravel energy, then divide energy by time to get the watts involved.

It all starts to get a little hazy here for me, as the reactive component I think of as stored energy(WxT)?? in the system, and so is not part of the watts, but part of the VA...... as VARS... and then it gets a bit ephemeral for me......... so it does not cost any power/watts to have poor VA, only in the transmission of it.......but here we can at least look at time(ing).

If anyone can explain VARS in simple to comprehend analogies.... I'm all for it.


...............oztules
Flinders Island Australia

bob g

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Re: Lots Of Nothing
« Reply #61 on: May 12, 2016, 08:16:07 PM »
thanks folks

i assumed a DC circuit, yes i understand power factor and its consideration in AC circuits

however for the sake of a simple discussion of a watt lets stick with DC for now
or at least unity power factor in an AC circuit.

to me, a watt is one volt at one amp, instantaneous measurement

and watt/hour is one volt at one amp for the time period of one hour.

therefore my question remains,
when defining a watt, and using volts and amps in a DC circuit or volts and amps at unity power factor in an AC circuit,
where does the time element come into play.

remember i am talking about a simple watt, not a watt/hour or watt/minute, or a watt/second.

just got my attention, and it has been quite a while so maybe i have forgotten what i once thought i knew?

:)

bob g
research and development of a S195 changfa based trigenerator, modified
large frame automotive alternators for high output/high efficiency project X alternator for 24, 48 and higher voltages, and related cogen components.
www.microcogen.info and a SOMRAD member

mab

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Re: Lots Of Nothing
« Reply #62 on: May 13, 2016, 02:25:41 PM »
I'm rather less sure I understand the question now, but..

Quote
to me, a watt is one volt at one amp, instantaneous measurement

and watt/hour is one volt at one amp for the time period of one hour.

therefore my question remains,
when defining a watt, and using volts and amps in a DC circuit or volts and amps at unity power factor in an AC circuit,
where does the time element come into play.

There is a time element in the definition of a watt: a watt is a Joule per second; in the context of 1 volt * 1 amp = 1 watt, the time element comes from the 1 amp, as an amp is defined as a charge of 1 coulomb per second, passing a point in the circuit.