Testing the TK Tar Baby

[Rosemary Ainslie]

Guys, picowatt and TK included,

Here's the thing.  IF one determines the wattage delivered or dissipated - one takes the sum of a fair sample range - and then one divides that sum by the number of samples in that range.  That gives you a 'fair' average - which represents the WATTS delivered - with that number being 'representative'.  In effect it IS an average of a sample range of voltage measurements that DO, in fact, represent an INSTANTANEOUS power measurement.  But the qualification is that it includes a full and representative sample range before one can arrive at that the required number.  Then.  That AVERAGE value is the ACTUAL rate of wattage.  And that's then a product represented as a second - over the TIME that the energy has been delivered or dissipated - to give the Joules or POWER.  Which ALWAYS incorporates TIME.  One small representative sample in one small section of one part of the duty cycle is NEVER, EVER, a WATT.  Nor can it be called a WATT.  Then.  The product of this number is applied to the value over time to represent the WORK that has been performed related to Joules.  The instantaneous power calculated in 1/6 of a duty cycle is NOT representative of WATTS.  It is merely representative of instantaneous power within a small fraction of the applied duty cycle. 

Those them are the facts guys.  And no amount of invective or protest is likely to alter those them facts.

Regards,
Rosie

[TinselKoala]

No Leon.  And instantaneous power measurement is an instantaneous power measurement.  A watt is ALWAYS factored over time.  IF this is a science forum - which one assumes - then you are advancing something that is ABSOLUTELY NOT science. 
And THIS is the proof that you really have no clue.  AGAIN.  A WATT is the amount of energy factored OVER TIME.  No amount of disclaiming by you will alter this simple fact.  And the longer you persist in this denial the more utterly discreditable you become.  Which makes your earlier and repeated criticisms of my definitions - laughably inappropriate.  JUST LOOK UP WIKI - if you're not going to refer to that VENERABLE authority that you published earlier - MR RALPH J SMITH.  Instantaneous power is MEANINGLESS.  Power measurements always need reference to time.  And the very first qualification is the duty cycle which is applied in any switched circuit.  You seem to forget that there are those readers here who KNOW how wrong you are.  And IF picowatt takes the trouble to confirm this your definition of a watt - then he is equally WRONG.  20 watts are 'roughly' equal to instantaneous power.  But instantaneous power - as mentioned - is MEANINGLESS.  We are - first and foremost - actually obliged to determine the RATE at which energy is delivered or dissipated - if we're to do power analysis.  And that requires an analysis over TIME.  So WATTS is, in that sense a RATE.
Which makes this just a whole lot of nonsense.
Which actually means that you're PERFECTLY explaining your own confusions.
Actually this is ridiculous.  You are the one who is UTTERLY confused and UTTERLY wrong.  And my saying this is NOT likely to convince you.  But at least we ALL now KNOW where your own confusions lie.

Rosie Posie.

You are simply wrong. A Watt is a rate of energy dissipation, it is a JOULE PER SECOND. It is an INSTANTANEOUS measurement.  When you see a 100 Watt light bulb.....  the energy used by that bulb is determined by multiplying its INSTANTANEOUS POWER USAGE, 100 Watts, by the TIME IT IS ON, and the answer is in JOULES, not watts.

Go ahead, find ANYONE who will agree with your characterization.  You aren't going to be able to, because this is so fundamental that EVERYONE who reads this site understands it except you.

Try it. Ask around. ASK YOUR ACADEMICS if they've woken up from their naps yet. LOOK IT UP IN WIKI for goodness sake. The Watt is an instantaneous measurement. The JOULE is a Watt PER SECOND. Your "averaging" idea is correct but you are doing it wrong because you are blindly applying what you THINK are the correct definitions of Watt and Joule, but they are not.

FIND ANYONE ANYWHERE who will agree with you.

SHOW how you arrived at your 3.33 Watt figure. You cannot: somebody probably TOLD it to you and you, in your ignorance,  can't figure out how to arrive at it with numbers and arithmetic operations. Or you are relying on some bogus temperature measurement that "relates to" some power in the load, in other words more garbage measurements that you don't understand.

The electrical calculations are as PW and I have said, and the Watt is an instantaneous measurement. Why else do you think people talk about "average power" at all? It is because AVERAGE POWER and instantaneous power are different things. A 100 Watt light bulb is a 100 Watt light bulb whether you turn it on for one second or for one hour or for a duty cycle of 5 percent or 95 percent: it is still a 100 WATT BULB. The ENERGY used is the AVERAGE POWER multiplied by the time. The INSTANTANEOUS POWER that the bulb draws will always be 100 Watts. The average power must factor in the on-time and the average power is always given as over a time period, or is assumed to be some constant value, as when you leave a bulb on and the supply voltage doesn't vary. The AVERAGE POWER considering ONLY the brief ON period of your pulse is 20 Watts FOR THAT FRACTION OF A CYCLE, and that's what PW and I have been TRYING to discuss, between your inanities and misrepresentations and misunderstandings and insults. Considering the WHOLE cycle, the AVERAGE POWER must also consider the oscillations and that is NOT what we are talking about.
PERHAPS, considering the oscillations during the OFF time AND the 320mA current during the ON time would add up to 3.33 Watts AVERAGE over an entire cycle. BUT THAT IS NOT WHAT WE ARE TALKING ABOUT, and the fact that you don't get it indicates... that you don't get it. You can parrot back words but you don't really understand the concepts of average versus instantaneous power.

WHY DO YOU THINK YOU HAVE TO DO ALL THAT SPREADSHEET STUFF? It's because you are taking INSTANTANEOUS power values and computing an average over time, then you are attempting to integrate that average power data over that time to get a TOTAL ENERGY FLOW in Joules. And you don't even realize it.

[Rosemary Ainslie]

20 watts flows during the "on" time in that 'scope shot.  Only need to factor in the duty cycle for average dissipation.

Watts is watts...

Sorry,
PW

Again.  Not actually.  20 watts is ONLY a small fraction of an ENTIRE DUTY CYCLE.  Unless you factor in the entire duty cycle you CANNOT referto WATTS.  Watts is the average over a wide sample in order to represent the ACTUAL rate of power delivered or dissipated.  It is a RATE.  It cannot be representative of anything at all if it is taken over an INCOMPLETE sample range.  The least requirement is a FULL DUTY CYCLE.  And that will change that 20 watts to 3.33 watts.. AT BEST. 

How many ways must I explain this?

Rosie Pose

[TinselKoala]

Guys, picowatt and TK included,

Here's the thing.  IF one determines the wattage delivered or dissipated - one takes the sum of a fair sample range - and then one divides that sum by the number of samples in that range.  That gives you a 'fair' average - which represents the WATTS delivered - with that number being 'representative'.  In effect it IS an average of a sample range of voltage measurements that DO, in fact, represent an INSTANTANEOUS power measurement.  But the qualification is that it includes a full and representative sample range before one can arrive at that the required number.  Then.  That AVERAGE value is the ACTUAL rate of wattage.  And that's then a product represented as a second - over the TIME that the energy has been delivered or dissipated - to give the Joules or POWER.  Which ALWAYS incorporates TIME.  One small representative sample in one small section of one part of the duty cycle is NEVER, EVER, a WATT.  Nor can it be called a WATT.  Then.  The product of this number is applied to the value over time to represent the WORK that has been performed related to Joules.  The instantaneous power calculated in 1/6 of a duty cycle is NOT representative of WATTS.  It is merely representative of instantaneous power within a small fraction of the applied duty cycle. 

Those them are the facts guys.  And no amount of invective or protest is likely to alter those them facts.

Regards,
Rosie

Here's the thing.
The JOULE is a quantity of ENERGY, not power.  The Joule is one WattSecond, NOT "one Watt per second".

The WATT is a RATE of ENERGY DISSIPATION. It, like ALL RATES, is an instantaneous measurement, just like MILES PER HOUR. A watt is a JOULE PER SECOND. Time does not enter the picture until you wish to get an AVERAGE over a time period.

When you do the averaging and integrating process you are attempting to describe--- and that ALL OF US FULLY UNDERSTAND EXCEPT YOU -- you are taking instantaneous POWER measurements in Watts and making what is called an INSTANTANEOUS POWER curve.

This is what is displayed on your scope's MATH trace: it is an instantaneous power curve.

THEN, you are taking those small timeslices and computing their AREAS: the horizontal duration of the slice times the height of the slice (the power at that "instant".)

Then you are SUMMING all those AREAS to arrive at a value that is in the units WATTS x TIME which is JOULES.

This is the process of INTEGRATION, a calculus concept that you do not grasp.

If you then simply take the total JOULES during the time of integration and divide that by the TOTAL TIME, you arrive at the AVERAGE POWER IN WATTS during that time interval, and this process takes into account all the duty cycle and wiggly bits of the original voltage and current data. And it is ENERGY that is the conserved quantity, not POWER.


That is what you are trying to understand and explain, but since you have your unit definitions muddled you ERR CONSTANTLY.


Take this to anyone you trust and have them explain it to you. Don't come back until you REALLY understand it.

[TinselKoala]

Again.  Not actually.  20 watts is ONLY a small fraction of an ENTIRE DUTY CYCLE.  Unless you factor in the entire duty cycle you CANNOT referto WATTS.  Watts is the average over a wide sample in order to represent the ACTUAL rate of power delivered or dissipated.  It is a RATE.  It cannot be representative of anything at all if it is taken over an INCOMPLETE sample range.  The least requirement is a FULL DUTY CYCLE.  And that will change that 20 watts to 3.33 watts.. AT BEST. 

How many ways must I explain this?

Rosie Pose

How many ways must WE explain that we are talking about the 20 Watts during the ON time of the duty cycle only. You are arguing against a phantom of your own creation and in the process you continue to reveal your ignorance of the basic concepts of power and energy.