PhysicsProf Steven E. Jones circuit shows 8x overunity ?

[yssuraxu_697]

The problem with large capacitor is that the internal resistance increases with frequency

Very good, maybe it will spark a discussion how to make system that does not self-run better.
Indeed ESR falls, Xc falls, but ESL rises. This makes "sweet" spot in cap freq response.
In general polypropylene caps should be good in terms of ESR while electrolytic are horrible.

As noted above, I do not intend to use the output without some kind of rectification;

DC pulse goes clean thru also. I'm using this effect in my pulse motor controller timing arrangement.

I am interested in finding a reliable way to measure output Power

I think that there is no other way besides looping or resistor heating. Other ways will spark endless discussions.
But you cannot argue with 1L of boiling water, for example.

I have seen endless burning of human resources on some other forums because some other forms of measurement were choosen...

[prm]

I am afraid I'm touching a tar baby here, but... here goes.

First, I am glad that you are using caps, because that does give you an accurate way of estimating the ENERGY that you are inputting to the circuit in a given amount of time. Please for the moment forget about POWER and especially "mean power".
Energy is not power and power is not energy. Very high power multiplication factors may easily be achieved in oscillating circuits with no gain in energy. And I think we are all clear that it is ENERGY that is the important parameter when claims of Overunity or COP>1 are being made.

Now.... you can measure the energy output of your JT by integrating the INSTANTANEOUS power curve over a time period. There is no need to get any kind of average power reading, in fact this is a major (and common) error.
If your scope can only do the one math function at a time, then you must do the integration manually. There are several ways to do this. First, get away from the habit of displaying so many cycles on the screen that they are uninterpretable. Display only 3 or 4 complete waveforms, or even a single one.
OK, so now you display, say, two complete cycles of the instantaneous power curve. Overlay a piece of tracing graph paper on the screen and trace out the curves carefully. The integral of this curve is the VOLUME occupied  by the surface defined by the vertical dimension (the inst. power value) and the horizontal dimension (time). Using the scope's graticle and the horiz and vert settings, calibrate your little graph paper squares. (they will be in Joules). Then count up the area of your waveform.... and don't forget to multiply that by enough to fill up your known 30-second input energy from the caps.

Compare and contrast.  You are comparing Energy IN, using the correct calculation you have shown above, over a 30 second period, with the Energy OUT, which is integral(VxI)dt, from 0 to 30 seconds. Only if Energy OUT exceeds Energy IN is there any reason to get excited at all.

No "average power" or especially "RMS voltage and current" goes into the calculation at all.

Of course, if your scope will do integration, your problem is solved.

(I get 6.8 microJoules; I suppose you are using "mF" and "mJ" to mean microFarads and microJoules. I am more used to using "m" as "milli" and "u" (like greek mu) for micro.)

EDIT.. Whoops, sorry, my bad... you DO mean "milliJoules". I misread the size of your cap bank, I didn't realize you were using 10,000 uF x 4. Apologies. I accept your 6.8 milliJoules figure.

Hello, everyone.  I am new to this forum and here is my 10 cents worth. 

The above post of TinselKoala is the crux of the whole matter.  It is not power per se that is the relevant issue, it is energy.  And this energy can only be ascertained by integrating power with respect to time.

Of course, this is easier said then done.  If the oscilloscope has the capability of integrating the power, then this feature should be used, assuming it is accurate. 

If integration of the instantaneous power can't be done by the oscilloscope then as TinselKoala points out, one must find some other way.  Using the method of a Riemann sum,for example, one must slice the time increments of the power signals as small as possible, then multiply these time slices by the instantaneous amplitude of the power for that time slice, and then sum over the total products of the times slices x instantaneous power amplitude. 

For this first-order approximation to approach an exact result, the time slices must be made as small as possible. As the time slices approach zero, the amplitude of the signal approaches a constant value.

There is no other way for an accurate determination of over/unity of this circuit unless one uses this Riemann sum approximation approach. Emphasizing power and only power leads to misleading conclusions.  Energy is king, not power.

[Hoppy]

John Bedini has always stressed the importance of calculating energy in and out when calculating COP for his monopole motors and the like, so I don't see why the approach to measuring this circuit should be any different. I've built Stevens circuit and cannot get it anywhere close to self-running. Before anyone goes to the bother of calculating energy for this device, just let the battery run the device over a period of time because as with any Joule Thief type circuit, it will run right down over time and that's a certainty!

Hoppy

[xee2]

@ JouleSeeker

If you do not believe amp meter you can use this circuit to measure the input power. By looking at the voltage on the scope you can see the amount of noise in the current. I think you will find the result is very close to that with just an amp meter.

NOTE - there will be very little noise in current.

[jmmac]

prm,

As I understand it:

- In the original circuit with battery, Dr. Jones used his digital oscilloscope to calculate the mean instantaneous power in and out. The instantaneous power: P(t) = I(t) * U(t) which changes over time. If you calculate the average of that instantaneous power over several cycles, you have a good measurement of the true power (oscilloscope measures current and voltage over time and multiplies the 2, then calculates the mean).
I believe the mean power in and mean power out were calculated (measured) at the same time with 2 oscilloscopes.
In conclusion: calculating mean instantaneous power over a period of time is equivalent to measuring the energy. Power is Work (Energy) by unit of time.

- In the experiment powered by the large capacitor, the energy came from that capacitor and you can calculate the total energy it contains knowing the capacity and it's voltage. Knowing the initial and final voltage of the capacitor and the amount of time it was connected to the circuit, you can calculate the energy it gave to the circuit in that time and the mean power. That value was calculated and is very small.

Regards,
Jaime

Hello, everyone.  I am new to this forum and here is my 10 cents worth. 

The above post of TinselKoala is the crux of the whole matter.  It is not power per se that is the relevant issue, it is energy.  And this energy can only be ascertained by integrating power with respect to time.

Of course, this is easier said then done.  If the oscilloscope has the capability of integrating the power, then this feature should be used, assuming it is accurate. 

If integration of the instantaneous power can't be done by the oscilloscope then as TinselKoala points out, one must find some other way.  Using the method of a Riemann sum,for example, one must slice the time increments of the power signals as small as possible, then multiply these time slices by the instantaneous amplitude of the power for that time slice, and then sum over the total products of the times slices x instantaneous power amplitude. 

For this first-order approximation to approach an exact result, the time slices must be made as small as possible. As the time slices approach zero, the amplitude of the signal approaches a constant value.

There is no other way for an accurate determination of over/unity of this circuit unless one uses this Riemann sum approximation approach. Emphasizing power and only power leads to misleading conclusions.  Energy is king, not power.