Parametric Charging

[TinMan]

Brad,

I'm no math guru, but what I am trying to convey with AVG[v(t) x i(t)] in words is:

Take the average (AVG) of the instantaneous voltage v(t) times instantaneous current i(t).

You do this by setting up one probe (CH1) measuring the input voltage, just as you have been, and one probe (CH2) measuring across the low-inductance (not wirewound power resistors) cvr for current. Set up a MATH trace for CH1xCH2, then set a measurement for the average value (or MEAN) of the MATH trace. You will have to scale the current based on the value of your CVR resistor. Some scopes allow you to scale, otherwise you do it in your head by dividing by 10 (for a 10R resistor).

That should now ring a bell with you...

This method has been discussed and recommended many times over the years, not only by myself, but by the true masters out there, TK, ION, etc. etc (apologies for those I have missed). It was used extensively during the Rosemary Ainslie saga as well. And I am fairly certain that we had you doing this as well on some test, or at least attempting to until we couldn't figure out how to get the AVG working on your MATH trace as I recall.

Anyway, give that a shot. It should be no problem with your new scope, and you very well may have already done it in recent times.

OK,this is how i have been doing it all throughout the thread,but manually,as i cannot measure the voltage across the primary only,and current through the primary via the CVR separately in the one go,due to the common grounds between the scope and SG. The voltage across the primary has to include the voltage across the CVR as well,so we cannot use RMS or average value shown on the scope to give us the voltage across the primary only to make any power calculations,as that voltage value will be higher than the actual value across the primary coil.

I can bring up the math trace of CH1 x CH2 and get the average of that --that is no problem.
But it will give a wrong value,as CH1 will be showing the voltage across both the primary and CVR,while CH2 will give the voltage across the CVR only. This result will give us the power dissipated by both the CVR and primary--not the primary alone.

This is the method i have been using throughout the thread,where the total power in is calculated,and then the calculated dissipated power of the CVR is subtracted from the total P/in to give us the P/in for the primary of the transformer.

I would like to do it the way you stipulate,but simply cannot due to the common ground issue between scope and SG.
I have tried a 1:1 isolation transformer,and an inverter to run the SG,in the hopes that i would be able to scope across circuits without any common ground issue's--but that dose not work as people say it dose,as i can always get an AC voltage reading between the two grounds/commons--even when !apparently! isolated from each other.

So,the best we can do is get the total P/in,and then subtract the power dissipated by the CVR,and use the remainder as our P/in value--which i have been doing--unless you have another idea i have overlooked?.


Brad

[poynt99]

It is a fairly straight forward setup and procedure Brad. Here's what you do:

1) Use the CVR1 setup as in the attached pic. Same common ground for both probes.

2) CH1 is v(t), and CH2 is i(t) (and is v(cvr1)/10).

3) Set up a MATH trace with CH1 x CH2.

4) Set up a measurement for the MEAN (or average) of the MATH trace. Divide the indicated measurement by 10 to correct for the current. This is the total corrected power going into the circuit after the diode.

5) Set up a measurement for the RMS value of CH2, and divide that by 10. This is the corrected RMS input current.

6) Make note of the total corrected average power in step 4).

7) Calculate the power dissipated in CVR1 by using the corrected RMS current in step 5), as: P(cvr1)=I(rms)² x 10

8] Subtract the CVR1 power calculated in step 7) from the total power noted in step 6).

9) The subtraction in step 8] results in you obtaining the net power going into the primary of the transformer, aka P(in).

[TinMan]

It is a fairly straight forward setup and procedure Brad. Here's what you do:

1) Use the CVR1 setup as in the attached pic. Same common ground for both probes.

2) CH1 is v(t), and CH2 is i(t) (and is v(cvr1)/10).

3) Set up a MATH trace with CH1 x CH2.

4) Set up a measurement for the MEAN (or average) of the MATH trace. Divide the indicated measurement by 10 to correct for the current. This is the total corrected power going into the circuit after the diode.

5) Set up a measurement for the RMS value of CH2, and divide that by 10. This is the corrected RMS input current.

6) Make note of the total corrected average power in step 4).

7) Calculate the power dissipated in CVR1 by using the corrected RMS current in step 5), as: P(cvr1)=I(rms)² x 10

8] Subtract the CVR1 power calculated in step 7) from the total power noted in step 6).

9) The subtraction in step 8] results in you obtaining the net power going into the primary of the transformer, aka P(in).

Ok,i have done what you suggested(see scope shot below),but i disagree with the highlighted above,where this is not showing total corrected P/in. This is showing total power dissipated by the CVR and Primary of the transformer,which is 69.4mW

By doing it this way,the scopes math is including power being sent back to the source-i would suspect via the diodes junction capacitance for a brief time,and then once the voltage inverts across the coil,current then flows to the SG via the ground rail,through the SGs circuit,and then back into the DUT.

How do we know this?--
Well,lets have a look at the scope shot below.
See the time period i have circled in green.
If this was power being sent to the circuit by the SG,how come the voltage is inverted across the primary?

This area in green is the primary coils magnetic field collapsing(the flyback period).
So,we know from years of testing,that this is the time when the supply is cut off,and we get our inductive kickback,where the voltage inverts. During the 80% off time of the SG,the transformer is now the source--not the SG,but the scope math still sees this as power flowing through the primary of the transformer,and so is adding that to it's calculations.

What we want to know is the power being delivered to the DUT by the SG only,during it's 20% delivery cycle.

Please see next post,where i show clearly when power is being delivered by the SG to the DUT.


Brad

[TinMan]

Ok,in this test i added a lightbox,which has an LED and solar panel inside.
It is housed in a sealed box to eliminate any outside light influence.
The circuit is as below.

I hooked CH3 across the solar panel,so as we can see exactly when and for how long current is flowing into the DUT.
If we look at the scope shot below,and take note of CH3,we can clearly see when current is flowing into the circuit,as we see a sharp rise in voltage across the solar panel,due to the LED lighting up.

As we can see,this rise on CH3 coincides exactly with the 20% on time shown via the voltage and current traces.
This is the only time power is delivered to the DUT by the FG.

You will also see a blue line showing peak current value,and a yellow line showing peak voltage value during the 20% on time. I think you would have to agree that i have been generous in my averaging,where actual values would be slightly less.

To get our P/in from the SG only,first we calculate the instantaneous power.
You will also note that the current and voltage are exactly in phase,which makes the calculations easy.
The instantaneous current is 1.1v across 10 ohms=110mA
Instantaneous power dissipated by the CVR is 121mW
The instantaneous voltage across the CVR and primary is 2.6 volts.
The total instantaneous power is there for 286mW
From that we subtract the 121mW dissipated by the CVR-->286mW-121mW=165mW
This 165mW is the instantaneous power dissipated by the primary of the transformer.
We now multiply that by our 20% duty cycle to get an average dissipated power of the primary.
165mW X 20%=33mW.
The voltage across R1/C1 is 22.1v,for a dissipated power of 32.8mW

Our COP is therefor 99.3% 

Poynt
Are you happy with the way those measurements were calculated?.


Brad

[Itsu]

Brad,

i replicated your circuit as much as possible, i only use a different transformer (Prim. 200uH / 0.5 Ohm,
Sec. 400mH / 106 Ohm) out of a flyswatter (ferrite core), see picture.

My signals are not that clean as yours (28.8KHz), especially the input diode causes massive ringing on the voltage.
As i can omit CVR1 by using my current probe, i can directly measure/calculate the input power using my scope.

First measurements show 9mW input for a 2.7mW across the 15K resistor for a cop = 0.3

Not sure if this transformer is messing things up here (to low ohmage primary for my 50 Ohm FG)

let me know if you want me to setup/measure/calculate things the way you do it to compare.


Itsu

[TinMan]

Brad,

i replicated your circuit as much as possible, i only use a different transformer (Prim. 200uH / 0.5 Ohm,
Sec. 400mH / 106 Ohm) out of a flyswatter (ferrite core), see picture.

My signals are not that clean as yours (28.8KHz), especially the input diode causes massive ringing on the voltage.
As i can omit CVR1 by using my current probe, i can directly measure/calculate the input power using my scope.

First measurements show 9mW input for a 2.7mW across the 15K resistor for a cop = 0.3

Not sure if this transformer is messing things up here (to low ohmage primary for my 50 Ohm FG)

let me know if you want me to setup/measure/calculate things the way you do it to compare.


Itsu

Hi Itsu

That is a big step up you have with that transformer,which may be the problem ?

Also,dose your FG have a function where you can set the impedance to 0 ,such as mine has?

Would be good to see what type of waveforms you have across the scope as well.

As seen in all my video's,i get very clean waveforms,and the results are very easy to see.
You should be able to get 20v across the 15kohm resistor with no problem at all--maybe some tuning is needed?,due to different components.

After testing many different transformers,i finally found another that yields the COPs i have been showing-im not sure why very few give me these results,and where others of the same type(E core ferrite)show below COP+ results.


Brad

[Grumage]

Hey Brad.

Is it possible that some of your Ferite cored transformers might have cracks in them?

Just thinking out loud based upon some of Verpies hypothesis.

Cheers Graham.

[gyula]

...
i only use a different transformer (Prim. 200uH / 0.5 Ohm,
Sec. 400mH / 106 Ohm) out of a flyswatter (ferrite core), see picture.
...

Not sure if this transformer is messing things up here (to low ohmage primary for my 50 Ohm FG)
...

Dear Itsu,

As you know the primary coil inductance of 200 uH represents roughly 36 Ohm inductive reactance load to your FG at 28.8 kHz. 

EDIT: Brad's measured transformer data is in his post #42, page 2 of this thread.

If you see feasable to separate the ferrite cores of the transformer from each other, then perhaps you could remove the many turns of the original HV winding ?  I know the two E cores are permanently glued together and the ferrite may break easily, perhaps heating up the glued area at the two sides may be successful.  If you see the separation is not possible without the risk of core break, then let's forget this.

Gyula

[TinMan]

This is what MH had to say about calculating power.
From the !Lawrence Tseung sent a prototype to test! thread

When it comes to a "power waveform," that is an abstraction derived from two other real-world variables.  The power waveform already factors in the "squared" factor associated with the voltage and current waveforms.  Therefore it makes no sense at all to "square power" and then take the mean value of that and then calculate the square root.  The only thing that you have to do is average out the power over an entire periodic cycle.

When you want to calculate energy over a cycle, you integrate the power waveform over that cycle to get your energy calculation.  You do not integrate over the square of the power waveform and then take the square root.  Again, that makes no sense.

  You have to multiply the instantaneous voltage by the instantaneous current and then take the average of the power waveform.Therefore the correct way of measuring the output power from the LTJT is for Poynt to use his DSO and measure the instantaneous voltage and current values and then do the associated calculations.  The same principle applies to measuring the input power because the LTJT itself is a non-linear load.

And from Poynt
I believe the issue at hand is even more basic. My understanding of the disagreement is simply regarding which computation should be used to obtain the REAL power in the circuit*, either:

Method 1: The Power value obtained from the MEAN of the product of instantaneous current and instantaneous voltage.
or
Method 2: The Power value obtained from the RMS of the product of instantaneous current and instantaneous voltage.

Again from Poynt
[I should mention, and I trust we are all in agreement on this, that all measurements being argued here are based on one that is obtained by first acquiring the instantaneous voltage and current wave forms, then multiplying them together to produce the instantaneous power trace. For circuits of this nature, there is no other sure method (using an oscilloscope) to obtain the value of average power in a circuit.]

At this time,i would like to confirm that the above method is the one i have been using--instantaneous voltage X instantaneous current. That result is then multiplied by the duty cycle to give us an average power input over each full cycle.
To Quote Poynt-->tthere is no other sure method (using an oscilloscope) to obtain the value of average power in a circuit


Brad

[TinMan]

Hey Brad.

Is it possible that some of your Ferite cored transformers might have cracks in them?

Just thinking out loud based upon some of Verpies hypothesis.

Cheers Graham.

Well,im not sure Graham

I have noticed that some of these cores are glued together,and some are not,they are just held together by the tape wound around them.

I have many of the second transformer i found that is giving the OU results,so i will check out another one,and see if it gives the same result as the identical one i have used. If not,then i will start looking for them cracks or loose glue joints.

I too remember Verpies mentioning something about the two halves of the core should be free from each other,and vibrate when being pulsed.
Any idea as to which thread that was in ?


Brad

[TinMan]

Dear Itsu,

As you know the primary coil inductance of 200 uH represents roughly 36 Ohm inductive reactance load to your FG at 28.8 kHz. 

If you see feasable to separate the ferrite cores of the transformer from each other, then perhaps you could remove the many turns of the original HV winding ?  I know the two E cores are permanently glued together and the ferrite may break easily, perhaps heating up the glued area at the two sides may be successful.  If you see the separation is not possible without the risk of core break, then let's forget this.

Gyula

Hi Gyula

I have tried many times to separate the two glued halves of E core ferrite transformers using heat to soften the glue,only to have them crack/explode due to localized expansion in the heated area,while no expansion in the non heated area. Ferrite has no forgiveness ,and simply will not flex.
On occasion i get lucky,and find a core now and then which is not glued together,but only held together by the tape wrapped around them.


Brad

[Grumage]

Hi Brad.

I'm pretty sure I launched the topic on my bench. CARA, or something like that.

http://www.overunityresearch.com/index.php?topic=2751.msg44488#msg44488

Do you have a means of mechanically stimulating the transformers ultrasonically? Might be interesting to see what output you get on the scope.   

Cheers Grum.

[TinMan]

Hi Brad.

I'm pretty sure I launched the topic on my bench. CARA, or something like that.

http://www.overunityresearch.com/index.php?topic=2751.msg44488#msg44488

Do you have a means of mechanically stimulating the transformers ultrasonically? Might be interesting to see what output you get on the scope.   

Cheers Grum.

Actually i do indeed.
I have a few of them 45 watt ultrasonic water misters from old home fogger cooling fans 

So i just sit the transformer on top of the pizo ?


Brad

[Grumage]

Ah, great.   

Yes. I did several videos on the subject perhaps 3 years ago?

Aided by Verpies we found that mechanical stimulation of Ferite cores can produce a voltage in a coil wound around them. Admittedly voltage ain't power and I didn't subject the coils to a load resistance, perhaps you could take things a step further?

I've just realised, this perhaps isn't the best place for discussion as we're getting a little off topic, my apologies PM.

Cheers Grum.

[TinMan]

Poynt

Please check the below.

This is a test carried out on another transformer that gave COP+1 results.
This is how P/in to the primary of the transformer only was calculated.

The measurements are taken from the maximum values shown in the scope shot below.
These values are slightly high than actual values,and so will yield a higher than actual P/in value.
I do this to eliminate any incorrect values that would be lower than actual P/in values.

As we can see from the scope shot,the voltage and current are in phase.
This is due to the very low inductance value of the primary coil in relation to the frequency.
So in this case,no power factor correction is needed.

First i get the instantaneous current value,which in this case is the V/max across the 10 ohm CVR
V/max is 1.6 volts over 10 ohms for an instantaneous current of 160mA
Now we need the instantaneous voltage across the primary coil of the transformer.
This is gained by the total instantaneous voltage across the CVR/primary coil series,minus the voltage across the CVR.
This gives us an instantaneous voltage across the coil of 1.9v - 1.6v=300mV
We now have a means of calculating the instantaneous power consumed by the primary coil,which is 300mV x 160mA=48mW.

The 48mW is for 25% of a complete cycle,and so is multiplied by the duty cycle to get an average P/in over a complete cycle.
So P/in to the primary of the transformer is--48 x 25%=12mW

P/out from the secondary is very easy to calculate,as it is 22 volts over our 15kohm resistor/C1 combo.



P/in=12mW
P/out=32.26mW
COP=268.8%

Is there anyone here that can carry out the manual calculations ,using the scope shot below,to confirm my results?.


Brad

[TinMan]

Ah, great.   

Yes. I did several videos on the subject perhaps 3 years ago?

Aided by Verpies we found that mechanical stimulation of Ferite cores can produce a voltage in a coil wound around them. Admittedly voltage ain't power and I didn't subject the coils to a load resistance, perhaps you could take things a step further?

I've just realised, this perhaps isn't the best place for discussion as we're getting a little off topic, my apologies PM.

Cheers Grum.

Well if you can find the old thread related to this Graham,then we can re-boot it.

Now that you mentioned this,i seem to remember doing some quick tests,where i just hit a MOT core with a hammer,and measured a voltage across the coils using my scope.

This has to mean that energy can be produced by vibrating the core of an inductor/transformer.

I might do a quick trip out to the workshop for a quick test 

Back soon.


Brad

[gyula]

Hi Gyula

I have tried many times to separate the two glued halves of E core ferrite transformers using heat to soften the glue,only to have them crack/explode due to localized expansion in the heated area,while no expansion in the non heated area. Ferrite has no forgiveness ,and simply will not flex.
On occasion i get lucky,and find a core now and then which is not glued together,but only held together by the tape wrapped around them.


Brad

Yes, I have had more failure than success in separating glued E cores. 

A question on your present setup:  do you plan to build a circuit around the setup to loop the output from C1 back to the input ? Such circuit should include the 28-29 kHz frequency source (with the 20-25% duty cycle) and should have roughly a 70-80% efficiency (to be on the safe side) if the setup has a COP between 1.7 to 2 as you measured.  The circuit should run from the DC output available across the output capacitor.

Gyula

[TinMan]

Yes, I have had more failure than success in separating glued E cores. 

A question on your present setup:  do you plan to build a circuit around the setup to loop the output from C1 back to the input ? Such circuit should include the 28-29 kHz frequency source (with the 20-25% duty cycle) and should have roughly a 70-80% efficiency (to be on the safe side) if the setup has a COP between 1.7 to 2 as you measured.  The circuit should run from the DC output available across the output capacitor.

Gyula

Sure
If you or some one can design a loop circuit,operating under the calculated excess energy output,where the output of that circuit is a 25% duty cycle,with a voltage output of around 4 to 5 volt's,and current of around 160mA,then i will build it,and give it a go.

Now,here is the problem--
The current through the 15kohm resistor at 22 volts is only 1.46mA 

Brad

[TinMan]

Ah, great.   

Yes. I did several videos on the subject perhaps 3 years ago?

Aided by Verpies we found that mechanical stimulation of Ferite cores can produce a voltage in a coil wound around them. Admittedly voltage ain't power and I didn't subject the coils to a load resistance, perhaps you could take things a step further?

I've just realised, this perhaps isn't the best place for discussion as we're getting a little off topic, my apologies PM.

Cheers Grum.

Ok.ill throw this in here quickly.

The quick and dirty test.
A MOT with a 100 ohm resistor across the primary,and me hitting the core with a small ring spanner,yielded the below results.
Looks like i hit at about 6 Hz 

Now,lets imagine this being two core halves being pulled together via the magnetic attraction force during the input pulse at a frequency of say 28KHz 


Brad

[gyula]

...
Is there anyone here that can carry out the manual calculations ,using the scope shot below,to confirm my results?.
...

Brad,

Your calculations numerically are correct from the data available from your measurements.  Due to the debate on measurement protocols, it seems the only convincing method would be the use of a correct looping circuit, that is why I asked. 

Thanks for the answer, 
Gyula

[gyula]

...

Now,here is the problem--
The current through the 15kohm resistor at 22 volts is only 1.46mA 

Yes, it sounds a problem.   If you reduce the value of the load resistance so that the C1 voltage go down to say as low as 6-7V only, then
1) what reistor value is needed for that?
2) how the input current changes then?

[TinMan]

Yes, it sounds a problem.   If you reduce the value of the load resistance so that the C1 voltage go down to say as low as 6-7V only, then
1) what reistor value is needed for that?
2) how the input current changes then?

OK,as C1 is charging,the current and voltage in value decreases.

If i decrease the value of the load resistor to 100 ohms,the P/in value go's up.

Can we use IONs circuit below,or a modification of it?


Brad

[gyula]

Well, Ion's circuit needs a negative resistance (breakdown) device that fires in the 10-20V range or so in your case.  A diac needs at least 30-35V to fire, more suitable for Pm setup.
I am thinking on a DC-DC converter circuit as previously I indicated in this thread but the energy available in C1 may prove low.

EDIT it is in my post #63,   for your setup a similar but a step down converter could be attempted.

[poynt99]

Ok,i have done what you suggested(see scope shot below),but i disagree with the highlighted above,where this is not showing total corrected P/in. This is showing total power dissipated by the CVR and Primary of the transformer,which is 69.4mW

Yes, exactly. I know this, and this is part of the procedure. There is a step that perhaps you skipped which subtracts out the CVR power.

By doing it this way,the scopes math is including power being sent back to the source-i would suspect via the diodes junction capacitance for a brief time,and then once the voltage inverts across the coil,current then flows to the SG via the ground rail,through the SGs circuit,and then back into the DUT.

How do we know this?--
Well,lets have a look at the scope shot below.
See the time period i have circled in green.
If this was power being sent to the circuit by the SG,how come the voltage is inverted across the primary?

This area in green is the primary coils magnetic field collapsing(the flyback period).
So,we know from years of testing,that this is the time when the supply is cut off,and we get our inductive kickback,where the voltage inverts. During the 80% off time of the SG,the transformer is now the source--not the SG,but the scope math still sees this as power flowing through the primary of the transformer,and so is adding that to it's calculations.

What we want to know is the power being delivered to the DUT by the SG only,during it's 20% delivery cycle.

Please see next post,where i show clearly when power is being delivered by the SG to the DUT.


Brad

If you wish for my help I'd like to remain focused on the procedure so that there can be an understanding of the what and why.

So you obtained a total power of 69.4mW (or is it 68.4mW?).

Can you carry out the rest of the steps in the procedure and let us know how the result compares with P(out)? I see you obtained the RMS of the input current (59.4mA), so you have the data you need.

[ion]

Well, Ion's circuit needs a negative resistance (breakdown) device that fires in the 10-20V range or so in your case.  A diac needs at least 30-35V to fire, more suitable for Pm setup.
I am thinking on a DC-DC converter circuit as previously I indicated in this thread but the energy available in C1 may prove low.

EDIT it is in my post #63,   for your setup a similar but a step down converter could be attempted.

Diacs and Trigger diodes are available in a wide range of firing voltages. You can even build your own from a pnp-npn regenerative pair and tailor the firing voltage with b-e resistors.

At this point I am running sims on such regenerative firing circuits and will post the results later.  I would hold off on this method at present.

When power measurements of the presently evolved OU circuits of PM and Tinman are proven with alternative measurement techniques we can then with confidence proceed to closing the loop.

If you wish to skip the alternative measuring methods, then to loop, I would recommend one of the many proven class C single transistor oscillators as a simple DC to AC converter.

Regards

P.S Thanks to Poynt for stepping in to clarify the measurement protocol. We enjoy your expert posts, so please continue.