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Author Topic: Parametric Charging  (Read 36860 times)

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PM,

i did it mixed, always with the DMM, and from time to time checked with the 2 probes method.
They agreed almost all of the time.

Itsu
   
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Itsu and all,

Here is another optional test that we will re-visit which uses two paralleled mosfets and in this case it is the 14N05L's.  See the attached schematic below.  If you were to substitute the mosfets with say Schottky diodes, the maximum voltage across C1 with a load would be slightly less than 1/2 the supply voltage at a 50% duty cycle.  Here however, we see a voltage across C1 with the load that is greater than 1/2 the supply due to the parametric pumping of the mosfet's non-linear capacitance.  This is the simplest configuration that demonstrates the principle I can think of at the moment.  This should be easy to replicate by anyone who desires and the results will vary with the devices and the component values used.

The tuning is easy.  Apply a frequency that is high enough to generate a voltage that is less than 1/2 the supply across C1 with the load.  Then, carefully lower the frequency until the point is reached where the C1 voltage increases to be >1/2 the supply and then suddenly jumps to a higher stable value.  Now raise the frequency until the voltage across C1 again drops to <1/2 the supply and lower the frequency again until you have the maximum output across C1 without the sudden jump.  IOW, we will now be operating in Mode1 not Mode2.  This may require several tries to find the "sweet" spot.

The load resistance can be found by experimentation if one does not the ability to do a 100ms or equivalent sweep as it is not that critical.

In the scope shot we see a C1 voltage of 22.28v with the 7.451 ohm load for a Pout = 22.28^2/7451 = 66.62mw.  Pin is seen to be 46.67mw for a COP = 66.62/46.67 = 1.43.  I used my current probe for this test but the results should be the same if a CSR is used.  Note the mean current value as it alone does not account for the load's output voltage.  The balance of output energy is supplied by the AC parametric pumping.

What I like about this circuit is the possibility of looping by using a low power highly efficient boost converter to build the supply voltage from the voltage across C1 with the load although it would help if the power levels were higher IMO. 

Pm


 
   
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All,

Here is a different driving scheme for the parametric charging circuitry.  IMO, this is just a reactive to real converter with a parametric "C" for resonance.  Other that that , I'm not going to comment except to say that the load resistance is 7.451k ohms.

Pm
   
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All,

Please ignore the previous post as there is measurement error which cancels the apparent gain.

Pm
   

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PM,

i did it mixed, always with the DMM, and from time to time checked with the 2 probes method.
They agreed almost all of the time.

Itsu

PM, 

i went back to that older circuit of post #248 and double checked the voltage across the load resistor (3902 Ohm).
It was 13.91V with my DMM (Fluke 179).

The blue and purple traces in the screenshot shows the means, so a very close difference (14.046V).


The input calculated in red shows 50.82mW, and the outputs:

(13.91²   / 3902) is 49.5mW.
(14.046² / 3902) is 50.5mW   

Both less (a fraction) then the input.

I repeated this severall times with similar outcomes.


Itsu
   
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PM, 

i went back to that older circuit of post #248 and double checked the voltage across the load resistor (3902 Ohm).
It was 13.91V with my DMM (Fluke 179).

The blue and purple traces in the screenshot shows the means, so a very close difference (14.046V).


The input calculated in red shows 50.82mW, and the outputs:

(13.91²   / 3902) is 49.5mW.
(14.046² / 3902) is 50.5mW   

Both less (a fraction) then the input.

I repeated this severall times with similar outcomes.


Itsu

Itsu,

Thanks for continuing to try this setup! O0  It must boil down to measurement error on my part so I don't think I will waste anymore time on it.  I did notice on your scope shot the slight amount of power consumption shown in the Math channel during the "off" time of your driver when the input current is negative.  If this was not there, you would probably have a slight gain but if it is due to offset in your CH1, it would be added on the positive half of the cycle so all would cancel.

Pm
   

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Hi Brad,

Would like to show you a possible looping circuit I think would be able to maintain a continuous operation of your setup shown in your reply #65 (provided the measured COP=2 was correct, no offense intended with this). In that circuit you had 110 mA input current instead of 160 mA, probably due to a certain transformator and also to the 20% duty cycle versus your more recent data with another transformator and a 25% duty cycle.

You can see that the looping circuit has two decent parts: an isolated step down DC to DC converter and a pulse generator based on a CMOS timer IC, the TLC555C in plastic DIP8 (PDIP8) package, made by Texas Instruments. The absolute maximum output current for this IC is 150 mA, so the 110 mA current needed from its output pin 3 to the input of your transformer would not kill the IC. The LMC555C is also a CMOS timer made earlier by National Semiconductor but its absolute maximum output current is only 100 mA.

First I would suggest to build only the pulse generator with a TLC555C, fed from say around 5 VDC, either from a variable power supply or from two super capacitors in series (each charged up to around 2.5 V). If such pulse gen is able to feed your setup with a very similar pulse wave shape you kindly showed in your post #65, both amplitude and current wise, then energy wise there would be an even clearer insight into your setup and also you then eliminated the use of the FG. Then the purchase of the DC converter chip could be decided and I would return onto that part later on. The timer has a variable frequency and duty cycle control, independently from each other. The CMOS version has a 300-350 uA maximum current consumption (typically 170-200 uA) to operate its internal circuit from 5 V at such a low 28-29 kHz frequency. 
Mouser and Digikey have the TLC555C and they have also the LT8301.  Data sheet for the latter is here:
http://www.analog.com/media/en/technical-documentation/data-sheets/8301f.pdf   

Gyula

PS edited for additional text

Thanks Gyula

Once im back on my feet,i will see if i can put it all together.


Brad


---------------------------
Never let your schooling get in the way of your education.
   

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Itsu and all,

Here is another optional test that we will re-visit which uses two paralleled mosfets and in this case it is the 14N05L's.  See the attached schematic below.  If you were to substitute the mosfets with say Schottky diodes, the maximum voltage across C1 with a load would be slightly less than 1/2 the supply voltage at a 50% duty cycle.  Here however, we see a voltage across C1 with the load that is greater than 1/2 the supply due to the parametric pumping of the mosfet's non-linear capacitance.  This is the simplest configuration that demonstrates the principle I can think of at the moment.  This should be easy to replicate by anyone who desires and the results will vary with the devices and the component values used.

The tuning is easy.  Apply a frequency that is high enough to generate a voltage that is less than 1/2 the supply across C1 with the load.  Then, carefully lower the frequency until the point is reached where the C1 voltage increases to be >1/2 the supply and then suddenly jumps to a higher stable value.  Now raise the frequency until the voltage across C1 again drops to <1/2 the supply and lower the frequency again until you have the maximum output across C1 without the sudden jump.  IOW, we will now be operating in Mode1 not Mode2.  This may require several tries to find the "sweet" spot.

The load resistance can be found by experimentation if one does not the ability to do a 100ms or equivalent sweep as it is not that critical.

In the scope shot we see a C1 voltage of 22.28v with the 7.451 ohm load for a Pout = 22.28^2/7451 = 66.62mw.  Pin is seen to be 46.67mw for a COP = 66.62/46.67 = 1.43.  I used my current probe for this test but the results should be the same if a CSR is used.  Note the mean current value as it alone does not account for the load's output voltage.  The balance of output energy is supplied by the AC parametric pumping.

What I like about this circuit is the possibility of looping by using a low power highly efficient boost converter to build the supply voltage from the voltage across C1 with the load although it would help if the power levels were higher IMO. 

Pm



Hmmm,


PM, i tried the above circuit, using 40V on the ixdd614pi,
L1 is the 322uH one,
2x 14N05L with schottky diodes (bat42)
C1 = 3.3uF
Rload is 8.14K
R1 = 10 Ohm optional csr.

Screenshot shows input calculated in red (from yellow x green) = 17.17mW
output across 8140 Ohm resistor is 23.55V meaning output power (23.55² / 8140) = 68mW.

Purple is voltage across 10 Ohm csr, so 1.25mA so confirms the green current probe value of 1.128mA.

Went from 650Khz slowly down to 638Khz after which the voltage across the load resistor switch to 33V or so.
So 638Khz gave the 23.55V across the Rload.

Tried severall times, and got similar results allthough the current (green) is not stable over long periods.

17.17mW input, 68mW output, COP = 3.96.

I did  not calculate the power loss across the 10 Ohm csr.

Itsu
   
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Hmmm,


PM, i tried the above circuit, using 40V on the ixdd614pi,
L1 is the 322uH one,
2x 14N05L with schottky diodes (bat42)
C1 = 3.3uF
Rload is 8.14K
R1 = 10 Ohm optional csr.

Screenshot shows input calculated in red (from yellow x green) = 17.17mW
output across 8140 Ohm resistor is 23.55V meaning output power (23.55² / 8140) = 68mW.

Purple is voltage across 10 Ohm csr, so 1.25mA so confirms the green current probe value of 1.128mA.

Went from 650Khz slowly down to 638Khz after which the voltage across the load resistor switch to 33V or so.
So 638Khz gave the 23.55V across the Rload.

Tried severall times, and got similar results allthough the current (green) is not stable over long periods.

17.17mW input, 68mW output, COP = 3.96.

I did  not calculate the power loss across the 10 Ohm csr.

Itsu

Itsu,

Excellent results!  O0 The input current waveform looks really good as the slopes are really linear rather than having a slight curving near the peaks which as a visual usually indicates low gain or non at all. 

Thank you for being persistent with this and now you get to play with the variable gain over time situation!  ???

Regards,
Pm
   

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Ok,  no problem  O0


Input from PS is 40V @ 44mA = 1.76W.

Also we have some input from the FG, like 4V @ 50% duty cycle over 50 Ohm = 80mA.

The IXDD614PI gets pretty hot, with heatsink (copper tape strip) about 40°C (104°F), so we dissipate some (most?) there.

Today again similar values as yesterday (weather similar, cold, rainy, windy).

Itsu
   

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I added a boost converter (max 30V out) with its input across the loadR from PM's circuit and set its output to 24V.
This boost converter powers with its 24V a series connection of 8 leds.
This converters input return line and its output return line are connected

After powering on and adjusting the frequency to about 247Khz now (just before the jump to higher voltage)
i got again a stable situation with about calculated 134mW input and about 384mW (24V x 16mA) output into the leds.
The 16mA was found by using a 1 Ohm csr in the return line of the leds 

Screenshot shows again the red trace input power (yellow x green) = 134mW
Blue is the voltage across the loadR and the input to the boost converter
Purple is the voltage across the 1 Ohm csr in the leds return line.

Video showing this setup here:  https://www.youtube.com/watch?v=3iUWYbY4ujg&feature=youtu.be

Need a boost converter capable of 40V to try a feedback loop.


Itsu
   

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Buy me some coffee
I wonder if replacing the IX fet driver with the following circuit would work, still need a FG to drive it, but higher voltage fets could be used.

http://www.discovercircuits.com/DJ-Circuits/pushpul.htm
   

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Thanks Peter,

i can give it a try, the 30V would be perfect for my present boost converter, not sure if i can get
the same COP with 30V though.

Itsu
   

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Tried Peters circuit using IRF4905 and IRF3205 MOSFETs, but cannot get any higher as 30Khz else the output signal
is just peaks, no more square wave.

Guess i need the specified MOSFETs ZVP2106 / ZVN2106.

Itsu
   
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All,

I would like to move the contents of this thread to public view on the forum so if you have contributed in a post that you would not like to have shared publicly, then delete that post or let me know and I will delete it for you.

I would hope that from this action, others will attempt replication like Itsu and Brad which perhaps could result in some practical application.

This thread will remain private over the next several days and then I will ask Peter to move it into public view.  Thanks for everyone's input up to this point.  O0

Regards,
Pm   
« Last Edit: 2018-09-24, 18:47:23 by partzman »
   
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All,

I would like to move the contents of this thread to public view on the forum so if you have contributed in a post that you would not like to have shared publicly, then delete that post or let me know and I will delete it for you.

I would hope that from this action, others will attempt replication like Itsu and Brad which perhaps could result in some practical application.

This thread will remain private over the next several days and then I will ask Peter to move it into public view.  Thanks for everyone's input up to this point.  O0

Regards,
Pm

    OK - I support this move, given the progress you have made and the encouragement of replications that such a move would provide.  Good idea, and my posts here can be included in the public arena.  No problem with me.
   
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Hi Pm,

It is ok for me to go public with this topic, including my posts too.

Gyula


I would like to move the contents of this thread to public view on the forum ...

   

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Buy me some coffee
This project has now been moved to an open part of the forum.
   
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Peter,

Thanks you very much for all your work on this!  O0 O0 O0

Regards,
Pm
   
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All,

Here is a different driving scheme for the parametric charging circuitry.  IMO, this is just a reactive to real converter with a parametric "C" for resonance.  Other that that , I'm not going to comment except to say that the load resistance is 7.451k ohms.

Pm

  First - thank you for making the thread open to the public and thus inviting replications.
   In that same altruistic spirit, is the circuit below your "best" for this approach? 
    -->  Itsu, is this the same circuit you used for your video above? 

   Or, what circuit would you all encourage would-be replicators to begin with?

I really appreciate it - and congratulate your progress (and that of Itsu and others) on this exciting project!

PS - is this device being discussed also on another forum?
   
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  First - thank you for making the thread open to the public and thus inviting replications.
   In that same altruistic spirit, is the circuit below your "best" for this approach? 
    -->  Itsu, is this the same circuit you used for your video above? 

   Or, what circuit would you all encourage would-be replicators to begin with?

I really appreciate it - and congratulate your progress (and that of Itsu and others) on this exciting project!

PS - is this device being discussed also on another forum?


Thanks for your comments!  Actually the circuit I would recommend for replication is the one shown below or in my post #251.  All the tuning instructions are called out there and are important to follow correctly.  It is still unknown (to me at least) as to what makes one mosfet a better candidate over another due to all the variables involved so experimentation is still the rule however, one can parallel as many mosfets as desired which of course increases the magnitude of the parametric "C" thus lowering the frequency and increasing the available energy.

I have also tried 'P' channel mosfets following the thinking of some who value 'hole' or positron flow verses electron or negatron flow but saw no real advantage with the few devices I tested.

Another area of experimentation could be the proper use of powdered iron cores for L1 to take advantage of their inherent increase in permeability with an increase in H field which should broaden the gain operating area.

In regards to the other forums, I haven't seen any serious efforts to measure pin verses pout especially in charging a capacitor but maybe I'm not that thorough.

Regards,
Pm
   

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  First - thank you for making the thread open to the public and thus inviting replications.
   In that same altruistic spirit, is the circuit below your "best" for this approach? 
    -->  Itsu, is this the same circuit you used for your video above? 

   Or, what circuit would you all encourage would-be replicators to begin with?

I really appreciate it - and congratulate your progress (and that of Itsu and others) on this exciting project!

PS - is this device being discussed also on another forum?



PhysicsProf,

Quote
-->  Itsu, is this the same circuit you used for your video above? 

No, that circuit you posted is not the one i used, its like Partzman also mentioned, the one from his post #251
and was linked by him just now.


I am waiting now for some parts (MOSFETs ZVP2106 / ZVN2106 (as in the suggested circuit by Peterae in post #261 above).
I hope i can ommit the power hungry IXDD614 MOSFET driver i am using now, so a feedback loop is more realistic.

Itsu
   

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Buy me some coffee
I hope that works out ok Itsu ;)

Thanks for opening the thread up to the public Partzman, a lot of hard work has been done and will it be interesting to see if other people get interested in the device, I think it must be stated that although there are COP > 1 results that it is still a good possibility there is some sort of measurement error causing these results which is why we have opened the thread up, with the hope others will find the circuit interesting enough to investigate and prove/disprove COP > 1 results, whether by looping or accurate power measurements.
   
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 Thank you PM and Itsu!
  And well said, Peter!

Watching science unfold!
   
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All,

This is a revised schematic of post #251 to help clarify some of the requirements.

Regards,
Pm
   
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