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Author Topic: Itsu's workbench / placeholder.  (Read 107680 times)

Group: Renaissance Man
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Dear Nelson.

I'm truly sorry to read of your news.

Please accept our deepest condolences.

Kind regards, Graham and Jules.


---------------------------
Nanny state ? Left at the gate !! :)
   
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Hi Nelson,

Sorry to hear about your loss, my condolences to you and yours.

Kind regards
Gyula
   

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Nelson,

i am also very sorry to hear about your loss, my condolences.

Thanks for still taking the time to explain some things.

Stay safe,   regards itsu
   

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Itsu,

One explanation that may provide the answer is that as far as I can see, the parameter list for BJTs in  LtSpice does not include any parameters for the emitter-base negative resistance region nor the typical zener voltage breakdown under reverse bias conditions.  Lacking these parameters could/would affect the simulation IMO.

For example in my sim with the output shorted, when Q1 has 42v peak on the emitter, the base voltage is 23.53v peak, and the collector is 23.03v peak.  The voltage differential between the reverse biased base-emitter junction is far above a normal NPN which would typically zener at ~7-9v. 

Also with the base-collector junction forward biased, in years past this would have been termed an "inverted" operation for the NPN.  IOW, with the b-c forward biased and the b-e reversed biased, the roles of the emitter and collector have been switched or inverted.  Most BJTs will operate in this manner although the performance is greatly reduced.

So without an accurate model for the BJT, it may not be possible to simulate Nelson's circuit accurately.

Regards,
Pm

Partzman,

thanks for the info, i do indeed read that most BJT's do not include any parameters for the emitter-base negative resistance region nor the typical zener voltage breakdown under reverse bias conditions.

This begs the question, could it be that Nelson has a partially defective transistor in his circuit.

If so, that could explain the differences between my replication and his original and the fact that the sim now shows similar effect as the original.

I also means that a working replication would be virtual impossible.

Far fetched i know, so i will continue to work on my circuit to get the effect to manifest.


Regards Itsu
   

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BTW: What were you doing there? Were you checking into Lanca's recuperation at the asylum, perhaps.
Just curious what are you up to and some of the remaining goodies there.
Lanca is something else. He has a real gift for friendly disruption or is an AI.
   
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Nelson,

I too wish to express my condolences for your most recent loss.  These are difficult times I'm afraid.

Also, thank you for responding to my post.  I will comment later at a more appropriate time.

Regards,
Pm
   
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Hi Partzman,

In the Help section of LTspice, this is written on the bipolar transtor model description:

The model parameter "level" can be used to specify another type of BJT in LTspice.

Set Level=504 to use the MEXTRAM 504 transistor due to NXP(Philips). 

Due to a generous contribution of source code from Dr.-Ing. Dietmar Warning of DAnalyse GmbH, Berlin, Germany; LTspice includes a version of VBIC. Set Level=9 to use the alternate device. Level 4 is a synonym for level 9. The following documentation has been supplied by Dr. Warning:

VBIC - Vertical Bipolar Inter Company model

The VBIC model is a extended development of the Standard Gummel-Poon (SGP) model with the focus of integrated bipolar transistors in today's modern semiconductor technologies. With the implemented modified Quasi-Saturation model from Kull and Nagel it is also possible to model the special output characteristic of switching transistors. It is a widely used alternative to the SGP model for silicon, SiGe and III-V HBT devices.

VBIC Capabilities compared to Standard Gummel-Poon Model

o Integrated Substrate transistor for parasitic devices in integrated processes

o Weak avalanche and Base-emitter breakdown model

o Improved Early Effect modeling

o Physical separation of Ic and Ib

o Improved Depletion capacitance model

o Improved temperature modeling

The question now is  where the parameters for this VBIC extended model can be obtained and applied.  Of course this may still not give real life transistor models.  And maybe these parameters were for internal company use only and the possibility for using them just remained inside the source code.

If you or anyone else can address these questions, please tell.

Gyula
   
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Buy me a drink
I want to thank you all very much for your words of comfort from heart.
Thanks


---------------------------
Best Rewards
Nelson Rocha

" The goal is not to be successful, the goal is to be valuable.
Once you’re valuable, instead of chasing success,
it will attract itself to you. "
   
Group: Experimentalist
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Hi Partzman,

In the Help section of LTspice, this is written on the bipolar transtor model description:

The model parameter "level" can be used to specify another type of BJT in LTspice.

Set Level=504 to use the MEXTRAM 504 transistor due to NXP(Philips). 

Due to a generous contribution of source code from Dr.-Ing. Dietmar Warning of DAnalyse GmbH, Berlin, Germany; LTspice includes a version of VBIC. Set Level=9 to use the alternate device. Level 4 is a synonym for level 9. The following documentation has been supplied by Dr. Warning:

VBIC - Vertical Bipolar Inter Company model

The VBIC model is a extended development of the Standard Gummel-Poon (SGP) model with the focus of integrated bipolar transistors in today's modern semiconductor technologies. With the implemented modified Quasi-Saturation model from Kull and Nagel it is also possible to model the special output characteristic of switching transistors. It is a widely used alternative to the SGP model for silicon, SiGe and III-V HBT devices.

VBIC Capabilities compared to Standard Gummel-Poon Model

o Integrated Substrate transistor for parasitic devices in integrated processes

o Weak avalanche and Base-emitter breakdown model

o Improved Early Effect modeling

o Physical separation of Ic and Ib

o Improved Depletion capacitance model

o Improved temperature modeling

The question now is  where the parameters for this VBIC extended model can be obtained and applied.  Of course this may still not give real life transistor models.  And maybe these parameters were for internal company use only and the possibility for using them just remained inside the source code.

If you or anyone else can address these questions, please tell.

Gyula

Gyula,

Very informative post!  I was not aware of the VBIC model levels available for bipolars.  I am a member of the LtSpice forum and will see if I can question the members on obtaining any info on the use of VBIC as there are some really knowledgeable people there.

Regards,
Pm
   

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Enjoy your trek through life but leave no tracks
Nelson, I’ve just learnt of your loved ones lose, pleas accept my deepest condolences at this uncertain time I sincerely wish you well.

AG


---------------------------
Be aware I'm moderated because I complained about persistent trolls to Chet, folowing me round and got same treatment as perpetrators..This is the third time, You aint doing this again.
   

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I am kind of stuck with this at the moment.

Nothing that i do seem to have any positive influence on the output current, it always stays at max. 10mA or so, not lightning up the output bulb.

A last resort would be to put the circuit on a PCB instead of a breadboard.

Itsu
   
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I am kind of stuck with this at the moment.

Nothing that i do seem to have any positive influence on the output current, it always stays at max. 10mA or so, not lightning up the output bulb.

A last resort would be to put the circuit on a PCB instead of a breadboard.

Itsu


Hello Itsu, what a pity that you still haven't made any progress in relation to the circuit. I wish I could help you more, but right now I don't have many ideas that I can help you move forward.
As I told you initially when we start debunking the circuit, I don't care if necessary, send the circuit by mail to you, so that you can analyze it personally, as you have tools that could help you better understand the circuit, and check the possibility of see  any possible anomaly or even to be replicated . 

I did not want to modify the original circuit, for fear of damaging something, in fact today I broke the terminals of the small lamp at the entrance :( when do some tests ,  but i confirm that even without the serial lamp on the (input), the circuit work normally, showing the same effect.  I will try a resistor in series with the input to see some possible change on input , the resistor should not have the same fluctuation in resistance like the small bulb face to their linearity  .
Is there a test that you want me to do in particular on the circuit? I could do just ask.

Thanks by your  availability in this theme.




---------------------------
Best Rewards
Nelson Rocha

" The goal is not to be successful, the goal is to be valuable.
Once you’re valuable, instead of chasing success,
it will attract itself to you. "
   

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Hi Nelson,

Thanks for the offer to send the circuit to me for investigation, we can keep that in mind if needed.
Also good to know that without the input bulb, things are behaving the same.

Let me put the circuit i have now on a PCB to see if it makes any difference (stray capacitance).

I cannot think of any other test to do other then trying to loop it to see what is going to happen.

regards Itsu
   
Group: Professor
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Hello Itsu, what a pity that you still haven't made any progress in relation to the circuit. I wish I could help you more, but right now I don't have many ideas that I can help you move forward.
As I told you initially when we start debunking the circuit, I don't care if necessary, send the circuit by mail to you, so that you can analyze it personally, as you have tools that could help you better understand the circuit, and check the possibility of see  any possible anomaly or even to be replicated . 
-->  THIS IS AN AWESOME OFFER TO SPEED THE PROGRESS OF THIS NOTABLE DEVELOPMENT! THANK YOU, NELSON.

"I did not want to modify the original circuit, for fear of damaging something..
-->>  EXCELLENT POINT, TO KEEP THE ORIGINAL CIRCUIT.

Is there a test that you want me to do in particular on the circuit? I could do just ask.
-->>  ANOTHER GOOD IDEA, THANK YOU, NELSON.

Thanks by your  availability in this theme.
   
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Buy me a drink


PhysicsProf ,
Thanks I appreciate that you recognize my sincerity and delivery on this topic.
I really don't know yet if is a Notable Development like you say , but hope could be , because it will be another great reason to motivate and keep some hope in the enthusiast of this theme OU that I sincerely feel that they are unmotivated in last times .

Many thanks by your support







---------------------------
Best Rewards
Nelson Rocha

" The goal is not to be successful, the goal is to be valuable.
Once you’re valuable, instead of chasing success,
it will attract itself to you. "
   

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I have put the circuit on a PCB as close to what Nelson has.

I had to move the switch input signal to "outside" the E1 bulb, so direct on the input voltage as it kept on blowing to bulb during start (switch on).

With the fixed 2 base resistors (330 and 3.9K parallel, so 303 ohm) i could not get it to oscillate without shorting the output, so i replaced them with a 500 Ohm potmeter.

Now after some tuning i got it running both without shorting the output as with shorting the output.
 
But the signal levels do not match the ones shown by Nelson.

I have 500Vpp on the emitter unshorted (192Vpp shorted) and 450V dc out unloaded, so way higher voltages.

Also input current is double that of Nelson with 70mA @ 24V.

But the good news is that when shorting the output i have much more current then with the breadboard version and the input current drops when shorting like Nelson showed.
Its 37mA out when shorting at 38mA in (so input current halfs).

Anyway, i blew up my matching input bulb, so have to replace it tomorrow to see the difference in lights.

Video here: https://www.youtube.com/watch?v=t-orpEbEzWY&feature=youtu.be

Question; is the switch input really behind the E1 bulb like the diagram shows or is it directly on the input voltage?


Lateron i found out that when i lower he input voltage to 15V, the input current drops to 30mA and the unloaded output voltage is 240V.
When then shorting the output the input current drops to 22.1mA and the output goes to 22.4mA!

The potmeter value was set to 120 Ohm during the tests.
 

Itsu
« Last Edit: 2020-05-10, 21:27:34 by Itsu »
   
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Buy me a drink
I have put the circuit on a PCB as close to what Nelson has.

I had to move the switch input signal to "outside" the E1 bulb, so direct on the input voltage as it kept on blowing to bulb during start (switch on).

With the fixed 2 base resistors (330 and 3.9K parallel, so 303 ohm) i could not get it to oscillate without shorting the output, so i replaced them with a 500 Ohm potmeter.

Now after some tuning i got it running both without shorting the output as with shorting the output.
 
But the signal levels do not match the ones shown by Nelson.

I have 500Vpp on the emitter unshorted (192Vpp shorted) and 450V dc out unloaded, so way higher voltages.

Also input current is double that of Nelson with 70mA @ 24V.

But the good news is that when shorting the output i have much more current then with the breadboard version and the input current drops when shorting like Nelson showed.
Its 37mA out when shorting at 38mA in (so input current halfs).

Anyway, i blew up my matching input bulb, so have to replace it tomorrow to see the difference in lights.

Video here: https://www.youtube.com/watch?v=t-orpEbEzWY&feature=youtu.be

Question; is the switch input really behind the E1 bulb like the diagram shows or is it directly on the input voltage?


Lateron i found out that when i lower he input voltage to 15V, the input current drops to 30mA and the unloaded output voltage is 240V.
When then shorting he output the input current drops to 22.1mA and the output goes to 22.4mA!

The potmeter value was set to 120 Ohm during the tests.
 

Itsu

Hi Itsu ,
Very thanks by your efforts that you put in this project .
I am happy, that somehow things start to make sense in the replication of the circuit and start to get more positive results.
I am sure that this result will further pique your curiosity and that should be a motivation to better results should be on the way.
About the switch:
The switch  input is really behind the E1 bulb, In my case at this momment, not because of the absence of E1 that I broke in an unintended way :) . I’m really happy with your first result’s !
I look forward to new developments;)!


---------------------------
Best Rewards
Nelson Rocha

" The goal is not to be successful, the goal is to be valuable.
Once you’re valuable, instead of chasing success,
it will attract itself to you. "
   
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Hi Itsu,

Very good progress and thanks for your arduous efforts too.  I think if you try to 'fine tune' the 300 Ohm resistor in the base circuit then input current could be reduced and this would then involve a reduction in the unloaded output voltage too when the input voltage is still 24V.

Greetings
Gyula
   
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To all readers here:

A few days ago I stumbled upon another circuit simulator, called Micro-Cap and the catch is that the owner of this software made it avalilable free of charge.    :D   
Note that this simulator used to cost USD 4495 till last November.

 Here is the link to have more info:  http://www.spectrum-soft.com/index.shtm  and you can dowload the full software here:
http://www.spectrum-soft.com/download/download.shtm   

The good news also is that this software includes more realistic transistor models than LTspice does, see this description:
http://www.spectrum-soft.com/demo.shtm   

I used to use a 'cracked' version of Micro-Cap 3 roughly 30 years ago and the protection code was changed back then so I abandoned using it. I will have to get acquinted with this latest version (12) and see how it simulates this oscillator.  It needs time of course.

If any of you wish to play with this software, just go ahead.  IT is very rare a software developer and seller freely gives away his product, maybe he has gone to pension (they started this software in 1980!).

Regards
Gyula
   

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Yesterday i showed that when the output was shorted, the input current and output current on the DMM's are similar (30mA).

The input bulb was not the same as the output bulb, so i could not show the visual difference.


Today i changed the input bulb to be a similar one as the output bulb and found that when shorting the output again, the output bulb got more brighter then the (dimmed) input bulb like Nelson showed in his video's.

The DMM's however showed still similar currents in this shorted situation (30mA), see end of the below video.

To rule out any ohmage difference between the 2 bulbs i put them in series and tested them to be the same, see begin of the below video.

Finaly the scope with current probe showed that the DMM's, at least the one on the output, can not handle the high frequency of the current signals and is way off.


But it also shows that during shorting situation, the input current is 30mA @ 20V and the output current 50mA rms.

Video here:  https://www.youtube.com/watch?v=6vFv_SPGu20&feature=youtu.be


Question now is; can we exploit this somehow? 

Itsu
   
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Buy me a drink
Yesterday i showed that when the output was shorted, the input current and output current on the DMM's are similar (30mA).

The input bulb was not the same as the output bulb, so i could not show the visual difference.


Today i changed the input bulb to be a similar one as the output bulb and found that when shorting the output again, the output bulb got more brighter then the (dimmed) input bulb like Nelson showed in his video's.

The DMM's however showed still similar currents in this shorted situation (30mA), see end of the below video.

To rule out any ohmage difference between the 2 bulbs i put them in series and tested them to be the same, see begin of the below video.

Finaly the scope with current probe showed that the DMM's, at least the one on the output, can not handle the high frequency of the current signals and is way off.


But it also shows that during shorting situation, the input current is 30mA @ 20V and the output current 50mA rms.

Video here:  https://www.youtube.com/watch?v=6vFv_SPGu20&feature=youtu.be


Question now is; can we exploit this somehow? 

Itsu

Now there you are! I hope you feel rewarded for your persistence, and i thank you for you giving to my word’s some credit.
I am very satisfied with your result, and in this way we have two circuits with practically the same behaviors, where we will be able to work and explore the possible potential of it. This should be considered a big little step, Itsu ☺

I think one of the advantages of this circuit is the fact that it does not use the signal generator to generate the signal to oscillation, which could motivate some doubts in persons about the possible introduction of an external source in the liability measurement process .
I really would like help improve and scale this small circuit with you,  because i can :) , but you already know my lack of important equipments to help you At this moment, and by now seems we are a bit alone on this theme with my help and of Gyula . Who know now , some other guys get their hands to Work too ? :)

Thanks and have a good night !



---------------------------
Best Rewards
Nelson Rocha

" The goal is not to be successful, the goal is to be valuable.
Once you’re valuable, instead of chasing success,
it will attract itself to you. "
   
Group: Tech Wizard
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Posts: 1121
....

But it also shows that during shorting situation, the input current is 30mA @ 20V and the output current 50mA rms.


Question now is; can we exploit this somehow? 


Hi Itsu,

Your achievent is amazing, thank you for persistence.

Tomorrow could you check the voltage across the output bulb when the black and red wires are shorted and the 50 mA RMS is flowing in the bulb?

Thanks and good night,
Gyula
   

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Thanks Nelson,  i am glad you are so excited like i am as its so amazing to me how you came up with this.


But lets do some quick input/output power calculations with my above data when in shorted situation (meaning we have the output bulb as a load):

Input power is 20V * 30mA = 0.6W
Output power is 2V * 50mA = 0.1W       (for the 2V see this post/graph: https://www.overunityresearch.com/index.php?topic=3691.msg81145#msg81145)

So efficiency would be 16.6%.


So there still must be a lot of improvement taking place before we are able to try a loopback.



Gyula,   your update seen,   see above.   I will double check/measure tomorrow.


Regards Itsu
« Last Edit: 2020-05-12, 08:51:25 by Itsu »
   
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Hi Itsu,

Thanks for referring back to the earlier graph on the bulbs V-I characteristic. 

Regarding efficiency: we know that no claim was made on "OU" so this is a secondary question now,  I believe. 
There are oscillators with measured 89 - 90% efficiencies (in some cases 92-93%) like Class-E oscillators, here is a link to such:
https://www.researchgate.net/publication/326616551_A_Self-Tuned_Class-E_Power_Oscillator   

But let's stay with Nelson's interesting oscillator.   Could you charge a 470 uF capacitor from the output and monitor input current during the charging process like Nelson showed in his video series? 

Gyula
 
   

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I’m so sorry for your loss Nelson. My heart goes out to you and your family.
   
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