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Re: How to create IEC 61000-4-5 surge waveform in time & s behavioral ?

 

The transfer function and time domain expressions look OK to me but the scope plot is obviously "wrong".
This could be caused by the sample-based Simulink implementation. What is the sample-rate / solver
algorithm? If there is aliasing all three representations could be correct.

-marcel


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 

That's exactly true. YIG are tuned by varying the magnetic field the element is in, hence the coils. This also defines the dynamic behaviour.

--
Regards,
Tony?

On 17 Mar 2025 05:06, "Andy I via groups.io" <AI.egrps+io@...> wrote:
On Sun, Mar 16, 2025 at 09:13 AM, Tony Casey wrote:
Typically, the TUNE coil will be 10s of mH and FM coil will be about 10uH. ...
This implies that both inputs might respond to current, unless the TUNE coil has enough resistance which is stable and predictable.
?
Andy
?


Re: How to create IEC 61000-4-5 surge waveform in time & s behavioral ?

 

In simple words, ...
The user's fault or math's fault ?
?
Beg your pardon first, so noisy, definitely my fault.
?
In fact, my default thoughts is 99% belong to user's fault, but I don't know what's wrong.
?
If any hint,?
?
Thank you very much.


Re: How to create IEC 61000-4-5 surge waveform in time & s behavioral ?

 

Hi, :
?
You know what ? I'm surprised about I do have the memory about using this in Matlab.
It got the same result. I worship the math as some kind of religion, but this time, I can't get the desired answer, what's going on ?
?
Is the math wrong ?
?
Can someone tell any configuration wrong ? It almost broke my religion. Hope someone recognize it.
?
I am wondering, how many people are you here...
?
Wish you all happy & healthy.
?
Best regards.


Re: proper way to simulate fluctuating load for voltage regulator

 

aside: please note that for time-varying resistors, the theoretical circuit equations will change and new derivative terms for (otherwise fixed) component parameters will enter into your equations. this may worry if not considered.


New LTspice 24

 

Hi
I have LTspice XVII installed in the directory:
C:Program files\LTC\LTspice XVII
Is it safe to install LTspice 24? so that I keep my old Auto_Genrated models?
Can you please advise? is the new LTspice 24 any better ?
Regards,
Suded


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 

On Sun, Mar 16, 2025 at 09:13 AM, Tony Casey wrote:
Typically, the TUNE coil will be 10s of mH and FM coil will be about 10uH. ...
This implies that both inputs might respond to current, unless the TUNE coil has enough resistance which is stable and predictable.
?
Andy
?


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 

On Sun, Mar 16, 2025 at 05:15 AM, john23 wrote:
How sould I use MODULATE to define this unique behavior?
john23,
?
I uploaded "YIG VCO.asc" to the "Temp" directory.? It models what you apparently wanted.? It has two inputs and one output.
?
The "Coarse" input is for your "TUNE" signal that sets the center frequency.? The "Fine" input is for your "FM" signal that modulates its frequency around the center.? Both inputs have infinite bandwidth.
?
Both inputs are ideal, so you should add whatever is needed to model each of their electrical characteristics:
  • The "Coarse" (or Tune) input is infinite impedance.? If you know its input impedance, connect it in parallel, between the two input pins.
  • The "Fine" (or FM) input is zero impedance.? If you know its input impedance, connect it IN SERIES with that input.
  • In simulations, both inputs should be given a ground reference, not left floating.
  • Both inputs have infinite bandwidth.? Add your own filtering if needed.
The output is +10 dBm when terminated in an external 50 ohms load.? The schematic I uploaded has a 50 ohm load, so remove that when driving something else that provides a termination.
?
Andy
?


Re: How to create IEC 61000-4-5 surge waveform in time & s behavioral ?

 

On Fri, Mar 14, 2025 at 06:35 PM, Tony Casey wrote:
On 14/03/2025 11:30, Andy I via groups.io wrote:
Tony uploaded "IEC_61000-4-2_Test.zip", but it has a symbol that LTspice might not have and can't be opened in older versions.
Oops. Zip file updated with symbol.

--
Regards,
Tony
?
?
Just to note, in the latest LTspice 24.1.5, it will have the following message... It seems 'SCOPEDATA=' is forced to replace the 'file='.
Looks like, compatible issue between newer & older...was used to the older XVII...
?
"Monotonically increasing value expected. You may want to use SCOPEDATA=<filename> instead. (See the LTspice help for more details.)
1.00E-09,0.9088###>
1.00E-09<###,0.9110"
?
And, Thanks for the inspiration of varistors.


Re: Parts Number Re-numbering

 

On Sun, Mar 16, 2025 at 07:48 PM, Hidehiko Komachi - JA9MAT wrote:
I heard "shift+ctrl+alt+R" is available.
But no change appear.
Did anything happen?? Was there a pop-up window asking you to confirm?
?
If no pop-up window, then perhaps you were not using Windows, or another program intercepted that key combination, or you had another key accidentally pressed or missed one of the four.? When I tried it just now, my first two attempts failed to make the pop-up window, but I tried again - more carefully - and it worked.
?
After that, a change can happen only if the part numbers need to be re-numbered.? If they are already numbered the way it wants, you won't see anything change after clicking OK in response to the pop-up confirmation.
?
If you have a small number of parts, you can change them one at a time, of course.
?
Andy
?


Re: Parts Number Re-numbering

 

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Right-click on the number, such as R1. An editing pane opens where you can change it to anything you like, within reason.

On 2025-03-16 23:36, Hidehiko Komachi - JA9MAT via groups.io wrote:
Sorry for FAQ.
How can I renumber the parts number?
I heard "shift+ctrl+alt+R" is available.
But no change appear.
?
Hidehiko JA9MAT.
--
OOO - Own Opinions only If something is true: * as far as we know - it's science *for certain - it's mathematics *unquestionably - it's religion

Virus-free.


Parts Number Re-numbering

 

Sorry for FAQ.
How can I renumber the parts number?
I heard "shift+ctrl+alt+R" is available.
But no change appear.
?
Hidehiko JA9MAT.


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 

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On 16/03/2025 13:31, Andy I via groups.io wrote:
Two ports, really?? I count three.
?
Add the Tune and FM inputs, to produce a single frequency-controlling voltage.? You have many ways to add signals, including a B-source.? You need to decide on the input resistance to use, for your Tune and FM ports.
?
Then connect their sum, to the FM input of the MODULATE component.
?
Set it's Mark and Space parameters to have the right scale (1.2 GHz/V) and offset.? This is simple Algebra.? It's very basic.
?
Depending on what john23 is wanting to model, it might be necessary to actually model the TUNE and FM circuits. They are both connected to coils internally, so the inductances might need to be included, particularly if the YIG oscillator is in a frequency control loop or synthesiser. Typically, the TUNE coil will be 10s of mH and FM coil will be about 10uH. (They also normally have internal heaters too, with additional connections, but that has not been mentioned.)

Coo, this brings backs memories from the 1980s.

--
Regards,
Tony


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 
Edited

Two ports, really?? I count three.
?
Add the Tune and FM inputs, to produce a single frequency-controlling voltage.? You have many ways to add signals, including a B-source.? You need to decide on the input resistances to use, for your Tune and FM ports.
?
Then connect their sum, to the FM input of the MODULATE component.
?
Set its Mark and Space parameters to have the right scale (1.2 GHz/V) oops! (0.7 GHz/V) and offset.? This is simple Algebra.? It's very basic.
?
Andy


Re: defining special kind of behavioral for current controlled oscilator in ltspice

 

Hello , My device has two ports .I have tested? its functionality in the lab and I saw the following behavior:
1. no voltage? on both ports-> output is 8GHz? 10dBm
2. 2V on tune ->output is 9.4Ghz 10dBm
3.each 1mA on FM input is adding 100Khz.
How sould I use MODULATE to define this unique behavior?
Thanks.


Re: "Physical" PTC model

 

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Take a look at the files I just uploaded to Files/Temp

A simple implementation of what I believe is a corrected form of Pascal's thermal expression,

?

Dave

?

From: [email protected] <[email protected]> On Behalf Of pilou via groups.io
Sent: Saturday, March 15, 2025 1:11 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] "Physical" PTC model

?

Thanks a lot for all your message.

But, excuses me for my ignorance, all theses modification have to be done in the model ?

Sorry but I don't know where.

Maybe can you upload your files ?

Thanks a lot in advance


Re: "Physical" PTC model

 

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We would have a MUCH better idea of exactly where to apply them, if YOU would upload YOUR models.

?

?

From: [email protected] <[email protected]> On Behalf Of pilou via groups.io
Sent: Saturday, March 15, 2025 1:11 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] "Physical" PTC model

?

Thanks a lot for all your message.

But, excuses me for my ignorance, all theses modification have to be done in the model ?

Sorry but I don't know where.

Maybe can you upload your files ?

Thanks a lot in advance


Re: "Physical" PTC model

 

Thanks a lot for all your message.
But, excuses me for my ignorance, all theses modification have to be done in the model ?
Sorry but I don't know where.
Maybe can you upload your files ?
Thanks a lot in advance


Re: "Physical" PTC model

 

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Oh, I forgot, you don’t need parentheses around emax, either

?????????????? V={1/(1/emax+0.5*(1+tanh((v(tptc)-ts)/c)))}

?

From: [email protected] <[email protected]> On Behalf Of Bell, Dave via groups.io
Sent: Saturday, March 15, 2025 12:05 PM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] "Physical" PTC model

?

Maybe some help, Pascal:

?

I got this to compile and “run” without errors, as below:

First, to fill in some unknown values:

?????????????? .params emax=10 c=5 ts=2

Made a voltage source to create and set a value for node “tptc”

?

Then applying your equation to a behavioral voltage source (BV) in the F2 menu:

?????????????? V={1/(1/(emax)+0.5*(1+tanh((v(tptc)-ts)/c)))}

(This syntax didn’t work with a normal V source.)

?

One set of curly braces surrounding everything that needs to be evaluated at run time.

Removing the square brackets? around “v” in v(tptc)

?

The BV source put out about 902mV, if that makes any sense in your circuit…

?

Dave

?

?

From: [email protected] <[email protected]> On Behalf Of pilou via groups.io
Sent: Saturday, March 15, 2025 11:16 AM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] "Physical" PTC model

?

On Sat, Mar 15, 2025 at 11:07 AM, John Woodgate wrote:

I can tell you that the error messages do not mean that there is a problem with the simulation. For example, a node connected only to a current source, which has infinite impedance, appears? not to be connected to anything.

Hello,

thanks a lot for your reply,

Ok I understand, it seems logical.

But how about the

Error: undefined symbol in: "1/(1/(emax)+0.5*(1+tanh(([v](tptc)-(ts))/(c))))"

?

?


Re: "Physical" PTC model

 

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Maybe some help, Pascal:

?

I got this to compile and “run” without errors, as below:

First, to fill in some unknown values:

?????????????? .params emax=10 c=5 ts=2

Made a voltage source to create and set a value for node “tptc”

?

Then applying your equation to a behavioral voltage source (BV) in the F2 menu:

?????????????? V={1/(1/(emax)+0.5*(1+tanh((v(tptc)-ts)/c)))}

(This syntax didn’t work with a normal V source.)

?

One set of curly braces surrounding everything that needs to be evaluated at run time.

Removing the square brackets? around “v” in v(tptc)

?

The BV source put out about 902mV, if that makes any sense in your circuit…

?

Dave

?

?

From: [email protected] <[email protected]> On Behalf Of pilou via groups.io
Sent: Saturday, March 15, 2025 11:16 AM
To: [email protected]
Subject: EXTERNAL: Re: [LTspice] "Physical" PTC model

?

On Sat, Mar 15, 2025 at 11:07 AM, John Woodgate wrote:

I can tell you that the error messages do not mean that there is a problem with the simulation. For example, a node connected only to a current source, which has infinite impedance, appears? not to be connected to anything.

Hello,

thanks a lot for your reply,

Ok I understand, it seems logical.

But how about the

Error: undefined symbol in: "1/(1/(emax)+0.5*(1+tanh(([v](tptc)-(ts))/(c))))"

?

?