Re: LTspice fails to launch.
I agree. I need to straighten out my onedrive settings
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Tony Casey Sent: Thursday, February 25, 2021 11:23 AM To: [email protected]Subject: Re: [LTspice] LTspice fails to launch. On 25/02/2021 16:33, garyminor@... wrote: I think that your question concerning "Documents\LTspiceXVII\lib
directory tree on your C:\ drive" is the key. For some reason it
wanted to use D:\Onedrive\documents, which wasn't there. I added the
drive and folder, and now it launches. I have some work to do to find
out more about why this is happening, but at least I have some idea of
the problem. Just a word of advice: you should probably avoid running LTspice with your default Schematics folder on Onedrive, if it's in your Documents tree. Onedrive will attempt to synchronise all your .raw files. This has the potential to max out your internet connection as .raw files can be very large and change all the time. -- Regards, Tony
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Hi Donald,
Agree with you, it performing as expected. Regarding increasing voltage, I have bit knowledge of BLDC motor so I thought lets change supply voltage instead of Back EMF for quick check.?
Kind Regards, Jayal Pansuriya?
On Thu, 25 Feb 2021 at 18:38, Donald H Locker < dhlocker@...> wrote: Again, increasing the supply voltage (the V source labelled VHV near the
top right of the schematic; it is set to 24V) will increase the motor
speed (and, consequently, the commutation frequency.)
Changing it to 12V will slow the motor to about half speed; increasing
it to 48V will approximately double the motor speed.
It is a brushless DC motor - speed is controlled primarily by the supply
voltage. Commutation frequency is a function of speed; speed is NOT a
function of commutation frequency. The way to change speed is to change
the supply voltage; commutation frequency will then also change.
Did I mention to change the supply voltage (change it from 24V) to
change the motor's speed?
Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
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On 2021-02-25 1:02 p.m., Jayal Pansuriya wrote:
> Hi Gents,
>
> Thanks for your comments,
>
> Initially, my thought was motor will spin faster by changing commutation
> frequency. Anyways, I have managed to change motor speed by increasing
> input voltage as it is function of Back EMF.?
>
> Appreciate for your comments.?
>
>
> Kind Regards,
> Jayal Pansuriya
>
> On Tue, 23 Feb 2021 at 23:51, Vlad <imbvlad@...
> <mailto:imbvlad@...>> wrote:
>
>? ? ?Hello Jayal
>
>? ? ?> I am have intermediate skill for simulation, just trying to
>? ? ?simulation BLDC
>? ? ?> motor from LTwiki example(
>? ? ?>
>? ? ?<>).
>? ? ?I managed to
>? ? ?> simulation with default parameters but not sure, if I can change
>? ? ?speed or
>? ? ?> commutation frequency.
>
>? ? ?The speed of the simulation is given (mostly) by the models. As for
>? ? ?the parameters, they are there, as long as you know what you're
>? ? ?changing, nobody is stopping you from testing.
>
>? ? ?--
>? ? ?Vlad
|
Again, increasing the supply voltage (the V source labelled VHV near the
top right of the schematic; it is set to 24V) will increase the motor
speed (and, consequently, the commutation frequency.)
Changing it to 12V will slow the motor to about half speed; increasing
it to 48V will approximately double the motor speed.
It is a brushless DC motor - speed is controlled primarily by the supply
voltage. Commutation frequency is a function of speed; speed is NOT a
function of commutation frequency. The way to change speed is to change
the supply voltage; commutation frequency will then also change.
Did I mention to change the supply voltage (change it from 24V) to
change the motor's speed?
Donald.
--
*Plain Text* email -- it's an accessibility issue
() no proprietary attachments; no html mail
/\ <>
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Show quoted text
On 2021-02-25 1:02 p.m., Jayal Pansuriya wrote: Hi Gents,
Thanks for your comments,
Initially, my thought was motor will spin faster by changing commutation
frequency. Anyways, I have managed to change motor speed by increasing
input voltage as it is function of Back EMF.?
Appreciate for your comments.?
Kind Regards,
Jayal Pansuriya
On Tue, 23 Feb 2021 at 23:51, Vlad <imbvlad@...
<mailto:imbvlad@...>> wrote:
Hello Jayal
> I am have intermediate skill for simulation, just trying to
simulation BLDC
> motor from LTwiki example(
> http://ltwiki.org/files/LTspiceIV/examples/Motors\MotorTest01
<>).
I managed to
> simulation with default parameters but not sure, if I can change
speed or
> commutation frequency.
The speed of the simulation is given (mostly) by the models. As for
the parameters, they are there, as long as you know what you're
changing, nobody is stopping you from testing.
--
Vlad
|
Hi Gents,
Thanks for your comments,
Initially, my thought was motor will spin faster by changing commutation frequency. Anyways, I have managed to change motor speed by increasing input voltage as it is function of Back EMF.?
Appreciate for your comments.?
Kind Regards, Jayal Pansuriya
On Tue, 23 Feb 2021 at 23:51, Vlad < imbvlad@...> wrote: Hello Jayal
> I am have intermediate skill for simulation, just trying to simulation BLDC
> motor from LTwiki example(
> ). I managed to
> simulation with default parameters but not sure, if I can change speed or
> commutation frequency.
The speed of the simulation is given (mostly) by the models. As for
the parameters, they are there, as long as you know what you're
changing, nobody is stopping you from testing.
--
Vlad
______________________
v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.
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Luca, this is how I see it:
Temp = the temperature used for this simulation.
Tnom = the temperature that was used to create the model.? Mostly, this means semiconductor models (but it also applies to resistors that have a temperature dependency).
So the transistor's model applies without adjustments when Temp = Tnom.? When the simulation's Temp differs from Tnom, then SPICE/LTspice needs to adjust the transistor formulas because of the difference Temp-Tnom, so that the result is correct for the current simulated temperature = Temp.
An analogy is this:? The normal human body temperature is 98.6F or 37C.? This is our Tnom.? Doctors know what is normal biology for a person at that temperature.? Using a thermometer, you can measure a person's actual temperature, which might not be 98.6F or 37C.? The actual temperature is his/her Temp.? It might be the same as Tnom (in which case we hope the person is healthy), or it might differ from Tnom (in which case the person might be unhealthy because his/her internal systems are not working normally).? Doctors know that a person with a higher or lower Temp has things that behave differently, because of that difference, Temp-Tnom.? If Temp>Tnom, they may have a fever.? If Temp<Tnom, they may have hypothermia.
Andy
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Maybe it will help a bit more to think of these in terms of a linear function:
f(x) = tnom + temp*x
tnom will set the initial value for the function, while temp will
determine the slope.
--
Vlad
______________________
ltspicegoodies.ltwiki.org v2:
quite universal analog/digital filter,
power electronics, signal processing,
easy to work with math functions,
digital models, and rants.
|
Hello Luca temp --> Default temperature for circuit element instances that don't
specify temperature.
tnom --> Default temperature at which device parameters were measured for
models that don't specify this temperature.
I've read the difference between those two parameters but I can't understand
their difference. when the first is used, when the other one is used? If you look in the help under `LTspice > Circuit Elements > R. Resistor`, you'll see a formula that's based on tnom and temp. That tells you that tnom is used to modify the default value for the resistance (or whatever <value> there is), while temp is used to calculate the device's <value> at a certain temperature. -- Vlad ______________________ ltspicegoodies.ltwiki.org v2: quite universal analog/digital filter, power electronics, signal processing, easy to work with math functions, digital models, and rants.
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Re: LTspice fails to launch.
On 25/02/2021 16:33, garyminor@... wrote: I think that your question concerning "Documents\LTspiceXVII\lib directory tree on your C:\ drive" is the key. For some reason it wanted to use D:\Onedrive\documents, which wasn't there. I added the drive and folder, and now it launches. I have some work to do to find out more about why this is happening, but at least I have some idea of the problem. Just a word of advice: you should probably avoid running LTspice with your default Schematics folder on Onedrive, if it's in your Documents tree. Onedrive will attempt to synchronise all your .raw files. This has the potential to max out your internet connection as .raw files can be very large and change all the time. -- Regards, Tony
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Re: LTSpice group question
On 25/02/2021 17:12, Tony Casey wrote: To be fair, this isn't a general design question. It's about SPICE defaults and the applicability of the two temperature keywords. Sorry, I got my threads mixed up. The OP continued his questioning in a separate thread. -- Regards, Tony
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Re: LTSpice group question
On 25/02/2021 16:52, BRUCE108 wrote: Questions should be about the operations of the LTspice simulator, or with respect to particular designs and applications and their interactions with the simulator. This is not properly a forum for generic design questions. To be fair, this isn't a general design question. It's about SPICE defaults and the applicability of the two temperature keywords. -- Regards, Tony
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Re: LTSpice group question
Questions should be about the operations of the LTspice simulator, or with respect to particular designs and applications and their interactions with the simulator. This is not properly a forum for generic design questions.
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Re: LTspice fails to launch.
Andy I,
I think that your question concerning "Documents\LTspiceXVII\lib directory tree on your C:\ drive" is the key. For some reason it wanted to use D:\Onedrive\documents, which wasn't there. I added the drive and folder, and now it launches. I have some work to do to find out more about why this is happening, but at least I have some idea of the problem.
Thanks to all those that responded.
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Hi all
temp --> Default temperature for circuit element instances that don't specify temperature.
tnom --> Default temperature at which device parameters were measured for models that don't specify this temperature.
I've read the difference between those two parameters but I can't understand their difference. when the first is used, when the other one is used?
Thanks
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Re: LTSpice group question
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Re: Change subscription not working
Also, I apologize to Michael for thinking that what he did caused him to be unsubscribed.
Andy
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Re: Change subscription not working
FYI -
We are still trying to figure out what was and is going on with Michael's Groups.io account.
I think we figured out that Michael himself has not caused this to happen.? It might happen as an automatic exchange between computers, without him involved.? The symptoms made it look as if Michael was doing it, but apparently he was not.
Still looking for an answer.......
Andy
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Re: LTSpice group question
Yes, but you will get an occasional snarky answer.? Just ignore those.
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Re: LTSpice group question
? ? "Is it possible to post questions in this group?"
That's what this group is for.
Anyway, that's what you just did.? Sorry, you've used up your quota.? (Kidding!)
Andy
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Hi all Is it possible to post questions in this group? Cheers
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Interesting -- seyedabrishami.se who asked this question has already left the group.
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Tony Casey
Roy McCammon