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Re: 74hc_v.lib file
Eric asked about the file "74hc_v.lib", needed in a downloaded simulation. I don't know if you found the answer to your question already (the replies I received might not be in order).? However, the file you were looking for is in the group's Files, here: ? ? Files > Lib > Digital 74HCxxx > 74HC_v.lib ? ? I remind people to try the "Table of Contents" file (all_files.htm) when something like this is needed. By the way -- the schematic uses the 74HC194 but not the original/bipolar 74194, despite the name of the schematic.? I guess that schematic was an answer to someone's question and you'd have to go back to that question (99370) if you wanted to see why the names didn't agree. Regards, Andy |
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Re: Saving and restoring inductor current
Hello analogspiceman. ? Thank you for enlightening me. I added the following to my collection of models: ? .subckt Lrememb 1 2? .param ? L=1 Rser=1m Rpar=1/Gmin ic=0 C1 3 0 {L} Rser={1/Rpar} Rpar={1/Rser} ic={ic} G1 1 2 3 0 1 G2 3 0 2 1 1 .ends Lrememb ? Bordodynov. 27.11.2018, 04:52, "analogspiceman@... [LTspice]" <ltspice@...>:
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Re: 74hc_v.lib file
Hi Eric. I opened your circuit and everything was modeled. I just did: .tran 0 10m 0 uic I have installed libraries in ../Documenty/LTspiceXVII/ .. You can find it on my page: ? Bordodynov 27.11.2018, 04:51, "eohenares@... [LTspice]" :
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Re: 74hc_v.lib file
Hi Helmut, I'm sorry I found the 74hc595 in the files which will also do and has both the .asy and .lib files. Pls no need to send the .lib of the 74194. Thanks and best regards, Eric
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74hc_v.lib file
Hi Helmut, Do you happen to have still the "74hc_v.lib file" used in the "74194 test.asc" schematic? It is not inside the zip file so I could not load it into the "sub" directory. The schematic would not run and is looking for it. I tried working through your instruction how to convert a .asc file into .lib but was too heavy for me. I reloaded the file dated Nov 19, 2016 for reference. I wrote an ealier email but seems did not go thru. Thanks and best regards, Eric ? ? ? ? ? ? ? ? ? ? ? ? |
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74hc_v.lib file
Hi Helmut, Do you happen to have the "74hc_v.lib" file that is in the "74194 test.asc" schematic? I reloaded the file of? Nov 19, 2016 for reference. The actual .lib file is not in the zip that I could load to my "sub" directory. So it would not run I tried working through your instruction to convert a .asc to a .lib file but just too heavy for me.? Thanks and best regards, Eric |
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Saving and restoring inductor current
LTspice can save and restore node voltages, but not branch currents.? This means that by using ".savebias time=<tstop>" and ".loadbias" a simulation with inductors is only partially saved and restored because inductor currents are ignored.? It occurred to me that by making a "dual inductor" using current sources and a capacitor, one might trick LTspice into saving "inductor" currents.? The inductor dual is very simple and can be a subcircuit with the inductor symbol edited to represent the dual inductor with the expected symbol. .subckt L 1 2 .param L=1 Rser=1m Rpar=1/Gmin C1 3 0 {L} Rser={1/Rpar} Rpar={1/Rser} G1 1 2 3 0 1 G2 3 0 2 1 1 .ends L This seems to work well and each run picks up where the previous run left off.? Here is a test simulation. V1 1 0 1 AC 1 Don't how this compares speed-wise and coupled inductors would require an extension, but this technique might prove useful in certain stepped simulations that could run much quicker if the operating point did not need to be refound each time. |
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hi, Andy:
Before your explanation, I didn't notice "complex logarithm" is a special case, maybe not supposed to be supported by any SPICE. About the compression application, I didn't really have the complete idea, maybe it would be like the,.... For example, when someone reading a book, the edge on every page often empty, and be used to sketch some thing on, some graphs/pictures to decorate the layout of the page. They often are not the primary parts. To analogy, if there are some main data, which typically are numerical values, and has its general scale on the range of greater than 0.01, though its format could support to very least 1e^-16, or some, such that, maybe I could merge those loged numbers secretly into the "main data", and leak .... to somewhere who concern it, without interference others who typically don't care those smaller values which is under 0.01. Just some ignorant ideas. I didn't implement it yet. Best regards. ---In LTspice@..., <ai.egrps@...> wrote : ericsson.sunshine wrote: ? ? "LTspice couldn't treat the negative value of nature log very well, which normally return the complex value ..." ? ? "LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world." I think most people here understand this: "The natural logarithm function ln(x) is defined only for x>0.? So the natural logarithm of a negative number is undefined."? Undefined means it has no defined value when x is negative, or zero.? I think in math, this would be represented by NaN (but I might be wrong). The "complex logarithm" is an extension to complex numbers, but it differs from an ordinary logarithm.? Perhaps you work in a math world that treats the complex logarithm as a normal logarithm function, but I think most of us engineers do not.? The logarithm functions in LTspice are not defined to be complex logarithms, therefore one should not expect them to behave as complex logarithms; they are the ordinary variety of logarithm functions, which are undefined for negative arguments.? The exponential function exp() is not the inverse of the complex logarithm function. Maybe it would help to understand what you are trying to accomplish.? I understand that you may be interested in compressing a wide dynamic range into a smaller one; but is this for signal processing?? Waveform visualization?? Theoretical analysis of non-physical signals or entities?? (Not that I'm asking for my own sake.? But it helps to know where one is going, before making the first steps, and finding that one has stepped into a hole.) Regards, Andy |
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Adding Potentiometer
Hey guys I¡¯m totally new to LTspice. I¡¯m using it to build guitar tube amps. One thing I need is to add a potentiometer. I tried following the help text file but could not get the potentiometer to actually work. I amable to use the symbol but that is as far as I¡¯ve gotten. I don¡¯t know how to install the .lib file to get it to work. I¡¯m sure this is very easy for everyone here but not for me as I am completely new to the program. If someone could provide a step by step instruction on how exactly to go about adding a potentiometer to LTspice I would greatly appreciate it. Thanks!
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Adding A Potentiometer
Hey guys I'm totally new to LTspice. I'm using it to build guitar tube amps. One thing I need is to add a potentiometer. I tried following the help text file but could not get the potentiometer to actually work. I am able to use the symbol but that is as far as I've gotten. I'm sure this is very easy for everyone here but not for me as I am completely new to this program. If someone could provide a step by step instruction on how exactly to go about adding a potentiometer to LTspice I would greatly appreciate it. Thanks! |
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How To Add Potentiometer
Hey guys, I'm totally new to LTspice. I'm using it for building guitar tube amps. I really need to add a potentiometer to LTspice. I'm sure it is probably simple to everyone here but not to me. I read the help text file and I'm not able to get the potentiometer to actually work. If someone can please help with this I would greatly appreciate it. I would like a step by step guide on how exactly I go about adding a potentiometer. As far as I could get is being able to use the symbol. But I can't figure out how to add the .lib file and have the potentiometer actually work. Again, if I could get a step by step explanation on how exactly to add a working potentiometer that would be awesome. Sorry if I sound like such a newbie, because I am. thanks! |
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Re: LTspice model for capacitor start single phase motor
¿ªÔÆÌåÓýTry these links: ? ? ? ? ? ? ? ? From: LTspice@... [mailto:LTspice@...]
Sent: Thursday, November 22, 2018 6:17 PM To: LTspice@... Subject: [LTspice] Re: LTspice model for capacitor start single phase motor ? ? just trying to study how to proper run/ start a single phase motor with a inverter, I already have the inverter model , but seems have problem with the motor model with speed/torque. ? I can find a two phase motor and three phase examples. but nut sure how to build a single phase one. ? any example of single phase motor would be very helpful ? thanks!! |
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Re: Dark lines on light screens was : LTSpice Model for Photo Triac - VOM160
Jim wrote:
"My assumption of the reason I like it, is that the increased overall light level, causes the pupil to shrink, giving you better visual acuity & focus. YMMV" Yup, makes sense. It used to be that all computer CRTs were green or white on black. In my workplace I was one of few (early adopters?) who inverted the colors to make it look more like a printed page. Andy |
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Dark lines on light screens was : LTSpice Model for Photo Triac - VOM160
¿ªÔÆÌåÓý¡°What I do even differently from you, is to use a white (or
very light grey) background. I'm not the only one doing that. I am not sure why I like dark waveforms on a light background, because oscilloscopes didn't do that; but I find it more pleasing to my eye.¡± My assumption of the reason I like it, is that the increased overall light level, causes the pupil to shrink, giving you better visual acuity & focus. YMMV
More of an issue for me with cad files, yellow on black?? Why ???????.? Give me dark blue on white, or light grey any day.
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R James (Jim) Klessig P.E. | Senior Power Systems Engineer |
Electrical Reliability Services, VERTIV jim.klessig@..., jim_klessig@... 1876 Gwin Rd, Mckinleyville | CA | 95519 | USA | Cell (707) 497-9611 | eFax 614-410-0653 ?
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
ericsson.sunshine wrote: ? ? "LTspice couldn't treat the negative value of nature log very well, which normally return the complex value ..." ? ? "LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world." I think most people here understand this: "The natural logarithm function ln(x) is defined only for x>0.? So the natural logarithm of a negative number is undefined."? Undefined means it has no defined value when x is negative, or zero.? I think in math, this would be represented by NaN (but I might be wrong). The "complex logarithm" is an extension to complex numbers, but it differs from an ordinary logarithm.? Perhaps you work in a math world that treats the complex logarithm as a normal logarithm function, but I think most of us engineers do not.? The logarithm functions in LTspice are not defined to be complex logarithms, therefore one should not expect them to behave as complex logarithms; they are the ordinary variety of logarithm functions, which are undefined for negative arguments.? The exponential function exp() is not the inverse of the complex logarithm function. Maybe it would help to understand what you are trying to accomplish.? I understand that you may be interested in compressing a wide dynamic range into a smaller one; but is this for signal processing?? Waveform visualization?? Theoretical analysis of non-physical signals or entities?? (Not that I'm asking for my own sake.? But it helps to know where one is going, before making the first steps, and finding that one has stepped into a hole.) Regards, Andy |
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Re: Using BV exp(), log() for numerical compression ,wrong result ?
Hi, Helmut:
Thank you for the suggestions, but if I use the IF() as you mentioned, x couldn't be recovered as it was before compression. But your answer seems LTspice couldn't treat the negative value of nature log very well, which normally return the complex value, eg: log(-2) =?0.6931 +? 3.1416i. As I said, LTspice couldn't see the complex (imaginary) parts. And treat it very well, as it should be treated in the normal math world. Though I found another solution, it's using the dc-bias in the source signal, after recovered it, eliminate the dc-bias, this could be done well, too. But I am thinking, why LTspice couldn't treat those math functions equal-footing, alternatively, some math functions are biased, while some are? "NOT SUPPORTED/PARTLY SUPPORTED". Is it fair , unfair ? Best regards, ---In LTspice@..., <helmutsennewald@...> wrote : Hello, You have used log() from negative numbers. Normal calculators will fail in this case. I recommend to use an IF() to workaround. V=IF(V(x)<1e-6,0,log(V(x)) Be aware that log() is the same as ln(). log10() is the logarithm base 10. Best regards, Helmut |
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Re: CD4060 and CD4063 LTSpice models needed
¿ªÔÆÌåÓý4063 is a 4-bit magnitude comparator (for
comparing the dimensions of 1 dollar bills?), so is a purely
digital device and not very suitable for Spice simulation at
all. Best wishes John Woodgate OOO-Own Opinions Only J M Woodgate and Associates Rayleigh, Essex UK On 2018-11-26 04:34, Andy
ai.egrps@... [LTspice] wrote:
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John Woodgate