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Re: The reordering of node numbers makes me crazy - is there a workaround?
To be honest I don't know the answer, but I might make a wild guess that A. it is more efficient, or safer, or something, that when a schematic is edited, to renumber unlabelled nodes as the simplest way to make sure they are all unique; B. the part that does the sim and plots is separate from the schematic editor so that it cannot possibly know beforehand, or be told even, that a node has been 'moved' to a different part of the schematic. I might also hazard a guess that it wasn't originally envisaged that anybody would edit and sim, edit and sim, edit and sim, with the plots window still open all the while, although that's what we do. I.e. by the time of the sim stage the schematic is assumed to be finished? Perhaps we're supposed to always close the plots window before changing it? Although we don't. :D
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Re: Solar cell in Lt spice
heitham_hh
--- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
thank you Helmut for the answer,just two more question : why in I=V(VLUX)*50u you have 50u? and how did you know R2=5? Best regards, Heitham |
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Re: European components
Ops, that didn't turn out that crisp. If you click reply you'll probably see the editing text and then what I tried to post.
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--- In LTspice@..., "per_normann@..." <per_normann@...> wrote:
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Re: European components
There is an other symbol. It's basically the same but with a European resistor symbol instead of the Usa symbol. How would I go about changing the looks of a LTspice-component?
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The symbol I look for looks something like this. | _|_ | | | |<--- |_| | | --- In LTspice@..., "Helmut" <helmutsennewald@...> wrote:
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Re: Worst case analysis
George
Helmut, are there formulas or equations to change those parameters?
On 04/10/2013, at 1:02 a.m., "Helmut" <helmutsennewald@...> wrote:
[Non-text portions of this message have been removed] |
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Re: European components
--- In LTspice@..., "per_normann@..." <per_normann@...> wrote:
Hello, I only know the potentiometer symbols from our Files section. Files > Lib > Potentiometer. You could simply modify one of these symbol. Best regards, Helmut |
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Re: The reordering of node numbers makes me crazy - is there a workaround?
Howie, Brian (Selex ES, UK)
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-----Original Message-----
From: LTspice@... [mailto:LTspice@...] On Behalf Of Panama Mike Sent: 09 April 2013 16:24 To: LTspice@... Subject: Re: [LTspice] Re: The reordering of node numbers makes me crazy - is there a workaround? It is not random whatsoever.? It just reflects that some people haven't really thought about how a schematic represents a circuit -- how nodes actually are depicted and how those lines are not wires but a graphical notation that both ends are the same node. ? Anyone who complains about node-renumbering, should be forced to type in their schematics as net-lists for a few months. Brian -- Brian Howie Systems Engineering Selex ES, A Finmeccanica Company 2 Crewe Road North Edinburgh EH5 2XS (Phone) +44 (0) 131 343 4653 (Email) brian.howie@... www.selex-es.com Don't send me HTML, it may be deleted unread Selex ES Ltd Registered Office: Sigma House, Christopher Martin Road, Basildon, Essex SS14 3EL A company registered in England & Wales. Company no. 02426132 *** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. *** |
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Re: Germanium transistor
Hi John Woodgate.
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Thanks for the info. In my Standard.zip file is 2N242 and germanium transistors 2N2955. Using these models and your information I will make models of transistors AC128 AC127 more believable. Bordodynov. 10.04.2013, 10:19, "John Woodgate" <jmw@...>: In message <367291365570925@...>, dated Wed, 10 Apr 2013, |
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Re: Germanium transistor
John Woodgate
In message <367291365570925@...>, dated Wed, 10 Apr 2013,
=?koi8-r?B?4czFy9PBzsTSIOLP0sTPxNnOz9c=?= <BordodunovAlex@...> writes: If you have the details of these transistors, then ask them to send toI have some data: AC127: NPN, Ptot max 340 mW, fT typ 2.5 MHz, Vcbo max 32 V, Vceo max 12, Vebo max 10 V, Ic (max) 500 mA, hFE 50 min @ 500 mA (typ), Tj max 90 C, Cob max 140 pF. AC128: PNP, Ptot max 700 mW, fT typ 1 MHz, Vcbo max -32 V, Vceo max -16, Vebo max -10 V, Ic (max) 1000 mA, hFE 80 min @ 1000 mA (typ), Tj max 100?C, Cob max 200 pF. Complementary only by a stretch of the imagination! -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk They took me to a specialist burns unit - and made me learn 'To a haggis'. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK |
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Re: Germanium transistor
Hi.
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Note that these models are not correct. Option model "IS=1.41f" is too small. Which produces a voltage drop on the emitter-base transition typical of silicon transistors. Unfortunately I have no data on the actual amount. Then you can easily calculate the "IS". I appeal to all. If you have the details of these transistors, then ask them to send to me. Then I can make the correct model. Bordodynov. 10.04.2013, 08:10, "aetuhf" <atupker@...>: Can someone fix the labeling of the AC127 file? |
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Re: Worst case analysis
--- In LTspice@..., "j_asoto" <jasoto32@...> wrote:
Hello, The change of the forward voltage versus temperature can be set with the parameter Eg. This allows you to adjust the -x.xmV/¡ãC. What also depend on temperature is leakage current in reverse operation and series resistance Rs in forward operation. Best regards, Helmut |
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Germanium transistor
aetuhf
Can someone fix the labeling of the AC127 file?
Files > Examples > Apps > Electric Guitar Fuzz Effect > Distortion Preamp ac127.mod: AC127 PNP Germanium Transistor Model Subcircuit File ac128.mod: AC128 PNP Germanium Transistor Model Subcircuit File The two files are both listed as PNP transistors as shown above. The AC127 is actually an NPN transistor. The text inside the model file is correct, just the labeling of the file is wrong. |
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Re: Worst case analysis
... Could happen that a worst case escenario of a test, shall have passiveLTspice lets you assign different temperatures to each component. See the optional "temp=<value>" qualifier, which can be added to any component that has a temperature dependency. It acts as an override to the global temperature set by the .TEMP statement. Andy |
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Re: Worst case analysis
George
The problem is that I have to indicate the worst case escenario even if this escenario never be possible in the real world. That's why I wrote Worst case analysis on the subject. I have to do many tests (simulations) to this circuit. Could happen that a worst case escenario of a test, shall have passive components in high temperature but active components at low temperature. What advice could any one give me for this case?
On 04/09/2013, at 9:30 p.m., "sawreyrw" <sawreyrw@...> wrote:
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Re: Worst case analysis
--- In LTspice@..., "j_asoto" <jasoto32@...> wrote:
Hello, The SPICE diode model handles various temperatures without any changes. If you want to simulate you circuit at different temperatures you need to put a .TEMP directive on your schematic. See .TEMP in the help file under Dot Commands. Rick |
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Re: Worst case analysis
... which parameters from the model above I have to change?Perhaps none. Semiconductor models in LTspice already have temperature dependencies built-in. For example, the ideal diode law has temperature in the denominator of the exponential function. That's not to say that the diode's characteristics could not be enhanced by additional tweaking to account for temperature dependencies that deviate from the norm, or from SPICE's equations. But at least to some degree of accuracy, it is already there. I think you may need to ask the manufacturer for better models if you need them. I don't think anyone else can predict how this diode differs from the SPICE model. Do you have different models to account for part-to-part differences too? That is probably a much bigger variation (than the difference between the real diode and how SPICE already handles its tempco). Andy |
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Worst case analysis
j_asoto
I have to simulate a complex circuit that have zeners, magnetics, MOSFET, resistors, capacitors and different diodes. the simulation shall be performed at three different temperatures (+25C, -34C, +71C). I already have all the components model at each temperatures, but there is a model of a SCHOTTKY DIODE, that is only at +25C, which is the following:
.MODEL 15ljq100 D(IS=6.15446e-05 RS=0.0153982 N=1.88088 EG=1.3 XTI=3.60437 BV=100 IBV=0.0001 CJO=1.08848e-09 VJ=0.4 M=0.371667 FC=0.5 TT=1e-09 KF=0 AF=1) These are the questions: In order to have the model behavior on other temperatures (-34C and +71C), which parameters from the model above I have to change? How the parameter are change?(there is a tutorial or formulas that take the temperature as a function of the parameters)? Thanks |
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Re: The reordering of node numbers makes me crazy - is there a workaround?
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I----- Original Message -----
From: analogspiceman To: LTspice@... Sent: Tuesday, April 09, 2013 6:32 PM Subject: [LTspice] Re: The reordering of node numbers makes me crazy - is there a workaround? --- In LTspice@..., Panama Mike wrote: > There will always be users who refuse to understand why > the software is doing the right thing because it would mean > admitting to himself he was wrong. They will never get over it. > But they also unfortunately refuse to uninstall the software. LOL, the wickedest humor always cuts with a sharp edge of truth, but perhaps you could coax clueless complainers to uninstall by offering them a generous refund, you know, something they couldn't refuse, like "Quadruple your money back!" Personally I think users who aren't willing to spend a few minutes to number all the nodes they consider interesting either are whiners or aren't serious users. Node labeling must represent less than a tenth of a percent of the total simulation time a user could expect to spend on a serious design. I have no problems with manual node naming, but apparently some other versions of SPICE allow users to use component pin names as aliases for nodes in a manner somewhat analogous to the way LTspice uses those type of names to designate branch currents. For example, these currents are permissible in LTspice: Ic(Q1), Ib(Q1), Ie(Q1), I(D1), I(R1), etc. For the voltage of nodes connected to device pins, this could be: Vc(Q1), Vb(Q1), Ve(Q1), Va(D1), Vc(D1), V+(R1), V-(R1), etc. Note that two-pin components would require that both pins be able to be designated (which could be a nice feature to add for currents, in my opinion). It may also prove helpful to slightly modify certain two-pin symbols (such as resistors) to make polarity more obvious. For currents and two-pin devices this would additionally allow: Ia(D1), Ic(D1), I+(R1), I-(R1), etc. This would yield the same currents as LTspice standard notation: I(D1), -I(D1), I(R1), -I(R1), etc. In the forum's past, inquires or requests for these types of features have come up from time to time, so I know some users would like to see it added to LTspice (but it probably would be too sophisticated an alternative to assuage the lazy bones of the node-renaming whiners). -- a.s. It's only LTspice , but I like your answer ! A great answer ! On a great tool! |
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