开云体育

Hi, : May I ask a question about to generate the surge waveform using time equation & s-equation, on how to do that in LTspice ? For example, I asked the ChatGPT, about the 6.0KV surge waveform of time domain, then same as the s-domain equation, but I don't quite know how to express the s-equation exactly. I presume maybe some initial condition needed to be given, but brain twisted. And not sure if that's supported in BV's laplace expression, often it's for transfer function. In the following, it shows the equation for time & s as well. Then since I can't upload the file , (the policy of ... some confidential reason, though I don't know what needed to be confidential), I beg your pardon, please allow me to paste the .asc content in the tail if this thread. Have a nice day. Thank you very much. Best regards. the image about equation description here. (I don't know how to insert picture correctly here, it said me don't have the privilege.) /g/LTspice/photo/301279/3895874?p=Created%2C%2C%2C20%2C2%2C0%2C0 Version 4 SHEET 1 1120 680 WIRE 0 112 0 96 WIRE 192 112 0 112 WIRE 672 112 672 96 WIRE 864 112 672 112 WIRE 0 208 0 192 WIRE 192 208 192 192 WIRE 672 208 672 192 WIRE 864 208 864 192 FLAG 0 208 0 FLAG 192 208 0 FLAG 0 96 V_time FLAG 672 208 0 FLAG 864 208 0 FLAG 672 96 V_s SYMBOL bv 0 96 R0 WINDOW 3 -274 178 Left 2 SYMATTR InstName B1 SYMATTR Value V=6000*( exp(-3.5e6*time) - exp(-0.14e6*time) ) SYMBOL res 176 96 R0 SYMATTR InstName R1 SYMATTR Value 1 SYMBOL bv 672 96 R0 WINDOW 3 -274 178 Left 2 SYMATTR InstName B2 SYMATTR Value V=1*u(time) laplace=6000*( 1/(s+3.5e6) - 1/(s+0.14e6) ) SYMBOL res 848 96 R0 SYMATTR InstName R2 SYMATTR Value 1 TEXT 148 -90 Left 2 !.tran 200u startup

Something burped, v24.0.12 I miss it Man, ADI has really ruined lots of features

Hello ,I am trying to test a voltage regulator by re[lacing a steady resistor with some sort of varying resistor. Given the circuit in the attached Zip file , what kind of "resistor" you reccomend? /g/LTspice/files/Temp/regulator.zip Thanks.

I’m trying to adapt and use the model in LampModel.zip, uploaded by analogspiceman last September. The test circuit supplied works fine for a 120VAC lamp. I want to adapt it to a small pilot lamp, as a stabilizer for a Wein network oscillator. There are a number of parameters defined in the model, but except foe ambient temperature, not well explained. I commented the .param block and passed them externally, and that works exactly the same, as expected. Now, can anyone suggest what needs “tuning”, to get about 600 ohms at 10mA, after warm-up? Ka, ambient temp (Kelvin) is easy. Kc looks like design voltage (120RMS), but doesn’t really act like it; left alone. Kf seems to be a heat transfer coefficient, maybe good for warmup timing, but slightly changes stable resistance. CTf is a coupling factor from Tambient to Tfilament, sets warmup timing; left alone. RTf is filament resistance, but changing that parameter makes only a very small difference to the preset, ~150 ohms. Thanks, Dave

Hello ... I need a BV source to use a TABLE to look up a response. This works if the controlling variable is a .param ( Static for the full sim) but I need the BV to be dynamic ( Use the TABLE lookup in response to a changing voltage and respond with the voltage result ) I have tried to do this, but no success yet. I uploaded LTspice_TableTest.zip to the temp folder. Thank you so very much for any help you can provide!! JD

Thanks for your help!

I am trying to work out some old schematic and circuit issues and am looking for a model for the old LM121 opamp. Anyone have such a thing? I found the LM118, as I can use the LTSpice LT118A model. Now for the front end.

Hello, I have a YIG device which has two inputs. Tune input at 2V puts my YIG to 9.4Ghz and 10dBm FM input is current input which moves the output 100Mhz each mili ampere. I can measure the transfer function as a table also to see the effect of each input on the output Is there some bahvior model in LTspice which could help me represent this device in simulation? Thanks.

Hi, using the TI model of LF356 on LTspice v24.1.0 result in strange behaviour, DC output from OpAmp is over 18V when the supply voltages are +/- 15V. In the "Component attribute editor" I've changed parameters for this version of LTspice, the original from the file area "LF356_test.zip" result in errors at simulation start. I want to simulate a input circuit of an test equipment (Boonton 4200) that is oscillating at 93Hz square wave with amplitude near the supply coltages. I'm curious to see the Phase Margin of this differential stage with three LF356. Clearly this pspice model is incompatible with this LTspice version, or there is a workaround possible to apply ? Thanks, Stephano

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

Hello to the community, I'm very interested by the "PTC Thermistors Physical model" found in /g/LTspice/files/z_yahoo/Lib/PTC%20Thermistors/Physical%20model and I have two questions about it. 1) When I try to simulate the example ptc_veijola2.asc it throw me several errors: LTspice 24.0.12 for Windows Circuit: * C:\users\pascal\xxx\ptc_veijola2.asc Start Time: Sat Mar 15 18:34:27 2025 Questionable use of curly braces in "begb 0 egb i={1/(1/{emax}+0.5*(1+tanh((v(tptc)-{ts})/{c})))}" Error: undefined symbol in: "1/(1/(emax)+0.5*(1+tanh(([v](tptc)-(ts))/(c))))" solver = Alternate Maximum thread count: 8 tnom = 27 temp = 27 method = modified trap ERROR: Node U1:N003 is floating and connected to current source B:U1:V Total elapsed time: 0.575 seconds. Can you help me with that ? 2) I would want to simulate this PTC to "measure" a MOSFET case's temperature. In my case the mosfet have an extra pin that output a voltage proportional to case's temperature. The above PTC model take the ambient temperature and have a third pin to reflect internal temperature. Is it possible to add an extra pin to be linked to the mosfet temperature pin ? Thanks a lot in advance, Pascal

Hello, I'd like to use the SOAtherm with an user defined MOSFET. Unfortunately, i can't get the relation between the DanTherm model and the manufacturer model. Example: FDB3632 DanTherm model: R6=2.42E-03 C6=1.21E-03 R5=2.95E-02 C5=6.20E-05 R4=2.03E-01 C4=2.69E-03 R3=2.34E-01 C3=3.21E-02 R2=5.94E-02 C2=1.81E-01 R1=2.47E-03 C1=8.25E-08 Manufacturer model: CTHERM1 TH 6 7.5e-3 CTHERM2 6 5 8.0e-3 CTHERM3 5 4 9.0e-3 CTHERM4 4 3 2.4e-2 CTHERM5 3 2 3.4e-2 CTHERM6 2 TL 6.5e-2 RTHERM1 TH 6 3.1e-4 RTHERM2 6 5 2.5e-3 RTHERM3 5 4 2.2e-2 RTHERM4 4 3 8.1e-2 RTHERM5 3 2 1.35e-1 RTHERM6 2 TL 1.5e-1 Does somebody know the relation between these values ? Thanks, Marc

after simulation, i do the following: e.g. on a resistor R1, holding alt button and hovering over the element R1 shows in the status bar "Left-click to plot R1 dissipation: ...". but doing so, does not add any plot. other than manually typing and adding the plot, is there a correct way for the same. or am i doing something wrong here? thanks.

Hi all, I'm working on a project that involves saturable transformer and when I try to model it in LTSpice, I can observe the saturation effects when there is sinusoidal voltage but I cannot really observe it when I supply pulsating DC voltage. Please find the LTSPICE files in here: /g/LTspice/files/Temp/SaturableTransformer.zip I went through all the information available on the internet and it helped me a lot. I am stuck with this since some time now. Can anyone please help me with it?

Looking for ideal fully differential amplifier spice model for XSPICE simulations. The one I have based on the XSPICE "gain" code model doesn't have any CMRR or care if outputs are swapped. Anything based on dependent sources would be good. * XSPICE Fully Differential OpAmp .subckt opamp inp inn outp outn in_offset=0 gain=300e3 out_offset=0 aint %vd(inp inn) %vd(outp outn) amp .model amp gain (in_offset='in_offset' gain='gain' out_offset='out_offset') .ends opamp The SE output OpAmp using the same structure works fine...

My file is AC_Coupling.asc and has text that has been made smaller than it was in older LTSpice versions. The weird part is some text is small but other text is normal. Using version 24.0.12.

I am still using version 24.0.11, and I am finding some problems with drawing a block diagram of a multi-stage circuit as a schematic. I know that LTspice isn't intended for that, but It's much simpler to use than some other drafting apps. The problems are: 1. I can't see the grid points. They have always been minute but now I can't see them at all. They used to be more visible on print-outs of schematics. 2. Drawing a wire with CTRL held down doesn't allow the wire to start and end off-grid. It's the same if I draw lines instead of wires. I can't find a 'Snap to grid' check box to untick. 3. Is there any way to change the dimensions of a rectangle after it is drawn? I guess not. Would it be better to use the symbol drafter? -- 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.www.avg.com

hello members, i was looking for a tool which can provide alternate diode models that match approximately to a given diode model. unfortunately, i could not find any website or software. it would great if anyone shares any information in this regard. thanking you in advance.

I am having issue with simulating experia BUK7S1R0-40H PET LTspice model characteristics https://www.nexperia.com/product/BUK7S1R0-40H when simulating mosfet with exact same setup as it is in application note i get quite different results for example output characteristic or transfer characterisitc. Anyone know what could be the problem here ?

Hello, I would like to use the LMR51606 in LTSpice. I only found an encrypted PSpice library on TI. I've already uploaded the file (LMR51606.zip). Unfortunately, I can't import the file into LTSpice. Is there a way to use the model, or does anyone have one? Thank you.