strange LT Spice s/h behavior

Started by John Larkin in sci.electronics.design4 months ago 13 replies

I figured that I could bootstrap an LT Spice sample/hold to make a stairstep waveform. Without the RC, the output jumps to +10 volts at the...

I figured that I could bootstrap an LT Spice sample/hold to make a stairstep waveform. Without the RC, the output jumps to +10 volts at the first clock edge. And the RC has to be right to get a proper stairstep. Version 4 SHEET 1 880 680 WIRE 144 -128 32 -128 WIRE 240 -128 144 -128 WIRE 448 -128 320 -128 WIRE 144 -80 144 -128 WIRE 448 0 448 -128 WIRE 144 16 144 -16 WIRE 32 96 3...


IGBT in Linear Mode

Started by Tim Wescott in sci.electronics.design4 years ago 37 replies

Any good articles in using IGBTs in linear mode? With all due respect for the uselessness of SPICE when you can't do the work on paper --...

Any good articles in using IGBTs in linear mode? With all due respect for the uselessness of SPICE when you can't do the work on paper -- does anyone know how good a SPICE model designed for an IGBT in switched service might work in linear mode? Who tends to have better models for linear service? Whether anyone has models specifically for IGBTs in linear mode? TIA -- IGBTs seem to ...


Measure input/output impedance with Spice

Started by Anonymous in sci.electronics.design10 years ago 6 replies

Could some electronics/Spice guru shed some light on this. Suppose I want to measure the input impedance of a test circuit. The impedance...

Could some electronics/Spice guru shed some light on this. Suppose I want to measure the input impedance of a test circuit. The impedance can be AC or DC. Let us consider DC. I set up the following circuit, with a DC voltage source, connected with a voltage source with zero DC and AC output, followed by the circuit under test. I sweep the DC voltage of the first DC voltage source....


2 component negative feedback oscillator and voltage "multiplier"

Started by Robert Baer in sci.electronics.design3 years ago 34 replies

Problems are: Spice version does not oscillate, and Spice LED voltage is not 3V. Go buy the Dollar Tree LED Flashlight and Lantern...

Problems are: Spice version does not oscillate, and Spice LED voltage is not 3V. Go buy the Dollar Tree LED Flashlight and Lantern Combination SKU: 286458 and see (do not forget it needs one AA cell). Version 4 SHEET 1 5945676 13421556 WIRE 2080 -592 1648 -592 WIRE 2080 -560 2080 -592 WIRE 2080 -496 2048 -496 WIRE 2176 -496 2080 -496 WIRE 1648 -480 1648 -592 WIRE 2048 -448 2...


Mike's new Spice

Started by John Larkin in sci.electronics.design1 day ago 5 replies

https://www.marcusaureliussoftware.com/ A bit vague, at present.

https://www.marcusaureliussoftware.com/ A bit vague, at present.


Phil,

Started by Anonymous in sci.electronics.design3 years ago 5 replies

Do you have a Spice model for SAV551 or something similar? -- John Larkin Highland Technology, Inc lunatic fringe...

Do you have a Spice model for SAV551 or something similar? -- John Larkin Highland Technology, Inc lunatic fringe electronics


LT spice _ LM7812

Started by nescafe in sci.electronics.design9 years ago 12 replies

What is the substitute for LM7812 in LTspice ? I can find any...

What is the substitute for LM7812 in LTspice ? I can find any...


LT spice error

Started by Anonymous in sci.electronics.design2 years ago 9 replies

On simulation, I am getting this error : trouble converting to curly brace notation: mismatched single quotes...

On simulation, I am getting this error : trouble converting to curly brace notation: mismatched single quotes in "K{(Uo*Cox/2)175.4-35.6uA/V^2" My connections are correct. What might be wrong?


LT Spice universal opamp

Started by Anonymous in sci.electronics.design3 years ago 5 replies

In universalopamp2, what does the "rail" parameter do? -- John Larkin Highland Technology, Inc The cork popped merrily,...

In universalopamp2, what does the "rail" parameter do? -- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"


CircuitMaker 2000: imported net lists not working.

Started by Anonymous in sci.electronics.design2 years ago 11 replies

With a working schematic loaded that simulates normally I use File > Export > Spice netlist . But when imported it does not simulate. I get just...

With a working schematic loaded that simulates normally I use File > Export > Spice netlist . But when imported it does not simulate. I get just an empty black window. It's been many years, but I’m sure I have done this successfully before.


LT Spice powering opamps

Started by John Larkin in sci.electronics.design7 years ago 5 replies

I usually have a couple of "voltage" things off to the side, making +5 and -5 or whatever, and have each opamp with little doglegs on...

I usually have a couple of "voltage" things off to the side, making +5 and -5 or whatever, and have each opamp with little doglegs on its power pins, same net names. Somewhere I thought I saw a circuit where the opamps were powered by little boxes with "+5" or something inside, with no other supply needed. Does that work? If so, how do you invoke it? -- John Larkin ...


Commercially available hetero bijunction transistor

Started by amal banerjee in sci.electronics.design9 months ago 2 replies

Could some electronics guri here help please ? Where could I find datasheets, specifications and SPICE models if any, of commercially available...

Could some electronics guri here help please ? Where could I find datasheets, specifications and SPICE models if any, of commercially available hetero bijunction transistors. Thanks in advance.


Spice modelling of back EMF

Started by Cursitor Doom in sci.electronics.design7 years ago 71 replies

Hi all, I've been unable to get sensible results from simulating the voltage spike inductors generate when their magnetic fields collapse....

Hi all, I've been unable to get sensible results from simulating the voltage spike inductors generate when their magnetic fields collapse. The only possibility I can think of for this failure is that the standard inductor models have insufficient parameters for this purpose and require an extended parameter set. Like many of y'all I use LTspice, btw. Any ideas?


How to select shunt capacitor for class E amplifier

Started by amal banerjee in sci.electronics.design3 years ago

Could some electronics guru please help ? I am trying to do some SPICE simulations for class E amplifiers. How is the shunt capacitor value...

Could some electronics guru please help ? I am trying to do some SPICE simulations for class E amplifiers. How is the shunt capacitor value calculated ? Any hints, suggestions would be helpful. Thanks in advance.


BD131 Spice Model Wanted

Started by Julian Barnes in sci.electronics.design7 years ago 15 replies

Hi all, It still amazes me after all the years LTspice has been around the standard parts library in it remains so tiny. I don't think this...

Hi all, It still amazes me after all the years LTspice has been around the standard parts library in it remains so tiny. I don't think this long- standing defect in otherwise very good program will ever be fixed. So like anyway, has anyone got a model for a BD131 NPN transistor they could post here? TIA folks. CD


inverting switcher

Started by John Larkin in sci.electronics.design3 years ago 14 replies

I have +12 from a wart, and I need -1.2 and -5 to power some analog stuff and ECL. I can do...

I have +12 from a wart, and I need -1.2 and -5 to power some analog stuff and ECL. I can do this https://www.dropbox.com/s/3b0iff93k1k2ct6/TPS_Inv_1.JPG?raw=1 Problem is, I don't want to run Tina and there is no LT Spice model. It may go into burp mode at my modest load currents, so I could get a lot of output ripple. It might want some lead compensation too. I guess I should br...


Quadrature Oscillator

Started by George Herold in sci.electronics.design9 years ago 49 replies

Quadrature oscialltor. Hi all, As part of the CV measurements (from a previous post) I'm thinking about a 1 MHz lockin. (Maybe a different...

Quadrature oscialltor. Hi all, As part of the CV measurements (from a previous post) I'm thinking about a 1 MHz lockin. (Maybe a different thread to talk about how to do the switching.) I was wondering if I could make a quadrature oscillator from opamps. (I've got some AD825's I thought I'd try.) Anyway spice seems to think it's possbile. Comments or ideas welcome. (Oh I had to add th...


LT spice, how to add model lib

Started by George Herold in sci.electronics.design4 years ago 3 replies

Hi all, simple question how do I add a library to ltspice. Lib from...

Hi all, simple question how do I add a library to ltspice. Lib from here. https://www.classe.cornell.edu/~ib38/teaching/p360/lectures/wk12/l35/11.1/74hc.lib I've watched a few videos, but not working so well. George H.


LT Spice problem

Started by krw...@att.bizzzzzzzzzzzz in sci.electronics.design11 years ago 26 replies

I'm trying to add the models of a couple of N-FETs I use to LTSpice. I'm getting a simulation-time error that I can't resolve. Any ideas? ...

I'm trying to add the models of a couple of N-FETs I use to LTSpice. I'm getting a simulation-time error that I can't resolve. Any ideas? Thanks. The error: |M1: Only a level 9 B3SOI can have 6 nodes It thinks I have six terminals on my transistor and only SOI models have that many? Looks like only three to me. The circuit: Version 4 SHEET 1 880 680 WIRE 144 -80 16 -80 ...


TVS diode in LT spice

Started by John Larkin in sci.electronics.design3 weeks ago 4 replies

.model SMCJ33A D(Ron=.4 Roff=8Meg Vfwd=.7 epsilon=100m Vrev=38.65 Vpk=33 revepsilon=4 mfg=Littlefuse type=TVS) That's in the standard library....

.model SMCJ33A D(Ron=.4 Roff=8Meg Vfwd=.7 epsilon=100m Vrev=38.65 Vpk=33 revepsilon=4 mfg=Littlefuse type=TVS) That's in the standard library. It behaves like a symmetric zener. Why? Does "type" do that? There are unipolar TVS diodes, too.