Questions tagged [non-linear]
The non-linear tag has no usage guidance.
99
questions
1
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0answers
27 views
Using a non-time domain equation for a nonlinear equation based device in QUCS
I'm trying to model a magnetron oscillator source in QUCS. I am only interested in the output of the magnetron, not how it is powered. Traditionally a magnetron is modeled the same as many oscillators,...
1
vote
1answer
73 views
How is constant on time control better than voltage mode control for transient response?
I am trying to understand the benefits of constant on time control (COT) over voltage or current mode control.
In voltage mode control, during a load transient (increase in load) an aggressive control ...
2
votes
3answers
113 views
Simple examples of higher order circuits and the cause of non linearity
In my previous question, I learned that resistance, capacitance, and inductance are not enough to capture the behavior of all circuits. This led me to the question, what are some examples of 'simple' ...
2
votes
1answer
57 views
Ian Fritz - Chaos - Cubic non linearity
I was reading Ian Fritz overview on chaotic circuits.
As an example of non-linear circuit, he presents the following schematics
This circuit is said to output a signal of the form x.(1-x^2) where x ...
1
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0answers
37 views
What's wrong with my experiment to observe harmonics caused by receiver saturation and non-linear behavior?
I've been trying to devise an experiment to produce a third order harmonic in radio receiver that's been saturated, but I'm not seeing the expected results.
My understanding of the theory is that when ...
1
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0answers
112 views
How do I simulate an RF mixer in PSS or harmomic balance with an autonomous local oscillator?
I am designing a CMOS RF downconversion signal chain comprised of a local oscillator and mixer (the LNA is not yet included) using the Cadence Virtuoso Circuit Design Suite with ADE XL as my simulator....
1
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0answers
204 views
Transient buildup of capacitively coupled transistor amplifier
I'm trying to understand the following section from "Communication Circuits: Analysis and Design" by Donald T. Hess:
Here \$W(t)\$ is defined by $$W(t) = e^{\frac{q(v_i(t) - v_{imax})}{kT}}...
3
votes
1answer
91 views
How to even start solving multi-diode problems?
For example, in the circuit below there are 5 diodes constant-voltage-drop diodes, I could have 2^5 circuits to solve. Is there something I'm not paying attention to, that would greatly simplify this ...
4
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2answers
189 views
Determine the output voltage
I'm trying to solve the following question:
Determine the output-tuned circuit voltage in Fig. 4.P-7. The tuned circuit is resonant at \$\omega_0\$ and has \$Q_T = 20\$.
My try: I don't know how to ...
2
votes
0answers
66 views
Nonlinear circuit and RLC
I'm trying to solve the following question from "Communication Circuits: Analysis and Design"
by Donald T. Hess:
For the circuit shown in Fig. \$1.P1\$, determine an expression for \$v_o(t)\...
1
vote
0answers
39 views
Correcting non-linear response of 5050 RGBW LED strips
I'm a non-engineer asking this question. I'm using a so-called 5050 RGBW LED stips for a project. The level of each colour is controlled by a mosfet transistor (IRLZ34N) which is in turn modulated by ...
2
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6answers
883 views
Prove that in a *nonlinear* circuit, adding resistor between equipotential terminals draws no current
If a circuit is linear, then you can use Thevenin equivalence to prove that if a port of a circuit has an open-circuit voltage of 0 V (the two terminals are at the same potential), then the resistor ...
1
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0answers
24 views
timestep too small error with non-linear capacitor - how to handle possible discontinuous points
I am using LT spice to simulate a thermal problem involving a phase-change material (a paraffin).
[
with the paraffin modeled as a non-linear capacitor and resistor (the capacitor represents the heat ...
0
votes
0answers
45 views
Single balanced mixer, multi-tone analysis
I realized the circuit shown below on ADS.
Schematic of the mixer can be shown below.
As can be clearly seen from the figure below, to perform a multi-tone analysis RF signal is feeded with two ...
0
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0answers
15 views
Is Image Based Visual Servoing a non-linear controller?
Is Image Based Visual Servoing a non-linear controller? I think it is as the Image Jacobian has square terms of u & v (image-plane coords).
Where \$p_u, p_v\$ are the width & height of each ...
1
vote
1answer
62 views
Modelling a non-linear resistor on ADS
How can I model a non-linear resistor whose current changes according to the equation shown below on Advanced Design System (ADS) or AWR Microwave Office?
$$i(t)=v-v^2-v^3$$
Where v is voltage ...
1
vote
1answer
97 views
non linear inductors characteristics
I have the following question: I have the characteristic of 2 non linear inductors and i want to find the equivalent for the following connections
my problem is with the series one, i know that the ...
2
votes
1answer
103 views
LTSpice light bulb nonlinear current
I'm in a lab and for some reason I cannot replicate my results on LTSpice.
I have gathered data from an experiment where I built the circuit shown in Figure 1. I then took that data, plotted it in ...
-1
votes
2answers
87 views
What is the physical meaning of reactive power in non-sinusoidal steady-state (with harmonics)?
In sinusoidal steady-state (linear loads, no harmonics), I understand what is reactive power \$Q = V_{\text{rms}} I_{\text{rms}} \sin{(\theta)}\$ where \$\theta = \theta_v - \theta_i\$: its absolute ...
0
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1answer
47 views
Difference between THD equation and design circuit current
Why does the summation of design circuit current equation (Ib) start with 1 while for calculating THD the summation starts with 2?
-1
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1answer
114 views
Colpitts oscillator bypass capacitors importance
A Colpitts oscillator makes use of the common emitter configuration, and the
indicated amplifier configuration is known to be a linear circuit. How come do we call the
stated oscillator a nonlinear ...
2
votes
1answer
71 views
If interharmonics are defined for periodic signals, aren't interharmonics misleading?
Before explaining my question, I'm going to assume that 1) interharmonics, just like harmonics, are sinusoids; and 2) to analytically represent the interharmonics of a signal, we sum them to the ...
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0answers
50 views
Linearization of nonlinear plant with system identification in Matlab
I hope this question fits in here and there is someone who can maybe help me.
I am new to control theory and I have a very complex Simulink model which is nonlinear. I want to have a linear ...
4
votes
2answers
165 views
When a signal has an interharmonic, is the signal periodic or non-periodic?
I have some questions regarding interharmonics. What I'm going to do is first ask just a few, and then as people answer them I would expand this post or create a new question.
Harmonics are sinusoids ...
2
votes
2answers
263 views
Temperature sensing with ADS1115
I am using an ADS1115 as an analog to digital converter to measure temperature. I am using an RTD100 temperature sensor to measure a temperature range of -40 to 150 degree celsius but the resistance ...
0
votes
1answer
70 views
Does a wide-band, high-current, inline ammeter circuit already exist?
I have an application where I would like to measure currents up to 1000 A, inline, but am also interested in using the same circuit for a low current part of the cycle. The thought is that if I can ...
2
votes
1answer
438 views
Variable-Gap Capacitors in LTSpice
I have seen several blog posts that discuss the concept of a nonlinear capacitor (or inductor) here, here, and here. Thanks to a concerned citizen for the references.
I'm still struggling with the ...
0
votes
1answer
157 views
Oscillator circuit using comparator and opamps
All opamps are ideal and Rx = 2R in the figure. The comparator is a nonlinear block which operates as follows: if its input Va < 0, its output is +1V. If Va > 0, its output is -1V. To simplify ...
0
votes
2answers
70 views
distance between linear and non-linear function of op-amp system
I have a circuit which I have taken a picture of as you can see, in which i have values of
$$R1=1k\Omega,R2=10k\Omega,R3=10k\Omega.R4=10k\Omega,R5=20k\Omega$$
and sine input signal with off-set value=...
0
votes
2answers
154 views
Why is the Hybrid-PI model like that?
The BJT and MOSFET can be modeled using the Hybrid-pi model. I only know that the transistor can be modeled with linear elements like that, but I don't know why.
There are a lot of things that confuse ...
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0answers
229 views
DAC "aliasing" of harmonics
While reading articles and application notes regarding DACs and their output spectrum, I stumbled across aliasing of higher harmonics to the first Nyquist band. For example, when generating a single ...
1
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1answer
58 views
Linearization of nonlinear system
I have a nonlinear system described by:
$$\begin{align}
V\,\dot x_1 &= Q_1 C_1 - (Q_1+u)x_1 \\
V\,\dot x_2 &= C_2\,u -(Q_1+u)x_2 \\
y &= -\frac{\log{\left[(x_1-x_2)+|x_1-x_2|+4K\right]}...
1
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3answers
225 views
what is the load line and operating point used for in practical?
I have a hard time understanding what an operating point and load line represent and why do we need them at all.
After reading some wikibedia,
What I got is this load line represent response of the ...
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votes
3answers
93 views
1
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1answer
90 views
Linearization of IR sensor GP2Y0A21YK
How do I linearize the graph analog output voltage against distance for IR sensor [GP2Y0A21YK][1]?
This is the non- linear graph, I’m not sure how to make it linear?
[1]: https://media.digikey.com/...
1
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3answers
451 views
Stuck on a simple piecewise linear element problem
See the schematic of interest on a picture. \$V_S = 5 \,\rm{V}\$, \$R_S = 4700 \,\Omega\$, \$R_P = 5800 \,\Omega\$. The cucumber-shaped element is a nonlinear element. The only thing we know about it ...
0
votes
1answer
140 views
How can the maximum average power transfer be negative in a power delivery circuit?
It is possible that the Thevenin resistance \$R_{Th}\$ of a circuit is negative. This occurs in non-linear circuits. Likewise, in AC circuits, the real part of \$Z_{Th}\$ can be negative.
For AC ...
1
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1answer
53 views
Non linear DC voltage conditioning
I do not want to use any adc or dac. I want to see if this is possible by pure analog circuit. Any google links or book names are welcome. From 0 to 1000mV output should be 0 to 100mV. Then from ...
3
votes
2answers
290 views
Linearizing hall effect sensors outputs
I'm trying to find a robust solution to linearize four hall effect sensors outout to obtain a signal that I can use in a PID control scheme.
The output data is collect via 4 ADC channels on an ...
6
votes
4answers
372 views
How can I realize this nonlinear resistor?
I want to know if it's possible to realize a circuit described by the equation
$$I = \sin(w V)$$
where \$I\$ is the current, \$V\$ the potential and \$w\$ a variable which characterizes the single ...
2
votes
2answers
630 views
Non-linear Inductor LTSpice
I am trying to implement a non-linear inductor in LTSpice and to get it to saturate.
I am using the following directive between N1 and N2 as advised in the help files:
L1 N1 N2 Hc=12 Br=0.2 Bs=0.4 A=...
0
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0answers
459 views
How to make a non-linear potmeter more linear
I have an "Expression pedal" that worked fine on my old keyboard (Gem WX2+) but works almost like a digital switch on my new keyboard (Roland VR-09).
The recommended expression pedal is a Roland EV-5 ...
0
votes
1answer
48 views
Normalizing a nonlinear plant in system identification in control
I have calculated the "active power" and the "the reactive" power of a system in dq axis in nonlinear form and I am doing system identification on this "nonlinear" plant as a MIMO system.
The problem ...
1
vote
3answers
172 views
Performing small signal ac analysis with non-linear components
I have written a circuit simulator that uses Kirchoff's voltage and current laws to solve linear circuits containing capacitors, resistors, inductors and op-amps (where the op-amps are assumed to be ...
1
vote
3answers
206 views
Bandwidth and stability of nonlinear circuit
I'm designing an antilog amplifier which produces an exponential output (0.4 mV to 4 V) for a 50 Hz sawtooth input waveform (4 mV to 4 V ramp). If this were a linear circuit, I could determine the ...
0
votes
1answer
306 views
Transfer function_Approximation of second order system for a linear actuator
I am trying to approximate a transfer function of a system. The system is a linear actuator, connected to a feedback potentiometer. The actuator has a mass on it. The following figure is a step ...
0
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1answer
252 views
How to plot response of a non-linear state space model in Simulink?
I am trying to plot a non-linear model in order to compare it with it's linearized counterpart.
I am following this paper Nonlinear Model & Controller Design for Magnetic Levitation System and ...
1
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0answers
106 views
2 tone test with RF mixer
I am designing a system that uses RF to probe the nonlinearity of a target. It works as follows.
Transmitter sends out 2 RF frequencies, such as 900 and 910MHz.
The target/reflector has a ...
0
votes
1answer
388 views
DC motor driver response [closed]
I have some trouble about the response of the L298N DC motor driver.
After some experiments, I have noticed that the output response of the L298N isn't linear.
In particular, if i give a ramp input ...
1
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0answers
41 views
Analyzing a non linear circuit with two sources [duplicate]
I want to analyze this circuit. V1 is a) +15V b) +10V c) -5V
I need V2, V3, I1, I2, I3
Uz=6,8V
UF=0,7V
And I hate to say this, but I'm absolutely lacking any approach. I don't know how to manage V1....
