Questions tagged [compensation]
For questions about designing electronics to account for undesirable characteristics or behaviors, such as frequency compensation in a feedback control system to avoid instability and/or improve gain and phase margin, reduce overshoot and ringing, improve bandwidth, etc. Consider using in conjunction with associated tags such as "feedback", "stability", "frequency-response", "nyquist-plot", "bode-plot", "operational-amplifier", etc., if appropriate.
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30 views
Reactive power compensation
For a solar power plant with a capacity of around 800 kW AC, the night time power factor reading was around -0.13 noted from the meter at interconnection. Night time reactive power consumption of the ...
1
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1answer
74 views
Phase Margin and Transient Response Contradicting?
I am designing a forward converter that is supposed to work as a pre-regulator for a linear supply. The forward converter is supposed to be able to give output from 4V to 34V and 0 to 5A. While ...
0
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1answer
93 views
Why this overshoot in transient?
I am designing a forward converter whose output can be variable from 4V to 30V, 0-5A. This is going to be a pre-regulator for a linear converter. This is the schematic:
I am using UC3844 controller ...
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36 views
Using UC3844 and TL431 to compensate a forward converter
I am designing a forward converter capable of providing 5A at 30V at the output. For the compensation part, I am thinking to use UC3844 in combination with TL431 to achieve peak current mode control.
...
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38 views
How to plot uncomensated loop gain in LTspice
I want to plot an uncompensated loop gain of a dcm flyback dc-dc converter. I know that I can derive the control to output transfer function and then plot the uncompensated loop gain but that just ...
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1answer
79 views
What is the better way to stabilize this discrete op-amp and why?
I have the following simple op-amp circuit, which is meant to drive a MOSFET (M1) gate and work as a voltage regulator. It is discrete for a mix of reasons (necessary bandwidth, using existing BOM ...
0
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1answer
32 views
Feedback loop design (buck converter): Output capacitance- effective value or nominal value to be considered?
In this TI datasheet of TPS62180, it was mentioned that the LC filter combination should be selected from a set of predefined values. I understand this is usually the case for an internally ...
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3answers
203 views
Problem stabilizing this PMOS LDO
I am considering a discrete LDO for a supply rail that needs ~\$m\Omega\$ impedance at 10 kHz.
While the following circuit does what I need (according to Spice), it becomes unstable if C2 is smaller ...
2
votes
1answer
128 views
Flyback power supply instability issue
I have created a switching power supply:
Input: 230 V AC
Output: 12 V DC, 1 A
Controller: UC3844
Topology: flyback
Switching frequency: ~ 100 kHz
Schematic:
When I start this power supply, output ...
0
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0answers
22 views
What is the term Flc in LM27402?
Hi while going through LM27402 IC, inorder to find compensate components of cc1,cc2 and so on, there is term called Flc, can anyone explain what it is?
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0answers
54 views
IGBT Temperature Drift: How to Achive Stability?
I remember the BJT transistor circuits are designed to compensate for the fact that the parameters of the transistor change with the temperature. I could not find similar ready-to-use solutions for ...
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1answer
129 views
Parallel plate capacitor level sensor
Hey all.
in a typical design of a capacitive sensor for level measurements, compensation capacitors are added as a reference. I struggle to understand why we need a reference capacitance to measure ...
0
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1answer
52 views
Temperature compensation equation?
I'm looking for the correct temperature compensation equation to use on our project.
We are measuring the output of a detector who's signal is very sensitive to temperature drift. Any external ...
1
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1answer
43 views
Trouble with meeting design specifications of a second order system using Matlab
I am trying to solve the following question.
Consider the transfer function $$G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ is in the forward path of a unity feedback control loop. Assume that it is ...
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0answers
52 views
How to find the compensating gain required for the 2nd order control system to have 5% overshoot
I have a unity feedback control system with $$G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ in the forward path. Now Imagine, I added a static gain K in the forwards path to make the %overshoot 5%. How can I ...
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2answers
90 views
Why is this buffered rail splitter oscillating and how can I compensate it?
Inspired by the question Op amp Power supply splitter with totem pole I played with the buffered rail splitter in LTspice. I placed a current sink as load on the output to simulate the current ...
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0answers
60 views
Underlying reasoning behind lead and lag nomenclature of compensation
If \$0<z, \;p\$, the Laplace transform transfer function \$\frac{s+z}{s+p}\$ constitute two distinct types of compensators.
If we look at this schematic, \$0<z<p\$ (lead compensation) implies ...
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0answers
33 views
Why are complex valued zero and pole not used in lead or lag compensation design?
Consider the compensation transfer function \$\frac{s+z}{s+p}\$ so that the inequalities \$0<z<p\$ and \$0<p<z\$ correspond to lead and lag compensation respectively. It can be seen that ...
2
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1answer
224 views
Do lead and lag filters have the behavior of high and low pass filters even if the zero and pole used are complex?
Consider the compensation transfer function \$\frac{s+z}{s+p}\$ so that the inequalities \$0<z<p\$ and \$0<p<z\$ correspond to lead and lag compensation respectively.
At very low ...
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0answers
47 views
LMH6629 Spice Model, where to put compensation pin?
I am trying to use a spice model from TI for the LMH6629 op amp and the model has a compensation pin. I pasted the code in a spice directive and tried to use a generic op amp model for it, but the ...
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0answers
45 views
Ratio of zero-pole in a lead compensator
I have a transfer function of a lead compensator designed for double integrator in the form
$$G(s)=\frac{2025}{s^2}\frac{s/39+1}{s/139+1}$$
The zero frequency is 39 rad/s and pole is 139 rad/s. I just ...
0
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2answers
119 views
How to improve the accuracy of measured ADC voltage in a circuit connected to Vcc
The question is based on the following setup.
As depicted there is an IC to measure the real value of the 3.3V supply voltage accurately. The measured value of the 3.3V source is transferred via SPI ...
2
votes
1answer
106 views
Offset problems with charge amplifier
I have a question about designing a charge amplifier.
I am currently using this simple setup for my application. As input, I can use several commercial piezo-based accelerometers. I need a pretty ...
0
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0answers
29 views
Isolated Type 3 Compensator
I'm trying to build a full bridge dc-dc converter and planning to apply a type 3 compensator(voltage mode). When I check the isolated feedback type 3, I've read some comments indicate that it's hard ...
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0answers
38 views
Phase Lag Compensator
I have a question on lag compensators in general.
Why do they increase both the rise time and the settling time? Is it due to the introduction of a slow pole?
Much thanks!
1
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1answer
144 views
Dual slope ADC circuit
I`m currently building a dual slope ADC with discrete components. As expected, some errors were observed. I have calculated both the gain error and offset error variables.
Now that I know these ...
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1answer
44 views
Designing a compensator - Control system - Missing value
I would like to determine the transfer function of the following circuit made of TL431. According to the different AN that I have read (and about this subject I really really thank Christophe BASSO, ...
2
votes
1answer
222 views
Tilt compensation for yaw calculation from magnetometer and accelerometer
I am working on a project where I have to calculate the roll, pitch, and yaw angles using an accelerometer and a magnetometer.
I calculate the pitch and roll angles using the accelerometer and I am ...
0
votes
1answer
45 views
Maths behing implementing temperature compensation on a signal
I have a fluid pressure sensor (blue line) whose measurements are affected by outdoor temperature (yellow line). So there is a 12 hours cyclic component (day/night) in my pressure measurements. How ...
4
votes
2answers
540 views
Why does overshooting occur when probe's adjustable capacitor is under-value
I can't wrap my head around how overshooting (the spike) happens when the 10X probe capacitor trimmer (Cp) is under-tuned (i.e. adjustable capacitor's value is not high enough). There are countless of ...
0
votes
2answers
137 views
butterworth configuration of multi-stage amplifier
When designing a multi-stage operational amplifier, people usually use butterworth polynomial to set closed loop pole location of the op amp in feedback configuration, and then back calculate to open ...
1
vote
0answers
65 views
fast analytical technique identifying poles/zeros using degree of freedom
I encounter some engineers who can quickly spot poles and zeros in the circuit by identifying "degree of freedom". For example, a typical technical discussion goes like : "a miller ...
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1answer
88 views
Questions about coil voltage and phase shift in the WPT system
I performed simulations of wireless power transfer in matlab simulink. It was powered with DC voltage which was then converted into a rectangular voltage with a frequency of several dozen kHz. The ...
0
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1answer
292 views
DC Gain of the System
I'm trying to design a feedbcak loop compensator and I'm following the instructions on power supply cookbook.
Book has calculations for DC gain like equations below:
in my situation Vin: 40V-60V and ...
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vote
2answers
83 views
Compensation of custom high voltage power supply
To test an offline switching PSU I decided to build a custom isolated high voltage variable PSU. The idea was to build a nice, small, low power equivalent of a variac and isolation transformer that is ...
2
votes
1answer
144 views
Microstrip blocking capacitor ground cutout -- large cutout size
I'm attempting to minimize the \$S_{11}\$ of a \$10\,\text{pF}\$ DC blocking capacitor on a microstrip trace for my signal frequency range, which is \$5.3-5.9\,\text{GHz}\$. My microstrip trace width ...
1
vote
1answer
719 views
3 wire load cell and HX711 weight compensation
in my project I use 3 wire load cell (like this (3wire 50kg) but mine are purchased from ebay) and HX711 for weighing.
My wiring is like this (but i use Arduino mini pro 3V3):
Apparently it should ...
0
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0answers
81 views
Using frequency-compensated resistive divider as digital level-shifter
We have all seen the "frequency-compensated resistive divider" circuit in, for example, 10X oscilloscope probes:
simulate this circuit – Schematic created using CircuitLab
Has anyone tried ...
0
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1answer
45 views
Sensor Error Adjustment
I have been asked to improve the high end accuracy of a pressure sensor (Without modifying hardware). I have collected data from 30 samples and found a trend to the error. My question now is if it is ...
0
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1answer
93 views
How to compensate an op-amp at a particular frequency?
I am trying to design an op-amp but because it is going to be used at a max frequency of 10kHz, I only need to make sure the phase margin is good enough at this frequency. Most of the methods for ...
2
votes
2answers
464 views
Frequency compensation and feedback capacitance
I was reading the chapter of Microelectronic Circuits (Sedra Smith) about negative feedback systems, and it shows an example of Miller frequency compensation with the capacitance Cf shown in the ...
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1answer
587 views
Two stage op-amp design with compensation ideas
I am trying to design an op-amp with a high-pass feedback. The diagram is shown below. The high pass feedback has a corner frequency at 1Hz.
The op-amp itself is two stage as can be seen below.
...
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0answers
49 views
How to determine these resistors in 2-pole 2-zero feedback loop compensation
I'm trying to build a 2-pole 2-zero feedback loop compensation for controlling a full bridge dc-dc converter. It's my first time doing this and I'm following the book power supply cookbook. Book is ...
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0answers
25 views
Slope compensation of MAX17498
I want to use MAX17498 in boost mode.
I have a problem setting the slope compensation. The slope (as I understand) is the gradient of the inductor's current ramp. The unit is [A/s] or [A/us]. However,...
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1answer
89 views
Stability of SMPS designed for a motherboard
Many books have covered the stability of many configurations of switch mode power supplies and they have given details on how to set the poles and the zeros of the compensator to make the the power ...
2
votes
1answer
999 views
Implementation of Adjustable Current Limiting Circuit
I have a circuit that can deliver 0-10V and 0-100mA to a load, and want to have an adjustable current limit that will limit the current delivered. To do this I have a current shunt that I monitor, and ...
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0answers
247 views
Type 3 Compensation on Full Bridge DC-DC Converter with SG3525
I'm trying to build a 48V-400V full bridge dc-dc converter. I'm using sg3525 as pwm IC and trying to get isolated feedback from output and planing to do it with TL431.
When I study on it people are ...
1
vote
1answer
107 views
Non Inverting Type 2 and 3 compensators
I'm looking for the topology and transfer function of a non-inverting type 2 and 3 compensators (PID controller). they are used in CC and CV feedback control in charging/Discharging circuits of ...
-1
votes
1answer
511 views
Designing a lead compensation for a 3rd order system
Question Title:
Consider the control system shown in Fig.1. Design a compensator such that the
unit-step response curve will exhibit maximum overshoot of 25% or less and settling time of 5 sec or ...
1
vote
1answer
1k views
How do we decide to use a lag compensation versus a PI compensation?
Although lag and PI compensation apparently have the same objective of improving the steady state response, how does one decide which one to use?
