Questions tagged [closed-loop]
The closed-loop tag has no usage guidance.
83 questions
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On the stability of differentiator based on OP amp with an example from TI manual
I am building a proportional-Differentiator circuit based non-inverting OP-amp. But I am confused with the stability condition of OP-amp.
The system will be unstable if the loop gain |T(s)|=|a(s)B(s)|...
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Is there a name for this looped power combiner circuit topology?
I've encountered a circuit topology that has an interesting effect that is so simple in design that I have a hard time believing that it hasn't been studied and named previously.
Here is a basic ...
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closed loop pole of negative feedback
given w be the pole of open loop what in the pole of the closed lop shown bellow?
i have found axpression for GAIN but for the pole i am not sure.
Thanks.
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Low speed brushless motor voltage feedback
A 4 poles brushless motor must spin at 527 rpm, which means each one of its 3 Hall sensors pulses at 17Hz. The STMicro L6235PD motor driver outputs 17 Hz PWM signal proportional to the speed.
To ...
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How to calculate the close loop gain? Am I solving it in the right way?
The following is a question from 8.18 in Design of Analog CMOS Integrated Circuit, page 342.
Consider the circuit this following Fig, \$(\frac{W} {L})_{1-4} =\frac{50} {0.5} \$, \$|{I_D}_{1-4}| = 0.5 ...
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How to handle the noise and wrong measurements due to the actuator in a close-controlled loop [closed]
My system has to inflate a rubber device using a diaphragm pump to a specified pressure (about 1000 Pa, with an ideal accuracy of ±50 Pa). The volume of the device is about 3 L.
The pump is connected ...
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Multi-loop systems block reduction techniques
Do I start by multiplying 18/s+3 * 1/s+3 = 18/(s+3)^(2)?
Then is it (18/(s+3)^(2))/(1+(18/(s+3)^(2)*4)) = 18 / ((s + 3)^2 * (72 / (s + 3)^2 + 1))?
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How to calculate the feedback loop gain with feedback \$\beta\$
The following is from the book Design of Analog CMOS Integrated Circuit, page 319.
Let's break the loop at the gate of M1.
$$V_{out} = - V_T g_m \biggr[ (R_S + R_F) \parallel R_D\biggr] $$
$$V_F = ...
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AND gate IC - "SN74LVC1G08DBVR" is giving a wrong output
I am working on a boost converter circuit that gets 12Volt as input (J1) and gives 18 Volts at the output (J4). I am having issues in the feedback circuit for this converter, especially with my AND ...
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Closed-loop Transfer Function [closed]
help me answer this. pls show me your solutions, that would be very helpful so i can understand how you did it.
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How do I explain this regulation action in terms of control theory?
Shown below is a current regulator circuit which ensures an almost constant current through R1 independent of Vin variations.
There is no closed loop feedback system evident- How can we explain this ...
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CL57T stepper driver not working in closed loop mode
I've bought https://www.ebay.de/itm/393715526356 CL57T with NEMA 23 and it works well in open-loop mode but in closed-loop it goes into 7-blink error mode.
https://photos.app.goo.gl/BnkV1mTWC3q8ZEC99
...
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Estimation of bode plot of closed loop system based on open loop characteristics [closed]
I just got an exam back in which I did the error of not drawing the phase part of the bode plot of a closed loop system. The question sparked, how does one estimate the shape of the phase plot of a ...
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3600PPR NEMA 17 Stepper Motor PPR
What if any additional components would I need to make a NEMA 17 stepper motor have 3600 pulses per revolution? Do I need one or both gearboxes and encoders. My application requires fine degree ...
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How to make a circuit of 6 lights connected to a single battery, with each light having its own switch [closed]
I have a school assignment on how to make a circuit with 6 lights connected to a single battery, with each light having its own switch. I'm wondering how to do this, and I'm hoping for guidance.
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Measuring Motor Speed in an analog circuit - (no digital components)
I have been searching for several resources on closed-loop analog motor control. Most of them used a tachometer for speed measurement, which makes a lot of sense because the tachometer is analog and ...
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Peltier quick heating and cooling
I am using a Peltier module to quickly heat and cool down the object placed on it to a particular temperature. My target is to heat the object to 90° and then cool it down to 54° and then heat it ...
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Why do we talk about system stability as a whole when Barkhausen criteria is valid only for one specific frequency?
The relationship AB=1 will be applicable only at a specific frequency. For instance, following is the bode plot for a circuit I have and as can be seen, the barkhausen criterion is met only at 6.3MEG ...
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How to determine the phase margin when the Bode plot never crosses 0 dB?
I have a graph that looks like this. I am tasked to measure the phase margin, but the graph doesn't exceed 0 dB.
The circuit is this. The input DC level is 0.6 V, which is the problem. When I change ...
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Closed loop system of servo motor for master and slave flex
I am really new in Arduino. So what I have is two flex sensor, a master flex for the left hand and a slave flex for the right hand. What it will do is that when the master flex is bent, the servo ...
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What would be the equivalent circuit of the following block diagram?
They gave me the following diagram, in the references they gave me I was able to obtain the PID block circuit, I only need the circuit of the \$\frac{1}{s-2}\$ function, It sounds like an RC circuit ...
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Controller for boost converter
I'm trying to design a controller for a boost converter by the "shaping loop gain" method as in the Fundamentals of Power Electronics textbook by Ericson and Maksimovic.
I see that there is ...
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Closed loop stepper with unshielded wires
I've bought a closed-loop stepper from a somewhat reputable manufacturer but was surprised to see 2 things:
Power cable is MUCH shorter than the signal cable (they both go to the same place - driver)
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Bode phase plot phase margin
From what I have studied so far, gain margin is defined as how much additional gain the system can be given before it becomes unstable, and this can be measured from the bode magnitude plot ...
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Multi-Pole System - Why is there no bandwidth extension if loop gain is reduced?
[Design of Analog CMOS Integrated Circuits by Behzad Razavi]
The author explains that if the feedback (beta) is made weaker, the plot shifts down and hence, we hit the GX earlier now, thereby ...
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Phase shift oscillator: what is reducing loop gain and how does changing feedback resistor affect things?
I have simulated the following circuit in LTSpice:
One can see that a stable sine wave with a peak of about 6.3 V is obtained, which has a frequency of 1 kHz (I calculated the RC network values to ...
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Phase margin is 90° but transient step response shows overshoot
The Bode plot of the loop is as shown here:
The transient step response looks like this:
The block diagram looks something like this -
basically a single stage op-amp (OPAMP in figure) with high ...
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Need help to understand op-amp input resistor and capacitor network
I'm trying to understand the circuit design from this application note.
Here is the figure:
The author said:
Resistor RIN provides a dc return path for the VS/2 reference voltage and sets the ...
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what is the open and closed loop function of this system?
i found this in the text book.
i solved by:
1- found the closed loop function of just the part of B(p) and its "feedback", let's call it B'(p).
2- after that i did H(p) = A(p) / ( 1 + A(p) * ...
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Closed loop control of a stepper motor (i.e. servo system)
Crucial to the performance of a CNC is its ability to precisely, accurately and quickly move
to the directed position. Stepper motors are perhaps the most popular (and therefore
cheapest) motors ...
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The output of PI controller using opamp is not working [closed]
I am designing a closed loop system for dc-dc converter for that I am using error amplifier and pi controller. For error amplifier and PI controller I am using OP177A opamp. The error amplifier ...
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How to deal with controling force by positioning oscillating magnet?
I am trying to code up a closed loop control system on force generated by the paring of strong rare earth magnets. I do not have much experience with PID logic but i have a weak grasp of the basics (...
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How can we confirm whether the op-amp has -ve feedback? [duplicate]
Many text books show an op-amp will have negative feedback when o/p is connected back to -ve input through some discretes and under such condition V+=V- is satisfied for op-amp input terminals.
In the ...
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SG3525 Closed Loop Inverter Waveform Problem
I'm using a sg3525 ic on a full bridge dc-dc converter in closed loop. The system is working fine, I don't have a problem with it. Output is just like what I want.
The problem is inverter part's ...
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Define input impedance of a buck converter for ideal converter (efficiency 100%) & practical converter
What I know was -The input impedance by the closed-loop buck converter in CCM mode, Zi and, in turn, that presented impedance is dependent on Zo and the duty cycle used by the buck converter
below is ...
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Can any one explain what type of compensation is this
I will be using the UC3844 controller IC in combination with TL431 to achieve peak current mode control in a 150W forward converter. After some research, I found this schematic on the internet:
There ...
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Find gain of this common-gate
I have a large circuit involving feedback as follows
I am trying to find the closed-loop gain of this. Before I can do that, I need to find the open-loop gain. Thus, removing the feedback loop, M2 ...
Null♦
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H-bridge class D amplfier [closed]
i am trying to make a closed-loop class D amplifier for a dissertation. I have the basics:
audio signal-->pwm modulator(LTC6992)-->gate drivers->H-bridge-->LC filter--> speaker
but i ...
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Ideal closed-loop gain derivation for negative feedback
Considering a negative feedback system, the closed-loop transfer function Af is given by:
where A is the open-loop transfer function and AB is the loop gain.
Every text I read says that if the ...
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Setpoint weighting algorithm for the PI controller
Some time ago I found an interesting modification of the standard PI controller algorithm.
The modification is called the setpoing weighting in the literature and regards the proportional component of ...
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4 wires encoder to 6 wires Hibrid Servo drive for closed loop stepper motor
I have the HBS860H driver and LPD3806.I wanna know if I can connect this 4 wire encoder, to this 6 wire driver.
HBS860H:
https://hardware-cnc.nl/images/PDF/ACT/HBS86H_English_Manuel.pdf
LPD3806: (i ...
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What is the significance of phase margin in an open loop amplifier?
I know the importance of phase margin to ensure stability in closed loop systems, but what about in open loop systems?
I am designing a regulated common based LNA IC that operates in open loop.
Can we ...
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Interesting driving circuit of a voice coil actuator
I have an interesting circuit to drive the voice coil stage of an old acoustic microscope. I am struggling to understand what the different functions of the opamps in this circuit are.
The circuit ...
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Determine if the system is stable [closed]
Determine if the system is stable?
How is this done? Is this at one frequency? Is the Loop gain is A x B x C = 0.5
Should phase angles be added together = 173 degrees?
Should I be considering the open ...
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Confusion regarding finding closed loop transfer function and damping constant from open-loop transfer function
I have second order transfer function $$ G(s) = \frac{1.247}{s^2+9.76s+23.8}$$ G(s) is in the forward path of a unity feedback system.
How do I find the closed loop transfer function and damping ...
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Understanding Total Response
QUICK INFO:
I am currently studying about closed and open-loops systems.
BACKGROUND STORY:
Imagine a big antenna is placed on a hill and there is a lot of wind. You want to turn the potentiometer so ...
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unstable systems with positive phase/gain margin
Open loop Phase/Gain margins provide information on how much margin the closed loop system have until it becomes unstable. In other words, how much you can increase the effective loop gain and or ...
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Circuit stable in the Bode diagram, unstable in step-response
I am designing a simple current control circuit and trying to simulate it in LT Spice. The circuit is not optimized for some real-world application, it's more a learning method for me to get grip on ...
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buck small signal modelling
I have a synchronous buck converter and my inductor current looks like this:-
To add voltage-mode closed loop control, I need to do the small signal modelling of the converter. I am a bit confused if ...
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Bode plot in Pspice
I want to get the bode plot of the controller part of my Buck converter. For this I looked online and saw a technique that mentioned to add an AC injection source from the voltage output to the top ...
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