All Questions
Tagged with closed-loop feedback
13 questions
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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 ...
- 179
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3
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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 ...
- 3,156
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967
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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 ...
2
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1
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98
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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 ...
- 3,235
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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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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 ...
- 91
1
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3
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410
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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 ...
- 305
1
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1
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65
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What is the controlled variable in this particular case?
I have a question, maybe you can help me because I am not sure of the correct definition.
As an example I have a plant with a measured output y in a closed loop system. But as the feedback variable I ...
- 21
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2
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Closed Loop Transfer Function - PD Control
For the following control system, I am trying to find the characteristics of the system.
I have firstly found the closed loop transfer functions \$T(s) =\frac{C(s)}{R(s)}\$ , to be:
\$G(s) =K_p(s+9)...
- 13
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1
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Closed loop vs. open loop system analysis and design
I have found questions similar to mine in the forum but none were quite answered to my full satisfaction. I have two questions:
1) Why is controller design is traditionally done with the open-loop ...
- 43
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152
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Closed loop equation initial value
I am doing math for a closed loop equation. I know the transfer function for a closed loop system is:
(Image copied from "Loop Gain and its Effect on Analog Control Systems" by Gabino ...
- 59
2
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2
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155
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Proportional Control Balance Beam
Bit of an unorthodox question I'm sure, but I'm making a balance beam (two rotors on either end of a see saw) with proportional control, and I can't seem to get it to balance at 0.
The proportional ...
- 39
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131
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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 ...
- 3,235