Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [control-loop]

45 questions
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How to achieve very accurate/fine rotation with motor

I am running an experiment where I need to rotate a lightweight dial (<5 grams, so very low torque requirement, and fairly slowly), but need to do very accurate, fine steps of 0.03 degrees. Something like this (shown as direct-drive here, but I'm…
boardbite
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Does this voltage regulator use "on-off" control, or is it a voltage follower?

In Electronics A2 (GCE), we are currently studying voltage regulators. An example voltage regulator circuit is provided using an op-amp and a power MOSFET. I would judge this to be a voltage follower. The workbook however claims it uses on-off…
Thomas O
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What is a Jaffe-Rechtin PLL?

Eberhardt Rechtin and Richard Jaffe (both involved in NASAs DSN) published this paper (paywalled) on PLL-design and -performance back in 1955. It is referenced quite often, so I wanted to understand what makes a "Jaffe-Rechtin"-loop or -filter. I…
Andreas
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Loop compensation design of buck converter

I am trying to design loop compensation with type-3 error amplifier for a buck converter. I'm a student and very inexperienced in this subject. Please bear with me. Here is the general procedure that I've gathered from reading many many application…
JGalt
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How to improve current control loop in power supply?

I'm working on MCU programmable bench power supply. Its range is 0-50V and 0-3A programmed in 10mV and 10mA increments. It will be published as open hardware and source code that anyone can use it if find it usable. My "expertise" is more on…
prasimix
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Operational amplifier using power supply current as output

I have come across a circuit (I am not allowed to share it) with an opamp that uses a special output. The opamp's output is loaded with a resistor and has no other connection. It is the current drawn by the opamp that is used as output instead. This…
Hyp
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Comparator as operational amplifier

Using an operational amplifier as a comparator was asked quite a lot times here, but how does it behave the way around? I've a really cheap one in my circuit with low hysteresis and a MOSFETt push/pull output stage. Using it as a two point regulator…
Florian
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PFC controller - How does it work?

I would like to better understand how a PFC controller works, especially PFC which work in CCM mode. I found the following documentation from International Rectifier:…
Jess
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What does Dominant pole/Pole mean related to capacitors and filters or Electronics in general for intuitive understanding

I am trying to understand the feedback compensation techniques of DC-DC Buck converters. And I drift to more and more small questions which make me want to understand the basics of poles/zeroes/frequency In this link the answer given by user Kaz, in…
user220456
3
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2 answers

Confusion in feedback for switchmode dc/dc converter

I have a slight confusion in how the feedback pin works. The "\$V_{ref} \times (1 + R_1 / R_2)\$" seems like a shortcut to me, and I have trouble understanding how to feed a voltage in to it, to say make a tracking pre-regulator to always maintain…
Sasha
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Nyquist stability criterion for positive feedback

it is known that the stability of a system with negative feedback may be analized through the Nyquist stability criterion, which is based on observing the number of turns around the point (-1;0) in the complex plane. But, what if we want to apply…
Kinka-Byo
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Trouble understanding Loop Filter in a PLL

I'm currently trying to understand the function of a loop filter. But where I'm stuck is that I know the output of the charge pump is a series of current pulses whose width is proportional to the amount of time that the there is mismatch between the…
user1505399
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Loop compensation of a Buck Converter

I have a buck converter. TPS54260 Vin = 7V-20V Vout = 5V Iload=600mA. I realise that there is a similar question in this forum but I was not able to get clarity. I want to understand what do you mean by loop compensation and how to select my output…
user220456
2
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2 answers

Transfer function of phase change controlled with capacitance

We have an RLC series circuit with sinusoidal voltage source of frequency \$\omega\$. The normal transfer function of current to voltage is: $$ G(s) = \frac{I(s)}{V(s)} = \frac{1}{R+s L+ \frac{1}{s C}}$$ We would like to find out the transfer…
dante
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Root locus of discrete time system

I have a question about a probably easy task, but I can't find the right K. I have the loop with an adjustable gain element given: $$Q(z) = \frac{H(z)}{1+ K\cdot G(z)H(z)} $$ I have given: $$H(z) = \frac{z}{z+0.5}$$ and $$G(z) =…
JavaForStarters
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