Control refers to systems that control other systems, whether that be industrial machinery, lighting or devices used in a home

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How to simplify this block diagram to get the given transfer function?

Given this block diagram, I'm trying to derive the transfer function. I've tried moving the 2 branch to either side of the then getting something like this But I'm not sure how to simplify it ...
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2answers
46 views

Finding transfer function of this RL circuit

Have a look at this circuit. I am to find the transfer function which is defined as \$V_L(s)/V(s)\$. Now I don't understand the solution. First of all, it defines \$V_L(s)\$ at the bottom as ...
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2answers
63 views

Slow down stepper motor's speed using stepper driver DRV 8825

I've got a Nema 17, rated at 0.8Amps, stepping angle of 1.8 degrees. The motor looks like this, and has six wires coming out of it: The four wires I've used are the ones labeled below (I was ...
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1answer
60 views

Need suggestions on control system engineering [closed]

I am sophomore studying control systems and the problems given in the books( like Norman Nise ) look too easy. Please suggest some good book with really good problems.
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2answers
93 views

How do I control several individual LEDs with Arduino?

I am working in a book store and I have the task of making an indication of a book place in the Library Cupboard with LEDs. I need to control about 300 LEDs with Arduino. What is the optimum way to do ...
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0answers
40 views

Any simple way to find the roots that lie on the left of s+1

The characteristic equation of a control system is $$s^5+15s^4+85s^3+225s^2+274s+120$$. What are the number of roots of the equation that lie to the left of the line \$s+1\$? My view: I have done ...
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2answers
111 views

How to calculate Kp, Kd and Ki?

The motor operates within 140 rev/min to 600 rev/min. The controller gives an output in the range 4 to 20 mA. The sensor output reading equivalent to 400 rev/min, actual reading was 404 rev/min. The ...
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1answer
40 views

Transfer Function: State Space for DC motor

General question on making state space equations for a DC motor. In the link below, why are both the electrical and dynamics equations 3 and 4 used to make a state space eqn.8, instead of combining ...
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1answer
40 views

How do I enable/disable a running 555 astable oscillator with a control signal?

I am going to control a fan using PWM signal. PWM is generated by a 555 IC. The duty cycle rate of the PWM is controlled by a PTC thermistor. And an NTC thermistor decides when to turn on and off the ...
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1answer
145 views

Linear Regulator: MOSFET vs BJT

Currently I am doing a project on a voltage regulator. Can you tell me some advantages of MOSFETs over BJT? Apart from a higher power loss, I can not find much. In control engineering it is much more ...
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1answer
64 views

Response of a stable second-order transfer function to a unit sine wave input

In the lecture slides from my university it says that: "The response of a stable second-order transfer function to a unit sine wave input is:" ...
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1answer
37 views

When do I have to use rectifier-inverter, and when is “dimmer circuit” sufficient in driving AC motor?

I'm trying to design a device that is to use a variable speed 1-phase AC motor. I still haven't decided upon power and other parameters of the motor. I have a few models to choose from, with "bigger ...
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2answers
169 views

130V DC Motor Control

I am interested in building a control circuit for a motor. More specifically this motor. The model I want to control is the 130V model, 0.48A, which should make it at ~62W for the motor, and 1/17 ...
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2answers
47 views

Model and Control of a Physical System [closed]

Suppose i have a physical system (set of interacting elements ) that i want to control. Best thing we can do to understand this physical system and hence control it, is to model it. We ...
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1answer
72 views

Contact arcing, how to avoid?

Recently my water heater's thermostat failed. It's just a simple mechanical one, with a piece of metal that "pops" and connects or disconnects the heating element. I would guess that what made it ...
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2answers
277 views

How do I find the second order transfer function from this step response diagram?

I have the following diagram of a system's step response: I'm having trouble understanding how to calculate the system's transfer function, given this diagram. Specifically, I don't understand how ...
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1answer
116 views

does Tera Term handle software flow control internally? [closed]

The title may be a little confusing but i'll explain the situation: We have the following situation: ARM MCU -> UART -> FTDI chip -> USB -> PC -> Tera Term terminal The FTDI chip has built-in hard- ...
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1answer
97 views

Practical Limit of Feedback Control Systems WRT Bandwidth

In a digital feedback control system, I'm interested in the practical limit of what the correctable bandwidth is. For example, given a very simple system: A sensor can sample a simple X position ...
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3answers
110 views

What is the usefulness of Internal Stability?

In the analysis of a feedback control system is it important that a sub-network be itself stable. i.e. if I were to break apart the main complex system and just study a single feedback loop, is it ...
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6answers
753 views

How to create an electronically controllable resistance to a physical movement?

What is the best way to create an electronically controllable resistance to a physical movement? For example, at the gym you control the resistance to movement by putting more load, more weight. Is ...
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0answers
187 views

How well does a Variac work for fan speed control?

I would like to run a standard multi-speed desk fan at a lower speed than its minimum setting. On Amazon, one reviewer recommended a variac for fan control, saying that it could adjust the fan from ...
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1answer
62 views

Digital Control Engineering book recommendations [closed]

What are good books on digital control engineering specifically? I'm a third year electrical/computer engineering student who will be doing a course on digital control next semester, but would like to ...
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1answer
59 views

Stepper Control using DC Brushed Motor Driver

Is there any way to control a bipolar stepper motor using one or more DC brushed motor drivers? My only interface to the motors is setting an integer to represent their speed, ex -100 to 100. I ...
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1answer
128 views

PID controller modelling

According to the following simple PID control system: We could create the equation: $$(R(s)-Y(s))C(s)P(s) = Y(s)$$ Wich will lead us to $$\frac{Y}{R}=\frac{CP}{1+CP}$$ So, if we want to ...
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2answers
355 views

Voltage regulator vs. voltage controller

I frequently meet the references to voltage-regulators and voltage-controllers. However, looking at the specs I find them to perform the same function. Is there a difference between the two, or ...
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1answer
74 views

Determine the robustness of a controller

How do I determine whether a PID controller I've designed is stable? How do I determine its stability due to the transfer function it's being applied to, and how well it rejects disturbance and ...
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1answer
69 views

Observer Based Control System Design

Consider the discrete-time system described by $$ x(k+1) = \begin{pmatrix}0 & 1 \\ -2 & -3\end{pmatrix}x(k) + \begin{pmatrix}0\\1\end{pmatrix}u(k) $$ a) Find a feedback state vector that ...
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1answer
41 views

State Feedback Controller

Are there any values of \$\alpha\$ for which it is possible to find a state-feedback gain for the system by bringing all closed-loop poles to zero? If your answer is affirmative, find a feedback ...
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1answer
73 views

Transfer function - get rid of zero

I have a close loop transfer function, consisting of a system and a controller (PID). For some reason does it create 2 zeroes which creates an undershoot which should not appear at all. I don't ...
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0answers
44 views

Nyquist VS Nichols plot

Which is the most commonly used: Nyquist or Nichols plot? Do they have their own particular use or is it just a matter of preference?
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2answers
184 views

Preventing relay contacts from sparking on disconnect

I am currently using an 80A automotive relay to control a motor. The relay seems to work great to control the motor, but on disconnect a visible spark can be seen through the clear relay housing. I ...
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1answer
92 views

Mode toggling circuit using only transistors, resistors, and capacitors?

I’m trying to build a circuit that: Does not draw power when in an idle state (when it’s not lighting up an LED). When the user momentarily presses a button, the circuit keeps an LED on for either 1 ...
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3answers
173 views

Auto detect LED failure

I'm using bunch of LEDs with red, blue and yellow colors in a product for sign indication. the product has total around 150 LEDs of all three different colors. As these LEDs are purchased in bulk, ...
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1answer
89 views

Calcultions to choose between a transistor (switch)

thanks in advance :). I am a little bit confused, i need to turn on a led lamp (5watts), using a light sensor from my Arduino. I was reading a lot of theory the past two days. Here is the deal: ...
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4answers
189 views

heat air with nichrome wire

108 rows of grapevines, each row 650 feet long. Suspend a nichrome enameled wire along each row in order to raise the temperature of the air within 18 inches of the wire 6 degrees Fahrenheit. What ...
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2answers
65 views

Arduino and several leds

Can an Arduino turn on multiple leds at the same time?. I want make a home made lamp with several less controlled with an Arduino UNO light sensor and i already have the light sensor, also i know how ...
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1answer
77 views

transfer function and error gain function

simulate this circuit – Schematic created using CircuitLab I know the difference between those two functions , but i want to see the relation between them , i think that the error gain ...
2
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4answers
275 views

Importance of keeping the electricity network frequency stable

The frequency in the electricity network is kept in balance by primary and secondary control among others (see e. g. here). I read that frequencies below 47.5 Hertz are dangerous and can lead to ...
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3answers
62 views

Erratic outputs from a second order system when input is too small

I'm modeling a simple Mass-Spring-Damper system to represent the torsional behavior of a micromirror. With references to some papers (this one mainly), I've constructed the model of a torsional mass ...
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2answers
150 views

3.7v > 3.3v voltage stepdown with logic-driven on/off control [paused]

(PAUSED): This topic is currently on hold as I source necessary hardware. I need to connect a Wi-Fi/RS232 module to a low-powered monitoring device, and for maximum portability, I'd like to power the ...
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1answer
77 views

Differential Drive for Heavy Robot

I'm asking here another question in relation to my previous one. I would like to know how would one proceed when you want to control a heavy robot with differential wheel drive. When it comes to ...
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2answers
51 views

Connecting DAQs in Parallel

I need to connect a DAQ to an existing system which uses a DAQ. The idea is to connect the DAQs in parallel so the existing system is not changed. It is likely that only one DAQ will be used at a ...
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1answer
296 views

Control 12V MOSFET with 5V, with PMW pass-through?

I am new to electronics, and still tying to fully wrap my head around MOSFETs. I have a few questions about controlling a 12v MOSFET using only 5v to the gate, and an incredibly small amount of ...
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0answers
73 views

Activating Triac, signal conditioning

I need help with the following circuitry. Basically it is a correction of a bug in one of my company's products, an automatic glass door controller. What it is meant to do is when I give the lock ...
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4answers
145 views

How can I control a LED with two separate control circuits?

I have a LED controlled by a microcontroller. I want to know how I can bypass this microcontroller so that I can control the LED with a separate current. Would I use transistors to switch between the ...
3
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5answers
138 views

System response types

Whenever I am given a system type with a certain transfer function, I am always asked to proceed to find out the 1. impulse response and 2. step response of the system. My question is, what is so ...
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1answer
65 views

SSR function con control panel

I'm new in electronics and would like to build an electric brewery with an electronic control panel. I found on www.instructables.com one control panel and is described as in following image. Could ...
3
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2answers
132 views

Pole-zero cancellation Paradox

Suppose we have an open-loop transfer function $$G(s) = \frac{1}{s(s+a)(s+b)}$$ If we plot the root locus for the closed-loop system we will get roughly something like this : Now the question is ...
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1answer
245 views

Regulating 220v AC voltage for halogen lamp with Arduino

I am making a project based on Arduino which is about regulating the brightness of 220v AC halogen lamp. I've read that halogen lamps are the easiest ones to regulate the brightness. However, ...
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1answer
138 views

how to regulate parallel port pin output voltage to 5V

simulate this circuit – Schematic created using CircuitLab Parallel port ideally gives TTL logic 0(low) and 5V (high). But my port gives 3.3V high. I have designed my controlcircuit ...