# Questions tagged [circuit-analysis]

Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network. Consider using in conjunction with tags for the particular analysis technique(s) in question: "nodal-analysis", "mesh-analysis", "superposition", etc.

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142 views

### automatic submersible pump actuation project

I have a project for automatic submersible pump actuation using a microcontroller. I've done for two voltages like 5 V and 12 V and its corresponding relay. Also, in each board there is a transistor ...
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### Need help to identify an unmarked SOT23-5 IC

I have come across a PCB which is a vibration sensor (switch) based motion detection logic, where on any vibration is detected, the circuit will turn on/off a load. It works in same way as a Push ...
342 views

### Transfer function of an electromechanical system

In this exercise I am asked to find θc(s)/θR(s), of which I am given the following indications. In the system shown in the figure, the motor is an armature-controlled dc motor, and there is also a ...
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235 views

### Can this Raspberry Pi UPS circuit work?

I created following UPS circuit to shutdown my Raspberry Pi 3A+ properly: I would really appreciate if somebody can review my circuit. I know it's a little bit hard to read, but I'm sorry. I'm a ...
190 views

### Appoximation of a transient response of a more complex circuit

I have a "complicated" circuit that I want to approximate as a simple harmonic oscillator. More info below. I have a parallel LRC circuit, with some extra input and output load resistors and coupling ...
42 views

### Find the open-circuit voltage ratio of the following two-port network

This is the circuit: Here's what I have done: I converted the part before the input of the two-port network (1 capacitor and 2 resistors) into another two-port network and derived the transmission ...
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### How does this capacitance measurement op-amp circuit work?

I'm studying this scientific paper where a capacitance measurement is done with the circuit shown at page 3. For simplicity I reported it here: A sinusoidal signal is applied at the input through a ...
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534 views

### Where does the 1 V voltage come from?

I have a PLC with many digital open collector outputs connected similarly to the schematic below. If I use a multimeter and measure the voltage between the two points in the schematic, it is showing 1 ...
2k views

### How to find new ABCD parameters when reversing 2-port network

I have an ABCD matrix represenataion which is defined as: For such a problem, what approach should I follow in order to organize the new ( reversed) network ports voltages and currents properly. I ...
29 views

### PSpice Error: Voltage source and/or inductor loop involving V_Vin

I'm trying to simulate the circuit in Pspice; the first few times it worked. However, I got an error when I tried to create a new page and copy all the circuits on it in order to do some circuit ...
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84 views

### Negative PSRR of Two-Stage Op Amp

From page 4-9 of this lecture note https://pallen.ece.gatech.edu/Academic/ECE_6412/Spring_2004/L180-PSRR-2UP.pdf, it gives example on how to model a Two-Stage Op Amp to find the PSRR- when $V_{Bias}$...
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### High pass filter simulation involving loop outside the circuit

I am trying to model a tweeter filter circuit from GR Research's X-CS Encore loudspeakers, more specifically get the transfer function Vo/Vi. I have included an example of how I did it for the woofer ...
84 views

### What is the purpose of connecting the series capacitor to the low side P- channel MOSFET gate?

The datasheet describes CAOUT as a decoupling capacitor. Not sure how it is so ? My guess on the working of the circuit: When AOUT is high, CAOUT is gradually charged with +(on left) and right ...
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### Selecting the proper resistors in a bi-directional level shifter?

How do you calculate the values of R1 and R2 in the circuit for a Bidirectional Logic Level Shifter if the high and low voltages are known? Searching on the Internet I found 10K is a good option to ...
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66 views

### Dependent current sources in Thevenin equivalent

In this question to find out ZTH, why have we put a 1 A current source? Can't we just short circuit the VTH potential and find the current across that to find ZTH? Source: https://i.sstatic.net/9KVGu....
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### Design of a DC motor controller

I want to design a control system to a DC motor using descrite component and not IC component. At the aim is to control the speed of that motor, but at the first time I want to design the inner ...
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### Connection from breadboard to stripboard

I already have my circuit placed on breadboard. Now I need to transfer it on stripboard. My question is I can just transfer the exact same connection and placement on stripboard right? I don't need to ...
487 views

### BJT amplifier design

I am trying to design a BJT amplifier with the given parameters and limitations. The circuit is shown below. Parameters: Vcc = 15 V RL = 20 kΩ beta = 180 Vbe(on)= 0.6 V Cµ = Cπ = 0 Limitations are: ...
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532 views

### Trying to perform transient frequency response with LTspice or Microcap, TL494 compensation

I have tried to do Bode plot of my uncompensated plant by myself in LTspice 17.1, but the result looks strange to me. This topic is a follow-on to this one.. I have no clue why it comes with 290 ...
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### Can anyone help me find this IC SZ9KH?

I tried looking for datasheet for SZ9KH but can't find anything. I encountered this IC on a board that needed to be amplified. Mostly i want to know how does the amplification works? Is it an op-amp ...
136 views

### How to solve the equivalent circuit of the induction motor?

Let's say I have below given equivalent circuit of the induction motor. The parameters $R_S$, $R_{Fe}$, $R_{load}$, $X_M=2\pi\cdot f\cdot L_M$ and $X_L=2\pi\cdot f\cdot L_L$ are known and ...
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When I look at the waveforms of simulated circuits, how do I know when their behavior (for example flipping value stored on a node, or an unexpected drop in strong level value...) is due to MOSFET ...
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51 views

### Sensitivity of Inrush Current Circuit

I'm new to LTSpice and analog design - I'm having a bit of a struggle getting a feel for the behavior of this inrush limiting circuit. Stole the design from another SE post, but playing with the ...
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122 views

### RHP pole of two stage OTA

I learnt that for any amplifier (with some capacitor) if we short/open the capacitor and the polarity of gain changes, it is a sign of RHP zero. Now, while applying the same analysis I obsevred that ...
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431 views

### Current Direction and Voltage Polarity in Capacitor/Inductor Circuits

I believe that this question may be simple for those with a little more experience, but it is still puzzling me. Studying capacitance/inductance, I understand that the capacitor in the DC case behaves ...
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### Can anyone help me figure out what this circuit does?

I wanted to see if anyone might be able to help me understand this circuit board a bit better. I am trying to trace some issues I'm having with my car stereo and this board is the furthest I can trace ...
186 views

### Small signal analysis of MOSFET circuit

The other day I got the following exercise on one of my exams: For those who don't speak German, for transistor 1 lambda is 0, but not for the others. The backgate-effekt should be neglected ...
50 views

### How to measure 10bit SAR ADC 's input Dynamic range after switch 9 time?

I want to know 10 bit SAR ADC , supply voltage 0.5V , Vcm based , after DAC switch 9 times , how to measure DAC input Dynamic range ? I need to know voltage range that I can use Voltage to time ...
395 views

### Ideal Transformer Currents Relationship

I'm currently quite confused with the relationship of the currents for an ideal transformer when it overlaps with multiple mesh currents. It was defined that for: \frac{\bf I_2}{\bf I_1}=\frac{1}{n}...
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### How should fuse selection be made in discrete-time alternating current?

My V(t) signal progresses for hours as 0.75 seconds on,5 seconds off.(Let assume V(t)=I_lamp(t),R_lamp=1 ohm) The general formula for fuse selection at room temperature is: In summary,what should I ...
370 views

### 555 PWM circuit set frequency shifting after 2 months

Please refer to post PWM generator circuit review for initial simulation and bugs on the circuit. In general, the circuit works very well and I can control a 12V fan with the PWM output of the 555 ...
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300 views

### finding state space equation in x=Ax+Bu form

Can anyone please help me to find the state space equation of this circuit diagram in the form of x=Ax+Bu? The equation I am getting is not giving me square matrix. Can anyone help please? These are ...
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### What is the effective value of the current of the voltage generator?

I need help with this task, if anyone had a similar problem it would help me. The task is: A voltage generator is connected to the primary of an ideal transformer, transformation ratio n rms values ​​...
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### karnaugh table issues

Hello,I have this truth table.I did this table and I am creating a demultiplexer 1 in 2.Not multiplexer. Second,I did and that I gave and those Am I right?I want to confirm that I have done it all ...
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1k views

### Left half and right half plane zeros

In the common-source on the left, one can solve for the transfer function and see that there's a right-half plane zero at $s_z = +g_m/C_{gd}$. For the source-follower on the right, similarly you can ...
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