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Questions tagged [circuits]

Use for questions primarily about circuit design, components, testing or other practical applications.

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18 views

I am a little confused about how a 2-bit adder works. For 1-bit adder, my understanding of it is fine and I am able to draw out the truth table for it. However, if lets say I have a 2-bit adder, I can'...
26 views

Cannot understand an equation related to impedance. (Power system analysis)

Can someone explain how can we find |Z| term and also from where does the cosine term arrive at the final equation.
20 views

Using TI-nspire CX CAS to expand a fraction with complex poles

For solving some circuits for a class I am trying to figure out how to expand a fraction of my calculator with complex roots. expand() expands a fraction with no complex roots. factor() factors the ...
36 views

What's the most practical way to measure angular velocity for small rotations?

I'm looking to measure the angular velocity of an arm as it moves. It seems to be a difficult thing to research, since the term 'angular velocity/frequency' is usually reserved for other areas of ...
51 views

I am trying to create an op amp based negative voltage regulator

I am trying to find simulate an op amp based linear regulator negative voltage regulator circuit. I have done the circuit for positive voltages, but does not know how to do it for negative voltage. ...
37 views

My output is much lower than I expect it to be for my transistor-zener diode voltage regulator

I have created this simulation ( see below) of a transistor and zener diode voltage regulator. The output is supposed to be a steady 5 V. But it is like the top bit s cut, to an approx 4.4 V value, ...
65 views

How do I calculate voltage at an LED in parallel?

I have this circuit: If D2 was a resistance, I could just combine it with R2 to get some composite resistance that I could put in series with R1. That way, I could calculate the resistance of the ...
47 views

How to choose type of output from a water level switch?

I need to buy a level switch for a quench tower water drainage system. I intend to use its output directly to open a solenoid valve to drain the tank when the switch detects water and close it ...
33 views

Voltage controlled switch?

So I am in the process of working on a rather strange and specific project. I am looking to capture as much energy as possible from a small steam turbine using a DC motor and then use that to power ...
29 views

Unbalance voltage mesurements from 63 kV power transformer

After testing a power transformer(pt) and closing its wiring terminals I've encountered that phase S 63 kV correct voltage and phases R and T shows incorrect voltage 32 kV. Can any body tell why?
33 views

How to prototype this circuit using an Arduino and breadboard?

I'm trying to build this circuit for a force transducer such that the data is logged by an Arduino Uno. I have the op-amp recommended in the schematic, but I haven't been able to get stable readings ...
22 views

Help on solving and deriving equations for the Output Voltage on a Voltage Divider with a Load Resistance?

I'm having trouble understanding how to derive the equation to solve the output voltage for a voltage divider with a load resistance. One of the problems that I'm solving says that the equation is Vo ...
77 views

Thevenin equivalent impedance in laplace domain

I can't understand why $Z_{th}$ doesn't include $3\ \Omega$ resistance.
116 views

I want to understand this pneumatic circuit

I have trouble understanding the following pneumatic circuit diagram: I am new to reading circuit diagrams and i am unfamiliar with some of the symbols. I would appreciate if somebody could explain ...
26 views

Utilize multiple vehicle power outlets to increase wattage capacity of inverter

I'm trying to determine whether it would be possible to use multiple power outlets in vehicle to increase the wattage that can be obtained. This question is driven from a desire to install an DC to ...
61 views

Mosfet switching circuit

I am trying to make a MOSFET switching circuit where its gate input is 12V clock pulse. Now when I put the load between (Vdd) and (Drain), there is no drop voltage VDS, but when the gate input falls ...
113 views

Simultaneously charging and transmitting data to an android phone using usb

Dear engineers, I have to make an engineering project which is a portable solar phone charger. One thing I need to do in it is to somehow charge the phone (android) from the battery (which is charged ...
76 views

How would I measure this battery circuit with a multimeter?

The wire is attached to the bottom of each D battery. I already know that I have to put the bottom of the light bulb on the positive side of the battery. My multimeter looks like this: I'm not sure ...
42 views

Using Stainless steel or iron pots in oven [closed]

Today I was using oven in my office with a plate of meal the plate was made of stain less steel, my colleague rushed and asked me to take it out otherwise the oven will be short circuit So please ...
58 views

Replacement components?

I'm building a tracker for a high altitude balloon but some of the components are out of stock and may not be in before our launch date. I'm good with an iron but have limited engineering knowledge. ...
87 views

Find average electron velocity on copper bus bar(um/s)

I was given this problem: A current of 1,400 Amps flows in a copper bus bar. The bus bar is 0.6 cm wide by 9 cm long. You can assume the current flows only on the surface of the bus bar (so you can ...
495 views

Which is the branch of engineering that deals with making gadgets?

Background I am currently preparing for Entrance Examination for Engineering college , somehow I noticed that I don't even know which branch I want to take and what is the kind of Education I am ...
66 views

Adding an R2R Digital to analog converter inline with TRS connector

I am trying to create a simple R2R DAC, maybe 8-16 bits. I want to be able to that type of DAC inline to a headphone line. Since the an 8 bit R2R DAC will need 8 pins, how exactly do I wire up a TRS ...
76 views

Help with two-port network parameters problem! [closed]

Help me, please. I im studying circuit analysis and i couldn't solve this problem.
54 views

Measuring Current In/Out of Resistors [closed]

The banana clips attach to a multi-meter out of view, the power supply wires are correctly in place, and the resistors are correctly in place. Would putting the red left-hand banana clip and its ...
126 views

Designing a Voltage Divider [closed]

I am struggling to solve this problem and my available time conflicts with my professors available time. Could any of you offer me some help, perhaps describe the method I would use to solve such a ...
43 views

Comparisons of multiplier circuits

Could someone please explain some of the advantages/disadvantages of the wallace multiplier circuit vs a shifting and adding multiplier circuit vs an shift register multiplying circuit? We went over ...
161 views

Calculating gain of an overall system. Analogue electronics

Our professor has given us a review for a upcoming exam. But he has never done anything like this question and it has stumped a quite few of us. We are hoping someone can walk us through this so we ...
32 views

Is the current on the terminals of an opened circuit is zero?

Say we got this circuit: Initially we had the X resistance, but then I opened the circuit in the terminals of resistance X, and I moved the resistance X to the equivalent circuit (my teacher says ...
152 views

Ideal op amp circuit with variable voltage gain, how do I calculate the current?

I am currently calculating various quantities for the circuit shown below. However, I am stuck on how to calculate the current (Ix) and the input resistance (0 output current). The circuit is an ideal ...
25 views

How do they get more signals simultaneously inside a node of a neural network? [closed]

Why the circuit does not freeze/lock when the signals SUM ? But the electrical signals are SUM together in what sense? This question is about neural network circuits because I don't understand what ...
517 views

Multi Ratio Current Transformers

I encountered a problem in measuring electrical energy using a multi ratio current transformer (CT). The catalogue of CTs is unavailable. I have little information about the type of CT I am using. I ...
203 views

How the electronic circuit control laser diode? [closed]

I find this scheme here 1 - is data stream come from computer. This 'data' is an electric signal moudulated by the n°2 2 - this is the electronic circuit inside printer that a) activates the corona ...
1k views

No Voltage appearing on Pspice

I am trying to compelte this question, however when i run the simulation there is no voltage atall on the output votlage, and cahnging the capacitor value as requested in the question does not chane ...
57 views

Help with reading resistor color codes

I'm having a difficult time identifying a resistor's value as I can't find the golden / silver tolerance line. The problem is that I can't see a silver or gold line here! They're both brown on both ...
96 views

Looking for a device that breaks the circuit if the voltage gets too low

I'm looking for a device that breaks a circuit once the voltage of my battery gets too low. This to protect the battery. Example: I have a 12V battery, once it reaches ~11V the huge voltage drop ...
122 views

What are the various lumped element dynamic system models called?

What are the various lumped element dynamic system models called? By lumped element dynamic system models, I mean the various nodal models comprised of things that look like capacitors, inductors, ...
120 views

I am having trouble finding a 3.4 µH through hole inductor that is in stock right now. I was wondering if I can just place 2 inductors that add up to 3.4 µH in series to solve this problem. I am not ...
89 views

In the equation for power as a function of current and resistance, what do the two factors for current represent?

In the electric power equation $P=RI^2$, $P$ represents the product of $RII$. I'm trying to understand the fundamental anatomy of the $RII$ term. More precisely, why does the current, $I$ appear ...
941 views

Transformers with no load [closed]

Could someone please explain why, when there is no secondary load, the applied voltage of the primary roughly equals the back EMF of the primary? Since the primary coil is an inductor I wondered ...
42 views

Units for plasma etching of circuits: A (with degree symbol)/min

Background: I'm a statistician working with a design of experiments example regarding plasma etching of circuits, and unfortunately, the author does not define what is meant by the units used for the ...
1k views

How do you find “this” Vx in the given circuit?

So I was told that $V_x$ is equal to 10V. I tried reasoning out why $V_x$ was 10V and this is what I got: -You can treat the Vx as an open circuit which means current does not flow through the ...
288 views

Is battery-charge-stop-at-XX-percent circuitry not cheap? [closed]

I'm curious why IBM/Lenovo ThinkPad line is basically the only manufacturer/brand of mobility devices that includes circuitry and software that allows one to vastly prolong battery life of laptops ...
269 views

What does this Logic Circuit do?

So I have to analyze this circuit, with inputs C0, A0, B0, A1, B1, A2 and B2, and outputs S0, S1, S2 and C3. It's been suggested I don't use a truth table to figure it out. I need to find out what the ...
1k views

SolidWorks circuit simulation?

I use Labcenter Proteus Circuit simulation - you create circuit design, then apply current and see simulation in action - for example leds are blinking, or motor is rotating. If there is ...
1k views

Is there current multiplier circuit?

Is there an electric circuit that can multiply the input current? if yes, what is that called, and how to make it? My input is DC from a small DC motor which I use as a generator. My input current is ...
126 views

Help with closed loop heat controller (for a non engineer)

I am interested in setting up a controller which can modulate the output of 2 hotpads based on input from an infrared thermometer. The hotpads have their own dials, but I am considering controlling ...