Questions tagged [circuits]
The circuits tag has no usage guidance.
32 questions with no upvoted or accepted answers
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Problem with battery power circuit
I am a 14 years old boy and I am currently making a MacroPad with a 3.7V battery and a charging circuit but powering the circuit with a battery does not seem to work. I also have made some ...
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Designing the first stage (common emitter) of an amplifier that will drive an 8 ohm speaker
I have to design an amplifier (can be one stage or multiple thought I am thinking multiple) that will drive an 8-ohm speaker and have a gain of at least 10 V/V (about 20 dB) given Vcc = 9 V. It also ...
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Working of the Peak Torque in a BLDC
We have a BLDC motor of the following specifications , and I wanted to ask that :- If the Peak Torque lasts for about 10 seconds once activated, then after what time interval can it be activated again?...
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Tricky AC power Question
Greetings all,
Just to be clear, I am not asking anyone to do my homework. I am simply asking for guidance and or to clarify any conceptual errors I am making. For the following question, ...
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2
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Circuit Schematics for water level controller
I'm a beginner here. I am trying to build a water level controller. This is my multisim schematic. I am trying to use a switch that would play the part of water and the LED will turn on when the water ...
1
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1
answer
93
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NMOS is high when gate is low
I’m trying to simulate DRAM with N-MOSFETs with row and column selecting logic. When I select my column, which is connected to the source of an N-MOSFET, the N-MOSFETs in that column all turn on, even ...
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I want to get a NRF24L01 transceiver to use as a switch to wake up a toy, but is it possible to use it without a separate controller attached?
To give more detail, the toy I'm trying to modify has a reset pin that I would like to tap remotely, as it goes to sleep after a few minutes and hitting that reset pin wakes it up. As such, while I do ...
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What could be the reason for the difference in current and voltage for this transistor?
I am supposed to be doing an online engineering assignment and was in the midst of simulating some circuits in Multisim when I noticed something. The placement of the ammeter before and after the ...
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Wiring an automatic solar light for a tiny library
I want to add a light that comes on when you open the door to my tiny library that's powered by a small solar panel. I'm no electrical expert but I do know basics enough to make simple circuits.
My ...
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1
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Current in delta connection
I know how to calculate current in delta connection but just for knowledge purpose I wanted to know from basics why this method(in image) of calculating phase and line current is completely wrong ...
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2
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Calculating voltage output from a circuit with capacitors
The question is outlined in the image below. I am having trouble solving this problem. If at all possible would one of you please provide the solution. Thank you
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271
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Superposition theorem for transient analysis
Can we apply superposition theorem in transient analysis of circuits? I don't think it can be used since during transient state the input and output relation is not linear and is rather explained by ...
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5
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111
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Diode-less op amp circuits that can simulate a diode
Gyrators can be used to simulate circuit properties of inductors. Is there something similar you can do, where you use a circuit with no diode to simulate a diode?
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1
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Cyclic Voltammetry for a Capacitor - Positive Current, Potential is decreasing?
In the boxed red region, why is the potential decreasing when the current is still positive? To my understanding, when the current is still positive (i.e. not changing direction), the capacitor will ...
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134
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How to find the strongest frequency in a signal using a microcontroller/circuit?
I am trying to implement a low-power backscatter transmitter+receiver and ran into some trouble on the transmission side.
Setup: My transmitter circuit sends a 50MHz wave, which the receiver circuit ...
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81
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PWM controller and analog circuits
I’m trying to fix an item controlled by analog circuitry. No luck on that. I can get a motor to run but can not figure out the speed control circuit. It uses NPN and PNP transistors with variable ...
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1
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Circuit to make toggle switch off temporarily pull low before going back high again
I have a toggle switch that outputs 5V when it is on. I would like to make the off functionality momentarily pull to 0V and then go back to 5V. So basically the off switch isn't really off, it just ...
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295
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Delay ON LED circuit with motion sensor OFF
I'm trying to make a circuit that goes:
Delay ON > Run for 5 minutes > Off.
But it also has a motion detector that will immediately switch the circuit off when it detects motion. I am ...
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34
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Usually AC quantities have the x-axis as time, but phase shifts are done in angles. How is there not a unit conflict?
This feels like a very specific and stupid question, but I have studied AC circuits for a while already. I just didn't think about it that much, but why is it established that the x-axis we use for ...
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739
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Induction heating directly from AC wall power
I am working on a project converting a 220 volt resistance heating kiln into an induction heating crucible furnace for melting black sand concentrates from a precious metals mine, which are comprised ...
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54
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Help with digital switching for use with 555 timer
I have a 555 timer set up in astable configuration to output simple audible tones. But instead of having mechanical switches to choose the resistor that ultimately determines the output frequency, I ...
user272076
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Understanding MOSFET circuit
I don't understand how I can find RS, RD and RG so that ID=0.1mA. Help.
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88
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Making waterproof LED circuit
If I am trying to make an led necklace with a few LEDs connected in parallel(each one separated by a little bit of wire) that connects back to a battery pack with 3 AAs, how can I make the necklace ...
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1
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84
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Parallel Resistance Confusion
When trying to calculate the Thevenin resistance, I end up with the following circuit:
When I measure the resistance at Terminals A and B in multisim, it is reporting a value such that R1 is in ...
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Help with determining the open circuit voltage
Can someone go through why Vxy= -84mV?
Given the values off VB=180mv
R1=22ohms
R2=68ohms
R3=150 ohms.
Many thanks
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2
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73
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Circuit analysis with node voltage method
The problem requires I determine the value of I0, I think my solution is correct but I don't know how to check because I got the problem from a text with no answers. Looking for more experienced eyes ...
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55
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Altium - Simulation of different circuits in the same project. What's the better way?
I'm working on a circuit simulation to understand the effects of the presence or absence of a determinate schematic parts. For example, I have one section with an high-pass and a low-pass filter
...
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2
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321
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How batteries create voltage? How do batteries in series increase voltage?
I'm trying to figure out how batteries and voltage work in actuality.
Statements I assume to be true.
At the negative pole of the battery a chemical reaction occurs releasing electrons that repel ...
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1
answer
2k
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How do we do source transformation in complex circuits to get one source
I have a problem in analysing complex circuits by source transformation like this circuit:
For the previous circuit, if the independent source of the simplified circuit is a voltage source, what is ...
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1
answer
851
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replace ceramic capcacitor with electrolytic one
I need help, that i have a lack of ceramic capacitor value variety in my country.
I need 47μF (microfarad) and 2.2μF (microfarad) ceramic capacitor and i can't get these values.
So the question is,...
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1
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Why do some flip flops have control inputs? In what ways do they differ from the normal inputs such as J and K?
I'm currently studying sequential circuits and came across this question. Can't figute out the answer. Can somebody help?
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I have two circuits, how will the second one interact with the first one?
Suppose we have 2 circuits :
One is this:
simulate this circuit – Schematic created using CircuitLab
We call that a circuit.
And the second is this :
simulate this circuit
How will the ...
