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2
votes
3answers
125 views
Advice Needed On Removing Stubborn Circuit
I'm new to soldering and I've done some research on what I need in terms of material and tools and what I need to do in terms of removing and replacing a circuit. The circuit I'm replacing is a Laptop ...
1
vote
2answers
44 views
Increasing the PWM voltage level from 1.8V to 3.3V
I need PWM pulses of 3.3V, and my micro-controller is giving 1.8V PWM signals. I have a voltage source of 3.3V. One way I am thinking is to use two cascaded inverters(like NOT-GATE) using MOSFETs. Is ...
0
votes
1answer
47 views
What is the significance of s-domain? [on hold]
We use laplace transform to convert time domain differential equation to frequency domain algebric equation. Due to this the equations become easier to solve.
But I am not able to analyse the ...
-2
votes
2answers
63 views
How many electrons does it take to switch on a transistor [on hold]
How many electrons does it take to switch on a transistor, I read somewhere that Inel had made some electrical "paths" so small that they can allow only individual electrons to flow at a time, or ...
2
votes
2answers
39 views
How to trigger reset at long press of button
I am trying to make a button control on/off and reset all in one, but I can't quite get my head around how to design it.
It should basically function like a PC power button. If short press it's ...
1
vote
1answer
38 views
How do external circuits in light switching units (such as Lightwave RF) use the mains wiring for power?
LightwaveRF is a simple switching unit that contains additional circuitry to enable automatic wireless switching. The additional circuit is powered by the mains light switching circuit.
This is my ...
0
votes
4answers
73 views
Open and Short Circuit questions
I am confused on the terms Open, Short, and Closed when talking about circuits.. As far as I know:
a) Open circuit means the wires are cut off so there will be no current will flow. But there is ...
0
votes
0answers
49 views
How can I replace this inductor with a transmission line?
I'm new in transmission line theory, hope you can help me. I have this circuit:
And I have the admittance; Yin=(1-j) x10^-3 [S] and its frequency f=100 [MHz].
What I need its first to find the ...
-2
votes
2answers
81 views
how to amplify 0.15 mA AC current to 500 mA without internal or external power [on hold]
Is there any possibility of amplifying 0.15 mA AC to 500 mA without any internal or external power?
1
vote
1answer
43 views
RC time constant and diode detector
For a better detection of the modulated signal with the diode detector below, one requirement is that the time constant of the RC filter conforms to:
$$ \frac{1}{\omega_{c}} \leq RC \leq \frac{ ...
0
votes
0answers
58 views
Can any one programmer to write for fun SPICE circuit simulator? [closed]
I am well versed in the electronic circuits and I have an average work experience in c++ and python. I reading a book on algorithms CLRS and Skiena and decided several Olympiad problems. I have ...
1
vote
2answers
76 views
Find total resistance of this circuit
I want to find the total resistance between A and B.
This is a HOTS mcq, which has the following options:
A: 45\$\Omega\$
B: 15\$\Omega\$
C: 5\$\Omega\$
D: 22.5\$\Omega\$
A book says that the ...
0
votes
0answers
36 views
How high is the current for the circuit to ignite? [closed]
I can amplify the input signal, or give the circuit a bias? Please formula.
It should be a thunderstorm detectors
Emergence on the antenna at all >= 0.7V?
-1
votes
4answers
102 views
How electron movement produces current,instead of having a slow drift speed? [duplicate]
Just need a clarification here, how the current is produced due to the movement of electrons, in an external circuit,having a very slow drift speed.
Normally in a battery there is high potential ...
-1
votes
2answers
96 views
Inductors Vs. Capacitor [closed]
What are the advantages/disadvantages of using a capacitor in filter circuits instead of other passive elements?
1
vote
2answers
63 views
System Identification (Linear Passive Circuit)
I'm need to find what's inside the following black box but I'm not sure how to exactly do this.
simulate this circuit – Schematic created using CircuitLab
I'm thinking that I might use ...
1
vote
2answers
98 views
12V or 24V switch circuit
I need circuit to choice between two voltages. So, circuit has two input terminals 12V,24V and one output terminal. If there is no 12V on input (floating) - output is connected to 24V, and if there ...
1
vote
1answer
48 views
about the diode detector
Suppose we have the following diode (ideal diode) detector:
In a Course notes, they did the following:
When the diode is on, it conduct current \$i_{d}\$ which is also equal to ...
1
vote
2answers
142 views
Grounds in AC circuit
I am trying to solve for Vo in the circuit above. The input voltage is a simple sinusoidal with Vp = 100V. And all R=2.2k . What I am confused about is how to deal with the two grounds. How do ...
0
votes
1answer
28 views
how to use MQ-2 module?
I am totally new to hardware.
Recently I bought this MQ-2 module, but I couldn't figure how to get it to work, the on the ship worked but where is the output? I mean the place where I place the ...
0
votes
2answers
53 views
What relation is valid for the voltage U6 in the adjacent circuit? [closed]
I have problem with the question, I always come to other results. Can you help me with this task.
1
vote
1answer
61 views
Can we say that the circuit is a circuit of Nand element
Can we say that this circuit is nand element ?
0
votes
0answers
57 views
How to draw a circuit with resistors for 3 nodes?
I am tasked to draw a circuit of a black box that had 3 plugs, and I was able to build the circuit by measuring resistance values across each set of plugs.
The plugs are A, B, C, so I had resistance ...
0
votes
1answer
46 views
sequential circuit chaser light
I am trying to implement a sequential circuit in logisim that has LED chaser lights (http://www.youtube.com/watch?v=Mo8Qls0HnWo) like on this car. I have tried using D flip flops with a clock and ...
0
votes
2answers
79 views
Need help finding Vo in this circuit
I tried to simplify the circuit as much as possible to find the voltage across the current source. Then, I used voltage division to find my answer. The possible answers are 24, 10, 36 and 12. Where ...
1
vote
1answer
63 views
How the envelope detector works?
Suppose we have an ideal diode cascaded with an RC filter , what is exactly the analytical expression of the voltage across the resistance R in terms of our initial (ac) voltage , that is : how to do ...
-2
votes
1answer
75 views
How to choose the right transistor for a circuit and its associated resistor? [closed]
Please bear with me. It's easier asking you guys opinion than to Google.
Especially choosing the right resistor when working with Arduino boards and transistors for relays.
0
votes
1answer
46 views
Simple node analysis
simulate this circuit – Schematic created using CircuitLab
I calculated the transfer function
$$\frac{I_L}{In}=\frac{R_1R_2}{s^2L^2+sL(R_1+R_2)}$$
starting from the node analysis at ...
0
votes
2answers
79 views
Help with my PCB connection. Seems reversed
Done this in Proteus. I printed this out in the copper board and soldered components.
But turns out my relay did not work.
I used a 9V battery in the the supposed to be 5 volts for the Arduino ...
0
votes
1answer
39 views
need advice on making a circuit [closed]
im wanting to make a circuit where i flip a switch, which then begins the circuit = turns off then on every 15 seconds 10 times.
After this "boot up sequence", (after the 10th time) i want it to stay ...
0
votes
1answer
79 views
What's the first step to learn Verilog coding to sort values?
I do not know how to start working on this problem. Should I first design the digital circuit of sorting? I am poor on both topic. Suppose I have four numbers R0, R1, R2, R3... What is the digital ...
1
vote
0answers
48 views
Difficulties with Representation of Half Wave and Full Wave Rectifiers on PartSim
After tweaking the domains, the run-time duration of the simulation and the location of the probe I discovered that there was no mistake. Below I've attached a picture of the graph blown-up.
...
0
votes
1answer
66 views
How can I find out which leads are +, - and video signal on this miniature camera? [closed]
I have this miniature camera but lost the cable connector. How can I find out which of the leads are positive, negative and video signals?
0
votes
1answer
91 views
Designing an Oscillator
I'm tired of having to resort to Google to find every single oscillator design. I would usually just try to search for a circuit using the same frequency crystal, and try to build that.
Right now, I ...
1
vote
3answers
253 views
How to drop 6 volts to 5 volts
I am designing a robot using the PIC16F877A microcontroller that will avoid walls and obstacles. I plan to have it run off of 4 AA batteries. I was wondering how i would convert the 6 volt input ...
0
votes
0answers
49 views
Which pspice model can I use in this circuit
In the below circuit diagram for Marked parts, which pspice models can I use?
1
vote
1answer
50 views
Linearity and time invariance
If the input of an unknown system is shown by:
\$x(t)= u(t)-u(t-1)\$
which results in the following output:
\$y(t)=u(t)-u(t-3/2)\$
then what can be said about the linearity and time invariance of ...
1
vote
3answers
116 views
Where do I adjust forward voltage on LED
I am learning basic electronics with iCircuit. I have build a very simple circuit with just a 5V battery and a LED connected in series, as seen in the image attached.
There is an option called "Fwd ...
9
votes
5answers
640 views
Control the hardware of an old phone using a Raspberry PI
I have a very old phone (60 years old) and I want to control its part using a Raspberry PI:
Microphone & speaker from the head set
The bell
The dial wheel
I have the electric circuit but don't ...
0
votes
1answer
196 views
1-Wire Network, Voltage and Current Questions
EDIT: Schematic updated to show multimeter test point as requested. Altered test points for first 3 questions.
EDIT: Added scope picture for Q4/5.
I have created the following test circuit to ...
0
votes
2answers
95 views
Isn't there a Voltage drop across a resistor?
I've been reading this Wikipedia - Electrical Load topic and there is a section which is confusing me... So what you do is go to the "A more technical approach" section in this topic and then read the ...
1
vote
2answers
130 views
Basic PIC circuit is not working
I have just begun in the world of micro-controllers, and the first micro-controller. I chose to work with was the PIC from Microchip. The PIC I am using is the PIC16F877A. I am using MPLAP IDE and ...
0
votes
2answers
70 views
How to take samples of 300V signal [duplicate]
I want to digitize (convert from analog to digital) a signal that can vary from -300 volts to +300 volts. Can anybody suggest how to handle this high voltage signal?
0
votes
1answer
31 views
Solving circuit with voltage and current sources in series
simulate this circuit – Schematic created using CircuitLab
only method i know i can solve with is superposition but that takes long! can you suggest some other methods that would be ...
1
vote
1answer
75 views
Can't figure out voltage-controlled current sources
I'm trying to teach myself how to wire circuits, but I don't know if I got the correct answer for this? Where is a good place for me to learn the order of operations for solving circuits? Thanks.
0
votes
0answers
28 views
Split common resistance to input and output port
I have a circuit like this.
simulate this circuit – Schematic created using CircuitLab
I need to represent R1 in both input and output side so that R1 can be removed from the circuit. I ...
0
votes
1answer
47 views
AC to DC Filter Confirmation
Of the circuit I need to know the name of and what it is; my guess is, is it an AC to DC current converter? Is anyone able to confirm or deny?
What does it act as when its all formed together? ...
0
votes
2answers
79 views
Find the voltage source in the circuit
Given \$v_2 = 600 i_2\$ and \$i_2 = 2 mA\$, determine \$v_s\$ in mV.
I know that \$i_2 = -9 * v_1\$.
I know how to find \$v_1 = -600/9 = -66.66 mV\$.
I am not sure how to find $v_s$, but I know ...
1
vote
2answers
55 views
Minimum input voltage for this Transistor circuit
I have a circuit below, which I am using in a Coil Gun to amplify a pulse which is generated when a projectile passes close to a coil. I was able to get it to work, however I had the question of what ...
1
vote
3answers
76 views
Need to close or open a circuit (and keep it that way) with magnet
I need to build a circuit that closes when it detects the passing of a magnetic card.
It should open again when the card passes again.
So I need a simple magnetic reed (like this one). And some kind ...
