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1answer
24 views

Finding Equivalent Thevenin Resistence

For the following circuit: I'm solving for the Rth at node 2. In the solution guide, it shows that the Rth = (10k || 10k). I don't understand how this is so, by following the resistence equivalent ...
0
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0answers
44 views

Info on the most used calculator ICs on the planet [on hold]

Pick any standard (non-scientific, 7-segment) pocket calculator today, and you'll find the functioning to be very, very similar. Here's a generic one: They all have the four basic functions (Add, ...
0
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0answers
13 views

Two outlets, two switches, two lights, no power [migrated]

I have a circuit for lighting and heating a reptile tank that I can't get to work. I did not create the circuit but it was in working condition when I got it. Two outlets each get power from separate ...
0
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3answers
76 views

Can inductor voltage and capacitor current change abruptly?

I understand that inductor current and capacitor voltage cannot change abruptly, but can inductor voltage and capacitor current change abruptly? I have a feeling the answer is no but I cannot explain ...
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2answers
72 views

Why are these two potentiometers affecting one another?

Let me first say, that I am no electrical engineer so thanks for taking the time to deal with a layman. Background In my workshop, I have two sets of speakers hooked up to a common 3.5mm audio ...
12
votes
4answers
902 views

Why use complex numbers to represent amplitude and phase of AC

Why is it that in AC circuits, sine waves are represented as a complex number in polar form? I don't logically understand from a physical perspective why there is an imaginary part at all. Is it ...
4
votes
2answers
308 views

For the resistor circuit shown in the picture, what must be the missing resistance to give a total resistance of 252 ohms?

After my calculations, I keep getting 1100 ohms, but the back of the book is saying 85 ohms. 85 seems to fit in better with the other numbers, but I can only get 1100 to add up. Here's my ...
1
vote
1answer
73 views

Deciding base resistor for transistor switch circuit

I'm building a transistor switch circuit and below is the schematic. simulate this circuit – Schematic created using CircuitLab I calculated R2 resistor (base resistor) value from this ...
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2answers
29 views

pSpice Question

I'm trying to simulate the above circuit in pSpice, but I am getting the error: Voltage source and/or inductor loop involving V_V5 I looked it up and it says ...
0
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3answers
125 views

Why do circuit analysis methods work?

Both the KCL and KVL equations are required to completely model a resistor network. However, the two main methods to analyze these circuits Nodal analysis and Mesh analysis only use KCL and KVL ...
0
votes
2answers
26 views

Set-Reset Latches and D Latches

I am trying really hard to understand the way SR Latches and D Latches work.I've realised that in a SR Latch we got a current state let's say Q(t) and Q'(t) and we want to predict the next state let's ...
2
votes
1answer
54 views

Circuits Homework Question

So I'm doing my Circuits homework and I got to the circuit above. Obviously \$i_4\$ would have to be 1A, because of KCL. However going further along, I can't find a way to make \$i_3\$ positive! ...
0
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1answer
75 views

FM Radio transmitter and receiver circuits

I'm planning on building a FM transmitter and receiver circuit for an electronics project. I was just wondering if these two circuits would work together. Also would they be suitable for transmitting ...
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0answers
27 views

proximity sensor as a switch [closed]

I want to design a circuit having proximity sensor as an on/off switch.The supply input is 12V DC . The circuit must be designed in such a way that , the output is zero(off) when the IR rays from the ...
0
votes
2answers
66 views

How to find current across a resistor using Thevenin Theorem

It's my first question here. How to find the current through 3 ohm resistor using Thevenin theorem?
2
votes
1answer
64 views

MOSFET H-bridge design

given the circuit below to be used as a H-bridge with AVR PWM. Is this a good desing to use? What can you recommend? I already built something like this but without the resistors. ( and so burned ...
12
votes
2answers
451 views

What does a “sad face with a bow tie” represent?

Some trains in the Madrid metro network have small metal boxes with this sign on them: There are no other signs on the box and some signs only have the "bow tie". I'm guessing it's two Zener ...
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2answers
58 views

Parallel circuit with equal resistance?

If a parallel circuit has 3 paths, all the same resistance will the current divide by 3, and will the voltage throughout all of those paths be the same?
2
votes
3answers
239 views

Why does this current source absorb but not deliver power?

Question (Extracted from a book): Determine the voltage across each current source, the current through each voltage source, and the power delivered or absorbed by each source. Official Answer: ...
0
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2answers
44 views

How did I calculate the power for this source?

Let the circuit be: Given that Ix = 5A and Vy = 10V, calculate the power absorbed or delivered by each source. My solution: 10A source delivers 100W (P=UI= (-10 + 20)x10 = 10 x 10 = 100W). ...
1
vote
1answer
121 views

I want to make an oscillator with 160 MHz

I want this for my project. So I have decided to make a basic Wien bridge oscillator. $$f = \frac{1}{2\pi R C}$$ So if I choose a capacitor of 0.1 nano farads and a resistor of 10 ohms, I should ...
1
vote
1answer
53 views

Nodal Analysis of a circuit with a dependent source

simulate this circuit – Schematic created using CircuitLab Hi, So the trouble I am having with this problem is that I don't know how to do nodal analysis with the dependent source. I ...
1
vote
4answers
93 views

Do cells phones put out a signal when charged through data out?

Do cells phones put out a signal when fully charged through data out? I am wondering this because there is a competition to see who can build the best and most efficient portable cell phone battery ...
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2answers
73 views

Question with solving for complex power, S, for each component

simulate this circuit – Schematic created using CircuitLab Hi! So I have a couple questions that I have already tried to solve that I think I am going in a little bit of the wrong ...
0
votes
2answers
52 views

Finding v0 on the right side of an op-amp?

I am trying to find \$v_0\$ in this circuit (voltage across \$R4\$): simulate this circuit – Schematic created using CircuitLab The issue I am having is that I would have known that ...
0
votes
3answers
74 views

Apply Thevenin Theorem to a circuit with 2 sources?

simulate this circuit – Schematic created using CircuitLab I have this circuit: Sorry the current source got cut off when loading. It is 3 Amps. I was trying to apply thevenin's ...
1
vote
1answer
51 views

Confusion on common node in a circuit

I am a bit confused related to the concept of common node in a circuit. I know that all voltages are measured with reference to this node. But here's the problem : I have some big circuit, ...
1
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0answers
47 views

How to get the value of a burned resistor on a PCB of Weanas® Plug Power Meter? [closed]

In my house electricity was shut down and came up again a several times during 5 seconds. After that my device - Power meter did not work. It was possible to turn on the device, but it was showing ...
0
votes
1answer
67 views

Drum machine circuit diagram

I'm having trouble understanding this circuit. Can someone help me get through it? I'm trying to understand what the signal is doing from start to end but keep running into electrical deadlocks.
1
vote
2answers
75 views

Any good method for the power down sequence?

In my circuit, +12V would be supplied by an external power source. After two regulators, two more voltage source(+5V and +3.3V) would be produced and supply power to adc AD7682.Because of the maximum ...
0
votes
1answer
60 views

Circuit Problem

RT = R6 + [ R5 || ( [R1||R4] + [R2||R3]) ] = 7.2 KOhm IT = 8 / RT = 1.11mA I2 ( current through R5) = (It Rt') /R5 where Rt' is everything excluding R6 My question is what is the easest way to ...
2
votes
4answers
189 views

Trace width and spacing

I'm designing a PCB board (low current, low frequency) mainly consisting of low frequency SPI and analog sensors. Are wider traces better or does it not matter? And which is better, consistent trace ...
2
votes
1answer
174 views

Why shorted resistor is ignorable?

I am having a little trouble understanding what results from short circuiting. The bottom circuit is the one we are given in the question, and we are asked to obtain the Norton equivalent. The above ...
-1
votes
0answers
72 views

Will this circuit function? [duplicate]

I have this circuit, based on this. I already have a question about this here, but it was getting really long, and hard to read. I created this to make it easier. My circuit: I use an 11.4V ...
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2answers
243 views

Problems driving electromagnetic mirror

EDIT: The question was completely edited because the major problem - overloading - was solved. One of the units in the OpAmp was damaged, so it was malfunctioning when connected to the load. ...
1
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4answers
1k views

Will my circuit work?

I have a circuit that I believe will work, but I was hoping someone could double check? Removed image to make room for edit. - Original schematic In my circuit, I use a MOSFET, a photo-interrupter, ...
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3answers
83 views

Determine break in long circuit

I have a circuit of switches like this. The switches are a long way from the supply and a long way from each other. ...
1
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0answers
21 views

How to calculate average delay time of circuit having several possible transition states

Is it possible to calculate average delay for all possible states directly without calculating them individually using Xilinx or with Cadence.
1
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1answer
109 views

Basic FM circuit

I have been messing around with a basic FM transmitter circuit, and I want to have a better explanation on how it works. I have searched around and found nothing. Can someone please explain how the LC ...
0
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3answers
98 views

Connect USB to microprocessor lacking a output port?

Sorry I'm sure this is a very simple answer but I know very little about how it works beyond serial ports and USB adapters for interacting with PCB circuits. I've taken apart an old junk flip ...
0
votes
2answers
63 views

How to design a power switching circuit using a photo-interrupter

Okay. I'm completely at a loss here. I was trying to design a switching circuit for a 3A load (Solenoid) using a photo-interrupter. I got to about here: But I have no idea what to look for in my ...
1
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2answers
104 views

Two relays for DRL on a car

I am trying to make a circuit for my newly installed DRL (Day running lights), what I am trying to do is have the DRL run all the time, turn off when using high beam, dimmed when headlights are on. I ...
0
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4answers
112 views

My thought on the reverse polarity protection

I am now designing a power reverse polarity protection circuit for my system. I found that most methods used for the protection would cause voltage drop in the power path. Even the MOSFET, which has ...
0
votes
3answers
91 views

Op-amp based audio amplifier not working

I have a problem with audio amplifier I am trying to build. Given my ignorance, I cannot figure out how to fix the issue. There is absolutely no sound on the output. This is what I have assembled: ...
1
vote
3answers
57 views

Would having no power supply but a large input signal damage the amplifier?

I am now learning about the power sequence of the circuit. And wonder that as every amplifier has its own limited input voltage (for example: ADA4004's input limit is V− < VIN < V+), would the ...
0
votes
1answer
50 views

Controlling AC devices using ATmega8

I have an microcontroller ATmega8, TRIAC MOC3083 and thyristor M166P. I need to develop and device which will turn on/off lamp(220V). But while I'm developing I don't want work with AC 220V now, DC ...
0
votes
2answers
80 views

How is this 3 VAC power supply charging this 18 VDC battery? [closed]

My cheapo 18V Black and Decker cordless drill recently died, and thinking I could maybe fix it, I took everything apart and then couldn't figure out how it was ever working in the first place! Here's ...
0
votes
1answer
31 views

Interpretation of rating of the primary voltage of a real transformer [duplicate]

The rating of a real transformer is 15 kVA , 2300/230-V then can we say that the primary rms is 2300 V or can we say that the secondary rms is 230 V or both. To clarify further, suppose to solve for ...
1
vote
1answer
86 views

2 Transistor XOR Cell Floating Output Problem

I designed the following 2T XOR cell for my full adder purpose: Theoretically it gives correct output for all input combinations. But on Tanner Eda using 180nm technology 5V supply, it gives logic ...
0
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0answers
36 views

WeMo Wireless Light Switch US convert to be used in UK?

I am in love with this thing and just cannot believe that it runs 120V 15A. Step down transformer would be too big since this thing should fit into the wall. http://www.belkin.com/us/p/P-F7C030/ ...