Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [line]

87 questions
33
votes
3 answers

Why 3 phase and not 1 phase power transmission?

Why does power transmission use three lines with three different phases? Why not three lines all in the same phase? Does it have to do with the alternators used for generating the power, or is there less loss when the phases of the three lines are…
Geremia
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9
votes
1 answer

Designing a cable for bidirectional communication between 2 iphones via TRRS (headphone jack)

I'm trying to design a cable that allows bidirectional communication between 2 iPhones, connecting into their TRRS jacks. I've made the cable but it is temperamental at best -- can anyone help me understand why it is misbehaving, and help me…
P i
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7
votes
1 answer

Identification of a very strange SMD component

Could anyone help me identify what component this is? It is the white component with a black stripe. What ever it is, it appears to be a open circuit. I couldn't measure any resistance (or capacitance). One pin of the connection has DC voltage while…
xydn
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6
votes
3 answers

Software based Caller ID project- Problem with getting caller ID signal

Nowadays, I am trying to make a Caller ID project without using Caller ID ICs. Firstly, I have done a lot of research in Google to get information of phone lines and their electrical properties. I have found and done: In my country Caller ID data…
Ebubekir Çağrı Şen
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5
votes
4 answers

What limits the speed at which information is sent/received over a fibre optic line?

I was trying to find an answer everywhere, but all I can find is absorbtion and scattering, which doesn't limit the speed itself, just the quality of the signal.
user43132
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4
votes
2 answers

How to reduce an audio signal to proper input level?

I'm working with an audio ADC that supports a max audio input of 500mVRMS before it will start clipping. This is sufficient for lots of equipment that does a 1VPP/.35mVRMS line level, but I'm finding that lots of equipment like computers, and MP3…
ArraysStartAtSeven
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4
votes
1 answer

how will a connector affect a transmission line?

I am laying out an RS485 driver and read a few design guides which recommend a 120 Ohm termination resistor. This makes sense since the characteristic impedance of twisted pair cables is in the 100 Ohm to 150 Ohm range. However what confuses me, is…
Shamus MacDonald
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4
votes
3 answers

Speaker level to line level

I want to reduce my amplifier output to line-level. I found this tutorial, Connecting speaker signals to line level inputs, which is compatible with 50 W output power. There is also mentioned what to do if amplifier is more powerful than that. So…
LiskoSlayer63
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3
votes
3 answers

Half-wave rectifier- How does the supply line current affect a transformer

i Have this half-wave rectifier circuit. i have placed a current probe on the input in order to measure the waveform of the supply current. The waveform is shown below. My question is what effect does this waveform have for example on a step-down…
Frantisek Balaz
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3
votes
3 answers

What would cause a square wave to become rounded?

I have a square wave going through a thousand feet of cable. The cable has \$120 \,\Omega\$ characteristic impedance. I measured the capacitance and inductance of the cable and they are pretty close to the spec sheet. According to PSpice, the…
user1416658
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3
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3 answers

Is the impedance control of differential pair traces a transmission line problem?

I read in an article of design reference that "If the length of the interconnect PCB is greater than 1/10 th of the wavelength, we should consider using the transmission line instead of ordinary interconnect." Now I have the following doubt: the…
asterix
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3
votes
1 answer

How to connect a diy audio signal to my "expensive" audio interface

I'm a hobbyist and after some experimentation (around 4 years) I want to connect my signals I create on the breadboard to my expensive audio interface. Until now I was using the "mic" input on my laptop to connect the signals and I haven't damaged…
John Am
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3
votes
1 answer

Is it safe to use an Y2 Capacitor where an X capacitor used to be?

Is it safe to use an Y2 Capacitor where an X capacitor used to be? I mean Y should be safer right? So Y2 where X should be is OK, but not the other way around, right?
JohnyTex
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3
votes
1 answer

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 values of L and C, so that the admittance of entry…
Rogan
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2
votes
2 answers

Line level to microphone level to record

I have a digital piano with an earphone output where I can connect a simple earphone (like in the picture below.) It works fine. I would like to connect this earphone output to my smartphone jack (TRRS - GND, microphone, left channel and right…
user314164
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