Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

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1500 questions
24
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5 answers

Powering laptop from 12V sources without inverter

This question has two parts: 1) How inefficient is it to boost 12V to 120V and then back to 12V as in using a traditional car power inverter to power a laptop (i.e. the 12V car battery power is boosted to 120V by a power inverter and then back to…
Reed G. Law
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5 answers

What's the best cable to transfer audio signal?

Sorry if this is the wrong place but I'm interested in a scientific and electrical explanation and not some HiFi voodoo magic. I guess you all have seen the discussions about expensive audio cables and "improved" sound quality. My question is,…
Duckers
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5 answers

OR-ing power supplies (diode or mosfet)

I have got two power supply options on my board: USB 5.0V DC Power Jack of 5.0V My intention is to design a or-ing power supply option, as either of them will be used at a time. Possible solutions are shown below: Using oring diodes or using two…
AKR
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When do we need an Operating System in Embedded System Design?

I have written plenty of bare metal code for PIC and x86 processors. Can someone tell me how and when should I need an operating system? Conversely, what application or situation can be dealt with or without an operating system as well?
quantum231
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4 answers

How is xΩ impedance cable defined?

This is probably a really simple question, but I can't seem to find a definite answer anywhere. I'm guessing 50Ω cable means 50Ω per unit length. What unit length is this? If this is not how its defined, how is it?
midnightBlue
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8 answers

How do components fail?

How do components fail? General rules with an answer per component type would be valuable. We can work as a community to build up a single question that holds valuable information about how components fail.
Thomas O
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7 answers

Can a diode fail to open position?

I know a diode can short out and fail closed. Is it possible for a diode to fail in the open position, and what would cause this to happen?
Daryl Becker
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Why does MOSFET pinch-off occur?

This question is about enhanced n-type MOSFETs. From what I understand, an inversion layer is formed underneath the insulating layer below the gate of the MOSFET when a voltage is applied to the gate. When this voltage exceeds \$V_\mathrm{T}\$, the…
user968243
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5 answers

Why is it desirable in an amplifier to have high input impedance and low output impedance?

I've learned that it's desirable in an ideal amplifier to have high input impedance and low output impedance. Why exactly? What are the implications an amplifier has the opposite- low input impedance and high output impedance. I don't exactly…
Prabhpreet
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4 answers

Compensating the forward voltage drop of a diode signal rectifier

I am reading Arts of Electronics and they are showing this circuit: It says that D1 compensates for D2's forward drop by providing 0.6V of bias. I don't understand this circuit at all. Is the +5V an external 5v source? How does it compensate?
Douglas Edward
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5 answers

Why edge triggering is preferred over level triggering?

I am trying to understand why edge triggering is preferred over level triggering. In my book it is not explained clearly. After searching online I came to know that edge triggering is insensitive to glitches whereas level triggering is sensitive.…
avi
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2 answers

How do I decide what capacitor to use in a circuit?

I am using a voltage regulator, and to get cleaner power, the datasheet recommends using a 0.33uF capacitor. However, it doesn't say what type it wants. Stupidly, I went out and bought a 10 pack of 0.33uF 50V Radial Electrolytic Capacitors. After…
Anonymous Penguin
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How does the switch on the back of older computer power supplies work to vary between 110 and 220 volt input?

There is a little switch on the back of older computer power supplies to select between 110 and 220 volt AC input. I imagine this switch enables/disables a 220 to 110 volt transformer. Or perhaps a different channel within the same transformer unit…
sebastian323
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3 answers

How does this old oscillating light board work?

I know EE.SE loves a good treasure hunt, so here's one to noodle on. This device was made in the 1950s or 1960s by a Bell Labs EE. He designed it as a toy to amuse his young son. Said child, now turning 70, has asked a family member (me) how it…
Kenn Sebesta
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9 answers

Single wire (no ground wire) long distance low frequency communication

In a cave we are currently exploring, there is a temporary siphon that sometimes blocks our way. I was thinking about monitoring it (pressure sensor or other level sensor at the siphon, transmitter via mobile phone outside the cave.) The problem is…
Sandro
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