Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [voltage]

Voltage, otherwise known as electrical potential difference (denoted ∆V and measured in volts) is the difference in electric potential between two points (adapted from Wikipedia). Voltage can be constant (DC) or varying (AC).

Voltage, otherwise known as electrical potential difference (denoted ∆V and measured in volts) is the difference in electric potential between two points (adapted from Wikipedia). Voltage can be constant (DC) or varying (AC).

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What is negative voltage?

Just a general electronics question: What is negative voltage, like -5 Volt? From my basic knowledge, power is generated by electrons wandering from the minus to the plus side of the power source (assuming DC power here). Is negative voltage when…
Michael Stum
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What exactly is voltage?

Bit of a strange question, but what is it? My physics teacher said it was kind of like a "push" that pushes electrons around the circuit. Can I have a more complex explanation? Any help is much appreciated.
imulsion
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Why is a current signal preferred to a voltage signal for long analog transmission?

Some sensors act like current sources, and I have seen it several times, especially for very long wires even at outdoors like wind vanes. 4-20 mA current loops are used instead of 0-10 V voltage for instance. What can be the physical explanation for…
cm64
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Does the word voltage exist in academic engineering?

In Portuguese, the word voltage does not exist. Neither academic nor technical. In engineering, Portuguese speakers refers to volt as electric tension or potential difference. The word voltage was popularized in the Portuguese language because some…
vianna77
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What's more dangerous : 110V or 240V

There lots of people claiming that 240VAC is much more dangerous than 110VAC. Some even find it insane to have 240VAC. I think this claim comes mainly from the fact that 240V will draw twice the current through a same resistor and that's what will…
Daniel P
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Why should we use 3.3 V instead of 3 V?

Why do we use 3.3 V in circuits? Why not 3 V? Is there a specific standard? Or do we use it because it was 3.3 V from the beginning? I am just curious to know.
Mohammad Kholghi
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Why is it important not to exceed Vcc at the input to a logic gate?

What happens to a logic gate (besides magic smoke discharge) seeing a voltage greater than Vcc? Is it just because the gate was not designed to handle a higher voltage than the recommended Vcc, or is it also usually important to limit the voltage to…
joeforker
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Is there a device to get modulo of voltage value?

This may sound very naive and impractical question, and most likely the answer is negative, but still: is there any more or less simple (simpler than ADC/DAC) analog component or circuit, which makes modulo operation on the value of voltage, given…
Roman Susi
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What would a voltmeter measure if you had an electromotive force generated by a changing magnetic field?

Suppose I had a circuit of this sort, and there was a changing magnetic field through the central triangle: Faraday's law suggests there will be a voltage through the loop. The voltmeter is supposed to measure the voltage but there is no notion of…
tryst with freedom
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What happens if an LED is connected to a supply voltage greater than its voltage drop?

My understanding of resistance and voltage is horrible. I heard that with Kirchhoff's law, (in my words, please correct) the voltage used by the circuit must equal the voltage supplied. For example, if I had a 9 V battery, I must use all 9 V of…
Blake
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Can I use a resistor in place of a transformer?

Why is a step-down transformer used instead of a resistor for reducing high voltage? For example: If input voltage is 230V and I have step down the voltage, can I use a resistor instead of transformer? If I cant, can any one explain the drawbacks?
Rahul Ramesh
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Is voltage a delta? Can it always be treated as a potential difference from a reference point?

I've always considered voltage to be absolute, i.e. something that is there or is not there. However, the more I think about it, it seems to be more like a delta. For example, let's say we have a supply that lists its pins as (A) -50V and (B) 0V. If…
Polynomial
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Why does measuring the voltage drop across a thing not simply measure the battery voltage?

Imagine a trivial circuit with battery and one resistor. To measure the "voltage drop" across the resistor, we stick a voltmeter in parallel with it. However, this means the voltmeter is also directly electrically connected to the terminals of the…
Boann
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Efficient way to regulate voltage

What is the most energy efficient way to lower voltage? I want to lower 9V to 5V. But if I use resistance doesn't it consume energy?
user16307
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Which one is better to say? Volt or Volts?

This question might be quite premitive, But I really want to know what is the standard way of saying for example: 2 Volts or 2 Volt 1 Volts or 1 Volt (the Volt seems to be a better choice!) 0.5 Volts or 0.5 Volt?
Dumbo
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