Questions tagged [polarity]

For questions about polarity considerations in electronics due to circuit components with polarity (e.g., diodes, transistors, polarized capacitors, batteries, etc.), polarity of quantities directional quantities (such as currents, voltages, electromagnetic fields, etc.), polarity symbols, etc.

Polarity is often an issue to consider in electronics since polarity is a property of certain electrical quantities (e.g., currents, voltages, electromagnetic fields, etc.) and circuit components (e.g., diodes, transistors, polarized capacitors, batteries, etc.). Correct polarity is often necessary for electronics to properly function, and circuit designers must often add protection for the possibly of incorrect polarity (e.g., batteries installed backwards).

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How does USB Type C handle reverse polarity / signal duplication

The new USB Type C connector doesn't have a physical reverse polarity protection any more. You can plug it in any way you want on both ends, there is also no A and B end any more, it's all the same. So how does this new USB type handle that the…
timonsku
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In an NMOS, does current flow from source to drain or vice-versa?

In an NMOS, does current flow from source to drain or vice-versa? This Wikipedia page is confusing me: http://en.wikipedia.org/wiki/MOSFET The above image confuses me. For the N-channel, it shows the diode's polarity going towards source in some,…
PitaJ
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Does MOSFET let current flow through source to drain as it allows it from drain to source?

Does a MOSFET allow current flow in reverse direction (i.e.; from source to drain)? I made a Google search, but couldn't find a clear statement about this matter. I have found this similar question, but it is about detecting current direction from…
hkBattousai
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Reverse polarity protection

I read somewhere that this can be used for the reverse polarity protection in the circuit. But I am quite confused with its operation. Can somebody help me with this. simulate this circuit – Schematic created using CircuitLab
IamDp
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Why do we use polarized capacitors?

I want to know if the polarized capacitor has some advantage that they are used in some circuits? For example, in a schematic of the BISS001 PIR controller IC, in some places, a polarized capacitor is used and in some places a non-polarized…
Hamid Mousavi
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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…
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Does an over voltage, over current and reverse polarity protection IC exist?

I'm designing a circuit that has the following protection requirements: Reverse polarity Over voltage (60v max) Over current (approx 1A) There's quite a large input voltage range, 10v to 60v. 48v is nominal, drawing about 150mA. At 10vin, it draws…
raaymaan
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What does the radiation from an antenna look like?

Just out of curiosity, I searched for antenna on Google Images, and what usually shows is something like this. So I really thought that an antenna radiates in a circular and equal pattern. But as I read the specs of an antenna and understand terms…
Black
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Why don't more devices incorporate full-wave rectifiers as reverse polarity protection?

Recently, I was introduced to the idea of using a full-wave rectifier, in order to protect against reverse polarity damage in DC devices. I hadn't even considered using a rectifier in an already DC circuit, but now that I think about it, why…
Jay Greco
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What are the disadvantages of using a diode bridge for DC polarity?

As far as I understand, diode bridges are mainly used to convert AC into DC, but one can also use them just to ensure an expected DC output polarity for arbitrary DC input polarity. I have some small energy devices (3V-5V, <1A) that require an…
Jakob
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Is this an AC or DC signal?

My teacher says that this signal is DC, but if the polarity varies from 0V to -8V , shouldn't it be AC? He says that DC + AC = DC
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Why does this two terminal inductor have a polarity?

The Murata LQP03TN2N0C02D 2nH 0201 size inductor apparently has a polarity marking on the package: I don't see anything on the data sheet that suggests there's a difference installing it in a circuit one way vs the other. Even if there are other…
Adam Davis
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SMD LED polarity marking: is the cathode marking standardized?

SMD LEDs normally have some kind of marking like the following image from here indicates: The site states The CATHODE lead is always the lead to be identified with ALL LEDs, including surface-mount LEDs. There are definitely manufactures that do…
Rev
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Are Peltier elements polarized?

I'm looking to add a Peltier element to one of my projects. However, I want to sometimes heat and sometimes cool, depending on the ambient temperatures on both sides of the element. Image from Wikimedia commons. My first thought was to use a…
Anonymous Penguin
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Why is this 3-way speaker wired this way?

I found a service manual of a pair of 3-way speakers that were part of a mini integrated stereo system. These are Sony SS-H77 speakers, which have served me very well back in the day. Looking at the wiring diagram (below), there is something very…
ysap
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