Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [cellphone]

Questions regarding cellphones, or cellular devices. Please note that repair questions are often closed for failing to follow the Scope of the Site as described in the FAQ.

Questions regarding cellphones, or cellular devices. Please note that repair questions are often closed for failing to follow the Scope of the Site as described in the FAQ.

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What makes smartphones tilt-sensitive? Will they retain this ability in zero-gravity conditions?

Most smartphones are tilt-sensitive, but what device makes this possible? Additionally, how does it (and the sensors associated with it) work? Also, since the working of these sensors seem, almost certainly, based on the presence of an external…
paracetamol
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Does leaving a cell phone on charge all the time weaken the battery, and why?

If I leave my cell phone with the charger plugged in all the time, would this weaken the batter, and why? I've heard that you should only charge the cell phone when you receive a 'battery low' message and leave it off the charger at other times? The…
Click Upvote
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What drives the advancement towards ever faster cellular network speeds?

I've always accepted that technology advances. Being born in the 90s, everything just becomes faster, smaller, cheaper and generally better if you wait a few years. This was most obvious with consumer electronics such as TVs, PCs and…
freejuices
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Cell Phone as Microcontroller

I have a couple of cell phones laying around, one of them being this one: http://www.gsmarena.com/sony_ericsson_elm-3057.php Is possible to clear the flash memory and replace it with a bootloader and then upload arduino sketches or pic32…
Harry Svensson
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How does the phone detect if 3.5 mm jack circuit is closed?

I have an android phone to which i have plugged an earphones. So at the top of the phone, I get the headphone symbol which indicates that the earphone is connected (In other words, the circuit at the 3.5 mm jack is closed). Then I cut the two…
Gautham
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Why do my speakers make a noise when my cell phone gets a call?

It's a very common sound but I've never thought to question why it happens.
Sean Southern
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How does a smart phone measure battery percentage?

A smartphone (assume it to be an Android) usually displays the battery percentage from 0 to 100%. I am assuming that this is the usable capacity of the battery. I have several questions: How exactly does it measure the remaining capacity? Assuming…
navigator
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Is it okay to keep a mobile phone connected to its charger, 24 hours a day, 7 days a week?

I want to ensure that a mobile phone is always charged, without requiring manual intervention: e.g. disconnecting/reconnecting the charger, switching the charger on/off, et cetera). One idea would be to leave the phone always connected to its…
bdutta74
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Why do only high-end phones support a lot of LTE bands?

Most lower and middle end phone only support 3/4 LTE bands. High end phones, like the iPhone, or flagships from Samsung and LG also support a lot of bands. iPhone 7: 1, 2, 3, 4, 5, 7, 8, 12, 13, 17, 18, 19, 20, 25, 26, 27, 28, 29, 30 LG G4: 1, 2,…
Jean
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Digital data coming out of a cell phone headset mic?

I want to connect a sound board / mixing console / whatever-you-prefer-to-call-it to the headset jack of my Motorola Android phone. I know the typical TRRS pinout of Left/Right/Ground/Microphone, and I know about the mic being phantom-powered by…
AaronD
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Why are 3.8V lithium-ion batteries used in mobile devices, rather than 3.6V or 3.7V batteries?

I've noticed an odd trend in the lithium-ion batteries used in smartphones and tablets: rather than the 3.6V or 3.7V per cell typical of most Li-ion batteries in other types of consumer devices, they use 3.8V batteries that are charged to a maximum…
bwDraco
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Can a credit card be demagnetized with a nearby cellphone?

Suppose I have a standard credit card with a magnetic stripe, lying right on top of a cellphone, or in a regular leather wallet that's lying right on top of a cellphone. The cellphone is on (but not in a call), uses a 3G network, and is in a…
Eugene Osovetsky
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Do 3G and phone calls(gsm) use the same antenna in a mobile phone?

When I disable "3G or EDGE" (cellular data) connection from my smart phone's settings, I can still make a phone call. Do phone calls and cellular data use different antennas and frequencies in a mobile phone? Or it is just an inner arrangement? I…
user16307
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Why do cell phones sometimes interfere with amplifiers

I have an old Sony amplifier (TA-F117R) next to my desk where I keep my cell phone. Sometimes I put it ontop the amplifier, because it is pervecly alighed with the surface. When I hang some call up and land the phone close to the amplifier the loud…
Crowley
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Do cell-phone base station antennas emit the same power as cell phones?

Do cell-phone base station antennas emit the same power of waves as from a cell phone? I would assume so because both waves need to travel the same distance, right?
JobHunter69
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