Questions tagged [mobile]
147 questions
72
votes
6 answers
Why do many laptops run on 19 volts?
Typically mobile devices that have a mains-powered supply will accept voltage that is multiple of some single battery voltage. For example, 4.5 volts is 1.5 volts (AA primary battery) 3 times and 36 volts is 3.6 volts (Li-Ion battery) 10 times.
Now…
sharptooth
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23
votes
2 answers
How do I make the Fairchild FSA9280/FSA9480/FSA880 BOOT pin trigger? (Samsung Galaxy S)
this is a bit of a long shot but I'm hoping someone has access to the full data sheet for one of the chips listed in the title, and can tell me what combination of VBUS_IN and resistors on ID_CON will make it trigger the BOOT pin on the chip.…
TheBeano
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20
votes
6 answers
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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15
votes
9 answers
Why doesn't higher frequency mean higher data rate?
My question is very primitive :) I've read multiple articles today and answers here, on Stack Exchange, but still don't understand one thing. Why doesn't frequency itself affect data rate in mobile networks? 3G/4G networks use QAM modulation, that…
Raiker
- 167
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10
votes
4 answers
Why are there no WiFi earbuds?
Because Bluetooth earbuds struggle in my home, due to its layout and electronic noise, I hoped to switch to WiFi technology, which has a good signal throughout the house. Either to connect earbuds and a mobile device directly, perhaps with some app,…
thegreatwhatsit
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9
votes
3 answers
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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8
votes
2 answers
Why does this mobile phone battery have 4 terminals?
Why do some mobile phone batteries have 4 terminals? I want to use a mobile phone battery for my project.
BASIL VARGHESE
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7
votes
4 answers
Strategies for mapping an area perimeter with a mobile robot
I'd like to build a bot that when placed in an area would have the ability to find the perimeter of the area and map the obstacles present. Later it should be able to navigate to different parts of the area on demand (e.g. navigate to the NW corner…
James Cadd
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6
votes
5 answers
Why are smartphones and tablets ARM based?
Why don't these devices use Intel processors like laptops do? Why are they restricted to ARM?
Also for Windows 8, do they want ARM just for tablets and smartphones or is it also for laptops/desktops (is that even possible)?
4thSpace
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6
votes
1 answer
How to make usb 3G modem signal stronger with aluminum foil antenna?
I'm in an area with weak signal reception, but I'd like to make my 3G connection better at very low cost.
I heard using aluminum foil as reflecting surface and placing the modem in some way in front of it will enhance the signal. Is there a…
user1306322
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5
votes
4 answers
Is it possible to make a usb charger to power multiple devices?
I was thinking how nice it would be to have a single wall plug with multiple (4-6) USB ports that would be capable of supplying enough power (at 5v) to charge say an iPad, smartphone, bluetooth headset etc. simultaneously at full capacity. But I…
immutabl
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5
votes
6 answers
Using LCD's of mobiles?
I was just giving my mother's mobile for repair at my local store and saw the owner stocking parts for them. I saw him stocking cheap (I mean really cheap) LCD (coloured and black & white). I was wondering where I can learn to use them in my…
Rick_2047
- 3,897
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5
votes
4 answers
How to power a phone with no battery properly?
I have an LG G3 phone that I want to use as a stationary device and leave it hooked up permanently.
I prefer not to do it with a battery for various understandable reasons.
My questions are:
What parts do I need to convert USB 5V to 3.8V?
(I guess a…
NoamC
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5
votes
2 answers
why smartphones don't cause noise on the around speakers
Before the smartphones (or maybe before the some new tech) when a cell phone rings, the speakers around it made noises. Hovewer, nowadays they do not. Why? What changed?
WhoCares
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4
votes
1 answer
Can the NFC antenna of smart phone read signals from (active) RFID tags/transmitters
Can the NFC antenna of mobile phone such as the Galaxy S4 or iPhone in addition to their NFC functionality, also be used to read signals from (active) RFID tags/transmitters e.g. from 20ft away not 20cms?
PatrickO'
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