Questions tagged [mobile]

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28 views

Details about Total Access Communication System (TACS)

I'm not sure if this is the right place to ask. I am trying to build a base station for a TACS (Total Access Communication System) phone, but I have not found any detailed document about it. The most ...
1
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1answer
115 views

Can mobile reception 4G/5G signal reception be affected by atmospheric changes?

For example, if it rains or there is smog in the air can this atmospheric change affect the signal quality of mobile phone devices such as 4G and 5G? I have been noticing changes in the reception ...
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0answers
72 views

Is there a way to switch between circuits without a relay?

So I'm trying to create a mobile phone charger inside an Altoids mint can, It uses two Panasonic NCR18650BD which have a discharge of 10amps. Anyways, I have it set up in parallel. It uses a zener ...
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1answer
54 views

CDMA basic working principle

I find it hard to find on the internet a simplified explanation of the principle of operation of the CDMA system. Could you give me an example of how it works and how a receiver can correctly identify ...
0
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2answers
87 views

Battery life impact with fast charging

Typically fast charging reduces backup time and life. Now a days almost all handsets are coming up with different fast charging capabilities. I'm currently using Galaxy Note9 which has fast charging ...
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2answers
86 views

Is there so much of a 'technological quantum leap' in 5G technology? [closed]

AFAIK, it is only the antenna hardware that goes into the smartphone/tablet and also the base-stations, where the technological breakthroughs can realistically be present. Every other component of the ...
2
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4answers
308 views

Does a poor mobile network signal cause faster battery drain? [closed]

Quite a simple question actually, does a poor mobile network signal cause faster battery drain? If so, is there a difference between 2g/3g/4g/5g in the speed at which the battery drains.
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0answers
40 views

Default behavior of a USB device in the presence of 5v [duplicate]

This is a follow on from this question Given a home made USB charger that simply provides 5 volts across the GND and VCC pins of a USB port, what should the default behavior be of any mobile device (...
4
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3answers
293 views

Why can't the orthogonal PN codes help in the near-far effect?

The CDMA near far problem arises because handsets may be anywhere within the particular cell boundaries. Some handsets will be close to the base station, whereas others will be much further away. In a ...
2
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2answers
127 views

Feasibility of custom parabolic mic (amplified, bandpass filtered) for use with mobile phone app [closed]

I am not an electrical engineer, but I am up for a challenge and this is my first venture into electrical engineering. However I am beginning to think this may be a step to far! As a hobby I survey ...
0
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1answer
49 views

What is sitting inside LED array so that I can create my own drivers?

I have a LED array and an app to drive it: https://itunes.apple.com/US/app/id1431362600?mt=8 https://play.google.com/store/apps/details?id=com.yskj.led&hl=en_US I connect to WiFi and I'm able to ...
0
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1answer
38 views

Reconfigurable antennas at base-station

Can reconfigurable antennas be used at base-stations and cellphone towers? I read that MIMO antennas are used at base-stations for 4G systems (and will be used for 5G). Are these antennas ...
0
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2answers
145 views

AC voltage on the outside surface of micro USB charger cable

My micro USB mobile charge cable is having about 98V AC voltage on the outside surface. (PFA measurement image. The black probe is connected to the Power socket Ground port. I could not take the whole ...
1
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1answer
1k views

Analog beamforming vs digital beamforming

I am reading some research articles on wireless communication where they talk about beamforming techniques and their differences in Multiple antenna Tx-Rx systems (MIMO). It says analog beamforming ...
0
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2answers
103 views

Batteries have a constant charging speed from 0%→70% instead of being any faster at 0%?

A mobile phone I tested keeps charging at the same constant speed from 0% to 70%, which is 10 watts. It uses MediaTek PumpExpress (input power: 12V 0.83A, despite the wall charger is capable of 12V 1....
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1answer
159 views

How is 4g much faster than 3g? [closed]

The data rate for 3g is up to 2Mbps but for 4g it's up to 20 Mbps or more. But the frequency Band of 3g is 1.8 - 2.5 GHz but for 4g it's 2 - 8 GHz. I understand that increasing the frequency band ...
-4
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1answer
94 views

Hack smartphone IC to draw more current and allow higher voltages? [closed]

Disclaimer: This is just a laboratory experiment I am willing to do at my own risk. I understand the risk of blowing up the phone (GT-S5280) pr charger (Powstro 30W charger). I already have a water ...
0
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1answer
699 views

USB-C UFP and DFP Not Working Properly with ONLY Samsung Mobile Phones

I have a UFP device (basically just a light) that I am trying to sink for power only. The "light" has a micro-B plug, which then plugs into a micro-B port on a PCB, that then includes a USB-C plug ...
0
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2answers
77 views

Does a mobile phone APP have the ability to control the output current?

After some brief research online, i found that the USB port is capable to start a simple fan. Meaning the USB charging port can output current into an external device. Which leads to my question, is ...
0
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2answers
25 views

Manually control smartphone power current drawing during charge?

How can I manually control, how much power the smartphone does draw? Sometimes, a smartphone does accidentally consider a charger as much weaker than it actually is. Sometimes, a boost converter/...
0
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1answer
91 views

What happens if more voltage hits your mobile phone charger? [closed]

I am new here an i want to know that in the country i love AC voltage is 240 volts but sometimes it exceeds the limit. what happens if voltage like above 300 volts hits your mobile phone charger what ...
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2answers
295 views

Power old Nokia phone from Bench Power Supply

I have an old Nokia Mobile that has a dead battery. I am trying to power it up to see if it works without having to purchase a replacement battery. I have a bench power supply but am confused as to ...
-3
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1answer
74 views

Is it possible to move an internal SD card from a Samsung Galaxy S3 into another phone (Galaxy S2) to retrieve the information from the card? [closed]

Is it possible to move an internal SD card from a Samsung Galaxy S3 into another phone (Galaxy S2) to retrieve the information from the card, or is there any other way to access the information from ...
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3answers
1k views

Can SMPS works as cellphone charger?

I tested for charging a mobile using SMPS, it charges the battery 10% percent in an hour. But when I connect the same mobile to the mobile charger it charges the battery 40% in an hour. The SMPS ...
0
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2answers
42 views

Connecting mobile battery and LED bulbs to 10.5v Solar cell

I want to connect a 10.5v solar cell to a number (say 10 to 20) of 3v LEDs with an ordinary mobile battery for power backup (charging the battery). Should I use a resistor? What else I can do in an ...
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1answer
44 views

(W)CDMA, any repeating information?

I am looking to characterize a WCDMA channel to study the effects of multi-path. In order to do this I need to be able to find some repeating information (bit sequence) being transmitted by a station. ...
0
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2answers
86 views

voltage output on double USB chargers

I'm a beginner: If the mobile phone charger has two USB ports for output and the charger is labeled 4.8A, does it provide 4.8 maximum to both ports or to each port when cables and mobile phones are ...
1
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1answer
81 views

Why do faulty headphones make MP3s sound low bitrate when I touch the wire? [closed]

I have a pair of headphones which came with my phone. They're the standard type that comes with a mobile phone - TRSS 3.5mm jack with an inline microphone. I was listening to Spotify on my phone. I ...
0
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2answers
78 views

I need an aerial adaptor for my 4G modem. What are the names of these types of coax connectors?

I have a 'Mifi'™ 4G modem. I ordered an external aerial for it, but the diameter of the connector is about four times the size I need. I want to buy an adaptor, but I don't know what search terms to ...
0
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1answer
95 views

Mobile Power Bank 18650 Battery Charger [closed]

My question is about the below power bank charging module. We connect 3.7V 18650 type batteries to this module. Then the output voltage of this module via USB is 5V. My question is how it returns 5V ...
0
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1answer
68 views

Will this N-Channel Mosfet work as high-current motor controller?

We are building a mobile robot which will use two motors in a differential drive configuration to maneuver and move around, and we want to choose the right driver IC or transistor circuit for the job ...
1
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2answers
107 views

Powering multiple cellphones with a DC power supply

I have about 100 cheap cell phones that need to be on 24 hours a day. Unfortunately (likely due to the cheap nature of these phones) the batteries end up bloating after a couple months of being ...
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1answer
82 views

How does signal 4G dial as a Wi-Fi signal through tethering? [closed]

I am looking for the datasheet (internal circuits of embedded mobile) of 4G modules, and I would like to understand how this module, electronically, is connected to the wi-fi module in the same phone. ...
0
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2answers
175 views

Anyone an expert on mobile LCD displays? [closed]

Reason I ask is, I've noticed with water damaged iPhone 6 screens if the pins on the connectors of the screen itself have corroded and you fix them with cleaning and fresh solder or jumper wires 8 out ...
0
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4answers
3k views

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 ...
1
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1answer
141 views

Does 2g/3g rf receive circuit path work for 4g if they are in the same band?

I am wondering that if the rf receive path for gsm/wcdma can be used to receive lte fdd signals? provided that gsm/wcdma/lte are in the same band e.g. band8 downlink frequency 925-960mhz, and the ...
1
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1answer
109 views

Making a mobile battery charger for smart phones [duplicate]

i want to make a mobile charger and charge multiple mobiles at a time therefore i select a 5V 2A adapter and a USB hub with 4 ports check the image what i am going to do with this adapter and USB ...
1
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2answers
693 views

Why do mobiles phones have non removable batteries at all? [closed]

Doesn't a removable battery have a lot of advantages over a non removable battery? In case the phone drops in water/the battery gets faulty due to whatever reason, we can always change the removable ...
0
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0answers
54 views

What is the SAR(Specific Absorption Rate) value near a Telecom Tower?

We know the SAR values of every smartphone. However we've got so many cellular towers in our neighborhood. How much of risk is there, health-wise, in being exposed to them daily? I mean is there any ...
-1
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4answers
1k views

practically how to estimate the exact distance between transmitter and receiver in wireless network [closed]

I want to know the estimation of exact distance between transmitter and receiver in wireless networks. Can the distance be calculated? What would I have to do to find the exact distance?
0
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2answers
278 views

Can you get electricity from your mobile phone [closed]

Does someone know if its possible to get energy from your phone (android/ios)? I want to charge a capacitor or a very little Battery and thought about the idea to get this energy from your mobile ...
-1
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1answer
107 views

Mobile device 2.6V power source required [closed]

The title says it all. I need a 2.6V voltage source for a selfmade mobile device. I would appreciate any help on wich batteries (rechargable or not) to use for that. Thanks! Further information, as ...
2
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1answer
4k views

Wiring power banks in series for 25V output to power e-bike

So I have an old electric bike sitting around, no battery. Replacement 24V 10Ah batteries are $200+. However, I have/can get 10Ah power banks (to charge phones) for under $10. They all have standard ...
0
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1answer
54 views

About charging Li-ion batteries in mobile devices [closed]

I've got some questions about charging Li-ion batteries in mobile devices. Does mobile phones that are made by major manufacturers like Samsung have solutions for charging safety in their devices? If ...
0
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4answers
320 views

Why is a cellphone charger rated like that?

Here is what I read on the nameplate of my phone charger: Output 5V DC 1A. So, I think the Max. Output power is 5 watts. Input: 100-240 AC 50/60Hz 200mA. I assume that the mains voltage is 100 ...
-1
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2answers
165 views

Which chip remains on when the phone is switched off but it has to detect if the power button is pressed to switch it on?

I wanted to know which is the chip that runs to detect when the power button is pressed to switch on the phone. Is the real time clock and circuit and this chip connected in any way?
0
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1answer
766 views

External power supply a mobile phone

I have an alarm device. It convert 12v to 4,3V to the phone. It's outputs are 4.7V, GND, and two output to the phone buttons If the inputs loop of the alarm device is opened that means the wire have ...
3
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2answers
2k views

cell phone detector circuit

i have successfully implimented below circuit for active cell phone detection but i dont seem to understand the working of this circuit,if someone could explain it would be a great help.Thank you.
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3answers
429 views

Commnication between mobiles which are in range of 100 meters without using any mobile tower for free [duplicate]

Every mobile radiates its signal to its nearest tower during phone call.Then is it possible for two mobiles to communicate with out using any tower with in range of 100 meters or more .If it is ...
4
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1answer
559 views

Getting started with Qualcomm reference designs

I am looking to get started with Qualcomm Reference Designs. I am partly inspired by this article: "Start Your Own Smartphone Company for $1,000". I have an application that I would like to be able ...