A device which controls the voltage and current being delivered to a capacitor or battery.
Questions tagged [charger]
919 questions
74
votes
3 answers
What is the ideal way to handle data pins D+ and D- on a USB power adapter to be compatible with fast charging on devices?
I have found that many USB wall chargers use a resistive voltage divider to set the D+ and D- pins to a specific voltage, usually between 2 and 3 volts. Other USB wall chargers short the D+ and D- pins together with no connection to anything else. …
ArraysStartAtSeven
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2 answers
Solution for adapting to USB current draw limits?
Summary: I'm setting up a USB-powered Li-ion charging circuit and would of course like to draw the maximum charge current possible situationally -- but also want to ensure I don't violate the USB specification on current draw. While I have been able…
boardbite
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3 answers
Using a 12V battery while simultaneously charging via solar panel
I have a couple of 12v batteries that I'd like to use to power a cooling apparatus while camping for several days.
I also have a 15W solar panel I'd like to use to top-off the battery.
Can I use the battery while it is charging? Or would I have to…
nimble
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4 answers
Cellphone charger has no transformer?
I opened up a really tiny mobile phone charger I have, to see how it is designed. The entire "charger" is integrated into a small 2-pin mains plug, 1 x 1.25 x 0.5 inch, that has an USB socket for the phone's USB charging cable.
I could not find…
Seemingly So
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How does a USB 2.0 Wall Charger negotiate current output?
I'm trying to use a mobile phone charger for my projects, and want a high current output. I have read this, however my measurements show something else.
Here is a link to the Battery Charging Specification Rev. 1.2.
1.4.7 Dedicated Charging Port
A…
tgun926
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13
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2 answers
How can I use two TP4056 with two li-ion batteries, but single load?
I have two TP4056 modules (with protection circuit), which I am using to charge two batteries respectively, off a single power line. The modules are the ones that have charge output (B+/B-), and another regular output.
I'd like to be able to use…
Mr.M
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How to start building lithium-ion battery charger?
Introduction
Wanted to start with my level in electronics. I am very beginner hobbyist & the last thing related to electronics I did in college was creating an 12V AC to DC Converter that was 15 years ago. I a Software Engineer by…
Kunal B.
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12
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6 answers
Converting and Stabilizing output voltage of a dynamo hub
Preface - I don't know much about electronics :P
I have ordered a Shimano dynamo hub for my bicycle. I have done a little homework and here are my findings about it:
The output of the above mentioned dynamo is a 6 volt AC.
The output voltage of the…
Raj Pawan Gumdal
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12
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1 answer
How to power a widget, while the li-ion battery is charging?
I am in need of a way to charge a 3.7V li-ion cell (probably an 18650 type) from a 4.5V - 20V input. That's not a problem, there are plenty of (switching) battery chargers around with that kind of operating range.
However, my difficulty now comes…
Thomas O
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How to autoregulate a TP4056 for maximum solar power extraction
I'm using a solar panel (6V - 600mA at peak power) to charge a Li-Ion (3.7V) battery using a TP4065. The TP4065 I'm using has this configuration:
Where the value of the resistor Rprog determines the charging current.
The issue is that the current…
Pat
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10
votes
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Why is earth pin absent in phone chargers plugs but present in laptop ac plugs?
Both mobile phones and laptop get dc voltage from ac source for charging.These chargers have transformer for isolation and rectifier + filter if i am not wrong.I guess the amount of output dc and charging current may vary.
Why do modern mobile…
Gopi
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votes
8 answers
Why don't we use the 7805 for car phone chargers?
What are the disadvantages of using a 7805 (with a heat sink) to use in a car USB phone charger?
Another option: It gives a 1 A current, so could I maybe wire two of those and give a 2 A output?
In past 10 years have tried more than a dozen chargers…
thevikas
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2 answers
How does a battery balance and protection circuit work?
I am building a 4S LiPo battery pack that I would like to incorporate in a portable speaker project and I need to make sure the batteries will never require maintenance beside replacing them completely in 5 years or so. The batteries I am using are…
Bogdan
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Why some phones need a 5V charger although the battery needs 3.7V only?
I've many mobile (smart phone) chargers. The output of them is 5 volts but the battery needs 3.7v only.
Why is it better to make a 5v charger then convert the 5v to 3.7v ?
Why don't we just make a 3.7v charger?
Michael George
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4 answers
Charging li-ion cell using constant-voltage only
Introduction
Various resources [1] [2] state that the optimal method of charging a li-ion cell -- such as one found in a mobile phone -- is to charge at a constant current (usually <1C) until a certain voltage threshold is reached, then switch to…
heypete
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