Questions tagged [charger]

A device which controls the voltage and current being delivered to a capacitor or battery.

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53
votes
3answers
72k views

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- ...
8
votes
3answers
639 views

Name of component on output side cable of a DC power adapter?

What is the name of this component (circled in red) of a charger? What are the uses of this component?
13
votes
5answers
11k views

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 ...
1
vote
1answer
920 views

Draw power from a portable mobile charger to power circuits

I usually power my beginner prototype circuits using mb102 power supply board, but it needs an external elimeter to draw power and then regulate it. I was looking for a portable solution for my 5 ...
0
votes
1answer
1k views

LiPo Charging Ciruit - Switching Help

I do understand that similar questions and maybe even the same question has been asked before, I've found them but unfortunately as a result of inexperience on my part I have been unable to adapt the ...
18
votes
4answers
12k views

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 ...
12
votes
1answer
980 views

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 ...
6
votes
4answers
21k views

Building a USB charger for camping

I was looking into building a battery powered USB charger for camping. It occurred to me that car chargers are pre-built and run off 12 V. If I made a battery pack out of 8x 1.5 V batteries in series ...
5
votes
1answer
4k views

Dirt cheap NiCad charger

So sharptooth has a question up for creating cheap charger units that uses battery packs to charge a phone: Is designing and producing a dirt cheap charger really that hard? My question is the other ...
4
votes
1answer
5k views

Smart charging circuit for NiMH battery pack

I want to build a solar powered charger for a niMh battery pack to run a microcontroller. What are the fundamentals of building a smart circuit that will not overcharge the battery and will also allow ...
3
votes
3answers
3k views

Mobile phone battery charger

I would like to know about the workings of mobile phone battery chargers. I know the basic principle, you take a transformer to bring it down to 9/6/3.7 volts then a bridge rectifier circuit and a ...
7
votes
2answers
15k views

Why are these USB data lines conned to pull-up resistors?

I recently got a car lighter to USB adapter which I planned to use to charge my mobile phone. Unfortunately, the phone won't charge (and I know that the phone is capable of charging over USB port), so ...
2
votes
2answers
869 views

Is this a viable mini wind turbine setup?

I'm going to build my first wind turbine. I have already constructed the prop, 5 blades 50cm long from PVC pipes. I've searched for a decent sized motor and charge controller. The turbine will be ...
0
votes
2answers
2k views

How does this wireless charger work?

I want to understand the way this circuit works. The following are diagrams of the transmitter and receiver of a wireless iPod charging circuit. I have added a link to the instructable that describes ...
4
votes
2answers
1k views

How to lay out a schematic for review? Please critique

So, because I haven't posted a schematic for review before, I have no idea how to do it. Apparently, my previous attempt was poor. I got some actionable feedback, but I'm looking for more! I would be ...
2
votes
6answers
5k views

Why is a laptop power supply output voltage different from its battery?

I hope you will not mind answering. This question has long been on my mind. Normally, the adapter output voltage is higher than that of the battery. In my laptop's case, the output voltage of the ...
0
votes
1answer
854 views

USB charging at 4.3 volts

I'm trying to create a charger that knows how to switch between OTG and charging mode. The OTG side is working, and my Samsung S4 goes into charging mode. However, charging is really slow. It even ...
0
votes
1answer
191 views

Charge controller for Li-ion or Li-Polymer battery

I am trying to work out the good charger for Mobile phones, which can serve as good performer for various smart phones out there in market these days & mostly using Li-ion battery. Charging has 4 ...
-1
votes
2answers
211 views

Solar panel lipo and usb

I connect a 5v 5w solar panel a usb port and a 3.7v 2.5A lipo with pcb. If I connect a phone to usb port it doesn't charge, but if I remove the battery from the circuit, it does. I suppose it's ...
-1
votes
1answer
1k views

What's the purpose of this bulky cylindrical part near the plug end of a laptop charger cord? [duplicate]

I want to fix my laptop charger cord, I used a multimeter to check the voltage and it gives me less than one volt. It feels very flexible near the plug, but I don't know if I can cut before or after ...
17
votes
3answers
85k views

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 ...
12
votes
5answers
20k views

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 ...
2
votes
2answers
4k views

Emulating a USB Standard Downstream Port Charging application

I have am using an LM5017 to step down a relatively high voltage solar panel (VOC over 90V) to 5V. I have bench tested my circuit and it is providing good buck regulation with input voltages up to 95V....
5
votes
6answers
18k views

How to charge Laptop Li-ion Battery cells manualy?

I have received some Li-ion batteries which were originally used in Asus A2 Laptop battery original one and I would like to know if it is possible to charge each cells independently with some device ...
8
votes
2answers
17k views

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 ...
7
votes
2answers
2k views

How do snap-on induction charging systems not interfere with device functioning

There's a variety of snap-on wireless charging solutions on the market. For example, this one includes a charging mat and a plastic case that is put onto iPhone. I suppose the winding is in the ...
0
votes
2answers
126 views

Can I keep my charger plugged in? [closed]

If I keep my charger plugged in while my phone is not connected, it does not heat up. So, it is safe to keep the charger plugged while it is not connected to the phone? Will it draw current?
5
votes
3answers
1k views

Why AC supply is rectified first before stepping voltage down?

I have opened one of my phone chargers and was trying to understand how it works.. I found IC MB6F just at AC input which came out to be a bridge rectifier. My question is why AC is first rectified ...
2
votes
4answers
15k views

How do we charge a small 12V battery from a large 12V battery bank

In a youth organization that I am part of we are building a traveling stand alone system, which will be put up on various fairs and music festivals. On one of the festivals there is a wish that we can ...
2
votes
3answers
383 views

Is designing and producing a dirt cheap charger really that hard?

Recently one blog service (all text is in Russian) published a curious post. The author proposes to add mobile phone charging capability to each 4-pieces pack of AA alkaline batteries. The idea is ...
2
votes
0answers
2k views

How to charge LiPo battery using a wind generator?

For a home robotics project I want to fly a kite using a computer. For this to happen I need an electro motor up in the air (attached to the kite) which obviously needs a battery up there as well. ...
2
votes
4answers
7k views

DIY NiCad charger

I have this Ryobi 12V NiCad cordless drill that was sitting in a drawer for the past 6 years or so due to dead batteries (2 of them). At least that's what I tought at the time but looking at it more ...
1
vote
1answer
476 views

Is it safe to charge a Li-Po battery at a lesser C rate than its usual routine?

On my Quad Copter I have a 5400mAh Li-Po battery (3S 11.1V) and its charger charges at 0.5 C since it takes 2 hours to charge the battery. That charger has broken down, I have ordered a replacement ...
1
vote
4answers
24k views

Charging 2 Li-Ion Batteries via a single charger

I'm currently building a portable USB charger. It uses 2 Li-ion batteries in series connected to a USB port via a 5V regulated buck converter. While a single Li-ion battery would suffice for most ...
0
votes
1answer
366 views

PMIC Battery charger and power path

I was looking for a PMIC with battery charger and built-in power path when I came across one of TI's new chip. BQ25601 http://www.ti.com/product/BQ25601. while I was trying its performance and doing ...
0
votes
2answers
529 views

tp4056 power consumption

I have replicated the li-po battery charger with the famous TP4056 , the protector DW01A and the mosfets FS8205A... exactly like the comertial board. I design a board that contains this circuit (and ...
5
votes
3answers
7k views

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 ...
5
votes
2answers
18k views

What might cause audible noise in an inductive charging system?

I have a pair of Qi-compatible wireless charging pads, and I've noticed that when a device is charging, the pad will emit a quiet but noticeable squeal in a relatively high frequency range. Perhaps it'...
4
votes
2answers
4k views

Building an inverter to charge various devices

With all the power outages being caused by Hurricane Irene, I thought it might be useful to have an inverter that I could charge my cell phone with. Plug in battery power on one end, cell phone on ...
4
votes
1answer
666 views

Parallel charger circuits

I'm constructing a power supply based on solar cells backed by batteries. The solar cells deliver between 0 and 4 A, depending on the time of day, while the charger I plan on using, the LT3652, has a ...
4
votes
1answer
2k views

Coin cell battery recharging circuit for RTC backup power

I am designing a system that contains an RTC to for displaying the date and time on a user interface, as well as log events with time stamps. In this particular case, the system gets powered-on at ...
3
votes
2answers
2k views

Is there a reason GaN chargers stop at 65W?

During the last year or so we have seen commercial release of USB chargers utilizing GaN technology. For some reason it seems no products go higher than 65W. The Navitas reference platform was 65W, ...
2
votes
2answers
1k views

Can I charge multiple devices from one transformer?

I am getting tired of bringing 3-4 power cables with me every time I travel and am thinking about building a multi-device power charger. In other words, this charger will have one transformer (and one ...
1
vote
3answers
9k views

How to efficiently charge a capacitor from AC source

I want to charge a capacitor at 200V DC from a 220V AC power supply (peak voltage = 311 V). Also I want no power disipation once it reaches full charge. This goes inside an equipment that discharges ...
1
vote
2answers
2k views

powering +5v device with usb and/or battery

I made a PCB with an arduino clone and a tiny motor driver. The arduino clone itself needs +5 volt power supply, so I decided to use a DC/DC boost converter to boost a 3.7 volt Li-Ion battery to +5 ...
1
vote
1answer
777 views

What causes the opamp to become warm in this charger? [question updated]

UPDATE I just realized that I posted the bad version of my circuit. I now swapped the + and - input of IC5A using a utility knife and short wire on my PCB after realizing that I was making the ...
1
vote
1answer
337 views

Li-Po charger booster circuit

I'm trying to design a simple circuit that has the ability to charge a single cell Li-Po battery and can be used as +5v power source. I chose the circuit from here. It seems that when ...
1
vote
3answers
469 views

Buck Converter for 59V to 58V?

Some batteries last twice as long if they are kept to 80 percent of their maximum charge. It's good to add a small adjustment to undervolt a charger output by 0.5 - 1V. Myself i have a CC/CV charger ...
0
votes
2answers
52 views

Battery Discharged - But Potential difference exists without any current flow

My below question is regarding batteries. I have a USB charger and a mobile battery (Li-ion battery). So, my mobile battery percentage has dropped to 0%. So, what I do now - Take the USB Charger. Plug ...
0
votes
1answer
139 views

Debugging a battery charger circuit

I have built a circuit of a battery charger here. Here is the circuit in the original project: However, it doesn't seem to work. The output I measure at the battery charging clips is only 1.2 V or so ...