Close or Esc Key

Arduino Projects   |   Raspberry Pi   |   Electronic Circuits   |   AVR   |   PIC   |   8051   |   Electronic Projects

Insight - How Mobile Phone Charger works

Written By: 

Ashok Sharma

 

Mobile phones are very common these days and so mobile chargers too. Most of us use it in daily life. In fact they are used to charge the batteries inside the mobiles by providing them a low level DC voltage and current. There may be different types of chargers used to charge different mobile phones but the key functioning of those all are almost same.
 
Cell Phone Charger
 
Fig. 1: Image of a Mobile Charger
 
The above image shows a commonly used mobile charger.

PCB with Components

Inside a mobile phone charger, pcb and components
 
Fig. 2: PCB Circuitry of Mobile Charger
 
On opening the outer screws, we can see the PCB having majority of the components as shown in the image above.
 
Rectifier Circuit in Mobile Phone Charger
 
Fig. 3: Four Diodes Imbibed in Mobile Charger PCB
 
Four diodes shown in the upper image are arranged to make a full wave rectifier circuit. The working of the rectifier is explained later in the article.

Other Components

Other Components of Mobile Phone Charger
 
Fig. 4: PCB Circuitry Components---Capacitors, Transistors, Diodes, and Resistors
 
The above image gives a clear look to the components that are used in the circuitry - capacitors, transistors, diodes and resistors.
 
 
Pulse Transformer in Mobile Phone Charger
 
Fig. 5: Pulse Transformer of Mobile Charger
 
A pulse transformer shown in the above image is a special purpose transformer.

Working

Mobile Phone Charger working
 
Fig. 6: LED of Mobile Charger
 
When charger is connected with the AC supply, the LED starts glowing to indicate the proper operation of the charger.
Working
Latest mobile chargers are kind of power supply units that use the Switched Mode Power Supply (SMPS) technology. To understand the working phenomenon of a mobile charger, we need to understand the concept of Power Supply Unit (PSU). PSU is a device that transfers electrical energy from one end to another by changing its fundamental characteristics according to the requirements. Example of a PSU is an application that converts AC mains voltage to regulated DC voltage. PSUs can be of two types depending on the mode of operation – Linier and Switching.
 
In these switching mode chargers, energy transfer is done by continuously switching electrical components (inductor, capacitor, etc) on and off. We can control the output voltage/current by varying the duty cycle, frequency or the corresponding phase. Using the SMPS technology makes the chargers smaller and lighter by elimination of low frequency transformers. It also presents a greater efficiency than the conventional methods which uses bulky transformers.
 
The AC supply first enters through the line filters in the charger. Line filters are the kind of electronic filters that are placed between an electronic device and an external line to alter/attenuate the electromagnetic interference effect. Now filtered signal are made to pass through the full wave bridge rectifier circuit. Rectifier converts the AC voltage to DC.
 
Output DC voltage from rectifier circuit passes through the PFC (Power Factor Correction) circuit which operates power circuits at their maximum efficiency. Further the voltage signal is transferred to the pulse transformer that is a special type of transformer optimized to produce rectangular electrical pulses.
 
Pulse transformers are categorized into two categories – power and signal transformers. The one used here is a power transformer. It reduces the voltage level of the input power and gives a low voltage power that is exactly required to charge the battery.

Comments

You're a real deep thinker. Thanks for sahring.

such a informatic article   :)

can you help me with provide schematic of mobile charger? i need small power supply in minimum size like it.. thanks :)

Hi,

What output Voltage are you looking for??

5v,9v,12v?

Please also specify the amp value you are looking for as output

 

Wait for Bluetooth charger....

gud 1

can u email me the schematic of it and also the component requirement....

 please any one send to what is paper presentation.

 

can u please mail me the same

Can you please mail me the same at riyagarg2212@gmail.com?

give the briefe information about the paper presentation

 

PLEASE SOMEONE REPLY TO THIS

 

DOES VOLTAGE IN A MOBILE BATTERY DECREASE?

IS THIS THE REASON WHY WE NEED TO CHARGE THE CELLPHONE?

IF VOLTAGE BECOMES ZERO THEN WILL MOBILE NOT LOOSE THE DATA AND EVERYTHING?

It's ur delusion that cellphone is charged..Actually, cellphone is not charged but battery placed inside it, is to be charged in order to access and applicate the data stored in the memory of cellphone....Are u getting me or not??

Got it bro..

what is the power transformer rating voltage used in cell phone chargers

Not much informative .

 

Everyone knows that mobile charger are used for charging mobile battery.

 

Nothing new available here ..

 

can u email me the circuit diagram of it and also the component requirement with their specification....

my email id is jm.lovemypassion@gmail.com..

thnk u in advance

 

Can you please email me the content to make the mobile charger circuit.

my email id is- riyagarg2212@gmail.com

Are the pulse transformers shown in the above circuit, available in market??

Actually the text z quite informatc but yet m not done wid actual arrangement of components on pcb...it wud b bettr if u wud hav introduced a schematic diagram of ckt instead...but anyways...thnx 4 sharing dude...

can u email me the schematic of it and also the component requirement.

I HAVE A 12V 5A BATTERY [ NEW ] OF MY U.P.S.....CAN ANYONE SUGGEST ME THROUGH CIRCUIT IDEA ,  HOW CAN I USE IT AS MY POWER BANK OF MY MOBILE ?

Hi,

You need a step down transformer. Replace the transformer with a  9-0-9 step down transformer to get the input to change into 7v and  then you need a 7805 IC to convert the output to 5V for your cell phone also remember to use the full wave rectifier diode to ensure the form of DC supply to your cell phone.

can you please mail me the components of the charger separately with how each is fixed and working functions

Hi, on a mobile phone charger that has 2 USB ports, does the voltage(?) get split between both outlets if charging two mobiles at once?  If only one cable is plugged in and charging only one mobile, does it get more voltage and therefore charge faster?  Say the charger is labeled as 4.8A.

Hi,

Yes absolutly, the cell phones are generally a 5v devices. Nowdays you have 9V cellphones also in the market. If a charger gives 2A output at 5v it gives 1.67 A output to 9V. So it is basically the relation between the ampere (A) and voltage (V). So putting 2 cell phones together divides the supply to the cell phones.