Cell Phone Charger Circuit Diagram

Mobile phones generally charge with 5v regulated DC supply, so basically we are going to build a 5v regulated DC supply from 220 AC. This DC supply can be used to charge mobiles as well as the power source for digital circuits, breadboard circuits, ICs, microcontrollers etc.

You can also build 6V DC, 9V, 12V, 15V etc by using proper transformer, capacitor and voltage regulator. The basic concept remains the same, you just need to arrange a heat sink for higher voltage and current.

This circuit mainly consists a step down Transformer, a Full wave bridge rectifier and a 5V voltage regulator IC (7805). We can divide this circuit into four parts: (1) Step down AC voltage (2) Rectification (3) Filtration (4) Voltage Regulation.

### 1. Step down AC voltage

As we are converting 220V AC into a 5V DC, first we need a step-down transformer to reduce such high voltage. Here we have used 9-0-9 1A step-down transformer, which convert 220V AC to 9V AC. In transformer there are primary and secondary coils which step up or step down the voltage according to the no of turn in the coils.

Selection of proper transformer is very important. Current rating depends upon the Current requirement of Load circuit (circuit which will use the generate DC). The voltage rating should be more than the required voltage. Means if we need 5V DC, transformer should at least have a rating of 7V, because voltage regulator IC 7805 at least need 2V more i.e. 7V to provide a 5V voltage.

### 2. Rectification

Rectification is the process of removing the negative part of the Alternate Current (AC), hence producing the partial DC. This can be achieved by using 4 diodes. Diodes only allow current to flow in one direction. In first half cycle of AC diode D2 & D3 are forward biased and D1 and D4 are reversed biased, and in the second half cycle (negative half) Diode D1 and D4 are forward biased and D2 and D3 are reversed biased. This Combination converts the negative half cycle into positive.

A full wave bridge rectifier component is available in the market, which consist that combination of 4 diode internally. Here we have used this component.

### 3. Filtration

The output after the Rectification is not a proper DC, it is oscillation output and has a very high ripple factor. We don’t need that pulsating output, for this we use Capacitor. Capacitor charge till the waveform goes to its peak and discharge into Load circuit when waveform goes low. So when output is going low, capacitor maintains the proper voltage supply into the Load circuit, hence creating the DC. Now how the value of this filter capacitor should be calculated. Here is the formulae:

C = I * t / V

C= capacitance to be calculated

I= Max output current (let’s say 500mA)

t= 10ms,

We will get wave of 100Hz frequency after converting 50Hz AC into DC, through full wave bridge rectifier. As the negative part of the pulse is converted into positive, one pulse will be counted two. So the Time period will be 1/100= .01 Second= 10ms

V = Peak voltage – voltage given to voltage regulator IC (+2 more than rated means 5+2=7)

9-0-9 is the RMS value of transforms so peak voltage is Vrms * 1.414= 9* 1.414= 12.73v

Now 1.4v will be dropped on 2 diodes (0.7 per diode) as 2 will be forward biased for half wave.

So 12.73 – 1.4 = 11.33v

When capacitor discharges into load circuit, it must provide 7v to 7805 IC to work so finally V is:

V = 11.33 – 7= 4.33v

So now C = I * t / V

C = 500mA * 10ms / 4.33 = .5 * .01 / 4.33 = 1154uF ~ 1000uF

### 4. Voltage Regulation

A voltage regulator IC 7805 is used to provide a regulated 5v DC. Input voltage should be 2volts more than the rated output voltage for proper working of IC, means at least 7v is needed, although it can operate in input voltage range of 7-20V. Voltage regulators have all the circuitry inside it to provide a proper regulated DC. Capacitor of  0.01uF should be connected to the output of the 7805 to eliminate the noise, produced by transient changes in voltage.

Here is the complete circuit diagram for cell phone charger circuit:

You need to be very careful while building this circuit, as AC mains 220V is involved here.

Video

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### Related Content

• siva
Dec 11, 2015

i need a charger circuit

• Peterwan
Jan 11, 2017

Good brother i think the schematic is clearly given on this page(:

• Muashra Nabi
Mar 26, 2018

Sir i don not know how to connect transformer to the circuit.

• Diler
Jan 31, 2016

What is output of circuit
If lower than 2A how to get it there

Feb 08, 2016

It will depend upon the Transformer, here 9-0-9 1A Transformer is used.

• Peter
Feb 29, 2016

The 7805 regulator will only supply up to 1A, so the circuit is not suitable for 2A even with a different transformer.

• Firoza patel
Feb 03, 2016

Hi. I'm making a similar circuit and would just like to know the specifications of the full wave bridge rectifier used above.
Thank you

Feb 04, 2016

sir what's value of C2

Feb 08, 2016

Its mentioned in circuit diagram, its 0.01uF (capacitance code 103)

• Firoza patel
Feb 08, 2016

Hi
I'm making a similar project. I'd just like to know whats the model of the rectifier that you've used.

Feb 08, 2016

Its 400v 1A Full Wave Bridge Rectifier, can be easily available on any electronics components shop or online stores like ebay.

Feb 27, 2016

How can this circuit be adapted in a locality where voltage fluctuate. What is the efficiency?. From your figure, the voltage measured was 5.11v. How about over voltage, overcurrent protection?ī

• Peter
Feb 29, 2016

I think you have drawn the circuit incorrectly. The way you've drawn it, diodes D1 and D3 short out the transformer output on negative cycles. Your circuit has the junction of D1 and D3 is connected to the transformer centre-tap, although that's not very clear the way you've drawn it.

You need to remove D1 and D3 completely, and the circuit will then work as you meant it to. You do not need and should not use a bridge rectifier with a centre-tapped transformer.

The other way to fix your circuit is not to connect the centre-tap of the transformer to ground, but then you'll have 18v AC across the bridge, which will be about 25v DC, and the regulator will then dissipate a lot of heat.

Also, you should put a 0.1uF or 0.01uF capacitor on the input side of the regulator as well as the output side.

• Annie_M
Feb 07, 2018

With the transformer shown as connected in the schematic (ie 9-0-9 - centre tap), you do not need & should not use a bridge rectifier, the common earth on the -ve side of the rectifier and the centre tap will sohort circuit one of the windings. If you use a single winding transformer, use a bridge rectifier; if you are using a cenrre tap transformer, use 2 individual rectifer diodes thus: the centre tap of the transformer is used as the -ve supply to the circuit & the two other winding ends go through the diodes which are commoned to gether at their + ends. This commoned connection is the +ve supply to the circuit.

• manish
Mar 01, 2016

How to designe a power supply used for mobiles in which rectifier is used before TRANSFORMER.

• Jeremy ronquillo
Mar 17, 2016

SIr i need help designing a power supply unit that has 5V DC output with 2A. Requirements sais i must use a supercapacitor so that the unit will continue to provide electrical energy for 2 minutes even if the unit is unplugged. I hope i can get a response. Thank youuuu

• bat-erdenr
May 07, 2016

I tried this circiut and output is 2.2v i need 5 volt when i missed pls help me iam Mongolia

• shinny
May 10, 2016

Hi Bat-Erdenr,
Could you provide more detail information about your question? Was your experiment result 2.2V? Did you use exactly same components which drawn on this circuit?

• Allen
May 10, 2016

Good day sir! I need to build a 220Vac – 5Vdc, 2A linear power supply. Which of your components do I need to change to accomplish this? Thank you!

• Biswanath gorai
May 10, 2016

I shall try make this charger

• Biddut kumar
May 11, 2016

Thank you for setting

• Atchyut Sreekar
Jun 01, 2016

I need the output to be 9V and 1.2A. How do I regulate or set the current at the output to 1.2A?
I guess the 78xx series IC's have a maximum current of 1A. Should I use an LM317?
Can I control current at output using additional circuitry?

Jun 11, 2016

Use 12-0-12 transformer and yes use LM317 for better results.

• Oba Isaac
Jun 06, 2016

• Vivek
Jun 16, 2016

This is a 5V adaptor not charger.

charger circuit is inbuilt in phone which gives 4.2V to battery and does cc+cv+trickle charging.

• Parag
Jun 20, 2016

Sir, i want to make adapter with output 5V , 1A.. please guide me which changes i have to do in above circuit. Thank you.

• Cvbjjv
Jun 25, 2016

How can we increase 1a to 3a

• Banjo
Jul 01, 2016

help in making a 5v 2a adaptor like this

• Abhishek
Jul 09, 2016

@Parag, @Cvbjjv, @Banjo: First you should select the Transformer accordingly, and then you need to select components, that can bear the current according to the Load, so that they wont burn up. Like roughly IC7805 can handle 1A current, depending upon the load.

• Jasveer Singh
Jul 10, 2016

Hello
how to make multiple mobile charger at least 10 mobiles charge at once.

• Musou
Jul 16, 2016

How to make the output becomes 12 V?

• Jc
Jul 20, 2016

Will this circuit still work if i replace the transformer . and make it like in a wireless charger, transmitter coil- receiver coil?

• Robert Clark
Jul 29, 2016

Could you run a phone charger, or any AC/DC adapter, backwards to attach a battery to the output leads and get AC out of the plug?

Bob Clark

• Melchor
Aug 01, 2016

i just have a stu[pid question..can i use the transformer found in the cellphone charger the opposite way?

• echo
Aug 11, 2016

Is it okay to use 5v zener diode and 1k ohm resistor to disipate the ripples?

• Soumen parui
Aug 13, 2016

My cell phone charger out put voltage only .3 volt.It is not desirable.But i can not under stand the problem .Please answer me

• Chintan
Aug 24, 2016

Dear Sir,
I am trying to make mobile charger using wind energy. I also prepared circuit with diode BR10-10, 1000UF/35V CAP., 7805 IC nd 10UF /63V cap. But I am getting only 2mAmp in place of 500mAmp. How can I achieve it? please help me. Nd I also use 500RPM - 12V DC Motor as generator.

Sep 19, 2016

How can I get an output current of 2 amps with 5v/any other voltage ....what are the changes to be made in the circuit toooo....please explain....????

• Surya
Oct 24, 2016

Hey I want the circuit design for making mobile charger........

• MEHMOOD
Nov 14, 2016

hey everybody...i want to design a multiple current ratings charger of values 1A 1.5A 2A....IN A SINGLE BOX...any knowledge about this project ???seriously neede.....

• Jean Marie
Dec 01, 2016

Hello,

i have a generator producing 8V AC 3 phases (3 wires) and i would like to charge my phone at 5V 1A DC
Can i skip the step 1 and directly go to step 2 ?
And how did you calculate the 100 Hz ?

Thank

Dec 10, 2016

Yes you can skip step first but you also need to consider the current rating your Generator. And AC is of 50Hz so we get 100Hz in DC.

• Sourav Chakraborty
Dec 07, 2016

I need a charger circuit without any tranformar

• Sourav Chakraborty
Dec 16, 2016

How to prepare mobile phone charger without any transformer??

• Ansar Hussain G...
Dec 18, 2016

Sir I want to make charger 5v to 12v Regulated output. what changes are required in this circuit? if we used SCR instead of Diodes what will the result?

• Sourav Chakraborty
Dec 18, 2016

How to prepare mobile phone charger without any transformer??

• ramoall
Dec 19, 2016

I want to prduce modulated phone wave from 1000 to 2500 Hz . and to be able to tune its intesity for biological stuy
many thanks

• Biju MS
Dec 21, 2016

I am trying to make a simple water level indicator using the data taken from internet only. i just wanted to know whether i could replace 9V 1A ac adapter in place of using 9V HW battery for making a simple water level indicator which has resistor 330 ohms and transistor BC 547 in it.

• Sravankumarneela
Dec 21, 2016

As in transformer o/p power =i/p power then how the electronic devices are working at our homes because of this high i/p power of a transformer.

• mohamed Azeem
Dec 22, 2016

how to 5v ?

• Mary Jane
Jan 03, 2017

Good Day Sir,,

what transformer should i use in reducing AC 85 - 270 v.

• tonny Anthony
Jan 05, 2017

How do i use a transformer with 11v output

Jan 28, 2017

You can use 11v transformer with this circuit, current rating should be less than 1A, what is the current rating of your transformer?

• Anik
Feb 10, 2017

Sir,
Please tell me why my mobile charger is showing charging but battery is not charging what could be the problem in any mobile?

• Pushpak
Mar 03, 2017

Hello sir i need sm help please
i hv transformer now its giving me dc output is near 13v but i wanted to charge my my 2.4v Ni-mh battery so i used 8v mosfet or i think its called as voltage regulator LM7808 and created a circuit but did not work my battery isn't charging...(i checked it using multimeter it gives 7.98v) but its not working at all i dont kno why i need sm solution or is thr any way to increase output voltage of mobile charger like my android charger gives 5v output so if i can increase it to 7-9 v ? please help me out

• Pushpak
Mar 04, 2017

i want to make charger thats gives at digit dc voltage between 7-10 v dc so i can charge my2.v battery using it
it wud be a big help of some1 show me how to increase voltage of normal mobile charger
thank you

• Pushpak
Mar 05, 2017

wow kind of a voltage regulator...thank you maddy but can u suggest me sm quick and lil cheap method...

and can use smtng else instd of LM317

• Chiranjeeb
Mar 04, 2017

i have done it but the percentage of battery coming down, what could do to up the percentage

• Andrew
Mar 05, 2017

which capacitor can i use when designing a mobile charger AC12 input?

• bahaa
Mar 27, 2017

What should we have to do if we need output current of 2A

• Firdous Khosa
Apr 15, 2017

Input is 100-220v~ 50-60Hz 1.5A
Output 19V=4.74A

• Faizal
Apr 21, 2017

good day sir..

may i know, what is the function for C1 capacitor?
thank you.. sorry for my bad english..

• sushahs
May 14, 2017

sir i want to make a fast charger which out put has 5 volt and 3 amp, do you have any diagram ?????????
i have already 3500 map lipobattrie

• Andrew Sims
May 31, 2017

Thank you Sir, I have copied the end of the circuit, after the bridge rectifier, because I don't need it as I am using a DC Motor. The Motor is rated 12V so the Voltage Regulator with the same Capacitors should do the job nicely, providing a 5V output to a mobile phone or power bank. Would I put a 100ohm resistor in my final circuit?

• Shahzaib Asif
Jun 10, 2017

How many ampere it gives at output ?

• Talha Tanveer
Jun 19, 2017

why you didn't used a resistor in smoothing?

• Usama Ejaz
Jul 05, 2017

Sir you just made my concepts better,
Thanku

• James
Jul 07, 2017

All chargers av seen contains resistors in them , why is that ?

• ajay
Aug 19, 2017

Sir,
What happen if I connect a 7V DC motor directly to a 220V AC supply by a charger and datacable
Is it work or get any short circuit???

• Aswinth Raj
Aug 20, 2017

Assuming your chargers output to be 5V 2A. Yes you can do it. It will not create a short circuit.

But, it is not an effective way of doing it. Because the 7V motor will be powered by 5V which will force it to consume more current and eventually damage it.

So this will be a temporary solution only.

• vishu
Aug 23, 2017

i need block daigram and circuit daigram power supply. one input and meny outputs.but output current will be different

• Rajiv rajput
Aug 28, 2017

LED in mobile charger is not glowing and mobile also is not charging..so, i want to take a risk of removing LED and joining both ends..will it work..what is the significance of LED apart from glowing indication..?

• Aswinth Raj
Sep 01, 2017

LED is given for indication purpose. Removing it might not help.

Which LED are you talking about? There is no LED in the circuit diagram

• Bhavesh Chudasama
Oct 05, 2017

1 Hors 80 % Mobaile Chargin & All Compny Mobaile Charge ?

• SANDEEP BERA
Oct 31, 2017

i want to know that is it the mobilecharger using buck converter or not?? pls clarify

Mar 04, 2018

good and simple

• moeez
Jun 02, 2018

what if 2A transformer is used ????

• Aswinth Raj
Jun 06, 2018

Yes you can use a 2A transformer, it will increase the output current of the circuit. But since 7805 can supply only upto 1.5A you will not be able to draw more than that without damaging the IC

• Manish Kumar Sr...
Jul 01, 2018

Plz,tell me how to connect a charger with USB.

• Aswinth Raj
Jul 04, 2018

Cut the charging cable of any old charger and find the positive and negative wire in the cable and connect it to the circuit.

However this circuit is only for educational purpose and is not intented to be used for practical applications without any modifications

• payam
Jan 08, 2019

is the above mentioned circuit unsufficient for a practical use? what else are necessry ? and why

how can we make our resolution stable enough for example if the input ac voltage changes?

• Aswinth Raj
Jan 09, 2019

The circuit can charge your phone for sure but is highly un effeceiant. All mobile chargers use Switching circuits. Here a linear regulator with Transformer is used.