The market is flooded with cheap mobile charger circuit. Some of you may be looking for this type of charger circuit diagram and components list.
These mobile chargers uses only few parts, very simple design. But there's a drawback too, they got damaged easily.
Some of my friends keeps asking how to repair mobile charger circuit, so I've decided to do a little reverse engineering of those chargers.
Contents
Cheap 220V AC mobile charger circuit diagram
First of all, lets have a look at the charger's circuit diagram. As transformer is a bit odd, so I've also decided to draw it by hands.
Unfortunately every charger circuit is not same, some of them contains few extra capacitors or resistors.
But even though, you can get a clear overview of the mobile charger circuit from the above diagram.
The design is quite straight forward, built on a paper phenolic PCB, could be easily repaired.
Part list of the mobile charger circuit
Finally the part list, you can replace most of them by their closest alternative.
- Q1 - 13001 transistor
- D1 - 1N4007 diode
- D2 - 6.2V Zener diode
- D3 - 1N4148 diode
- D4 - SB260 schottky diode
- R1 - 6.8 Ohm - 1/2 watt
- R2 - 1 MOhm - 1/4 watt
- R3 - 6.8 kOhm - 1/8 watt
- R4 - 330 Ohm -1/4 watt
- C1 - 2.2uF - 450V
- C2 - 4.77uF - 50V
- C3- 680pF ceramic (681)
- C4 - 470uF - 10V
As I've said before, this type of 13001 transistor charger circuit may vary in design and part number. But the basic circuit is same, few of them have a little LED as indicator.
Transformer details:
- Primary: Around 250 turns of 36 to 40 SWG enamelled copper wire.
- Secondary: 6 turns of 26 to 28 SWG enamelled copper wire.
- Auxiliary feedback: 8 to 15 turns of 36 to 40 SWG copper wire.
If the transformer is broken, you can use the transformer from other broken charger of similar type.
Working of mobile charger circuit
Let's discus about how this circuit works, first have a look at the picture below.
- The first stage is a half wave rectifier, made with D1, R1 and C1. It rectifies and filters the AC input to high voltage DC. So, the voltage between point A and poing B is approximately 170 volt for 120V AC input and 311 volt for 220 volt AC input.
- The Second step is a self oscillating(ringing choke converter, RCC) flyback oscillator, consisted of all the parts shown inside the red box and the primary+auxiliary winding of the transformer.
- So how the flyback oscillator oscillates? When the AC power is connected, base of the transistor starts opening as it's biased by the Resistor R2. The current through primary winding starts rising rapidly, and reaches to the threshold level within no time.
- But at the same time, an opposite(but low) voltage starts rising across the auxiliary winding of the transformer. This opposite voltage starts charging the capacitor C3 negatively, much faster than charging it through R2, thus ultimately blocks current flow through primary winding.
- As there's no more current flow in the auxilary winding, C3 starts discharging through R3 and the current through R2 again starts opening the base of transistor Q1.
- This process repeats itself again and again very fast. May be around 10,000 to 50,000 times a second, depending on various parameters. So ultimately we got the circuit oscillating.
- As the circuit is oscillating, the energy stored in the primary winding is dumped in the secondary winding as well, when the transistor is in off state.
- The Rectifier 2 stage is responsible for rectifying and filtering the induced current and voltage on the secondary. The rectified and smoothed voltage apears between poing C and D. Which could be as high as 8-9 volt under no load. But very quickly drops when a load is connected.
- The resistance R4 ensures a little current flow, thus prevents the capacitor from being over charged.
As there's no feedback mechanism between low voltage side and the oscillator, the voltage drops between point C and D when a load is connected.
Conclusion
Well, that's certainly not the easiest explanation, but I think simple enough to understand what's happening inside the mobile charger circuit.
If you have any question or suggestion, please feel free to ask through the comments.
AURABINDO says
hello Mr.Arnab,
I want to design a mobile charger with 1 ampere output and variable output voltage from 3.6 -4.6 v. can u please help me in designing that using LM317
AURABINDO says
got it Mr.Arnab, from ur previos coments thanks for sharing usful website
http://danyk.cz/li-ion_en.html
Arnab says
It's simple, use something like this
AURABINDO says
Hello Mr.Arnab,
In the following link,
http://danyk.cz/li-ion_en.html
If I am using Proteus to simulate the circuit
For 4.7 I'm I am getting maximum current as 400m ampere instead of 200ma. What to do?
Arnab says
Never simulated anything with Proteus, better check their forum.
Manish Malik says
hello Mr.Arnab
I want to learn how chargers work,I an curious about ist working.need your help, my email is is malik2624@gmail.com
Arnab says
Please stay tuned, I'll update this post by adding how it works.
Dominion says
How to connect usb charger with 2.1A output with 8volt solar panel pls what components should i use thank.
Arnab says
It depends, how you want to connect the charger? What are your requirements?
Harold says
Hello Mr Arnab.
can I use a mobile phone charger to get 15 volts 6-8 amps output, I want to build a dimmer switch for 15 volts LED lamps. please help.
Arnab says
6-8 Amps of current from this circuit is not possible. You should have a look here, https://www.circuitsdiy.com/diy-led-driver-for-5watt-leds-12v-strips-from-100-240-vac/
Irfan says
Your calculation is wrong. In primary 250 turns, in secondary 20 turns and for feedback 15 turns then you will get 7.5 volts without load and 5v while charging.
Arnab says
Hi Irfan, I think 20 turns in secondary is too much.
I've never seen any 5V SMPS with so many turns in primary, do you have any document/link/previous experience to support your claim ? Thanks!
Irfan says
Hi Arnab,
Yes i have made many of these chargers by myself. I was just correcting your calculations. and this charger can supply 1A to charge devices like phones and tabs etc
qaiser says
when charger connect to mobile motorola turbo,connect done but not increasing in %
Arnab says
There's not enough current to charge the phone, this circuit can supply merely 300-500 mA at it's best.
Parman Josan says
HI,
will you please tell me from where I can buy this transformer in India?
Arnab says
Salvage one from a broken charger, the easiest.
Search prominent electronics component markets, they're available.
suny says
how can i make 6volt charger. am i using the same components listed above or what should i add.
Arnab says
Increase the secondary coil winding to 7 turns, the output should be around 6.5 volt.
Aravind says
Hi sir
I have a 10000 mah power bank bt the board is dead.can i have a charger ckt for that.
I need 5v,2amp output
Please help me
Thanks
ARORA says
Sir I want to build a 1 ampere constant current source.can u please help
Sumit says
please help me to make a usb mobile charger using mosfet or transistor only....!!!!!
Aman says
Hello. Thanks for article. I would ak you. What about transformer? what kind and if it is possible please link in alibaba. And what exactly Zener diode neede? I want to assembly own usb charger for bussines in Kazakhstan. Can you help me?
Damith says
Hi Arnab,
Can I use this concept to develop dual or multiple outlets by changing the transformer secondary windings? I mean 15v-015v with 24v supply...
Thanks
manik says
Why need hifrequency oscillating for charger.why not 220vac to 5vac ,50hz using transformer and rectification?
GOUR CHAKRABORTY says
Hi, I have made my mobile charger using your common circuit as 1x 2.2 ohm resistor, 1x 13001, 3x 33 ohms resistor, 1x6.8k resistor, 1x150k resistor, 1x1k resistor, 1x222 capacitor, 1x152 capacitor, 1x2.2uf400v, 1x22uf50v capacitor, 2x4007 diode, 1xred led,1x6.2v zener, 1x4148 diode. Initially it is running but after giving load with my old Nokia mobile 13001 becomes terrible hot & 33ohms resistors are blowing with 13001.Sometimes 2.2 ohm is blowing. I don't understand the fault. Please give me a good stable circuit for mobile charging in my mail.