I made a charger using 7805 and used a PNP to increase current. Output side was connected as shown in figure.

But when i connect it to mobile, mobile shows that it is charging and drawing 1200mAh

But battery goes on decreasing and when i connected a multimeter, it showed that no current is going into the phone.

Then i removed phone and connected a 3.3 ohm 5 Watt resistor, circuit was perfectly working. Can anyone suggest a solution?

 

I'm not very clued up on this, but I would like to ask a few questions. How well does your circuit's characteristics, i.e. volts, ampere, match that of the branded charger? Does the phone charge through a branded charger? (Has the phone been damaged?) How can it be that there is no current going into the phone if the reporting software tells you on the screen there is something going on?

Maybe there is (most likely) some sort of protection circuitry in place in the phone. The charging circuitry may be separated from the input to the reporting software. These systems may run in parallel and not in series.

Then, something seen on sspence's Green-Trust site - knowledge new to me - your charging voltage has to be higher than the battery's stored voltage.

 

How did you connect the multimeter to test current? When measuring amps you must put the meter in series with it, meaning you need to break the positive wire and put the meter between the two halves.

In order to get the phone to charge, you really shouldn't be using it while plugged in. Otherwise you may be draining it faster than you're charging.

 

What's your calculated wattage of the charger and what's the mAh value on the phone's battery?

 

I'm not very clued up on this, but I would like to ask a few questions. How well does your circuit's characteristics, i.e. volts, ampere, match that of the branded charger? Does the phone charge through a branded charger? (Has the phone been damaged?) How can it be that there is no current going into the phone if the reporting software tells you on the screen there is something going on?

Maybe there is (most likely) some sort of protection circuitry in place in the phone. The charging circuitry may be separated from the input to the reporting software. These systems may run in parallel and not in series.

Then, something seen on sspence's Green-Trust site - knowledge new to me - your charging voltage has to be higher than the battery's stored voltage.

Voltage was 5.07 v as measure by multimeter.
I broke the charging cable and soldered it petmanently to the ckt as i didnt have the female USB port. So current measurement was not a problem because I only had to melt the soldering and put ammeter.
My circuit was efficient because with 3.3 ohm resistor connected, 1.4 amps was going through thr resistor and 4.98 vilts were accross the resistor. Good load regulation.
Yeah might be some kind of protection.
By the way I am try to charge my Note 3, phone is good because it is charging whith any other chargers.

 

You need to post the whole circuit here not have . Also 2 lines are power and the others are data .. I could be wrong here but I believe that apple products are the only one that uses the resistor network to get a higher charging rate or even charge.. Most times I just run to my local flea market for chargers for a buck a piece.

 

I used this circuit

 

Some USB devices use a pulldown/pullup resistor on a separate pin to "enable" charging (most of the time its molded into the smaller connector on the charge/data cable. I have done something similar to what you are trying to accomplish here and I found that i needed to pull one of the pins low. I dont remember which one it was a long time ago. Are there any other pins in the connector of the phone besides the outside shield, +5, GND, d+, and d-?

 

Some USB devices use a pulldown/pullup resistor on a separate pin to "enable" charging (most of the time its molded into the smaller connector on the charge/data cable. I have done something similar to what you are trying to accomplish here and I found that i needed to pull one of the pins low. I dont remember which one it was a long time ago. Are there any other pins in the connector of the phone besides the outside shield, +5, GND, d+, and d-?

Yeah a pin that tells whether it OTG cable or Normal USB cable. But it is not connected during charging process.

 

I don't have any insight into the current issue but the 7805 has a 2V dropout voltage. To get regulated 5V out you need at least 7V in.

 

I don't have any insight into the current issue but the 7805 has a 2V dropout voltage. To get regulated 5V out you need at least 7V in.

No drop out sir. Perfect 5.07 Volts.

 

I'm going to change data pin connections to see what happens.

 

What input voltage are you using on your voltage regulator circuit? And did you change data pin connections?

 

Hello,

Perhaps this info will help:
http://blog.curioussystem.com/2010/08/the-dirty-truth-about-usb-device-charging/

Bertus