vahbhaiv
Newbie level 1

I was trying to program an AVR tiny to make a pwm based charger out of it ,
A charger which could be used for charging mobile batteries...
for this I experimented using the Nokia-1100 phone battery ..
When I checked the signal at the o/p of the charger ,it was a pure ,regulated DC power supply of ~5 V..
But when I tried to charge it(phone) using the DC power from a power supply at 5 Volts ,the charging never started .
The Nokia charger provides a current of 0.8 A for charging purposes ,and the power supply which I used is capable of much more ....
I was completely amazed to notice that the charging occurred from the DC supply from the ( nokia )charger ,but however if the same DC power when provided from an external source is unable to charge the hone battery ....
I have even known and seen devices called mobile USB chargers which sink in current from the USB port of a computer and these devices work fine...
then why does it not work from a power supply....
Somebody please help...
Any kind of help would be highly appreciated .
A charger which could be used for charging mobile batteries...
for this I experimented using the Nokia-1100 phone battery ..
When I checked the signal at the o/p of the charger ,it was a pure ,regulated DC power supply of ~5 V..
But when I tried to charge it(phone) using the DC power from a power supply at 5 Volts ,the charging never started .
The Nokia charger provides a current of 0.8 A for charging purposes ,and the power supply which I used is capable of much more ....
I was completely amazed to notice that the charging occurred from the DC supply from the ( nokia )charger ,but however if the same DC power when provided from an external source is unable to charge the hone battery ....
I have even known and seen devices called mobile USB chargers which sink in current from the USB port of a computer and these devices work fine...
then why does it not work from a power supply....
Somebody please help...
Any kind of help would be highly appreciated .