I made an adopter to deliver variable voltages using an LM 317 IC. The voltage is observabale on the multimeter. But When I try to charge a Nokia phone, a message called 'not charging' is displayed. What could be wrong ?
Use ≈10-12Ω resistor rated to at least 2W and connect to the output of your power supply; using voltmeter, measure the output voltage with resistor attached: you should read ≈3.7Vdc (Nokia). If voltage under load is much lower than that your phone will just ignore it ..
I just found out that the wire I was using to connect to the phone had a resistance of 2k2Ω.... So the voltage drop across the wire was so large that the phone did not get the required voltage. The original nokia charger was rated 800mA and 5.7v. I shall try changing the wire.