cell phone charger

[donskister]

- I know and i really have good understanding about the input ac source, frequency and output voltage..But i dont understand Wheres the 100mA & max 750mA come up? Can u give me some idea & mathematical explanation to come up for 100mA & 750mA.. thanks
- How can i compute the power rating of these charger??

INPUT AC. 120~240
50-60 hz
100mA
Output DC. 4.8-12
max 750mA

[ante]

Hi don,

Max 750mA is the maximum secondary load and 100mA is the mains current at the primary! Input power is 120 * 0.1 = 12W and output power is 12 * 0.75 = 9W.

[donskister]

Hi ante.

[Roomi]

http://Then multiply 240 instead of 120!

Simple..Isn't  it???

[ante]

Hi Don,

Since the charger is marked 100mA this is assumed to be the maximum current. The maximum current occurs at the lowest voltage. At 240VAC we can assume the current to be about 50mA.