Hi,
Today measured my cell phone's charging voltage and current and got unexpected result. Nokia genuine adapter (charger power supply) of my simple java phone (Nokia 201) is rated Output= 5V, 450mA. Measurement was--
- Output voltage with no cell phone connected +7.5V.
- Output voltage with cell phone +5.8V charging voltage.
- Battey was almost 20% charged.
- Current was 600mA to cell phone.
Just then I measured another Chinese adaptor--
Rated- 5V, 0.5A
- Output voltage with no cell phone connected +5.6V.
- Output voltage with cell phone +4.7V charging voltage.
- Battey was almost 20% charged on phone.
- Current was 250mA to cell phone.
According to my 1st measurement my cell phone is having 5.8V and 600mA current. So I think 5V input is not critical. Isn't it? It seems very rough arrangement!
Another- how much power and heat will the MOSFET dissipate? I wish not to use heatsink.
[Going to use '45N03' MOSFET, 30V, rDS (on)= 0.02 ohm, 45A]