My friend has been living with an old flip-phone with a crack in the still readable screen and just basic phone service, so I thought it would be good to get him a used phone, but something a few generations newer. I got a used Samsung Zeal, which is (I call it) a flip-flop phone. It has a flip-up lid, which displays a phone number pad. But if the lid is flopped sideways, the keyboard is displayed. It’s pretty cool.
But the charger that came with it has a special Samsung plug that only fits the connector on the phone. I can’t use the standard micro USB charger cord. The other end is a 120 VAC to 5 VDC converter, not a USB connector.
I ordered some ‘lipstick’ phone chargers. They are a round case with a lithium rechargeable cell and the circuitry inside and a USB connector to output the 5 VDC to the cell phone. The problem is the phone’s cable needs to plug into 120 VAC, not 5 VDC. I can’t replace the cord because it has the special Samsung connector.
So what I need is to go from 5 VDC to 120 VAC. I think if I used a 120 VAC to 6.3 VAC center tapped filament transformer with a power transistor, it might be able to put out 120 VAC at 10 watts. The frequency is probably not critical as long as it’s somewhere in the audio range.
I was thinking of another solution. I could tap into the plus and minus wires of the special cable. I could then solder a 1N5817 Schottky diode and a cable with a USB connector on the end so it can be plugged into the ‘lipstick’ or any other charger. I may not have to have the diode at all, depending on the output circuit of the charger.
