$2 Cassette Box Cellphone/USB Charger

Step 2 The Simple Version

The simplest means of setting up and using this regulator is to simply take the cellphone connector wire from a broken wall charger and solder the red(positive) lead to pin 3, and the black/white(negative) lead to pin 2 (ground). You can then cut the end off of any used DC wall wart (make sure that the milliamps is AT LEAST the same, or more than what's listed on your original cellphone wall wart), and solder the positive wire to pin 1, and the negative wire to pin 2.

I went ahead and used an old leftover female USB port (leftover from a motherboard add-on) instead of wiring directly into my cellphone wire, as I had a USB charger adapter readily available. I also used alligator clips which would allow me to attach any available DC power power supply, including batteries, instead of wiring directly to a DC wall wart.

Here you can see that I'm actually charging my cellphone from a 9 volt battery! 4-6 AAs also work, and even a cordless drill battery...