Home Brew USB Charger / Power Supply
Over the years I think we’ve all gathered some extra power supplies and wall adapters. Here is a quick guide to a home brew USB charger or USB power supply. This USB tutorial is from the Hacked Gadgets website and Alan runs a good site – check’em out.This unit is great for charging your iPod, PSP or any USB device and only costs pennies to make.
- 330 ohm 1/4 watt resister
- 10k ohm 1/4 watt resister
- 3mm LED (any color)
- USB type A jack (female)
- Pin 1 is bent over and soldered to the case of the jack. The case of the jack is then connected to the wallwart ground.
- Pins 2 & 3 are connected together then soldered to one end of the 10k ohm resister. The other end of the 10k ohm resister is connected to +5vdc.
- Pin 4 is connected to +5vdc. One end of the 330 ohm resister is also connected to +5vdc. The other end connects to the anode of the LED. The cathode of the LED is grounded.
- The 10k ohm resister is used to pull the USB data lines high. Some devices require these lines to be at +5vdc before initiating charging.