Archives For USB

This is a USB interface board I’ve built around a PIC 18f4550 microcontroller from Microchip. As many of you probably know, I’ve used my computer’s parallel port to connect many things to my computer. However, most laptops don’t have parallel ports these days, so I needed a way to connect things without a parallel port. Continue Reading…

Now you can charge your Mobile Phone from the USB outlet of PC
This simple circuit can give regulated 4.7 volts for charging a mobile phone. USB outlet can give 5 volts DC at 100mA current which is sufficient for the slow charging of mobile phones. Most of the Mobile Phone batteries are rated 3.6 volts at 1000 to 1300 mAh. These battery packs have 3 NiMh or Lithium cells having 1.2 volt rating. Usually the battery pack requires 4.5 volts at 300-500 mA current for fast charging.
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