In a commercial manner, “usb condom” is a security device for preventing data theft through universal serial bus (usb) interface, and is widely used by many smart phone owners to protect their ...

Here is a tried and tested sample circuit of a Li-Ion battery charger that can be used to charge any 3.7V Li-Ion battery using a 5VDC (USB, Solar Panel…) power supply. At the heart of the circuit is ...