Simple Logic Gates using Diodes

Diodes can be used for implementing simple logic gates such as AND or OR combinations. For AND gate, all inputs must be tie to high, 5V for the output logic high. For OR gate, the output is high if any input(s) are high.

Emergency Phone Charger From 3 x AA Battery with output Protection

Three AA batteries (3 x 1.5V) is using as emergency power source for mobile device or phone charging. Output current is limited to 0.5A and protected from out short circuit or high current drawn from the batteries.