I would like to detect motion to turn off my 3.8 V, 0.3 A DC light bulb using a PIR motion sensor.
Recently I tried to connect it to a 5 V relay, Arduino Uno, and two 3.7 V Li-ion batteries, and the bulb seemed to burn out.
Any ideas on what should I do to my circuit, and what values of battery I need? Or should I put in a resistor instead?
I tried to modify the schematic with battery and DC light bulb referring to the schematic from here: