Running small (2.5v) light bulbs through arduino?

Using Arduino General Electronics
5

To light up a 2.5 Volts bulb using Arduino you will need following things.

  1. A power Transistor(like 2N3055 or BD series) OR a Relay
  2. A 5V 300mA DC power supply (If not readily available then make it using a step down transformer and diodes and filtering Capacitor)

Connect GND of arduino and GND of power supply .
Connect the power transistor base to arduino digital out pin using a appropriate series resistor.
Emitter to GND and collector to one pin of the bulb and other pin goes to DC supply +ve pin.
If bulb burns too bright... put a series resistor of say 100R or so.
OR
You can drive bulbd using relays(If you are OK with TIC TOC sound :slight_smile: )
Let me know if that's clear to you.