Controlling a solenoid (TIP120 Arduino)
From bildr
This Module is part of the grouping: Controlling a solenoid
Because an Arduino can only output 3.3 or 5v, a transistor must be used when controlling a 12V or 24V solenoid. The TIP120 Darlington Transistor (available at many places including Radio Shack) will allow the Arduino to control the device quite easily.
The transistor acts as a switch, and when the Base (B) on the transistor is held low, the Collector is disconnected from the Emitter. When the Base goes high, EG, when the arduino sends a 5v signal to the Base, the transistor will connect the Collector and Emitter together, closing the circuit and , powering the solenoid.
Do not connect positive ends of the 12/24V supply to the arduino, as this could easily destroy the arduino.
This page is a Module on bildr. Modules are how-to pages on the creation of objects designed to be expanded upon.