Solenoids are essentially electromagnets: they consist of a coil of copper wire with a framework (a piece of metal) in the middle. When the coil is energized, the metal end is pulled out at the center of the coil. The electromagnet is thus capable of pulling (from one end) or pushing (from the other).

This solenoid in particular is very small, with a 30mm long body and a "captive" armature with a return spring. This means that when activated with ~12VDC, the solenoid moves and if the voltage is removed, it returns to its original position, which is very convenient. Many low-cost electromagnets are of the push or pull type only and may not have a captive armature (it will fall!) or have no return spring. This one even has nice fixing tabs, it is an excellent universal solenoid.

To drive a solenoid, you will need a power transistor and a protective diode, check this diagram to find out how to connect it to an Arduino microcontroller or other. You will need a good enough power supply to drive a solenoid, as a lot of current will rush into the solenoid to recharge the electromagnet, about 250mA so be careful if you try to power/activate from a computer's USB.

Features

• 12 VDC operation (please note lower voltage results in weaker/slower operation) - 250mA current draw   
• Push or pull type with 5.5 mm throw  
• DC coil resistance: 40 ohms   
• 5 Newton starting force (12VDC)   
• 1.4 oz / 39 grams