A Reed blade, commonly known as an armature, is one of the two flattened parts that form the cantilever and current carrying parts of a reed switch. Two of these reed blades are hermetically sealed at either ends of a glass tube to form a Reed Switch.
In electrical engineering, an armature is the power-producing component of an electric machine. The armature can be on either the rotor (rotating part) or the stator (stationary part) of the electric machine.
The armature interacts with the magnetic field (magnetic flux) in the air-gap; the field component can comprise either permanent magnets, or electromagnets formed by a conducting coil, such as another armature (i.e., doubly-fed electric machine).
The armature, in contrast, must carry current, so it is always a conductor or a conductive coil, oriented normal to both the field and to the direction of motion, torque (rotating machine), or force (linear machine). The armature's role is twofold. The first is to carry current crossing the field, thus creating shaft torque in a rotating machine or force in a linear machine. The second role is to generate an electromotive force (EMF).
In the armature, an electromotive force is created by the relative motion of the armature and the field. When the machine is used as a motor, this EMF opposes the armature current, and the armature converts electrical power to mechanical power in the form of torque, and transfers it via the shaft. When the machine is used as a generator, the armature EMF drives the armature current, and the shaft's movement is converted to electrical power. In an induction generator, these distinctions are blurred, since the generated power is drawn from the stator, which would normally be considered the field.
A growler is used to check the armature for shorts, opens and grounds.