Abstract: A burglar alarm provided with a housing which contains a bell assembly and a battery compartment connected in series with a switch assembly having a linearly movable element which can be displaced a predetermined threshold distance by a chain extending to a magnet temporarily joined to a metal bracket attached to a movable surface. The switch assembly contains a pivoted contact which moves against a fixed contact when the linearly movable element is displaced a predetermined distance, and remains there regardless of the subsequent position of the linearly moveable element until a button operationally connected to the switch assembly is moved to the "off" position. The bell assembly includes a motor having a clanger support mounted on its shaft, the clangers being loosely mounted on the clanger support so that they can strike the bell without impeding the rotation of the motor.