Safety floor and sweep with line power

A mobile storage system includes movable carriages that are stoppable by solenoid operated mechanical safety brakes. The solenoids are controlled by an electrical circuit that includes a safety floor and/or a safety sweep. Actuating the respective safety switches activates the circuit to energize the solenoids for operating the brakes. The safety floor portion of the circuit is designed to energize the brake as long as a safety floor switch is actuated. The safety floor circuit portion contains a timing device that holds the solenoid in the energized condition for at least 3 seconds after deactuation of the actuated safety switch, so that a person walking across the floor does not cause the solenoids to chatter. The safety sweep circuit contains first timing means for deenergizing the solenoid approximately 3 seconds after safety sweep switch actuation. If the actuated switch remains open after approximately 5 minutes, or if a safety sweep switch fails, an audio alarm sounds. Both the safety floor and safety sweep portions of the circuit include indicator circuits having light emitting diodes. The light emitting diodes are placed in appropriate control boxes within the mobile storage system to facilitate maintenance.