Method steps and component combinations for establishing a telephony exchange, with benefits of hardwiring, free of a requirement for first installing telephone copper wire service to a concentration of electric power consumers. The floor pan has a drain, an integral water receptacle and a trough for guiding fluid to the drain. A permanent magnet is configured to provide a permanent magnetic field oriented in the axial direction, and a coil disposed on an interior side of the piston produces an alternating magnetic field in the region of the permanent magnetic field.