The Electronic Janitor product is a ready-made set of school bell control, using the SDM-10 device. The set is intended for the modernization or construction of a new bell installation. The EW-01 set is equipped with a switch disconnector, a bell controller, parallel relays and special control buttons enabling the activation of the short lessons mode and an alarm button with acoustic signaling. The basic control element is the SDM-10 school bell controller designed to control the acoustic signaling used in schools using bells (e.g.: DNT-212, DNS-212, DNT-212M, DNS-212M - manufactured by Zamel). The control is carried out automatically according to the set algorithm. The program is arranged by specifying the time of the lesson, the duration of the subsequent breaks and specifying the starting time. The device is prepared to run special functions (alarm bells, short lessons) through programmable control inputs. Note: The device works with bells with a rated supply voltage of 230 V AC. It is possible to use 8, 24 V Ac bells through the bell transformer type TRM-8 or TRM-24 exta series.