# US 2019/0246207 A1 · Sound system, end of line device and end of branch device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0246207 A1 - Document ID: US20190246207A1 - Status: Published application - Kind: A1 - Application number: 16/267,913 - Filed: 2019-02-05 - Published: 2019-08-08 - Earliest claimed: 2018-02-06 - Assignees: Robert Bosch GmbH - Applicants: Robert Bosch GmbH - Inventors: Guus Kleeven; Kees Nuijten - Web page: https://patentgrep.com/patent/US20190246207A1 ## CPC - H04R 3/12: for distributing signals to two or more loudspeakers {(specially adapted for hearing aids H04R25/407)} - H04R 27/00: Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; {monitoring or testing arrangements for public address systems H04R29/007}; amplifiers H03F) - H04R 29/002: {Loudspeaker arrays} - H04R 29/007: {for public address systems (public address systems per se H04R27/00)} - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A sound system 1 comprising at least one monitoring device 8, a source device 4 and a transmission medium 6, wherein the monitoring device 8 is connected with the source device 4 via the transmission medium 6, wherein the monitoring device 8 is adapted to receive a monitoring signal 9 sent by the source device 4, wherein the monitoring device 8 is a passive device and adapted to send at least one harmonic of the monitoring signal back to the source device 4. ## Claims ### Claim 1 A sound system (1), comprising at least one monitoring device (8), a source device (4) and a transmission medium (6), wherein the monitoring device (8) is connected with the source device (4) via the transmission medium (6), wherein the monitoring device (8) is configured to receive a monitoring signal (9) sent by the source device (4), and wherein the monitoring device (8) is a passive device and configured to send at least one harmonic of the monitoring signal back to the source device (4). ### Claim 2 (depends on 1) The sound system (1) according to claim 1, wherein the harmonic sent by the monitoring device (8) is the second harmonic. ### Claim 3 (depends on 1) The sound system according to claim 1, wherein the monitoring device (8) is configured as an end of line device. ### Claim 4 (depends on 1) The sound system (1) according to claim 1, wherein the monitoring device (8) comprises a resonant circuit with a capacitor (13) and an inductor (14). ### Claim 5 (depends on 4) The sound system (1) according to claim 4, wherein the monitoring device (8) comprises at least one diode (15), wherein the diode (15) is connected parallel to the inductor (14). ### Claim 6 (depends on 1) The sound system (1) according to claim 1, wherein the monitoring device (8) is configured as a filter for suppressing an audio signal. ### Claim 7 (depends on 1) The sound system (1) according to claim 1, wherein the source device (4) comprises a measurement unit to detect the harmonic sent by the monitoring device (8). ### Claim 8 (depends on 1) The sound system (1) according to claim 1, with at least one switch (12) device for connecting and disconnecting the monitoring device (8) and the source device (4). ### Claim 9 (depends on 8) The sound system (1) according to claim 8, wherein the switch device (12) and the monitoring device (8) are forming an end of branch device (11). ### Claim 10 (depends on 9) The sound system (1) according to claim 9, wherein the end of branch device (11) comprises a supply unit (16) for converting energy of the monitoring signal (9) into usable voltage. ### Claim 11 (depends on 9) The sound system (1) according to claim 9, wherein the switch device (12) comprises one shot unit (18), a counter unit (19) and a jumper unit (20), wherein the one shot unit (18) is configured to be triggered by the monitoring signal to send out an pulse, wherein the counter unit (19) is configured to count the pulses sent out by the one shot unit (18), wherein the jumper unit (20) is configured to connect and/or disconnect the monitoring device (8) based on the pulses counted by the counter unit (19). ### Claim 12 (depends on 9) The sound system (1) according to claim 9, wherein the supply unit (16) is configured to charge the switch device (12) for a first triggering with the monitoring signal (8). ### Claim 13 (depends on 9) The sound system (1) according to claim 9, wherein the switch device (12) comprises a band pass filter (17) tuned for the monitoring signal (9). ### Claim 14 An end of line device for a sound system (1), comprising a monitoring device (8), wherein the monitoring device (8) is connectable with a source device (4) via the transmission medium (6), wherein the monitoring device (8) is configured to receive a monitoring signal (9) sent by the source device (4), and wherein the monitoring device (8) is a passive device and is configured to send at least one harmonic of the monitoring signal (9) back to the source device (4). ### Claim 15 (depends on 14) The end of branch device (11) for a sound system (1), comprising the end of line device according to claim 14 and a switch device (12), wherein the end of line device is connected with the switch device (12).