TH21955A - "Phone" - Google Patents

Abstract

Telephone (1) with handset (14) can be connected to a telephone exchange (5) by means of first and second switch (6,7) by two wires (2,3). When switch (6,7) is electrically connected The telephone terminal (1) can be electrically powered from the interchange (5) via wires (2,3) inside the telephone (1) switch one (6) the first coil (8) circuit section. (10) The second coil (9) and the second switch (7) are electrically connected in series, the switch (6,7) activated by the handset (14) of the telephone. (1) These two coils (8,9) are wound in opposite directions around the body (12) of the magnetic object.A measuring coil (11) and a measuring circuit are provided. (13) for building The alternating magnetic field in the trunk (12) and for the dB / dt timing measurement of the magnetic inductance B (t), which takes place in the trunk 12 and for generating the signal for the switch-on ( 6,7) If the measured dB / dt determination has been performed according to the specified measures, the measuring coil (8,9), magnetic body (12), measurement coil (11) and measurement circuit (13) will Used to protect Attempt to defraud

Claims (1)

1. A telephone (1) with a handset (14) a first and second switch (6,7) by means of which a telephone (1) can be connected by two wires (2 , 3) to the telephone exchange (5) where switch (6,7) is electrically connected. A telephone (1) is able to be supplied with electricity. From the telephone exchange (5), through the wires (2, 3) and the circuit (10), the first switch (6), the circuit (10) and the second switch (7) are electrically connected. Serial and switches (6, 7) are triggered by the handset (14) of the telephone (1) with the tag: