摘要:
A Radio Frequency Interference Filter (10, 12) is connectable in series in the tip (T) and ring (R) branches of a telephone circuit. A first suppression stage (20) has a first inductor (L1) connectable to the tip (T) branch of the circuit and a second inductor (L2) connectable to the ring (R) branch of the circuit. The second suppression stage (22) of one embodiment of the filter (10) has a transformer (T1) with one winding (W1) connected in series with the first inductor (L1) for the tip (T) branch of circuitry and the second winding (W2) connected in series with the second inductor (L2) for the ring (R) branch of circuitry. In a second, alternative embodiment of the filter (12), the second suppression stage (22) has one ferrite-core inductor (L3) connected in series with the first inductor (L1) for the tip (T) branch of circuitry and a second ferrite-core inductor (L4) connected in series with the second inductor (L2) for the ring (R) branch of circuitry. A fuse (F1, F2) may precede each inductor (L1, L2) to protect the filter (10). The filter (10, 12) may be encapsulated to provide protection from adverse environmental changes.
摘要:
An acoustic feedback suppression device, particularly for auxiliary ringers in plug-in telephone systems, includes diodes (17,18) in addition to a rectifier bridge (11) of the ringer (14). The circuit provides direct-current decoupling and limits the AC voltage present across the auxiliary ringer.
摘要:
A protection circuit for a telephone having a two wire subscriber line (L1, L2) and an earth line (E) comprises a single surge protection device (2) connected between a bridge rectifier polarity-guard (D1, D2, D3, D4) which is across the subscriber line and the remainder of the telephone circuitry (1, 4) which is connected to the output of the polarity guard. Three diodes (D5, D6, D7) are used to interconnect the earth line and the pair of output lines from the polarity guard to the protection device in such a way as to prevent surges from being fed to the remainder of the telephone circuit, the surge paths including one or two arms of the polarity guard.
摘要:
Schaltungsanordnung zur Unterdrückung von Störsignalen auf dem Empfangszweig einer unter Verwendung von elektronischen Bauelementen aufgebauten und damit ohne Sprachübertrager realisierten Teilnehmeranschlußschaltung. Schaltungsanordnung zur Unterdrückung von Störsignalen auf dem Empfangszweig einer unter Verwendung von elektronischen Bauelementen aufgebauten und damit ohne Sprachübertrager realisierten Teilnehmeranschlußschaltung. An den Empfangszweig der Teilnehmeranschlußschaltung (SLIC) ist eine Zweipolfilterschaltung (ZF) angeschlossen, die aus der Parallelschaltung eines Parallel- und eines Serienresonanzkreises (LPCP und LSCS) besteht, deren Resonanzfrequenz der Frequenz der zur Gebrührenimpulsübermittlung eingespeisten Signale entspricht, die ohne die genannten Maßnahmen bei Reflexionen als Störsignale wirken können.
摘要:
A surge protection device for a telecommunication system is in the form of a component (10) which may be interposed in a line of the system. Positioned across conductors (32, 34) of the component (10) which conductors (32, 34) are, in use, connected to conductors of the system line, is a gas arrestor (36) which operates to deflects surges reaching the component along the system line.
摘要:
Apparatus (1) for damping of voltage and current peaks in a telecommunications network/system, comprising an input data connector (2a) and an output data connector (2b) arranged serially on a voice and/or data electric line, and a damper (3) having a casing (8) comprising a mixture of particles of a piezoelectric material and a refractory inert material, configured to transform the energy load of electromagnetic stress which causes overvoltages and overcurrents into mechanical energy and into thermal energy, into which mixture a plurality of input electrodes (5), that are connected to respective cables (6a) of the input data connector (2a) and to respective cables (6b) of the output data connector (2b), and an earth-connected conductive heat dissipation bar (7) are partially immersed.
摘要:
In examples of the embodiment, a surge-proof interface circuit (100) comprises a rectifier circuit (20) which is configured to produce a rectified rectifier output voltage at the rectifier output terminals (20c, 20d), in accordance with a rectifier input voltage at the rectifier input terminals (20a, 20b), and a Darlington circuit (30) which comprises at least two transistors (Q3, Q4). Said Darlington circuit (30) comprises a current path (35) which can be controlled on the output side in accordance with a control signal (62) and said current path (35) which can be controlled on the output side is coupled between the rectifier output connections (20c, 20d).