CN2406428Y - Telephone line disconnection alarm - Google Patents

Abstract

The alarm for broken telephone line has polarity converting circuit, signal detecting circuit, signal processing circuit, alarm signal control circuit and alarm signal, and the signal control circuit has photoelectric coupler for powerful alarm when the telephone line is cut off.

Description

The telephone wire wire break alarm

The utility model belongs to a kind of electronics autoalarm.

Existing telephone line wire break alarm device, when telephone wire was cut off by the robber, this device can send alarm signal, reminded the watch to arouse vigilance.This device is owing to adopt direct connecting circuit, the clock pulse of in the main frame to whole burglary-resisting system at ordinary times, sending, particularly the interference signal that is produced behind the keyboard data wire of lengthening main control system can form interfering noise, influences the speech quality in the phone use.

The purpose of this utility model provides a kind of new telephone wire wire break alarm, inserts after the telephone line, can obtain good break alarm effect, does not influence the speech quality in the phone use at ordinary times again.

Line interrupted alarm provided by the utility model, comprise polarity switching (1), signal deteching circuit (2), signal processing circuit (3), warning signal control circuit (4) and warning warning signal (5), photoelectrical coupler (6) is set in signal deteching circuit (2), and its input, output are connected with the output of polarity switching (1) and the input of signal processing circuit (3).

Fig. 1 is a circuit block diagram of the present utility model, and Fig. 2 is circuit theory diagrams of the present utility model.

Earlier the course of work of the present utility model is described in conjunction with Fig. 1.

The utility model telephone wire L1, L2 two ends inserted in parallel, when telephone wire is cut off, the signal level that polarity switching (1) offers signal deteching circuit (2) becomes low level zero volt from high level, signal deteching circuit (2) comprises that photoelectrical coupler (6) no current wherein flows through, signal processing circuit (3) will make the triode conducting in the warning signal control circuit (4), impel the normally opened contact adhesive of the relay in the warning signal control circuit (4), connect warning signal, send chimes of doom.At ordinary times, because of being provided with photoelectrical coupler (6) in the signal deteching circuit (2), the front and back level is isolated, can cut off the interference signal that whole burglary-resisting system host aspect is produced, can not produce interfering noise.

In conjunction with Fig. 2 electronic component annexation of the present utility model and operation principle are explained again.

The 12V power supply that power supply of the present utility model provides for the main frame of whole burglary-resisting system, that inserts VCC and ground wire asks that D1 is for protecting triode, F1 is a fuse.L1, L2 are connected with parallel way with telephone wire among the figure, B1 is the bridge heap, constitute polarity switching, IC1 is the integrated circuit (TLP521-4) as photoelectrical coupler, IC2 is NOR gate integrated circuit (TC4001), and J1 is a relay, and J1-1 is its normally opened contact, Y1 is active warning signal, and S1 is for detecting with often opening knob.

IC1, IC2-2, T2, R1, R2, R3 constitute signal deteching circuit among Fig. 2, and IC2-3, IC2-4, IC2-1, R7, R8, D2, C1, R9, T3, J1 constitute signal processing circuit and warning signal control circuit.When the phone on-hook, L1, L2 two ends 48V voltage flow through 7,8 pin of IC1-1 by the B1 polar switching by R1, this electric current makes 10, the 9 pin conductings of IC1-1,10 pin are connected with power supply, so 9 pin output high level makes 2 pin of IC2-1 obtain high level, thereby 3 pin that make IC2-1 are low level, 4 pin of IC2-3 are high level, and 10 pin of IC2-4 are low ordinary telegram, and T3 ends, J1 can not adhesive, and Y1 does not ring.When the phone off-hook uses, L1, L2 both end voltage are reduced to about 10V, IC1-1 can not conducting, 9 pin output low levels, 2 pin of IC2-1 are low level, 11 pin of IC2-2 are high level simultaneously, by R5, T2 conducting, supply voltage is delivered to IC1-2 after the R4 current limliting, make 12,11 pin conductings, the voltage on the telephone line makes 14, the 13 pin conductings of IC1-3 through IC1-2, the supply voltage that 14 pin of IC1-3 are connected is delivered to 1 pin of IC2-1,3 pin that make IC2-1 are low level, and T3 is ended, and Y1 does not ring.At this moment owing to the photoelectrical coupler IC1 in the signal deteching circuit cuts off interference signal and the conversation signal that the burglary-resisting system host aspect produces, so the speech quality in the phone use is unaffected.

If telephone wire is cut off, L1, the L2 two ends are low level zero volt, and IC1-1 ends, because 9 pin of IC1-1 are by R2 ground connection, and output low level, thereby 2 pin of IC2-1 are low level, 11 pin of IC2-2 are high level, T2 conducting, 12 of IC1-2,11 pin conductings, but 12 pin are low level, thus IC1-3 3,4 pin do not have electric current, and 14,13 pin end, 1 pin of IC1-2 arrives ground by R11, make that 1 pin of IC2-1 is a low level, at this moment 1 of IC2-1,2 pin are low level all, and making its 3 pin is high level, charge to C1 by R7, about 3-5 is after second, 5 of IC2-3,6 pin are high level, and 4 pin are low level, 10 pin of IC2-4 are high level, to the T3 base stage, the T3 conducting is through the R9 current limliting by R8, the J1 adhesive, the supply voltage of Y1 is connected, and warning signal is sent chimes of doom, and LED is luminous simultaneously.D3 among Fig. 2 is anti-negative peak diode.

The utility model also is provided with the manual detection circuit that T1, S1, R6 form, in Fig. 2, because the T1 base stage is connected to power supply by R6, thus the T1 conducting, thus the working power of IC1 and T2 is provided, after S1 is pressed, T1 base earth and ending.The working power of IC1 and T2 is disconnected, the 3 pin output high level of IC2-1, the J1 adhesive, Y1 connects, and reaches testing goal and send to report to the police.

When the utility model uses, get final product operate as normal as long as receive L1, L2 on the telephone wire and connect the 12V working power, can send warning when telephone wire is cut off, do not influence the speech quality in the phone use at ordinary times again, result of use is very good.

Claims (1)

1, a kind of telephone wire wire break alarm, comprise polarity switching, signal deteching circuit, signal processing circuit, warning signal control circuit and warning warning signal, it is characterized in that being provided with in the signal deteching circuit photoelectrical coupler, its input, output are connected with the output of polarity switching and the input of signal processing circuit.

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