JPH03245617A - Alarm system for communication equipment - Google Patents

Abstract

PURPOSE:To prevent a mischievous operation by providing two or over of a line interrupt detection circuit, a tilt detection circuit and a power interrupt detection circuit in the inside of a communication equipment, raising an alarm by the logic operation of an output value of each circuit and displaying the alarm as required. CONSTITUTION:Respective output lines a, b, c of a line interrupt detection circuit 2, a tilt detection circuit 3 and a power interrupt detection circuit 4 inserted in a telephone line 1 being a communication line are connected respectively to a relay or buzzer 5 via an AND arithmetic circuit X1. An AND circuit 20 and an OR circuit 21 being component of the logic arithmetic circuit X1 take logic of each output from the output lines a, b, c of the line interrupt detection circuit 2, the tilt detection circuit 3 and the power interrupt detection circuit 4 to activate the relay or buzzer 5. Since the integration of the alarm circuit is not recognized externally, the theft of the alarm device is avoided. Since the alarm is raised by the AND logic, the possibility of erroneous alarming even in the case of a tentative interruption of a line due to an installation work is precluded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alarm system for communication equipment that issues an alarm when communication equipment used by an unspecified number of people is operated with malicious intent.

[Conventional technology] Conventionally, a microswitch or the like is attached to the outside of the communication device and a buzzer or the like attached to the outside is used to detect when a communication device used by an unspecified number of people is maliciously disabled or moved. Ta.

[Problems to be Solved by the Invention] For this reason, it is found that the alarm device is attached, and the alarm device is removed and then the above-mentioned malicious operation is performed, resulting in the disadvantage that the alarm device cannot be effective.

In order to solve these conventional drawbacks, the present invention provides a communication device that incorporates an alarm circuit into a communication device, detects line disconnection, power line disconnection of the communication device, and movement of the communication device, and issues an alarm. The aim is to provide a warning system for this purpose.

[Means for Solving Problem 1] A solution to the above problem is that the alarm method of a communication device of the present invention includes at least a line disconnection detection circuit that connects to a communication line and detects disconnection of the line, and a slope detection circuit. , characterized in that two or more of the power failure detection circuits for detecting power failure of the communication device are provided inside the communication device, and an alarm is generated and displayed as necessary by a logical operation of the output values of the respective circuits, This is achieved by employing the above configuration means.

[Function] The present invention takes the above-mentioned means, connects two or three of the line disconnection detection circuit, the slope voltage detection circuit, and the power failure detection circuit to the alarm circuit and the display circuit via a logic operation circuit, and Since all the circuits for the line are mounted inside the communication equipment, if someone were to intentionally cut off the communication line or communication equipment power to make communication impossible, or try to steal it from the designated installation location, at least the line disconnection detection circuit and tilt detection circuit would be protected. When any two or more of the power cutoff detection circuit and the power cutoff detection circuit detect an abnormality and are activated, a third party is notified by sounding an alarm such as a bell or buzzer or by flashing a warning light or the like.

[Example code] A first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a circuit configuration diagram according to this embodiment.

In this embodiment, the outputs @a, b, and c of a line disconnection detection circuit 2, slope detection circuit 3, and power supply disconnection detection circuit 4 inserted into a telephone line 1, which is a communication line, are transmitted through a logic operation circuit x 1. Connected to relay or buzzer 5.

The line disconnection detection circuit 2 includes a line voltage detector 6.7 and an inverter circuit 8 for converting the signal logic in the same parallel circuit.
, an exclusive logic circuit 9, and an inverter circuit 10.

The tilt detection circuit 3 includes a tilt sensor 11, a time constant circuit 12 having a large charging time constant and a small discharging time constant (for example, charging time constant: about 2 seconds, discharging time constant: about 100 m5), and an inverter circuit 13. , monostable multivibrator 1
4 and a monostable multivibrator 14 (e.g. 452
The circuit is composed of a time constant (for example, 30 seconds) circuit 15 of 8@) and a reset time constant circuit 16 when the power is turned on.

The power failure detection circuit 4 includes a terminal 17 connected to the power supply of communication II@, a photocoupler 18, and an inverter circuit 19.
The circuit consists of

The logic operation circuit x1 is configured with a logic including an AND circuit 20 and an OR circuit 21.

22 in the figure is a driver circuit for the relay and buzzer 15;
23 is a lithium secondary battery, and 24 is a protection circuit for the lithium battery 23.

Therefore, to explain the operation of the line disconnection detection circuit 2, when the polarity of the up line terminal 1a is + and the polarity of the down line terminal 1b is -, the output of the line voltage detection circuit 6 is logic "0". The output of 7 becomes logic "1". Also, line 1a
, 1b are opposite in polarity, the outputs of the line voltage detection circuits 6, 7 are opposite. In this way, lines 1a and 1b
When a voltage is normally applied to , the output of exclusive OR circuit 9 is logic "1". For example, when the line 1 is disconnected, the outputs of the line voltage detection circuits 6 and 7 are both logic "'1", so the output of the exclusive OR circuit 9 is "0".

Next, the tilt detection circuit 3 will be described. The tilt sensor 11 is, for example, a TDK tilt switch, has a contact output, and is turned on when a preset tilt angle is reached. This type of sensor 11 is sensitive and generates an output when, for example, a fixed base of a communication device moves or vibrates. For this reason, time constant circuit 1
2 absorbs these spurious signals and generates an output only when there is a true slope. Monostable multivibrator 14
is a circuit that holds the sloped signal for a certain fixed period of time, and that period is determined by the time constant circuit 15.

Furthermore, to explain the power-off detection circuit 22, since the terminal 17 connected to the power supply of the communication equipment is always connected to the power supply of the communication equipment, the photocoupler 18 is always on, and its output is in the logic “On” state. be.

The AND circuit 20 and the OR circuit 21 that combine to form the logic operation circuit x 1 of this embodiment are connected to the line disconnection detection circuit 2. Tilt detection circuit 3. A relay or a buzzer 5 is operated based on the logic of the respective outputs from output lines a, b, and c of the power-off detection circuit 4. In the logic operation circuit x 1 of this embodiment, the outputs of the line disconnection detection circuit 2 and the power disconnection detection circuit 4 are logically ANDed, and the output is logically summed with the output of the slope detecting circuit 3, and the relay 5
An example of how to operate the above is shown below.

In this embodiment, since it is operated by logical product, false alarms are not issued when the line is disconnected due to line construction or when there is a power outage.

Further, in addition to this embodiment, it is easy to operate the relay and the buzzer 5 by combinations such as the following embodiments.

■As shown in Fig. 2, in the second embodiment with two logic operation circuits, the outputs of the slope detection circuit 3 and the power-off detection circuit 4 are logically summed, and the output is combined with the output of the line-disconnection detection circuit 2. Perform a logical AND operation.

In the figure, 25 is an OR circuit, and 26 is an AND circuit.

■As shown in FIG. 3, in the third embodiment with three logic operation circuits, the outputs of the line disconnection detection circuit 2 and the slope detection circuit 3 are logically summed, and the output is ANDed with the power disconnection detection circuit 4. Take it and make it work. In the figure, 27 is an OR circuit, and 28 is an AND circuit.

(2) As shown in FIG. 4, the four logic operation circuits are operated by taking the AND of the respective outputs of the line disconnection detection circuit 2, slope detection circuit 3, and power disconnection detection circuit 4. 29.30 in the figure
is an AND circuit.

(2) As shown in FIG. 5, the five logic operation circuits are operated by taking the AND of the respective outputs of the line disconnection detection circuit 2 and the power disconnection detection circuit 4. In the figure, 31 is an AND circuit.

(2) As shown in FIG. 6, the six logic operation circuits are operated by taking the AND of the respective outputs of the slope detection circuit 3 and the power-off detection circuit 4. In the figure, 32 is an AND circuit.

(2) As shown in FIG. 7, the 7 logic operation circuits are operated by taking the AND of the respective outputs of the line disconnection detection circuit 2 and the slope detection circuit 3. In the figure, 33 is an AND circuit.

In all of the above embodiments, the operation after detection is performed by a relay or a buzzer 5, but it is also possible to make a display using this or to make a notification using another line.

Further, this embodiment can be easily constructed using general-purpose parts such as a commercially available C-MOS IC (for example, 4000 series). As a tilt switch, a sensor with a 5° step from 5° to 45° is commercially available from TDK, and this can be used. Although μPA53C is assumed in this embodiment as the driver 22 for the relay, buzzer 5, etc., it is also possible to replace it with a normal transistor or the like. Further, the transistor used in the line voltage detection circuit 6.7 must be, for example, a 28C1841 transistor with a large DC amplification factor.

In addition, in this embodiment, for convenience of explanation, one telephone line terminal 1 is used.
Although protection circuits against surges such as lightning are omitted in a and 1b, it is necessary to add these protection circuits.

[Effects of the Invention] Thus, since the present invention is built into a communication device, it is not possible to tell from the outside whether or not the alarm circuit is built in.
It is highly effective because the alarm device does not have to be removed in advance.

In addition, since the alarm is issued based on the logical product of the line disconnection detection circuit, power disconnection detection circuit, slope detection circuit 9, etc., there is no need to worry about erroneously issuing an alarm even if the line is temporarily interrupted due to construction or the like or the power supply is temporarily interrupted. Qin etc. excellent effect.

[Brief explanation of drawings]

FIG. 1 is a circuit connection diagram according to an embodiment of the present invention, and FIGS. 2 to 7 are logic configuration diagrams of second to seventh embodiments of logic operation circuits applied to the embodiment of the present invention. 1... Telephone line 1a... Up line terminal 1
b...Down line terminal 2...Line disconnection detection circuit 3.
...Tilt detection circuit 4...Power failure detection circuit 5...
・Relay or buzzer 6.7... Line voltage detector 8.10.13.19... Inverter circuit 9... Exclusive logic circuit 11... Inclination sensor 12... Time constant circuit 14...・Monostable multivibrator 15...Time constant circuit 16...Reset time constant circuit 17...? l1ii connection terminal 18... Photo coupler 20.26.28.29.30.31.32゜33
...AND circuit 21.25.27 ...OR circuit 22 ...driver circuit 23 ...lithium secondary battery a. b. C... Output line 24... Protection circuit ~ x7... Logical operation circuit Figure 2 116 Figure 6 Figure 8 Figure 1

Claims (1)

[Claims] 1. At least two or more of a line disconnection detection circuit that connects to a communication line and detects disconnection of the line, a tilt detection circuit, and a power disconnection detection circuit that detects a power disconnection of the communication device are provided inside the communication device. , by logical operation of the output values of each circuit,
An alarm method for communication equipment that is characterized by issuing an alarm and displaying it as necessary.