JPH10307973A - Device for preventing burglaries - Google Patents

Abstract

PROBLEM TO BE SOLVED: To alarm by an easy and inexpensive circuit constitution that a switching part of a door or the like is illegally opened. SOLUTION: When the opening state of switching part of a door is maintained longer than the specified time, a signal outputted from a detection circuit 3 is latched to a latch circuit 4. An alarm is raised by making the output of this latch circuit 4 operate a singing driving circuit 5 and sound a speaker 6 and a singing state of the speaker 5 is maintained, even if the switching part of the door is closed again, by making the latch circuit 4 hold the output signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-theft device applied to a vehicle, a house or the like, and more particularly to an anti-theft device for sounding an alarm when a door is opened illegally for a predetermined time or more. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, an anti-theft device used in an automobile or the like detects a sign or movement of an object approaching an anti-theft object by ultrasonic waves or infrared rays, and sounds a buzzer or the like based on the detection signal to warn the user. It is configured to generate sound.

[0003]

However, in the above-described conventional anti-theft device, since an ultrasonic wave or an infrared ray is used for detecting a sign or movement of an object, an element for generating an ultrasonic wave or an infrared ray, and In addition to sensors that detect ultrasonic waves and infrared rays generated from these elements, a signal processing device that processes signals detected by these sensors to identify the sign and movement of an object is required, and the circuit configuration of the device is complicated. There was a problem that it became expensive.

The present invention solves such a conventional problem, and provides an anti-theft device capable of alarming that an opening / closing portion such as a door has been opened illegally with a simple and inexpensive circuit configuration. The purpose is to:

[0005]

According to the present invention, there is provided an anti-theft apparatus comprising: a switch which is turned on / off in conjunction with opening / closing of an opening / closing unit such as a door; Detecting means for outputting a signal when the opening / closing portion is kept open for a predetermined time or more based on the detection signal; and a latch operation performed by an output signal from the detection means to perform a latch operation. A latch circuit for holding an output state, a sounding means for generating a sound, and a drive circuit activated by an output signal from the latch circuit and driving the sounding means.

According to the present invention, it is possible to warn that an opening / closing section such as a door has been opened illegally with a simple circuit configuration.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The anti-theft device according to the first aspect of the present invention is turned on / off in conjunction with opening and closing of an opening / closing portion such as a door.
F, a switch that detects ON / OFF of the switch, and a detection unit that outputs a signal based on the detection signal when the opening / closing unit is kept open for a predetermined time or more. A latch circuit for performing a latch operation by the output signal of (1) to hold the output state of the output signal, a sounding means for generating a sound, and a driving circuit activated by the output signal from the latch circuit to drive the sounding means When the open / close portion is kept open for a predetermined time or longer, a signal output from the detection means is latched by a latch circuit, and the output of the latch circuit activates the drive circuit to sound. By sounding the sounding means, an alarm is issued and the latch circuit holds the output signal, so that the sounding state of the sounding means can be maintained even when the opening / closing section is closed again.

According to a second aspect of the present invention, the sounding means comprises a speaker or a horn.

According to a third aspect of the present invention, there is provided an inverter for inverting a signal generated by ON / OFF of a switch, and an output when the output of the inverter is inverted to "H" by an opening operation of a switch. And an integrating circuit for integrating the signal and outputting the signal to the drive circuit when the "H" output of the inverter continues until the integrated value reaches a predetermined value.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of the anti-theft device according to the embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a switch that is turned on / off in conjunction with opening / closing of an opening / closing unit such as a door, and 2 denotes a door switch.
The door switch 1 and the door lamp 2 are connected in series between the drive power supply voltage Vcc and the ground. Numeral 3 detects the ON / OFF state of the door switch 1 as a change in the power supply voltage Vcc and the ground potential, and outputs a signal when the OFF state of the door switch 1 is continued for a predetermined time or more by opening an opening / closing unit such as a door. The detection circuit 3 includes an inverter 31 that inverts and outputs a power supply voltage Vcc and a ground potential when the door switch 1 is turned ON / OFF, and a CR integration that is operated by the “H” output of the inverter 31. And a circuit 32.

Reference numeral 4 denotes a latch circuit which performs a latch operation in accordance with a signal output from the detection circuit 3 and holds the output of the detection circuit 3.
Is connected. The sound drive circuit 5 controls the sound of a speaker 6 which is sound means by the output signal of the latch circuit 4, and includes a transistor 51 having a base input of the output signal of the latch circuit 4, and an emitter of the transistor 51. And a sounding transformer 52 connected between the ground and the ground. A speaker 6 that sounds when the theft occurs is connected between the driving power supply voltage Vcc and the ground via the sounding transformer 52 of the sounding drive circuit 5.

Next, the operation of the present embodiment configured as described above will be described with reference to FIG.

When the door of the vehicle or the like is closed, the door switch 1 is kept in the OFF state, so that no current flows through the door lamp 2, and as a result, the input terminal of the detection circuit 3 A voltage substantially the same as the drive power supply voltage is applied, and is maintained in the “H” state (step S1). At this time, since the input terminal of the inverter 31 of the detection circuit 3 is held at “H”, the output of the inverter 31 becomes “L” and the detection circuit 3 does not operate.

In this state, when the door of the vehicle or the like is opened illegally (step S2), the door switch 2 is turned on.
Then, a current flows through the door lamp 2 and the door lamp 2 is turned on, and at the same time, the potential of the input terminal of the detection circuit 3 changes from the ground potential, that is, "H" to "L" (step S4). When the potential of the input terminal of the detection circuit 3 becomes “L”, the output of the inverter 31 of the detection circuit 3 is inverted from “L” to “H” (Step S5). Thereby, the capacitor C constituting the integration circuit 32 of the detection circuit 3 is charged according to the CR time constant. After a few seconds set by the CR time constant, the voltage between both ends of the capacitor C becomes the power supply voltage V
When it reaches cc, the output signal of the integration circuit 32 changes from "L" to "H" (step S6). Here, the resistance R of the integration circuit 32 is constituted by a variable resistor, and the output signal of the detection circuit 3 rises from "L" to "H" by changing the constant of the integration circuit 32 with this variable resistor. You can adjust the time.

When the output signal of the detection circuit 3 becomes "H",
This output signal “H” causes the latch circuit 4 to perform a latching operation, and its output is inverted from “L” to “H” (step S).
7) The output state of "H" is held (step S8).
When the output of the latch circuit 4 becomes "H", the transistor 51 of the sound drive circuit 5 is turned on (step S9), and when the transistor 51 is turned on, the sound transformer 52 is turned on.
Operates (step S10), and the sounding transformer 52 is operated.
Operates, the sounding transformer 5 is connected to the speaker 6.
The current controlled by 2 flows, and the speaker 6 sounds (step S11). The sound of the speaker 6 cannot be stopped unless the latch circuit 4 is reset.

To stop the sound of the speaker 6, the owner of the apparatus operates a reset switch 41 provided in the latch circuit 4. Thereby, when the latch circuit 4 is reset, its output is inverted from “H” to “L”, so that the transistor 51 of the sound drive circuit 5 is turned off,
At the same time, the sounding transformer 52 is also turned off. Thereby, the sounding of the speaker 6 can be stopped.

Next, the operation when the door is closed after the latch circuit 4 is latched at the output "H" will be described. When the door is closed again after the latching operation of the latch circuit 4, the door switch 1 is turned off. Therefore, a voltage substantially equal to the drive power supply voltage of the door lamp 2 is applied to the input terminal of the detection circuit 3. Of the inverter 31 is inverted from “H” to “L”. Accordingly, the integration circuit 3
Since the charge charged in the second capacitor C is discharged through the inverter 31, the output of the integration circuit 32 is inverted from “H” to “L”. Here, even if the output of the integrating circuit 32 is inverted to "L", the latch circuit 4 retains the state of "H" before the opening / closing section is closed again. The sounding state is continued, and the owner or the like is continuously warned.

According to the anti-theft device of this embodiment as described above, the signal output from the detection circuit 3 is latched in the latch circuit 4 when the open state of the door or the like is maintained for a predetermined time or more. When the output of the latch circuit 4 activates the sound drive circuit 5 to sound the speaker 6, an alarm is issued, and the latch circuit 4 holds the output signal. Also, the sounding state of the speaker 5 can be maintained.

The anti-theft device according to the present embodiment comprises a door switch 1, a detection circuit 3 including an inverter 31 and an integration circuit 32, a latch circuit 4, and a sound drive circuit 5 for a speaker 6. The circuit configuration is simplified, and the cost can be reduced.

In the above embodiment, the case where the speaker 6 is used as the sounding means has been described. However, the present invention is not limited to this, and the horn of a vehicle can be used.
Further, the detection circuit 4 is not limited to the configuration described in the above embodiment.

[0021]

According to the present invention, as described above,
In addition, it is possible to warn that an opening / closing section such as a door has been opened illegally with an inexpensive circuit configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an anti-theft device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining an operation according to the embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Door switch 2 Door lamp 3 Detection circuit (detection means) 31 Inverter 32 Integrating circuit 4 Latch circuit 5 Sound drive circuit 6 Speaker (Sound means)

Claims (3)

[Claims] An ON / OFF switch is provided in conjunction with opening and closing of an opening and closing unit such as a door.
Switch to be turned off and ON / OFF of the switch
Detecting means for outputting a signal when the opening / closing portion is kept open for a predetermined time or more based on the detection signal; and a latch operation performed by an output signal from the detection means to perform a latch operation. An anti-theft device comprising: a latch circuit for holding an output state; sounding means for generating a sound; and a drive circuit activated by an output signal from the latch circuit and driving the sounding means. 2. The anti-theft device according to claim 1, wherein the sounding means comprises a speaker or a horn. A detecting means for inverting a signal generated by ON / OFF of a switch, and an output signal when the output of the inverter is inverted to "H" by an opening operation of an opening / closing section; 2. The anti-theft device according to claim 1, further comprising: an integrating circuit that outputs a signal to a drive circuit when the "H" output of the inverter continues until the integrated value reaches a predetermined value.