JPH0562078A - Burglar alarm device - Google Patents

Abstract

PURPOSE:To obtain a bulglar alarm device which can easily fit a new detecting sensor at an existing burglaryproof device. CONSTITUTION:The device is provided with a transistor 11 to become an ON condition when door switches 34-37 are ON, a transistor 12 to become ON when the transistor 11 is ON, an alarm control circuit 45 switched from an armed condition to an alarm condition when the transistor 12 is ON, and an invasion sensor device 42 connected to the base of the transistor 12. When the invasion sensor device 42 generates the output, the transistor 12 becomes ON and the output is sent to the alarm control circuit 45. When the door switches 34-37 become ON, the transistor 11 becomes ON, the voltage level of the base of the transistor 12 is reduced, and therefore, the transistor 12 becomes ON and the output is sent to the alarm control circuit 45. The current toward the invasion sensor device due to the high voltage at the door lamp side is stopped by the transistor 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burglar alarm system, and more particularly to a burglar alarm system capable of adding a new intrusion detection sensor to an existing burglar alarm system.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Patent Laid-Open No. 3-61149, there is a known anti-theft device in which an alarm device is activated when an opening / closing part in an armed state is illegally released. In this anti-theft device, a switch that detects opening and closing of a door, an alarm device, and an armed state that does not generate an alarm signal that activates the alarm device when the output of the switch is received or a disarmed state that does not occur and an alarm device are generated. It has an alarm control circuit that is switched to an alarm state to be activated and an indicator that blinks due to the output of the alarm control circuit in the armed state.

On the other hand, for example, US Pat. No. 3,781,85
Alarm control circuits for motor vehicles, as disclosed in No. 4, are known. This vehicle alarm control circuit switches from the disarmed state to the armed state when the door is locked by closing all the opening / closing parts of the vehicle and operating the cylinder lock. If an opening / closing part such as a door, a trunk or a hood is illegally opened in an armed state, an alarm is automatically generated to prevent the automobile from being stolen.

Further, as disclosed in, for example, Japanese Patent Laid-Open No. 62-98280, a device for detecting a moving object using ultrasonic waves is known. A moving object detection device using ultrasonic waves includes an ultrasonic wave transmission circuit, a reception circuit that receives a sound wave that is transmitted from the ultrasonic wave transmission circuit and reflected on the surface of a moving object, and a detection circuit that detects a change in the output of the reception circuit. I have it.

[0005]

By the way, there has been proposed a new anti-theft device provided with the moving object detection device as one of the detection sensors of the anti-theft device. This anti-theft device requires a moving object detection device that uses ultrasonic waves in order to prevent unauthorized intrusion into the automobile by breaking the window glass of the automobile. However,
When connecting a moving object detection device to a commercially available antitheft device, the alarm control circuit itself composed of a one-chip microcomputer must be replaced. Therefore, the replacement parts are expensive and the replacement work is complicated.

For example, as shown in FIG. 2, when a new intrusion detection sensor device 30 is added to the burglar alarm device, the contact of the relay 31 is connected to the control circuit of the burglar alarm device, and one end connected to the power source is connected. The other end of the winding 32 of the relay 31 is connected to each of door switches 34 to 37 that detect opening and closing of the door via a diode 33 and door lamps 38 to 41. The intrusion detection sensor device 30 connects the collector of a transistor 44 having a base connected to the output terminal of the intrusion detection circuit 42 via a resistor 43 to the other end of the winding 32, and grounds the emitter of the transistor 44.
In this configuration, when the intrusion detection sensor device 30 detects unauthorized intrusion, the intrusion detection circuit 42 causes the transistor 4
Since the base current is applied to 4 and the transistor 44 is turned on, the winding 32 is energized and the ON signal of the relay 31 is transmitted to the alarm control circuit 45 of the theft alarm device. As a result, the alarm device can be operated for a fixed time. The diode 33 prevents unnecessary voltage from being applied to the transistor 44 side through the door lamps 38 to 41.

In the circuit shown in FIG. 2, since the relay 31 is used, there are disadvantages that the cost of parts is increased and a miniaturized board cannot be used.

Therefore, an object of the present invention is to provide a theft alarm device in which a new detection sensor can be inexpensively attached to an existing antitheft device.

[0009]

A theft alarm device according to the present invention includes a door switch for detecting opening / closing of a door, a first switching element which is turned on when the door switch is turned on, and a first switching element which is turned on when the first switching element is turned on. Second turned on
Switching element, an alarm control circuit for switching from an armed state to an alarm state when the second switching element is turned on, and an intrusion sensor device connected to a control terminal of the second switching element via a rectifying element. There is.
The first switching element is a pnp transistor,
The second switching element is an npn transistor.

[0010]

When the intrusion sensor device produces an output, the second switching element is turned on and the output is sent to the control circuit. Also, when the door switch is turned on, the first
Since the switching element is turned on, the voltage level of the control terminal of the second switching element is lowered, so that the second switching element is turned on and the output is sent to the control circuit. The current to the intrusion sensor device due to the high voltage on the door lamp side is blocked by the first switching element.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a theft alarm device according to the present invention will be described below with reference to FIG. In FIG. 1, the same parts as those shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

The burglar alarm device 10 according to the present invention includes a transistor 11 as a first switching element which is turned on when the door switches 34 to 37 are turned on and a transistor 11 as a second switching element which is turned on when the transistor 11 is turned on. 12 and 12. The transistor 11 is a pnp transistor and the transistor 12 is an npn transistor. Resistors 13 and 14 are connected in series between the door switches 34 to 37 and the base of the transistor 11. Resistor 13 and door switch 34
To 37 are grounded via a constant voltage diode 15. The resistors 13 and 14 are grounded via capacitors 16 and 17 connected in parallel. The emitter of the transistor 11 is connected to the power supply, and the collector is the resistor 1
It is connected to the base of the transistor 12 via 8. A rectifying diode (rectifying element) 19 is connected between the resistor 18 and the intrusion detection circuit 42. The collector of the transistor 12 is connected to the alarm control circuit 45, and the emitter is grounded. The alarm control circuit 45 is switched from the armed state to the alarm state when the transistor 12 is turned on.

When the intrusion sensor device 42 produces an output, the transistor 12 is turned on and the alarm control circuit 45 is activated.
Output is sent to. When the door switches 34 to 37 are turned on, the transistor 11 is turned on, so that the voltage level of the base of the transistor 12 is lowered, so that the transistor 12 is turned on and the alarm control circuit 45 is turned on.
Output is sent to. The transistor 11 blocks the current flowing toward the intrusion sensor device 42 due to the high voltage on the side of the door lamps 38 to 41.

In this embodiment, when a new sensor device such as the intrusion sensor device 42 is added, the theft alarm device 10 can be manufactured compactly and inexpensively without using a relay.

[0015]

As described above, according to the present invention, when the sensor device is added, the burglar alarm device can be manufactured in a small size and at a low cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an anti-theft device according to the present invention.

FIG. 2 is a circuit diagram of a conventional antitheft device.

[Explanation of symbols]

10. ． Theft alarm device, 34-37. ． Door switch,
11. ． Transistor (first switching element), 1
2. ． Transistor (second switching element) 4
5. ． Alarm control circuit, 19. ． Diode (rectifying element), 42. ． Intrusion sensor device,

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[Procedure amendment]

[Submission date] October 17, 1991

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

Claims (2)

[Claims] 1. A door switch for detecting opening / closing of a door, a first switching element which is turned on when the door switch is turned on, a second switching element which is turned on when the first switching element is turned on, and Theft including an alarm control circuit for switching from the armed state to the alarm state when the second switching element is turned on, and an intrusion sensor device connected to the control terminal of the second switching element via a rectifying element. Alarm circuit. 2. The burglar alarm device according to claim 1, wherein the first switching element is a pnp transistor and the second switching element is an npn transistor.