JPH0231436B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a warning circuit for a theft or fire alarm.

[Prior Art] Conventionally, a typical warning circuit for an electric or electronic theft alarm system consists of sensing switches 1a, 1b, and 1c connected in series, each of which has a closed contact during warning, as shown in Fig. 1. However, when the sensing switch is opened or the security line 5 is disconnected, the receivers A and 4
A type that detects the signal and issues an alarm, or a type that detects a signal when a switch connected in parallel, such as open contact switches 2a and 2b, closes during alarm, or a type that uses both. etc. were hot.

On the other hand, in conventional fire alarms, switches 2a', 2b', and 2c', which open when there is an alarm, are connected in parallel as shown in Figure 2, and a switch that closes when heat or smoke is detected is used. It's here.

[Problems to be Solved by the Invention] However, in the case of these conventional security lines used as burglar alarms and fire alarms, electric wires are stretched around the entire circumference of the security area.
Because the system detects the voltage caused by the opening and closing of the contacts of the sensing switch, false alarms due to so-called electrical noise other than the voltage caused by the opening and closing of the sensing switch's contacts cannot be avoided. Additionally, as a countermeasure to this, it was necessary to install a noise input prevention device in the receiver.

In addition, among the detection switches of conventional burglar alarms, the vibration switch that detects when a glass window etc. is broken has a receiver function that simply determines whether the switch is open or closed. It also sent out a signal when it hit a window, causing false alarms.

The present invention adopts a method of sensing the intermittent and strength of light instead of the voltage sensing method described above.
The present invention relates to a new vigilance circuit which eliminates these drawbacks and also provides a number of advantages.

[Means for Solving the Problems] In order to solve the above problems, the photoelectric warning circuit of the present invention includes an optical fiber cable whose one end is connected to an optical transmitter, an optical fiber cable whose one end is connected to an optical receiver, and a sensing switch interposed between the other ends of the pair of optical fiber cables.
The switch has a box-like shape with a hollow part formed therein, holds the other end of the optical fiber cable facing each other with the hollow part in between, and has a plurality of holes formed in the outer periphery to communicate the hollow part to the outside. The main body and the sky above
A light shielding piece, at least a part of which is made of an elastic material, is provided in the switch body so as to be movable between the other ends of the optical fiber cable, and a light shielding piece, at least a part of which is made of an elastic material, is provided in the switch body so as to be able to move toward and away from the optical fiber cable. The magnet is moved forward and backward between the other ends of the magnet.

[Embodiment] FIGS. 3 and 4 show an embodiment of a photoelectric warning circuit (hereinafter abbreviated as "warning circuit") of the present invention.

In FIG. 3, this warning circuit includes an optical transmitter X, 14 and an optical receiver Y, 16 at each end.
It is roughly constructed by an optical fiber cable 15 connected to the optical fiber cable 15, and a plurality (three sets in the figure) of sensing switches 11a, 11b, and 11c interposed in the optical fiber cable 15. Here, the optical transmitter X, 14 can be used for either visible light or infrared light depending on the size of the guarded area, but it is determined by taking into account the loss of the transmission path.

FIG. 4 shows the sensing switches 11a, 11b,
This is an example of what is used as 11c. This sensing switch 11 includes a switch body 12 having a box-like shape as a whole, and a light shielding piece 22 provided inside the switch body 12, at least a part of which is made of an elastic material, and further, at least a part of which is made of a magnetically sensitive material. The switch body 12 is provided with a magnet 26 provided separately from the switch body 12.

A cavity 13 is formed inside the switch body 12, and each end of the cut optical fiber cables 15, 15' is held facing each other with the cavity 13 in between. Further, a plurality of holes 35 are formed in the outer circumference of the switch body 12 to communicate the hollow portion 13 with the outside of the switch body 12. Note that reference numerals 23 and 24 in the figure are lenses disposed in front of each end of the optical fiber cables 15 and 15'.

The light blocking piece 22 has one end fixed to the switch main body 12 and the other end fixed to the empty space 1.
3, optical fiber cables 15, 15'
The magnet 26
When the magnet 26 approaches the switch body 12, it is attracted by its magnetic force and retreats from between the optical fiber cables 15 and 15', as shown in FIG. The fiber cables 15 and 15' are cut off.

Next, to explain the function of the above-mentioned warning circuit, when this warning circuit is used for detecting the opening and closing of windows and doors, as shown in FIG. 13 or 14,
Sensing switches 11a, 11b and magnet 26a,
26b is attached to the window 32 or door, and the other is attached to the frame 33. As a result, when the window is closed, the magnet 26 in FIG. 4 approaches in the direction of the arrow 29, and the light blocking piece 22 is attracted to the magnet 26.
Then, the optical signal emitted from the optical transmitter
24 and is received by the optical receiver Y, 16 through the optical fiber cable 15'. The optical signal level in the optical receiver Y, 16 at this time is
It is indicated by R in FIG.

On the other hand, when the window 32 or door is opened, the magnet 2
6a, 26b are separated from the sensing switches 11a, 11b. Then, as shown in FIG. 5, the light blocking piece 22 of the sensing switch 11 returns by the force of the spring in the direction of the arrow 28 and blocks the light 25b, so that the light does not reach the optical fiber cable 15'. At this time, the level of the optical signal in the optical receiver Y, 16 is at the sixth level.
The state is 0 as shown in the figure. FIG. 7 shows that the state shown in FIG. 4 described above has changed to the state shown in FIG. Note that the optical signal from the optical transmitter X, 14 is
It may be pulsed to reduce power consumption.

Further, according to the above warning circuit, the sensing switch 1
When smoke occurs around 1, arrow 3 appears in Figure 12.
As shown by 0, this smoke flows from the hole 35 to the empty part 13.
The light 25a from the optical fiber cable 15 is blocked. FIG. 11 shows the level of the light signal in the optical receiver Y, 16 when the light is blocked by smoke as shown in FIG. 12. In this way, the above warning circuit can also be used as a smoke detector.

By forming the light blocking piece 22 with an elastic material, when attached to a window glass as shown in FIG. 14, the vibration of the glass when an object hits the window glass can be used as an intermittent light signal. It is also possible to detect it with the optical receiver Y, 16 instead. Figure 8 shows the intermittent light signal when something hits the glass, Figure 9 shows the intermittent light signal when the glass is shaken by the wind, and Figure 10 shows the signal when the glass breaks. , it is possible to detect various phenomena.

Furthermore, if the light blocking piece 22 is made of a thermally deformable material such as bimetal, it can also be used as a heat sensor, as shown in FIG. In this way, by observing various phenomena in advance and comparing them with the signals, it is possible to understand each phenomenon accurately. This makes it possible to immediately know the cause of phenomena that were previously treated as false alarms.

[Effects of the Invention] As explained above, according to the warning circuit of the present invention, one warning circuit can open and close doors, detect smoke, etc., and furthermore, because it is a light signal, electrical signals can be detected. It is completely free of noise and can be used in any place where strong noise occurs. In addition, even if there is a high temperature point in the circuit, such as 200°C or 300°C, which would burn the insulation of electric wires, the various types of detection described above are possible by using quartz-based optical fiber. Not only that, but it can also be used in many environments that have traditionally been weak points of electric types, such as in explosive gases, underwater, and in humid areas.

Furthermore, since the optical switch for sensing has a simple structure, it can be made inexpensive and compact, and if transparent transmission paths such as optical fiber cables are used, guidance etc. can be installed without spoiling the aesthetics. It has excellent advantages such as

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the warning circuit of a conventional burglar alarm; Figure 2 is a schematic diagram of a conventional fire alarm;
FIG. 3 is a schematic configuration diagram showing one embodiment of the warning circuit of the present invention, FIGS. 4 and 5 are side sectional views of the sensing switch, and FIGS. Fig. 12 is a side sectional view of the detection switch showing the state of smoke detection;
Figure 3 shows a heat sensing light switch, and Figures 14 and 15 are schematic diagrams showing an example in which a sensing switch is attached to a window. 11, 11a, 11b, 11c...sensing switch, 12...switch body, 13...empty part, 1
4... Optical transmitter, 15, 15'... Optical fiber cable, 16... Optical receiver, 22... Light blocking piece, 26, 26a, 26b... Magnet, 35...
hole.

Claims (1)

[Claims] 1. An optical fiber cable having one end connected to an optical transmitter, one end connected to an optical receiver, and a sensing switch interposed between the other ends of the pair of optical fiber cables. The sensing switch has a box shape with a hollow space formed inside, and holds the other end of the optical fiber cable facing each other with the hollow space in between, and has the hollow space on the outer periphery. A switch main body having a plurality of holes communicating with the outside, and at least a portion of the optical fiber cable movably provided between the switch body and the other end of the optical fiber cable within the hollow portion have elasticity. a light shielding piece whose portion is made of a magnetically sensitive material; and a magnet which is provided on the switch main body so as to be movable toward and away from the switch body and moves the light shielding piece forward and backward between the other ends of the optical fiber cable using magnetic force. A photoelectric warning circuit characterized by: