JPH0330916B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention includes a transmitter that detects surrounding abnormalities such as smoke or gas leaks and generates a signal voltage, and a transmitter that receives the signal voltage from the transmitter. The present invention relates to an abnormality detection circuit including a receiving section that detects an abnormality.

[Conventional technology]

An example of a conventional abnormality detection circuit is shown in FIG. In Fig. 1, the transmitting section 1 is driven by the driving power source received at the power supply terminal 2 and the common terminal 3, and always sends out a constant voltage V ₀ from the current terminal 4. When the transmitting section 1 detects an abnormality in the surroundings, the constant voltage Generates a signal voltage V higher than V ₀ . The receiving section 5 connects the transmitting section 1 to the power supply terminal 6 and the common detection terminal 7 via the power supply line 8 and the common line 9.
The output of the voltage terminal 4 of the transmitter 1 is received by the voltage detection terminal 11 via the voltage line 10, and detected. This result is alerted by a display or a sounder (not shown) depending on the detected content.

In this abnormality detection circuit, when there is no abnormality around the transmitting section, a constant voltage V ₀ is always transmitted to the receiving section 5 via the voltage line 10. It is detected that there is no abnormality in the connections 8, 9, 10 such as the power line, common line, voltage line, etc. between the transmitter 1 and the receiver 5. If an abnormality occurs around the transmitter 1 and the transmitter 1 catches it,
The transmitting section 1 generates a signal voltage V higher than the constant voltage _V0 , and the receiving section 5 receives this and detects that the transmitting section 1 has captured an abnormality. Further, if a power outage accident or a disconnection accident occurs in the connection line between the transmitting section 1 and the receiving section 5, the constant voltage _V0 becomes 0, and the receiving section 5 immediately detects this.

[Problem to be solved by the invention]

As described above, this abnormality detection circuit reliably detects abnormalities and disconnection accidents when there is a one-to-one relationship between the transmitting section and the receiving section, and is extremely effective. However, if you try to detect abnormalities at multiple locations with one receiver and connect the second transmitter 1' in parallel with transmitter 1 as shown by the dotted line, if both transmitters 1 and 1' P between the power supply line 8 and the common line 9 or voltage line 10, respectively.
Even if a disconnection accident occurs at any of points P ₁ and Q, the constant voltage V ₀ of the transmitter 1' is received by the receiver 5, so the receiver 5 can prevent disconnections at points P, P', and Q. The drawback is that it cannot be detected. In particular, if the power line 8 or the common line 9 is disconnected at P or _P1 between the two transmitters 1 and 1', the power to the transmitter 1 will be cut off and the transmitter 1 itself will be unable to operate. This has the disadvantage that the transmitter connected after _{the first} point cannot transmit the abnormality detection signal.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device, and even when a plurality of transmitters are connected in parallel to one receiver, two different abnormalities detected by each transmitter can be detected. In addition to detecting disconnection of the connection line between the transmitting units or between the transmitting unit and the receiving unit,
In particular, it is an object of the present invention to provide an abnormality detection circuit that can reliably identify a disconnection point in a power supply line or a common line.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a receiving section and at least two transmitting sections connected in parallel to the receiving section, and the receiving section always sends out a constant voltage and detects at least one abnormality. The receiver has a voltage terminal that detects and operates and generates a signal voltage of a magnitude different from the constant voltage, and a current terminal that always sends a constant current and causes the constant current to disappear when the abnormality is detected. The unit has a voltage detection terminal to which the voltage terminal of each of the transmitting units is connected, and a current detection terminal to which the current terminal of each of the transmitting units is connected, and inputs are input to the voltage detection terminal and the current detection terminal, respectively. It is characterized by detecting the type of abnormality and the location of the disconnection by determining the magnitude of voltage and current.

[Effect]

A constant voltage V ₀ and a constant current I are sent from the transmitter, and when one abnormality (e.g. smoking) occurs, the constant current becomes 0, and when another abnormality (e.g. gas leak) occurs, the constant current I returns to zero. A voltage V of a magnitude different from the voltage V ₀ is delivered. Therefore, depending on the combination of the signal voltage and the signal current, the transmitter has a voltage V ₀ and a current I during normal operation, and one abnormality (e.g. smoking).
Sometimes it sends a voltage V ₀ and a current O, and when other abnormalities (eg gas leak) it sends a voltage V and a current O, and two different kinds of abnormalities can be transmitted. Also,
Current input in the receiving section is as current I is sent out from each transmitting section, so if the number of transmitting sections is N, then N x
I, so if there is a current input of N × I, it is in a normal state, and if there is a current input of (N - M) × I (however, M < N), when the voltage input is V ₀ , it is in the M position. If there is an abnormality (smoking) and the voltage input is V, it means that an abnormality (gas leak) has occurred at point M.
If there is no smoke abnormality at all when the voltage input is V ₀ despite the current input of (N-M)×I, the power line between the Mth and (M+1)th from the receiver side Or it is determined that the common line is disconnected.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 2 to 6. FIG. 2 shows an example of a transmitter for implementing the present invention. In Figure 2,
The transmitting section consists of a voltage output circuit 12 and a constant current circuit 13, and the voltage output circuit 12 has a resistor 16 connected to the power supply terminal 2 and a constant voltage diode 17 connected in series to the terminals of the comparator 14 and the comparator 15. A reference voltage obtained by the circuit is applied, and an abnormal signal captured by a sensor or the like is applied to the terminal of the comparator 14 (referred to as S ₁ terminal) and the terminal of comparator 15 (referred to as S ₂ terminal) to detect this abnormality. It is determined whether the signal is at a lower or higher level than the reference voltage. The output of the comparator 15 is divided by voltage dividing resistors 18 and 19 and connected to the base of a transistor 20. The transistor 20 has a collector connected in series with a resistor 21 and connected to the power supply terminal 2, and an emitter connected to the common terminal 3. Further, the transistor 22 has a collector connected to the power supply terminal 2.
and to the base via a resistor 23, and its emitter is connected to the voltage terminal 4 via a diode 24. Further, a constant voltage diode 25 is connected between the output terminal of the comparator 15 and the base of the transistor 22. 26 is a stabilizing resistor connected between the voltage terminal 4 and the common terminal 3. The constant current circuit 13 includes a transistor 2
A series circuit of the collector/emitter of No. 7 and a resistor 28 and a series circuit of a resistor 29 and a constant voltage diode 30 are connected in parallel. are connected to each. Also, resistance 29
The connection point between the voltage regulator diode 30 and the voltage regulator diode 30 is connected to the transistor 27, and this connection point is connected to the output terminal of the comparator 14 via a diode 32 and to the collector of the transistor 20 via a diode 33, respectively.

At all times, the terminals of comparator 14 and comparator 15 are at a low level. Therefore, the output of comparator 14 is at a high level, and no current flows through diode 32. Further, since the output of the comparator 15 is at a low level and the transistor 22 is always on, the output of the voltage terminal 4 is approximately a constant voltage V ₀ determined by the constant voltage diode 25. When the output of the comparator 15 is at a low level, the transistor 20 is not turned on, so the collector voltage of the transistor 20 is high and no current flows through the diode 33. When no current flows through the two diodes 32 and 33 in this way, the base voltage of the transistor 27 is high and the transistor 27 is turned on. Therefore, the constant current circuit 13 is in a state where current flows, and when the receiving section 5 is connected to the current terminal 34, the constant current circuit 13 sends out the constant current I. That is, this transmitter always sends out a constant voltage V ₀ from the voltage terminal 4 and a constant current I from the current terminal 34, respectively.

When an abnormal phenomenon occurs around the transmitter and the _S1 terminal captures it, and the terminal of the comparator 14 becomes higher in level than the terminal, the output of the comparator 14 becomes a low level. Therefore, current flows through the diode 32, and the base voltage of the transistor 27 decreases.
Transistor 27 is turned off. Therefore, the current at current terminal 34 becomes zero. Further, when the _S2 terminal captures an abnormal phenomenon and the terminal of the comparator 15 becomes higher level than the terminal, the output of this comparator 15 becomes high level. Therefore, the output voltage of the voltage terminal 4 becomes the signal voltage V, which is the sum of the output voltage of the comparator 15 and the constant voltage V ₀ of the constant voltage diode 25. Furthermore, when the output of the comparator 15 becomes high level, the transistor 2
0 is turned on, the collector voltage of the transistor 20 decreases, and current flows through the diode 33.
Therefore, the base current of transistor 27 decreases, transistor 27 is turned off, and current terminal 34
The current sent out from will be 0. The output form of the transmitter due to the abnormality detected by the S ₁ and S ₂ terminals is summarized as shown in FIG. In other words, the output of the transmitter is a constant voltage V ₀ and a constant current I during normal operation,
When the S ₁ terminal captures an abnormality, the constant voltage V ₀ does not change and the current becomes 0. When the S ₂ terminal captures an error, a signal voltage V higher than the constant voltage V ₀ is sent out, and the current becomes 0.
It is. Of course, the voltage output is also 0 during a power outage.

The two transmitters 1 and 1' as described above are connected to a common 1
In FIG. 4, which is connected to the receiving section 5 of the stand,
The two transmitting units 1 and 1' are driven by the drive power that is received by the power supply terminal 6 and the common detection terminal 7 of the receiving unit 5 through the power supply terminal 2 and the common terminal 3 via the power supply line 8 and the common line 9, respectively. The voltage output and current output shown in FIG. 3 are sent out from the voltage terminal 4 and the current terminal 34, respectively. The receiving section 5 receives the output of the voltage terminal 4 of both transmitting sections 1 and 1' at the voltage detection terminal 11 via the voltage line 10, and receives the output of the current terminal 34 via the current line 36 at the current detection terminal 35. The inputs are received, and each input is integrated to detect normality, abnormality, the contents of the abnormality, and disconnection of the connection lines 8, 9, 10, and 36, respectively.

FIG. 5 is a diagram showing the detection mode of the receiving section when the abnormality detection circuit shown in FIG. 4 is normal, when the transmitting section captures an abnormality, and when the connection line is disconnected.
The figure shows the case where each condition occurs independently, and shows the case where the transmitter _S1 terminal detects smoke and the _S2 terminal detects gas leakage. In FIG. 5, first, when both transmitting sections 1, 1' and each connection line 8, 9, 10, 36 are normal, the voltage input is V ₀ and the current input is 21. At this time, an alarm device (not shown) connected to this detection circuit displays a normal display. Next, when the transmitting units 1 and 1' detect an abnormality (smoking), when one of them captures the smoke, the constant voltage V ₀ and current input I are respectively detected. Further, when the two transmitters 1 and 1' capture smoke, a constant voltage V ₀ and a power input of 0 are detected. At this time, the receiving section 5 issues a smoke alarm. Further, when one transmitter 1 captures a gas leak, a signal voltage V and a current input I are detected. Further, when the two transmitters detect gas leakage, a signal voltage V and a current input 0 are detected. At this time, the alarm device issues a gas leak alarm.

Next, when the connecting wires 8, 9, 10, and 36 are disconnected, the following symbols are attached to each point indicated by an X mark in FIG. 4 and shown in the table. In other words, the power supply line 8 and the common line 9 are connected between the receiving section 5 and the transmitting section 1', respectively.
P ₂ , P ₂ ′, voltage line 10, Q ₁ between receiving section 5 and transmitting section 1', Q ₂ between both transmitting sections 1, 1', current line 3
6, it is assumed that the distance between the receiving section 5 and the transmitting section 1' is _R1 , and the distance between the transmitting sections 1 and 1' is _R2 , and that a disconnection at each of these points occurs independently. first
If there is a disconnection at either point P ₁ or P ₁ ' (similar to a power outage), both voltage input and current input will be 0, and if Q ₁ is disconnected, the voltage input will be 0 and the current input will be 21.
In this case, the alarm device issues a disconnection alarm.

Next, if there is a disconnection at each point R ₁ , P ₂ , P ₂ ', R ₂ , the voltage input will all be a constant voltage V ₀ , but the current input will be 0 if there is a disconnection at _one point R, P ₂ ,P ₂ ′,
R If the wire is broken at _two points, each becomes I. In this case, the voltage input is a constant voltage V ₀ and the current input is 0 or I, so it is actually a disconnection accident, but here the situation is the same as when the transmitter captures smoke, and the alarm device does not operate. Same as smoke alarm.
When the voltage input becomes a constant voltage V ₀ and the current input becomes 0 due to a disconnection at the _R1 point, first check and inspect for a smoke abnormality, and if there is no smoke abnormality, it is determined that the _R1 point is disconnected. When the voltage input becomes a constant voltage V ₀ and the current input becomes I due to disconnection at the _two points P ₂ , P ₂ ′, and R, check and inspect for smoke abnormality in the same way as above, and if no smoke abnormality occurs. is P ₂ ,
It is determined that there is a disconnection at _two points, P ₂ ′ and R. In addition, when the wire is disconnected at the _Q2 point, the voltage input is a constant voltage V ₀ and the current input is 21, which is the same as the normal state, so it is displayed as normal. However, in this case, the transmitter 1
Since power is applied to the transmitter 1 via the power line 8 and the common line 9, the transmitter 1 is in an operable state. Therefore, when an abnormality is detected in the transmitting section 1, the current input to the receiving section 5 changes from 2I to I, so that the receiving section 5 issues a smoke alarm and is notified of the abnormality. Based on this notification, inspection and inspection for smoke abnormalities are carried out.
If there is no smoke generation abnormality, it can be determined that a gas leakage abnormality has occurred along with a disconnection at the _Q2 point. As is clear from the above, in reality P ₂ , P ₂ ′,
Disconnection detection at _{the two} points R ₂ and Q determines that one of the wires between transmitters 1 and 1' is disconnected if there is no abnormality in smoking even though a smoke abnormality alarm has been issued. It is.

FIG. 6 is a diagram showing the voltage input and current input of the receiving section, mainly in the case where wire breakage and abnormality capture occur at the same time. A indicates a normal state, and A constant voltage V ₀ and a constant current I are sent out, and the receiving unit 5 receives the constant voltage V ₀ and the sum 2I of the two constant currents I. In B, this signal voltage V and the constant current I of the other transmitter 1' are received in a state where one transmitter 1 captures the gas leak. Of course,
Even if the other transmitter 1' captures a gas leak, the input is the same. C is a state in which both the transmitting sections 1 and 1' have captured the gas leak, and only the signal voltage V is received, and both currents have disappeared due to the abnormal capture and are both zero. D and below are each connecting wire 8, 9,
Including the case where there is a disconnection in 10 and 36, there are a plurality of cases when an abnormality is detected. First, D is both transmitting parts 1, 1'
Either one of them, for example, the transmitter 1 has captured the smoke, or the other transmitter 1' has captured the smoke, and Q ₂
Either there is a disconnection at the P 2 and P 2 ' points, or both transmitters 1 and 1' do not detect an abnormality, or there is a disconnection at the P ₂ and P ₂ ' points.
R indicates a state where there is a disconnection at _two points, and the voltage input is V ₀ ,
The current input is I. E is a state in which both transmitters 1 and 1' have captured smoke, or both transmitters 1 and 1'
does not detect any abnormality and there is a disconnection at _one point R.
The voltage input is V ₀ and the current input is 0. F is a state in which both transmitters 1 and 1' have detected an abnormality and there is a disconnection at point _Q , or either _P1 or _P1 ' is disconnected, and both voltage input and current input are 0. .

In this abnormality detection circuit, if there is a disconnection in the connection line as in the condition D or below, even if the same signal is received,
Although it may be difficult to detect what state this is, the presence of some kind of abnormality, including a disconnection, can be definitely detected.

Here, if the power line 8 and the common line 9 are active, the transmitter can detect an abnormal state, so the disconnection of the power line 8 and the common line 9 is a problem. Therefore,
The disconnection between the power supply line 8 and the common line 9 is detected as described above, and the method of specifying the disconnection point by inputting a current to the receiving section will be explained.

Now, assuming that the number of transmitters is N, the current input to the receiver during normal operation is N×I. If there is no abnormality even though the current input to the receiver is (N-M)×I (where M<N), power is not applied to the M-th transmitter or later from the receiver. Therefore, it can be determined that there is a disconnection between the Mth and (M+1)th transmitters from the receiver.

〔Effect of the invention〕

As described above, the present invention includes a receiving section and at least two transmitting sections connected in series to the receiving section, and the receiving section always sends out a constant voltage and at least one transmitting section. It has a voltage terminal that operates upon detecting an abnormality and generates a signal voltage of a magnitude different from the constant voltage, and a current terminal that always sends out a constant current and causes the constant current to disappear when the abnormality is detected, The receiving section has a voltage detection terminal to which the voltage terminal of each of the transmitting sections is connected, and a current detection terminal to which the current terminal of each of the transmitting sections is connected, and the voltage detection terminal and the current detection terminal each have a voltage detection terminal connected to the voltage terminal of each of the transmission sections. By determining the magnitude of the input voltage and current to detect the type of abnormality and the location of the disconnection, even when multiple transmitters are connected in parallel to one receiver, each transmitter By the combination of a constant voltage sent from the constant voltage, a signal voltage of a different magnitude from this constant voltage, and a constant current, two different types of abnormalities can be captured in each transmitter and sent to the receiver. In addition, by adding the constant current sent out from each transmitting section and inputting it to the receiving section, it is possible to determine which transmitting section is operating based on the added input current. This has the advantage that the location of the wire breakage can be specified based on the method.

[Brief explanation of drawings]

FIG. 1 is a wiring diagram showing an example of a conventional abnormality detection circuit, FIGS. 2 to 6 are diagrams relating to an abnormality detection circuit according to the present invention, and FIG. 2 is a wiring diagram showing an example of a transmitting section. 3 is a diagram showing the output form of the transmitting section in FIG. 2, FIG. 4 is a block diagram of the abnormality detection circuit, FIG. 5 is a diagram showing the detection form of the receiving section, and FIG.
FIG. 3 is an operational diagram showing the relationship between the states of each part of the abnormality detection circuit shown in the figure and the input to the receiving section. 1, 1'... Transmission section, 4... Voltage terminal, 5...
Receiving section, 12... Voltage detection terminal, 34... Current terminal, 35... Current detection terminal.

Claims (1)

[Claims] 1 comprising a receiving section and at least two transmitting sections connected in parallel to the receiving section, the transmitting section always transmits a constant voltage and operates upon detecting at least one abnormality, The receiver has a voltage terminal that generates signal voltages of different magnitudes, and a current terminal that always sends out a constant current, and the constant current disappears when the abnormality is detected, It has a voltage detection terminal connected to it and a current detection terminal connected to the current terminal of each of the transmitting sections, and determines the magnitude of the voltage and current input to the voltage detection terminal and the current detection terminal, respectively. An abnormality detection circuit characterized by detecting the type of abnormality and the location of the disconnection.