JPH074718Y2 - Gas leak alarm device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a gas leak alarm device which generates a signal when a power plug is pulled out or a breaker is turned off.

[Prior Art] A conventional gas leak alarm device stops a gas supply by detecting a gas leak and outputting a detection signal to ring a buzzer or operating a gas cutoff valve. .

[Problems to be solved by the invention]

By the way, in recent years, gas suicide has been regarded as a social problem, and countermeasures against it have been demanded. That is, a person who commits gas suicide pulls out the power plug or turns off the breaker to stop the operation of the gas leak alarm buzzer and the gas cutoff valve. On the other hand, even if there is a power failure, the gas leak alarm will be in the same state, so it is difficult to distinguish between them, and there is a problem in gas suicide countermeasures.

The present invention has been made to solve the above-mentioned problems, and a gas leak alarm device capable of distinguishing the case where the power plug of the gas leak alarm is unplugged or the breaker is turned off and a power failure occurs. Aim to get.

[Means for Solving Problems] The gas leak alarm device of the present invention is provided with a power backup circuit which becomes a power source when the capacitor is charged and the AC power source is off, and the AC power source is cut off. The power supply disconnection detection circuit that detects that the AC power supply has been detected, the oscillation circuit that generates a signal with a frequency higher than the frequency of the AC power supply, and the output of this oscillation circuit is applied to the grounded terminal A continuity detecting circuit for detecting and a circuit for outputting an alarm signal when the power failure is detected by the power failure detecting circuit and the disconnection of the power plug is detected by the continuity detecting circuit are provided.

[Action]

In this invention, when the AC power supplied to the gas leak alarm is cut off, the power cutoff detection circuit detects this, and if the continuity detection circuit detects detachment of the power plug, the so-called An alarm signal is issued when it is judged that the gas leak alarm has been intentionally turned off instead of a power failure.

〔Example〕

The drawings show an embodiment of the present invention, in which 1 is an indoor wiring, 2 is a breaker, and 3 is an outlet. I is a gas leak alarm, and II is a power failure detector.

In the gas leak alarm I, P is a power plug, T is a power transformer, and has a primary winding W ₁ , a secondary winding W ₂ , and a tertiary winding W ₃ . S is a gas sensor, and the electrodes Sa and Sb also function as heaters.
The electrode Sa is heated by the tertiary winding W _{3 and} is integrally covered with a gas-sensitive metal oxide semiconductor.
The output of the secondary winding W ₂ is rectified and smoothed by the diode D ₁ and the capacitor C ₁ and supplied to each part as a DC power supply. R ₁ ~ R ₄
Is a resistor, and the DC power supply voltage from the diode D ₁ divided by the resistors R ₁ and R ₂ is applied to one input of the comparator IC as a reference voltage and divided by the resistors R ₃ and R ₄ . The output from the electrode Sb is rectified and smoothed by the diode D ₂ and the capacitor C ₂ and added to the other input of the comparator IC as a DC power supply. BZ is a buzzer for generating an alarm sound of gas leak, and the circuit in the gas leak alarm I is configured as described above.

In the power failure detector II, D ₃ is a diode and C ₃ is a capacitor, and these constitute the power supply backup circuit 10,
It becomes a power source when the power supply voltage from the gas leak alarm I is cut off. R _5, R ₆ are resistors, Tr1 is a transistor, resistor
R _5, constitute a power supply interruption detecting circuit 20 in transistors Tr1, it detects the disconnection of the power supply voltage. An oscillating circuit 30 is composed of an oscillator OSC that emits a signal of a frequency higher than the frequency of the AC power source, a transistor Tr2, etc., and is applied to the output of the oscillator OSC or the base of the transistor Tr2. The output of the transistor Tr2 is transmitted electromagnetically from the coil L ₁ in the coil L _2. Reference numeral 40 denotes a continuity detection circuit, which is connected in series with a resistor R ₇ , a coil L ₂ , and a capacitor C _{4, and} is connected between the emitter of the transistor Tr 2 and the ground, and a diode D ₄ and an inverter at one end of the resistor R _7.
INV is connected in series. C ₅ is a capacitor for smoothing. G is a gate circuit that takes an AND, and a power failure detection circuit
The collector of the transistor Tr1 in 20 and the output of the inverter INV in the continuity detection circuit 40 are added as inputs. LE is a grounding wire, and the power plug P is an outlet 3
It is inserted in and is supplied with power from a commercial power source,
One pole of the power plug P is grounded, but this power plug P
It is connected to one pole.

Secondary winding if power plug P is inserted into outlet 3
A predetermined voltage is generated in W ₂ and the tertiary winding W ₃ , and the gas is in a waiting state.

When gas leakage occurs, the electrodes Sa, the voltage resistance between the Sb is divided by it resistors R _3, R ₄ low gas sensor S is higher than the gas leakage before. Therefore, an output is output from the comparator IC and the buzzer BZ sounds.

Next, pull out the power plug P from the outlet 3,
Alternatively, when the breaker 2 is turned off, the AC power is not applied to the gas leak alarm I, the transistor Tr1 is turned off as described above, and the capacitor C ₃ is connected via the resistor R _6.
A signal whose voltage is "H" level is input to the gate circuit G.

On the other hand, when the breaker 2 is turned off or the power plug P is detached, the ground in the continuity detection circuit 40, the capacitor C ₄ ,
Since the closed circuit formed by the coil L ₂ , the resistor R ₇ , and the ground of the power plug P becomes an open circuit when the ground of the power plug P is released, the coil L is changed by the AC voltage applied via the coil L _{1. The} current due to the voltage induced in ₂ does not flow in resistor R ₇ , therefore the voltage across resistor R ₇ is “0”,
Therefore, there is no output of the diode D ₄ and the inverter INV
Is at "L" level and its output is at "H" level, which is input to the other side of the gate G.

As a result, the alarm signal AL is output from the gate circuit G.
If an emergency buzzer (not shown) is sounded using this alarm signal AL or if it is notified to the management room by wire or wirelessly, whether the power plug P of the gas leak alarm I is pulled out or the breaker 2 is turned off. It can be determined that

In the case of a power failure, the output of the power failure detector circuit 20 becomes "H" level as described above, but in this case, since the power plug P and the breaker 2 are not turned off, grounding,
Since the closed circuit formed by the grounding of the capacitor C ₄ , the coil L ₂ , the resistor R ₇ , and the power plug P is still configured, it is induced in the coil L ₂ by the AC voltage applied via the coil L ₁ . Current due to voltage flows in the closed circuit,
AC voltage is developed across resistor R ₇ . This AC voltage is smoothed by diode D ₄ and capacitor C ₅ , becomes “H” level, and is applied to inverter INV.
Output becomes "L" level and this is applied as one input of the gate circuit G, so that the gate circuit G remains closed and the alarm signal AL is not output.

In this way, the continuity detection circuit 40 detects the presence or absence of continuity between the power plug P and the ground, and from the detection result,
It is possible to detect insertion / removal of the power plug P or ON / OFF of the breaker 2.

The reason why the oscillation frequency of the oscillator OSC is set higher than the frequency of the AC power supply is to increase the impedance of the coil L ₂ so that the current does not flow from the AC power supply when the power plug is connected.

That is, in the illustrated embodiment, when the power plug P is inserted in the opposite direction, the resistor R ₇ , the coil L ₂ , the capacitor
This is because the commercial power supply is directly applied to the C ₄ circuit, which may occur when a large current flows.

[Effect of device]

As described above, the present invention is provided with a power supply backup circuit that normally becomes a power supply when the capacitor is charged and the AC power supply is off, and a power supply cutoff detection circuit that detects that the supply of the AC power supply is cut off. An oscillation circuit that generates a signal with a frequency higher than the frequency of the AC power supply; a continuity detection circuit that applies the output of this oscillation circuit to a grounded terminal to detect insertion / removal of the AC power supply plug; Since a circuit for outputting an alarm signal when disconnection of the power plug is detected by the continuity detection circuit is detected by the continuity detection circuit,
Because it is possible to distinguish whether the gas leak alarm is off from the AC power supply or due to a power outage,
Not only is it particularly effective in preventing suicide, but it is also extremely useful in terms of gas leak alarm management and security.

[Brief description of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. In the figure,
1 is indoor wiring, 2 is a breaker, 3 is an outlet, I is a gas leak alarm, II is a power failure detector, P is a power plug, S is a gas sensor, D _{1 to} D ₄ are diodes, and C _{1 to} C ₄ are Capacitors,
R ₁ to R ₇ are resistors, IC comparators, BZ is a buzzer, Tr1, Yr2 transistors, 10 is a power supply backup circuit, 20 is a power supply interruption detecting circuit 30 is oscillating circuit, 40 is conductive detector, G is It is a gate circuit.

Claims (1)

[Scope of utility model registration request] 1. A power source is supplied from an AC power source when the power plug (P) is inserted into an outlet (3), and one pole of the power plug (P) is grounded and further connected to this one pole. In a gas leak alarm device that has a grounding line (LE) and operates at a predetermined gas concentration to generate an alarm, the capacitor (C ₃ ) is normally charged and the AC power source is turned off. Power supply backup circuit (10), a power interruption detection circuit (20) for detecting that the supply of the AC power supply is cut off, and a coil (L ₁₎ for generating a signal having a frequency higher than that of the AC power supply. ), A capacitor (C ₄ ) and a resistor (R ₇ ) connected in series with the coil (L ₂ ) to which the output of this oscillator circuit (30) is applied. Has one end connected to the ground terminal and the other end connected to the ground wire (LE). Detecting the presence or absence of conduction of the power supply plug (P) and the ground by the presence or absence of current flowing through the Rutotomoni resistor (R _7), an indoor insertion and removal or the power plug (P) of the power plug of the AC power supply (P) A continuity detection circuit (40) for detecting ON / OFF of the breaker (2) connected to the wiring;
A circuit which outputs an alarm signal when the power failure is detected by the power failure detection circuit (20) and the continuity detection circuit (40) detects the detachment of the power plug (P) or the breaker (2) being turned off. Gas leak alarm device characterized by having and.