JPH04260998A - Security unit - Google Patents

Abstract

PURPOSE:To obtain a simple and inexpensive security unit by connecting a non-voltage type gas leakage detector to a voltage type gas leakage detector and using a detecting circuit in common. CONSTITUTION:This security unit is constituted of the 1st change-over switch 14 connected between a circuit power supply 12 and the non-voltage type gas leakage detector 1, the 1st wiring 15 for serially connecting the detector 1 and the voltage type gas leakage detector 6, the 2nd change-over switch 17 connected to the power supply 12 through a resistor 18, and the 2nd wiring 16 connecting one end to the 1st wiring 15 and connecting the other end to a voltage detecting circuit 9 through the 2nd terminal 4.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a security unit, and more particularly to a gas leak alarm device.

0002

2. Description of the Related Art FIG. 2 is a diagram of a gas leak detection circuit of a conventional security unit. In the figure, reference numeral 1 denotes a non-voltage gas leak detector, which is connected to a first terminal 3 and a second terminal 4 of a terminal block 2, and is connected to a gas leak detection circuit 5 via this terminal block 2. Reference numeral 6 denotes a voltage type gas leak detector, which is connected to the third terminal 7 and fourth terminal 8 of the terminal block 2, and is also connected to the voltage detection circuit 9 via the third terminal 7. 10 is an OR circuit connected to the leak detection circuit 5 and voltage detection circuit 9 so as to input the signals of the gas leak detection circuit 5 and voltage detection circuit 9; 11 is a microcomputer for signal processing; It is connected to the voltage detection circuit 9.

Next, the operation will be explained. The non-voltage type gas leak detector 1 has an internal contact, which is OFF when normal and ON when abnormal, and its operation is controlled by the gas leak detection circuit 5.
is detected by changes in input voltage. Output is OR in case of abnormality
is transmitted to circuit 10. On the other hand, voltage type gas leak detector 6
is connected to the voltage detection circuit 9, and outputs 6V when normal, 12V when abnormal, and 0V when faulty. The voltage detection circuit 9 identifies the voltage and determines three conditions.In the event of a gas leak,
The signal is outputted to the OR circuit 10, and in the event of a failure, it is transmitted to the signal processing microcomputer 11. The OR circuit 10 also transmits the output from either of the gas leak detectors 1, 6 to the signal processing microcomputer 11.

[0004] As a similar conventional example, Japanese Patent Laid-Open No. 2-18
Publication No. 3396 "Security Sensor" and JP-A-2-
No. 157992 ``Alarm determination method and environmental level determination method for crime prevention sensor'' is available.

[0005]

[Problems to be Solved by the Invention] When using both a non-voltage gas leak detector and a voltage-powered gas leak detector in a conventional security unit, each has its own connection terminal and dedicated input. A signal processing circuit was required.

[0006] This invention was made in order to solve the above-mentioned problems, and it makes the connection part common in connecting a non-voltage type gas leak detector and a voltage type gas leak detector, and also The purpose of this invention is to obtain a simple and inexpensive security unit in which the detection circuit can also be shared.

[0007]

[Means for Solving the Problems] A security unit according to the present invention is a security unit equipped with a voltage-free gas leak detector and a voltage-powered gas leak detector. A first changeover switch provided between the two, a first wiring connecting the non-voltage gas leak detector and the voltage gas leakage detector in series, and a second changeover switch connected to the circuit power supply via a resistor. A second wiring is provided, one end of which is connected to the first wiring, and the other end of which is connected to the voltage detection circuit via a second terminal.

[0008]

[Operation] The security unit in this invention changes the circuit constant by switching two switches, and receives normal and abnormal inputs from the voltageless gas leak detector.
The normal and abnormal input voltages from the voltage type gas leak detector can be set to 6V and 12V, respectively, using a common voltage detection circuit.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 12 is a circuit power supply, which is connected to the voltageless gas leak detector 1 via the first terminal 3 of the terminal block 2, and a first changeover switch 14 provided in parallel with the first resistor 13 in the middle. are connected. 15 is a first wiring that connects the voltage-free gas leak detector 1 and the voltage-powered gas leak detector 6 in series; 16 is a second wiring; one end is connected to the first wiring 15;
The other end is wire-connected to the voltage detection circuit 9 via the second terminal 4 of the terminal block 2 . A second changeover switch 17 is connected to the circuit power supply 12 via a second resistor 18, and has the other end connected to the voltage detection circuit 9. 19 is a third resistor.

Next, the operation will be explained. First, when using the non-voltage gas leak detector 1, turn on the first and second changeover switches 14 and 17, insert the first resistor 13, and
Resistor 18 is shorted. Therefore, the voltage of the circuit power supply 12 is applied to the first terminal 3, and the voltage obtained by dividing the voltage of the circuit power supply 12 by the second resistor 18 and the third resistor 19 is applied to the second terminal 4. On the other hand, when the first changeover switch 14 and the second changeover switch 17 are turned off, the second resistance 18
is disconnected from the circuit, and the first resistor 13 is inserted into the circuit. As a result, the voltage of the circuit power supply 12 is applied to the first terminal 3 via the first resistor 13. First changeover switch 14
, the second terminal 4 when the second changeover switch 17 is turned on.
The voltage of the second terminal 4 is 6V, the voltage of the second terminal 4 when the first terminal 3 and the second terminal 4 are short-circuited is 12V, and the voltage of the first terminal 4 is 12V.
When the changeover switch 14 and the second changeover switch 17 are OFF, 0V, 6V, 12V is applied between the second terminal 4 and the third terminal 7.
the first resistor 13, the second resistor 13, so as to apply a voltage of V;
By selecting the resistance value of the third resistor 19, when the voltageless gas leak detector 1 is connected between the first terminal 3 and the second terminal 4, the first changeover switch 14 and the second changeover switch 17 can be changed. When turned on, the detection voltage is 6V when normal and 1 when abnormal.
2V, and if the voltage type gas leak detector 6 is connected between the second terminal 4 and the third terminal 7 and the first changeover switch 14 and the second changeover switch 17 are turned OFF, the detected voltage is 6V under normal conditions.
, becomes 12V during abnormality.

[0011] In the above embodiment, the circuit switching is performed in two steps.
Although this is done using two switches, it is also possible to use semiconductor circuits such as transistors as switching elements, and it is also possible to switch the switching elements using switches or under control from a microcomputer.

0012

As described above, according to the present invention, the first changeover switch provided between the circuit power source and the non-voltage gas leak detector, A first wire connecting the leak detector in series, a second changeover switch connected to the circuit power supply via a resistor, and one end connected to the first wire.
Since the configuration includes a second wiring that connects to the wiring and connects to the voltage detection circuit via the second terminal, the number of connection points can be reduced, and a common circuit can be used to connect a non-voltage gas leak detector and a voltage-powered gas leak detector. This allows use with a leak detector and has the effect of obtaining an inexpensive security unit.

[Brief explanation of the drawing]

FIG. 1 is an electrical circuit diagram showing an embodiment of the present invention.

FIG. 2 is an electrical circuit diagram showing a conventional security unit.

[Explanation of symbols]

1. Voltageless gas leak detector 4 Second terminal 6 Voltage type gas leak detector 12 Circuit power supply 14 First changeover switch 15 First wiring 16 Second wiring 17 Second changeover switch 18 Resistance

Claims (1)

[Claims] Claim 1: In a security unit equipped with a voltage-free gas leak detector and a voltage-powered gas leak detector, a first changeover switch provided between a circuit power source and the voltage-free gas leak detector; A first wiring that connects the voltage type gas leak detector and the voltage type gas leak detector in series, a second changeover switch that is connected to the circuit power supply via a resistor, and a second wiring that connects one end to the first wiring and A security unit comprising a second wiring connected to a voltage detection circuit via a terminal.