JPH0241404Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a gas cutoff valve that checks the charging voltage of the capacitor before operating it when the capacitor's charge is used to shut off or restore the gas cutoff valve. This relates to an interlocking device.

First, the outline of the gas cutoff valve interlocking device will be explained with reference to FIG. In Fig. 1, A is a gas alarm, which normally outputs a 6V voltage signal, and when a gas leak is detected, it outputs a 12V voltage signal. Also, when the wire is disconnected, it becomes 0V. B is a gas cutoff valve interlocking device which is the subject of this invention, and C is a gas cutoff valve. The gas cutoff valve interlocking device B normally receives a 6V voltage signal, that is, a normal signal, from the gas alarm A, and uses this as a power source to operate various internal parts, and receives a 12V voltage signal from the gas alarm A, That is, when an abnormal signal is received, it is distinguished from a normal signal, and the gas cutoff valve C is operated to cut off the gas supply. D is a centralized monitoring system, and the status of the gas alarm A is constantly transmitted from the gas cutoff valve interlocking device B.

In the conventional gas cutoff valve interlocking device B, the capacitor is normally charged, and when the gas cutoff valve C is shut off or reset, the charged charge is discharged.
However, if the gas is discharged when the charging voltage is low, the gas cutoff valve C may not operate as expected, which has been a major problem in automatic cutoff systems.

This idea was developed in consideration of the above-mentioned points, and is configured to perform discharging after determining whether the charging voltage of the capacitor has reached a predetermined value. This idea will be explained below.

First, the entire gas cutoff valve interlocking device to which this invention is applied will be explained, and then the details of the main parts of this invention will be explained.

FIG. 2 is a block diagram of a gas cutoff valve interlocking device to which this invention is applied. In this figure, reference numeral 1 denotes a surge reverse connection prevention circuit, which is composed of a surge absorber and a capacitor, and protects the repeater from surge voltage generated in the signal line or when + and - are connected in reverse. 2 is a current consumption limiting circuit, which limits the current when the input reaches 12V (in case of alarm state) in order to reduce current consumption. 3 is a 10V, 20V booster circuit, and the release pulse is approximately 5V to 6V from the input voltage.
20V, and also requires an output voltage of 5.5V to 7.5V, so
This is to increase the voltage. 4 is the return pulse generation circuit, which requires an instantaneous voltage of approximately 20V to change the gas cutoff valve C from "closed" to "opened".
Charge a 2200μF capacitor. 5 is a backup circuit that charges a large capacitor to keep the gas cutoff valve C open for 5 minutes even if the input voltage of the repeater drops to 0V due to a problem with the gas alarm A or the like. 6 is an alarm detection circuit that detects whether the input signal has reached the alarm level. 7 is a trouble detection circuit that detects whether the input signal has reached the trouble level (0V). 8 is a standby detection circuit, which is the main part of this invention, and detects whether the capacitor of the return pulse generation circuit 4 has been charged to a specified voltage, and also generates a return pulse to detect the gas cutoff when it is "open". It is determined whether the valve C can supply the necessary electrical energy to maintain its state, and a signal is sent to a return pulse switch circuit 11, which will be described later. 9
is a one-minute timer that reaches the alarm level (12V), determines whether this state continues for one minute, and sends a signal to the output voltage control circuit 13, which will be described later. 10 is 5
The minute timer determines whether the trouble level (0V) has been reached and this state has continued for 5 minutes, and sends a signal to the output voltage control circuit 13. A return pulse switch circuit 11 discharges the capacitor charged by the return pulse generation circuit 4 in a state confirmed by the standby detection circuit 8, etc., and generates a return pulse. 12 is an alarm trouble recovery detection circuit that judges whether the alarm or trouble continues for a predetermined time or longer and outputs a cutoff signal (0V), and if the cutoff signal is output, it returns after the alarm or trouble is cleared. Emit a signal to generate a pulse. Reference numeral 13 denotes an output voltage control circuit that generates 0V, 6V, and 19V signals to be output to the gas cutoff valve C, and outputs a signal corresponding to each state depending on the state. In other words, in the event of an alarm, the voltage will be 0V after 1 minute, in the event of a trouble, the voltage will be 0V after 5 minutes, and in normal conditions it will be 6V.
Upon recovery, a 19V pulse voltage is generated. Reference numeral 14 denotes a manual closing circuit which generates a signal to immediately shut off the circuit by means of a manual switch. Reference numeral 15 denotes a current limiting circuit which limits the current of the centralized monitoring output so that the repeater operates even if the centralized monitoring output is shorted on the signal line.

FIG. 3 is a circuit diagram showing details of the standby detection circuit 8, which is the main part of this invention. In this figure, the return pulse generation circuit 4 is composed of a resistor R ₁ and a capacitor C ₀
10V, as shown in Figure 2, is connected between input terminals 4A and 4B.
When a voltage of 20V is applied from the 20V booster circuit 3,
Capacitor C ₀ is charged through resistor R ₁ .
The standby detection circuit 8 is a Zener diode
ZD, resistors R ₂ , R ₃ , and transistor Q. A series connection of Zener diode ZD and resistor R ₂ is connected in parallel with capacitor C ₀ , and resistor R ₃ and resistor R 2 are connected in series. transistor Q
The collector and emitter of transistor Q are connected in series between input terminals 4A and 4B, and the base of transistor Q is connected to the connection point between Zener diode ZD and resistor _R2 . The connection point a between the resistor R ₁ and the capacitor C ₀ and the connection point b between the collector of the transistor Q and the resistor R ₃ are input to the reset pulse switch circuit 11.

Next, the operation will be explained. Input terminal 4A, 4
When an input voltage is applied to B, the capacitor _C0 is charged through the resistor _R1 , and when the charging voltage reaches the specified value, a reverse current begins to flow through the Zener diode ZD, and the transistor Q is biased to operate and turn on. , drop connection point b from high potential to low potential, and connect capacitor C ₀ between connection points a and b.
Apply a charging potential of . Therefore, the return pulse switch circuit 11 operates.

In this way, after the capacitor _C0 is charged to a specified voltage, the return pulse switch circuit 11, which is a load, is activated to generate a return pulse, so that reliable operation can be achieved.

Note that in the above embodiment, the standby detection circuit 8
was used to check the voltage of the capacitor C ₀ of the recovery pulse generating circuit 4, but it can be similarly used to check the voltage of the backup circuit 5. Further, although the reverse current of the Zener diode ZD is used as the voltage detection means of the capacitor C ₀ , it is also possible to use a comparator for detection.

As explained in detail above, this invention uses a voltage detection means in a gas cutoff valve interlocking device that charges a capacitor using a voltage signal as a power source and shuts off or returns the gas cutoff valve by discharging the charged charge. A standby detection circuit is provided that operates a switching circuit that discharges to the load when it is detected that the charging voltage of the capacitor has reached a predetermined value.This ensures that the gas cutoff valve is shut off or restored. This has the great advantage of greatly increasing the reliability of the automatic shutoff system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram for explaining the outline of the gas cutoff valve interlocking device, Fig. 2 is a block diagram of the gas cutoff valve interlocking device to which this invention is applied, and Fig. 3 is a standby detection which is the main part of this invention. FIG. 3 is a circuit diagram showing details of the circuit. In the figure, 8 is a standby detection circuit, A is a gas alarm, B is a gas cutoff valve interlocking device, C is a gas cutoff valve,
D is a central monitoring system, R ₁ to _{R 3} are resistors, ZD is a Zener diode, Q is a transistor, a, b
is a connection point.

Claims (1)

[Scope of utility model registration request] In a gas cutoff valve interlocking device that charges a capacitor using a voltage signal from a gas alarm as a power source and controls a gas cutoff valve by discharging the charged charge, it is detected that the charging voltage of the capacitor has reached a predetermined value. 1. A gas cutoff valve interlocking device comprising: a standby detection circuit comprising a voltage detection means for detecting the voltage, and a switching circuit operated by the output of the voltage detection means to discharge the charge in the capacitor.