JPS591925A - gas safety device - Google Patents

Abstract

PURPOSE:To provide a gas safety device which functions to maintain the charging voltage of condenser at a constant value and shorten the period of time required to charge the condenser, by connecting the base terminal of transistor with a point where a resistor and a voltage regulating element are branched off. CONSTITUTION:A condenser 24 is charged merely up to a voltage equivalent to the base voltage of transistor 21 subtracted by a voltage drop occurring at a space between base emitters, and after this voltage has reached the target value, the transistor 21 is turned OFF for stopping the charging operation. Besides, the amplifying function of transistor is utilized to preset an initial charging voltage at a larger value and therefore duration required for charging is shortened. That is, when the condenser 24 has no voltage at a space between the terminals thereof, there takes place no flow of electric current to a voltage regulating element 20 and thus all amounts of electric current flowing to a resistor 19 are rendered as the base current of transistor 21, which leads to the securing of greater amount of electric current flowing to the resistor 22. When there is no voltage present at a space between the terminals of condenser 24, the flow of current does not take place to the voltage regulating element 20 and all amounts of electric current flowing to the resistor 19 are rendered as the base electric current for the transistor 21 with a result in securing a greater amount of electric current flowing to the resistor 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to gases such as thermoelectromotive force of thermocouples installed close to the combustion part of gas appliances such as gas cookers, or currents from other current sources. This invention relates to a gas safety device consisting of a safety valve that keeps a supply passage open.

Conventional Structure and Problems Conventionally, this type of gas safety device has been structured as shown in FIG. That is, a dry battery 1 is used as the power source 2, and when the cox inochia provided in the gas supply path 6 to the burner 9 is closed, the switch 3 interlocked with the cock switch 7 is operated to charge the capacitor 4, and then the capacitor 4 is charged. Switch 3 switches in conjunction with opening cock switch 7,
The capacitor 4 supplies a full current to the electromagnetic coils to open the safety valve 8 in the gas supply path 6, and at the same time, the ignition device 19 ignites the burner 9. When the capacitor 4 is completely discharged, the electromagnetic coil 6 is operated by the thermoelectromotive force of the thermocouple 10 heated by the gas flame, and the safety valve 8 is held open, so that the cock switch 7 should not be opened. When the flame of the gas burner 9 goes out, the thermoelectromotive force of the thermal lightning pair 10 disappears, and as a result, the safety valve 8 completely closes the gas supply passage 6, so that it functions as a gas leakage safety device. It has become.

In this configuration, when the dry battery 1 is exhausted, the dry battery 1 must be completely replaced, which is a disadvantage for the user. Therefore, as a general solution, it is possible to use a transformer 12 from the commercial power supply 11 instead of the dry cell battery 1 shown in the previous figure, as shown in FIG. 2, and charge the capacitor 4 through the entire rectifier circuit 13, but this method is capacitor 4
The charging voltage changes when there is a voltage fluctuation in the commercial power supply 11, and the charging time also depends on the internal resistance of the transformer 12, etc. Also, in order to reduce this internal resistance, it would be best to lower the winding resistance, but this would make the transformer louder than necessary and would not yield good results in terms of cost or ease of assembly. The purpose of the present invention is to keep the above-mentioned conventional intermediate layer in mind, and to use a transformer to maintain a constant charging voltage of a capacitor and a constant discharging time, the operating time of an electromagnetic coil can be maintained constant.
It is an object of the present invention to provide a gas safety device that has the function of reducing the battery life and also shortening the charging time.

To achieve the above object, the present invention connects a series circuit of a resistor and a constant voltage element to a DC power source, a base terminal of a transistor is connected to a branch point between the resistor and the constant voltage element, and one terminal of the DC power source is connected to a base terminal of a transistor. A capacitor is connected between the collector terminal of the transistor and one end of the resistor and the emic terminal via a switch that operates in conjunction with a cock switch,
An electromagnetic coil is used as a discharge loop of the above-mentioned condenser/sustainer.
The gas safety device is equipped with a parallel connection circuit with a thermocouple placed in the area so that it can receive heat.

DESCRIPTION OF EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. The power supply unit 14 includes a commercial power supply 15, a step-down transformer 16,
It consists of a rectifier circuit 1T and a smoothing capacitor 18, forming a DC power supply r. A current is caused to flow from the DC power supply through the resistor 19 to the constant voltage element 2o to obtain a predetermined constant voltage.

The operating voltage is applied to the transistor 210, and a resistor 22 is connected between the collector of this transistor 21 and a DC power supply, and the emitter is connected to a changeover type switch 23.
The capacitor 24 is connected to the capacitor 24 through a contact point. In the figure, 25 is an electromagnetic coil, 26 is a thermocouple, 27 is a gas supply path, 28 is a cock switch, 29 is a safety valve, 30 is a gas burner, and 31 is an ignition device.
The configuration is similar to that shown in the figure, and the explanation thereof will be omitted.

According to this configuration, the charging voltage of the capacitor 24 is only charged to a voltage obtained by subtracting the base-emitter voltage drop from the base voltage of the transistor 21, and after that, the transistor 21 is turned off and charging is stopped. become. Also, the charging time largely depends on the charging current value,
This circuit is constructed so that the initial charging current noise can be increased by utilizing the transistor's widening effect. In other words, when the voltage between the terminals of the capacitor 24 is zero, no current flows through the constant voltage element 20, and all the current flowing through the resistor 19 becomes the base current υ of the transistor 21, and accordingly, the resistor 22
The current flowing in the area can also be ensured on a large scale.

As can be seen from the above explanation, even if there are voltage fluctuations in the commercial power supply, a specified voltage can always be maintained, and instead of using an excessively high voltage capacitor, it is possible to use a capacitor with withstand voltage within the required limit, making it smaller and cheaper. It is possible to measure the
The setting of the discharge time can also be set as a d1 function.

In addition, since the initial charging current value can be increased, charging time can be shortened, and even if the cox inch is opened and closed repeatedly, the capacitor is rapidly charged, so the thermoelectromotive force of the thermocouple due to insufficient charging The capacitor will be completely discharged before the gas rises sufficiently, and the gas supply passage will be closed.
This will completely prevent such inconvenience from occurring.

Effects of the Invention From the above, the present invention maintains the charging voltage of the capacitor constant while using a commercial power supply, making it possible to set the adsorption time of the magnet coil due to capacitor discharge. The aim is to provide a gas safety device that can quickly charge a capacitor using a small transformer.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional gas safety device, FIG. 2 is a circuit diagram of a power supply section of the conventional gas safety device, and FIG. 3 is a block diagram of a gas safety device of the present invention. 14...Power supply section, 15...Commercial power supply,
16...Transformer, 17...Rectifier circuit, 18...Smoothing capacitor, 19...
・Resistance, 20... Constant voltage element, 21...
・Transistor, 22... Resistor, 23...
...Switch, 24...Capacitor, 26...
... Electromagnetic coil, 26 ... Thermocouple, 27.
... Gas supply path, 28 ... Cock switch, 29 ... Safety valve, 30 ... Gas burner, 31 ... Ignition device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A series circuit of a resistor and a constant voltage element is all connected to a DC power source, a base terminal of a transistor is connected to a branch point between the resistor and the constant voltage element, and a resistor is further connected between one terminal of the DC power source and a collector terminal of the transistor. , a capacitor is connected between the other end and the emic terminal via a switch that works with a cock switch, and a parallel connection circuit with an electromagnetic coil and a thermocouple arranged so as to receive heat in the burner part is used as a discharge loop of the capacitor. A gas safety device characterized by: