JPS6117833A - Control device for gas rnage - Google Patents

Abstract

PURPOSE:To prevent a firehazard or the like by a constitution wherein combustion can be stopped by comparing any set voltage with the voltage of a temperature sensor. CONSTITUTION:The control device is provided with a voltage comparating circuit 29, comparing three values of reference voltages, generated by the output of a flame detecting circuit 15, with the voltage of the temperature sensor, and a temperature reporting voltage comparating circuit 57, comparing the voltage of temperature sensor with a voltage setable arbitrarily. The device is also provided with a NAND circuit 36, into which the turnover output of the circuit 57 and the output of the comparating circuit 29 are inputted, and the NAND circuit 35, into which the output of the circuit 36 and the output of an ignition timer circuit 8 are inputted while the secondary side output of a Palma transformer driven by the output of the circuit 35 is communicated by a transistor. A DC-DC converter circuit 37, holding a safety valve 3, a reporting timer circuit, having the turnover circuit of the circuit 37 and OR inputs of the output of the turnover circuit and the output of the circuit 57, and an intermittent oscillating circuit 82, into which the output of the circuit 72 is inputted, are also provided in the device. Further, the circuit is constituted of a battery check circuit 52, informing the consumption of a battery, and a buzzer drive circuit 87, having the OR input of the outputs of the circuit 82, 52.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for a piezoelectric ignition type gas stove.

Conventional configurations and their problems In recent years, in order to prevent tempura fires in kitchens, there has been a demand for the development of safety devices that can automatically extinguish gas stoves when tempura oil or the like overheats abnormally.

FIG. 1 shows a conventional control device for a piezoelectric ignition type gas stove. In FIG. 1, 1 is a thermocouple that is a flame sensor, and 2 is a safety valve, which is held by the electromotive force of the thermocouple 1. 4
is a dry battery, which charges the capacitor 3 through the normally closed contact of the switch 5.

The operation of the piezoelectric ignition type gas stove control device configured as described above will be described below.

1. When the cock of the piezoelectric ignition type gas stove is closed, the capacitor 5 is connected to the normally closed terminal 5 of the switch 5 linked to the cock.
The electromotive force of the battery 4 is charged through a. When the cock is opened, the switch 5 is switched to the normally open terminal 5b, and the safety valve 2 is forcibly opened at the same time as piezoelectric ignition, and the capacitor 3
Due to the electric charge charged in the capacitor 3, the safety valve 2 is instantly attracted and held and the gas is ignited.The thermocouple 1 is heated by the combustion flame and an electromotive force is generated, and even if the electric charge in the capacitor 3 is discharged, the safety valve 2 2 can be adsorbed and held. When the combustion flame disappears due to a misfire or the like, the electromotive force of the thermocouple 1 disappears, and the safety valve 2 closes to cut off the gas. However, the above configuration has a drawback in that it is not possible to prevent a fire in the tempura frying pan due to ignition of the tempura oil due to abnormal overheating of the tempura oil or the like.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention has been proposed to not only cut off the gas in the event of a misfire, but also to prevent tempura fires in the kitchen, and to automatically extinguish a gas stove when tempura oil or the like overheats abnormally.
The present invention provides a control device for a piezoelectric ignition type gas stove that can cut off gas when the set temperature is reached by comparing an arbitrary set voltage with the voltage of a temperature sensor.

Structure of the Invention In order to achieve the present invention, the present control device includes a dry battery, an operation switch, an oscillation circuit that serves as a reference for the control device, a flame detection circuit that generates a pulse output due to the electromotive force of the thermocouple, and a an ignition timer circuit that holds the safety valve until the electromotive force is sufficiently built up; a pulse voltage comparison circuit that compares the three-value reference voltage generated by the output of the flame detection circuit with the voltage of the temperature sensor; and the voltage of the temperature sensor. a temperature alarm voltage comparator circuit that compares the temperature alarm voltage with an arbitrarily settable voltage; a NAND circuit whose inputs are the inverted output of this temperature alarm voltage comparator circuit and the output of the pulse voltage comparator circuit; and an output of this NAND circuit. - NAN whose inputs are the power and the output of the ignition timer circuit;
D circuit and the output of this NAND circuit are used to rectify the secondary output of the palm transformer with a transistor, and a DC-'DC converter circuit is used to hold the safety valve.
an inverting circuit of the DC, -DC converter circuit; a notification timer circuit having an OR input of the output of the inversion circuit and the output of the temperature notification voltage comparison circuit; and an intermittent oscillation circuit having the output of the notification timer circuit as an input; It consists of a battery check circuit that notifies you of battery exhaustion, and a buzzer drive circuit that OR-inputs the output of the intermittent oscillation circuit and the output of the battery check circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a control device for a piezoelectric ignition gas stove according to an embodiment of the present invention, in which 1 is a dry battery, 2 is an operation switch that is linked to a cock that opens and closes the fuel supply path of the piezoelectric ignition gas stove, and 3 29 is an oscillation circuit that serves as a reference for this control device; 8 is an ignition timer circuit; 15 is a flame detection circuit;
is a pulse voltage comparison circuit, 35.36 is N A N D
The circuit includes a DC-DC converter circuit 37 for holding a safety valve, 52 a battery check circuit, 57 a temperature alarm voltage comparison circuit, 72 an alarm timer circuit, and 87 a buzzer circuit.

When the cock of the piezoelectric ignition type gas stove is opened (hereinafter referred to as ON), power is supplied from the dry battery 1 by the operation switch 2 linked thereto, and the oscillation circuit 3 starts oscillation, which is the reference of this control device.

The oscillation circuit 3 includes inverters 4 and 7, a resistor 5, and a capacitor 6. Next, when the operation switch 20 is turned on, the capacitor 11.12 is charged through the resistor 9.10, and this charging voltage V. The output of the ignition timer circuit 8 becomes a pulse for a period of time during which the charging voltage is charged to the threshold voltage vTH of the OR circuit 14 by the OR circuit 14 which receives the output of the oscillation circuit 3 as input. This state is between t and t2 in FIG. Assuming that no electromotive force is generated by the thermocouple 21, which is a flame sensor, the output of the flame detection circuit 15 becomes the power supply voltage vDD, the transistor 30 is turned off, and the ■ input type voltage of the voltage comparator 33 becomes Vl-□・■ However, since no electromotive force is generated in the couple 21, the output of the pulse voltage comparison circuit 29 is vL. ■Yo regardless of other input signals. Other input signals are provided by the temperature notification voltage comparison circuit 5.
7 output, resistors 58, 59, 60, variable resistor 61
This voltage is obtained by comparing this voltage with the voltage divided by the resistor 64 and the temperature sensor 67 using the voltage comparator 68. As mentioned above, since no electromotive force is generated in the thermocouple 21, the input voltage of the voltage comparator 68 is higher than the input voltage of the voltage comparator 68, and the output of the temperature notification voltage comparison circuit 57 becomes ■□. . This output is inverted by an inverter 70 and is input to the NAND circuit 35.

The output of the NAND circuit 36 which receives the output of the NAND circuit 35 and the output of the ignition timer circuit 8 becomes a pulse output while the output of the ignition timer circuit 8 is a pulse, and is forcibly adsorbed by turning on the cock of the piezoelectric ignition type gas sump. The switching transistor 42 of the pC-DC humbator circuit 37 supplies the voltage that maintains the safety valve 47.
43 is driven, a pulse voltage is generated on the secondary side of a pulse transformer 44, rectified by a transistor 45, smoothed by a capacitor 48, and supplied to a safety valve 47. Resistors 38, 40, 41, 46 are current limiting resistors, resistors 39I-j and base of transistor 43.
It is an emitter resistance. If no electromotive force is generated in the thermocouple 21 during the pulse of the output of the ignition timer circuit 8, that is, from time t1 to t2, the output of the ignition timer circuit 8 becomes VH at time t3, and the output of the NAND circuit '36 becomes VH. , so that
The DC-DC converter circuit 37 cannot be driven, no voltage is generated on the secondary side of the pulse transformer 44, and the safety valve 47 is cut off.

The voltage across the safety valve 47 becomes zero, and the output of the inversion circuit 49 becomes vH, which charges the capacitor 80 of the notification timer circuit 72 and generates a voltage across the resistor 810, causing the -NAND circuit 8 of the intermittent oscillation circuit 82. The output of the intermittent oscillation circuit 82 can oscillate and the buzzer 92 can sound only for a time higher than the threshold voltage V +H of 3.

Next, when an electromotive force is generated in the thermocouple 21 between time t1 and t2, the O input voltage of the voltage comparator 26 of the flame detection circuit 15 is changed to VL by the oscillation circuit 3 (dotted line A in FIG. 4). -0 or more, and the output of the voltage comparison circuit 26 is the load resistance 27
．． 28 as a load and becomes a pulse. FIG. 4 shows this state. Incidentally, the dotted line indicates that the output of the flame detection circuit 15 is also no longer a pulse, and the output of the ignition timer circuit 8 is no longer P)V, that is, NAN after time t2.
This becomes the output pulse of the D circuit 36, drives the DC-DC converter 37, and makes it possible to continue holding the safety valve 47. Next, when the temperature sensor 67 is heated by the combustion flame, the ○ input voltage of the voltage comparator 68 changes from the variable resistor 6
1 can be arbitrarily set. ■Since the input voltage also becomes low, the output of the voltage comparator 68 changes to vL-+vH, and N
The input of the AND circuit 35 is set to V□ by the inverter 70, and the output of the NAND circuit 35 is set to ■. becomes. For this reason, N
, the output of the AND circuit 36 is VL9, the DC-DC converter 37 is not driven, and the output of the pulse transformer 44 is
Since no voltage is generated on the next side, the safety valve 47 is turned off and combustion can be cut off.

Further, the battery check circuit 52 detects that when the divided voltage of the resistor 54 and resistor 55 becomes lower than the base-emitter voltage of the transistor 56 due to battery consumption, the transistor 56 switches to ○F.
F L, the output of the battery check circuit 52 becomes ■Y, and the output of the buzzer drive circuit 87 also becomes VH, causing the buzzer 92 to sound continuously, thereby informing the user that the battery is exhausted.

The thermistor 53 is for temperature measurement.

The pulse voltage comparison circuit 29 is designed to turn off the safety valve 47 at time t2 when the temperature sensor 6'7 has an open or short-circuit failure.

As described in detail, according to the piezoelectric ignition type gas stove control device of the present invention, the user's arbitrary settings (approximately 50°C to 20°C)
50°C), and can automatically stop combustion when tempura oil etc. is abnormally overheated (set at approximately 250°C) to prevent fires, etc. Not only that, but it also saves energy because unnecessary heating is not performed.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional piezoelectric ignition type gas stove control device, and FIG. 2 is a circuit diagram 1 of the same device according to a sixth embodiment of the present invention.
FIG. 3 is a time chart showing the input/output waveforms of the ignition timer circuit, and FIG. 4 is a time chart showing the input/output state of the voltage comparator of the flame detection circuit. 1 Dry battery, 2... Operation switch, 3... Oscillator, 8... Ignition timer circuit, 15... Flame detection circuit, 29... Pulse voltage comparison circuit, 35.36...
- NAND circuit, 37-... DC-DC converter circuit, 52... Battery check circuit, 57 - Temperature notification voltage comparison circuit, 70... Impark, 72... Notification timer circuit, 82...・Intermittent oscillation circuit, 87...
Buzzer drive circuit.

Claims (1)

[Claims] A dry battery, an operation switch, an oscillation circuit that serves as a reference for the control device, a flame detection circuit that uses a thermocouple as a flame sensor, and the electromotive force of the flame sensor generates a pulse output, and the thermoelectromotive force of the flame sensor is sufficiently raised. an ignition timer circuit that holds the safety valve until a temperature notification voltage comparison circuit for comparing the voltage; a NAND circuit that receives the inverted output of the temperature notification voltage comparison circuit and the output of the pulse voltage comparison circuit; and an output of the NAND circuit and an output of the ignition timer circuit. a NAND circuit whose input is
A DC-DC converter circuit that is driven by the output of this NAND circuit and rectifies the secondary output of the pulse transformer with a transistor and holds a safety valve, an inverting circuit of this DC-DC converter circuit, an output of this inverting circuit, and a notification timer circuit that uses the output of the temperature notification voltage comparison circuit as an OR input; an intermittent oscillation circuit that uses the output of the notification timer circuit as an input; a battery check circuit that notifies battery consumption; and an output of the intermittent oscillation circuit and the battery. OR the output of the check circuit
A gas stove control device consisting of a buzzer drive circuit for input and a buzzer.