JPH1194250A - Combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion device in which a voltage monitoring circuit is made less-expensive and a gas flow passage can be closed positively when a voltage of a cell is decreased less than a predetermined value. SOLUTION: A Zener-diode 14 connected to a base of a first transistor 12 monitors a voltage of a cell 16 of which voltage is increased by a voltage increasing circuit 11. In the case that this voltage exceeds a Zener voltage, the first transistor 12 is turned on and a magnet-type safety valve 8 is kept opened. In addition, when the voltage of the cell 16 of which voltage is increased is lower than the Zener voltage, the first transistor 12 is turned off to close the magnet-type safety valve 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device, and more particularly, to a combustion device using a battery power supply.

[0002]

2. Description of the Related Art Conventionally, a stove has been provided with various safety devices, and the state of the device is detected by a sensor or the like, and combustion is controlled based on the result of determination by a controller. For example, the stove shown in FIG. 2 includes a CPU constituting a well-known arithmetic and logic operation circuit at the center of the controller 60, a ROM for storing a control program, a RAM for temporarily storing various data during arithmetic processing, and the like. Microcomputer 100
It has. In order to make it easier to understand the functions of the software of the microcomputer 100, the functions are roughly classified into functions. The microcomputer 100 includes a battery voltage monitoring unit 6a that monitors whether the voltage of the dry battery 16 drops below a predetermined level.
A pot bottom temperature detector 6b for monitoring whether or not the pot bottom temperature of the cooking pot 2 placed above the burner 1 is below a predetermined level;
The battery power is supplied to a flame detection unit 6c that monitors whether the thermoelectromotive force of the thermocouple 4 heated by the combustion flame is equal to or higher than a predetermined level, and a holding coil 8a of a magnetic safety valve 8 that opens and closes a gas flow path. It has a function of a valve opening holding section 6d for holding the valve open, and a timer section 6e for stopping combustion after a predetermined time has elapsed in order to prevent forgetting to turn off the stove.

For example, a thermistor 3 for detecting the temperature is provided on the burner head in order to prevent a tempura fire, burning and the like, and the thermistor 3 detects the pot bottom temperature of the cooking pot 2, and determines whether the detected temperature is higher than a set upper limit temperature. Whether or not the gas flow path is determined is determined by the pan bottom temperature detector 6b of the microcomputer 100 provided in the controller 60, and the opening and closing of the gas flow path is controlled based on the determination result.

[0004] The stove is provided with an extinguishing safety device for monitoring the presence or absence of a combustion flame. That is, a thermocouple 4 that generates a thermoelectromotive force by heating the combustion flame is provided in the burner head, and a flame detector 6c provided in the microcomputer 100 determines whether the thermoelectromotive force generated by the thermocouple 4 is equal to or greater than a predetermined value. The presence or absence of a flame is determined based on the result, and the opening and closing of the gas flow path is controlled based on the determination result.

In the stove, a dry battery 16 is used as a power supply of the microcomputer 100, and a voltage drop of the dry battery power supply is monitored by the battery voltage monitoring section 6a of the microcomputer 100. When determining that the voltage of the dry battery 16 has dropped below the predetermined voltage, the battery voltage monitoring unit 6a stops energization of the magnet type safety valve 8 by the valve opening holding unit 6d of the microcomputer 100 so as not to burn. For example, when the battery voltage drops to 2.1 V, the battery replacement lamp 17
Lights to inform the user of the battery replacement time. The battery is used without replacement, and when the voltage of the dry battery 16 drops below 1.8 V, the power supply to the magnet type safety valve 8 is cut off. In this case, the microcomputer 100 operates with the power supply boosted to 5V, and the booster circuit 11 for boosting the battery voltage always boosts the battery voltage to 5V and supplies it to the microcomputer 100 when the battery voltage is 0.9V or more. Therefore, when the battery voltage drops to 1.8 V or less, the power supply voltage to the microcomputer 100 is 5 V, so that the power supply to the magnet type safety valve 8 can be reliably turned off. However, 0.9v from the beginning
When a battery less than the battery is inserted, the boosted voltage falls below 5 V, and the operation of the microcomputer 100 becomes unstable. For example,
When the dry cell voltage becomes 0.9 V or less, as shown in FIG. 3, the booster circuit 11 cannot secure a constant voltage of 5 V,
This boosted voltage is the operation guarantee limit of the microcomputer 100 (2.7
v) If the voltage drops below v, there is a possibility that the battery voltage monitoring unit 6a of the controller 60 will not make a normal determination and the valve opening holding unit 6d will not be able to close the gas flow path. Therefore, in order to confirm that the power supply voltage of the microcomputer 100 is equal to or higher than the operation guarantee voltage (2.7 V),
A boosted voltage monitoring unit VD130 that monitors whether the voltage is 3 V or less is provided. When the voltage drops to 3 V or less, the combustion is stopped immediately.

[0006]

However, there is a problem that such a voltage monitor VD130 is expensive. In addition, the voltage of the dry battery 16 not only decreases gradually according to use, but also drops significantly due to discharge due to non-use for a long time, or a large voltage drop occurs due to an increase in internal resistance inside the dry battery. When the battery is replaced with an old battery 16, the voltage of the battery 16 may be extremely low. Even in this case, if the boosted voltage monitoring unit VD130 that operates by the boosted voltage operates normally, combustion can be stopped, but the boosted voltage further decreases and the operation assurance voltage of the boosted voltage monitoring unit VD130 (0.9 V ), The boosted voltage monitoring unit VD130 finally stops operating normally. Therefore, in order to further enhance safety, there has been a demand for a boosted voltage monitoring circuit that does not lose its voltage monitoring ability even when the battery voltage drops.
Therefore, it is an object of the present invention to solve the above-mentioned problems, to reduce the cost of the boosted voltage monitoring circuit, and to increase the safety by monitoring the voltage reliably even when the battery voltage drops extremely. .

[0007]

According to a first aspect of the present invention, there is provided a combustion apparatus comprising: an electromagnetic safety valve provided in a gas supply path to a burner; and a step-up means for stepping up a voltage of a battery as a power supply. An energization control means for controlling energization of the electromagnetic safety valve using the boosted power as a power supply, and monitoring a voltage of the battery using the boosted power as a power supply, wherein the battery voltage is a first predetermined voltage. A voltage monitoring unit that outputs a valve closing control signal for the electromagnetic safety valve when it is determined that the voltage is equal to or lower than a voltage; a switching element that cuts off an energizing line to the electromagnetic safety valve according to the valve closing control signal; The Zener voltage or the forward voltage is set so that the switching element is turned off when the voltage drops below a second predetermined voltage higher than the limit value of the power supply voltage at which the means can operate. A diode and summarized in that provided in the control signal input lines of the switching element.

In the combustion apparatus according to the first aspect of the present invention, the voltage monitoring means monitors the voltage of the battery using the boosted power as a power source and determines that the battery voltage is equal to or lower than the first predetermined voltage. , Outputs the valve closing control signal of the electromagnetic safety valve,
The switching element shuts off the current supply line to the electromagnetic safety valve and closes the gas supply path. Further, when the boosted voltage drops below the second predetermined voltage, the diode provided on the control signal input line of the switching element turns off the switching element, cuts off the current supply line to the electromagnetic safety valve, and disconnects the gas supply path. close. That is, the boosted voltage by the boosting means is applied to the diode connected to the control signal input line of the switching element, and when the boosted voltage exceeds the Zener voltage or the forward voltage, the switching element is turned on to open the electromagnetic safety valve. Hold. When the boosted voltage becomes lower than the Zener voltage or the forward voltage, the switching element is turned off and the electromagnetic safety valve is closed. Therefore, even if the battery voltage drops extremely and erroneous control is output from the voltage monitoring means to the switching element, the switching element is reliably turned off. For example, unlike a voltage monitoring IC, which loses monitoring capability when the voltage becomes too low below the operation guarantee voltage, when the boosted voltage exceeds a second predetermined voltage set by a zener voltage or a forward voltage. 0N switching element
If it does not exceed it, it is turned off. Therefore, even if the battery voltage becomes too low and the boost voltage drops below the second predetermined voltage, the electromagnetic safety valve is reliably shut off. Further, since the second predetermined voltage is set to a value exceeding the limit value of the operable power supply voltage of the voltage monitoring means, the power supply to the electromagnetic safety valve is cut off before the voltage monitoring circuit performs an unstable operation. Safety can be improved. Further, since the boosted voltage can be monitored only by providing a diode having an appropriate zener voltage or forward voltage, the boosted voltage monitoring circuit can be inexpensive.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of a combustion apparatus of the present invention will be described below. FIG. 1 is a schematic configuration diagram of a stove as one embodiment. The stove includes a burner 1 that burns a mixture of fuel gas and air, a cooking pot 2 is placed above the burner 1, and the cooking pot 2 is heated by a combustion flame. At the center of the burner 1 of the stove, a sensor section (thermistor) 3 for detecting temperature is provided. Sensor part 3
Is in contact with the bottom of the cooking pot 2 placed on the burner 1 to detect the temperature of the cooking pot 2. Further, the burner 1 is provided with a thermocouple 4 that generates a thermoelectromotive force by combustion heat, facing the flame port.

A push-push mechanism (not shown) is provided for the ignition button 5 which advances and retreats by pressing operation, which alternately determines the advance and retreat position of the ignition button 5 when igniting and when extinguishing. The push-push mechanism locks the ignition button 5 at the intermediate position (combustion position) when the ignition button 5 is pushed to the end position during the ignition operation and then releases the pressing, and the ignition button 5 is pressed by the fire extinguishing operation by the second pressing operation. It is provided to return to the start position (stop position). An ignition switch 7b and an Mg switch 7a that are turned on / off in conjunction with the advance / retreat of the ignition button 5 are provided near the ignition button 5. The ignition switch 7b is turned ON only at the terminal position by the ignition button 5 to activate an igniter (not shown) that generates a high voltage for ignition, and is turned ON at the intermediate position and the start position.
It is provided at a position where it stops at F. The Mg switch 7a is turned on at the end position and the intermediate position by the ignition button 5 to energize the controller 6, and the 0F at the start position.
F is provided at a related position.

The gas supply path of the burner 1 is provided with a magnet type safety valve 8 which is opened by the pressing force of the ignition button 5 at the time of the ignition operation and which can be closed after releasing the pressing operation force. The magnet-type safety valve 8 includes a holding coil 8a to which the battery power boosted from the controller 6 is connected, an iron core (not shown) that generates an electromagnetic force when the holding coil 8a is energized, An attraction piece (not shown) for holding the valve element (not shown) open by being attracted to the iron core and a spring (not shown) for urging the valve element in the valve closing direction are provided. Downstream of the magnet-type safety valve 8 is provided an instrument plug 9 that is linked with the ignition button 5 and is pushed when the ignition operation is performed to open the gas passage and close during the fire extinguishing operation.

An electrode (not shown) for igniting the fuel gas of the burner 1 is connected to an igniter (not shown) for generating a high voltage, and the igniter is turned on / off in conjunction with an ignition button 5.
The battery is connected to the dry battery 16 via the ignition switch 7b which is turned on.

The controller 6 is connected to the dry battery 16 to be supplied with power, and operates in conjunction with the ignition
The operation is started and stopped by being connected to the Mg switch 7a for turning on / off. At the center of the control unit of the controller 6, a CPU constituting a well-known arithmetic and logic operation circuit is provided.
A microcomputer 10 including a ROM for storing a control program, a RAM for temporarily storing various data during arithmetic processing, and the like is provided. The functions of the microcomputer 10 can be roughly classified into a battery voltage monitoring unit 6 for monitoring whether the voltage of the dry battery 16 drops below a predetermined level.
a, a bottom temperature detector 6b for monitoring whether or not the bottom temperature of the cooking pot 2 placed above the burner 1 is below a predetermined level;
And a flame detector 6c connected to a thermocouple 4 for generating a thermoelectromotive force and monitoring whether the thermoelectromotive force is equal to or higher than a predetermined level, and a valve opening for supplying battery power to the holding coil 8a of the magnet type safety valve 8. 6d. Further, the valve opening holding section 6d is provided with a timer section 6e for limiting the continuous combustion time (for example, 2 hours). The valve-open holding unit 6d controls energization of the holding coil 8a, and continues to supply battery power to the holding coil 8a if the thermoelectromotive force of the thermocouple 4 is equal to or higher than a predetermined level. Then, when a certain time (two hours) elapses from the ignition, the timer unit 6e cuts off the current to the holding coil 8a to prevent the stove from being forgotten to be turned off.

A booster circuit 11 using a DC / DC converter is connected to the dry battery 16, and a first transistor 12 is provided between the booster circuit 11 and the magnet type safety valve 8. The boosted power is supplied to the safety valve 8. First transistor 1
The 2 (PNP type) emitter is connected to the booster circuit 11, and the collector thereof is connected to the holding coil 8a of the magnetic safety valve 8. Further, the microcomputer 10 includes the booster circuit 1
1 is connected to the booster circuit 11 so as to be driven as a power source, and similarly, the controller 6
Reset unit 13 for initializing the microcomputer 10
Is connected. The battery voltage monitoring unit 6 a
The voltage of is detected. Further, the booster circuit 11 includes a dry cell 16
Output a constant voltage of 5V whenever the voltage of the signal is 0.9V or more. The microcomputer 10 using the output of the booster circuit 11 as a power supply is set to operate normally when the power supply voltage is 2.7 V or more, and to operate stably even when the voltage of the dry battery 16 fluctuates. . Also, the first transistor 12
Is connected via a Zener diode 14 to the collector of a second transistor 15 (NPN type). The second transistor 15 has its emitter grounded and its base connected to the output port of the microcomputer 10 (the conduction control signal output port 8a). Therefore, the valve-opening holding portion 6d is
When the transistor 15 is turned ON / OFF, the first transistor 12 is turned ON / OFF accordingly, and the energization of the holding coil 8a of the magnetic safety valve 8 is controlled. At this time, if the voltage boosted by the booster circuit 11 does not exceed the voltage set by the Zener diode 14, the Zener diode 14 does not flow a current,
The first transistor 12 does not turn on even if the second transistor 15 turns on. In this embodiment, the voltage drop between the collector and the emitter of the second transistor 15 is reduced by 0.7
If the boosted voltage does not exceed 3.7 V, the first transistor 12
Does not turn on. Voltage monitoring by this will be described later.

Next, the ignition / extinguishing operation of the stove will be described. First, at the time of ignition, the device stopper 9 is opened by pushing the ignition button 5 and the magnet safety valve 8 is opened to open the gas passage. At the same time, when the ignition switch 7b is turned on, power is supplied to an igniter (not shown), and the igniter continuously discharges to the burner 1 to ignite the air-fuel mixture and start combustion. The thermocouple 4 provided in the burner 1 generates a thermoelectromotive force by being heated, and when the microcomputer 10 detects a thermoelectromotive force of a predetermined level or more, the thermocouple 4 is energized, and the electromagnet of the magnet safety valve 8 is energized. Electromagnetic force is generated. The magnet type safety valve 8
Even if the pushing operation is released, the valve continues to be opened by this electromagnetic force until the fire is extinguished.

At the time of fire extinguishing, the operation of releasing the ignition button 5 closes the instrument plug 9 and closes the gas flow path to extinguish the fire.

Next, the extinguishing safety function and the overheating preventing function will be described. The extinguishment safety function closes the gas flow path and extinguishes the fire by reducing the thermoelectromotive force of the thermocouple 4 when the flame goes out during combustion. That is, the flame detection unit 6c of the microcomputer 10 monitors whether the thermoelectromotive force of the thermocouple 4 is equal to or higher than a predetermined level, and cuts off the power supply to the magnetic safety valve 8 when the thermoelectromotive force drops below the predetermined level.
Then, the magnet type safety valve 8 loses the electromagnetic force due to energization and closes the gas flow path. On the other hand, the overheating prevention function closes the gas flow path and extinguishes the fire when the pot bottom temperature of the cooking pot 2 rises to a predetermined temperature due to forgetting to extinguish or burning when burning. That is, when the thermistor 3 in contact with the bottom of the cooking pot 2 detects a temperature equal to or higher than the predetermined level, the pot bottom temperature detection unit 6b of the microcomputer 10 shuts off the power supply to the magnet type safety valve 8 and closes the valve.

Next, the voltage monitoring function will be described. The voltage monitoring function stops the combustion of the device when the voltage of the dry battery 16 decreases. In the stove powered by the dry cell 16, it can be used up to low voltage,
The replacement frequency of the dry battery 16 is reduced. For example, just one
In a stove using two dry cells (the voltage of a new dry cell is 3.3 V), in order to use the burner for more than one year, the burner is not replaced until the voltage of the dry battery 16 drops to 2.1 V. To be able to use. And
The battery voltage monitoring unit 6a of the microcomputer 10 monitors the voltage of the dry battery 16, and when the voltage reaches 2.1v, turns on the battery replacement lamp 17 to inform the user of the battery replacement time and urge the user to replace the battery. If the battery is used without being replaced, the energization control signal to the transistor 15 is dropped to the Low level when the voltage of the dry battery 16 drops to 1.8 V or less, and the magnetic safety valve 8 is turned off. on the other hand,
The booster circuit 11 is provided so as to have a capability of boosting the voltage of the dry battery 16 to a constant voltage of 5 V when the voltage of the dry battery 16 is 0.9 V or more, and supplies a power supply 5 V to the microcomputer 10.

When the voltage of the dry battery 16 has dropped to 0 to 0.9 V, the boosted voltage drops below 5 V (FIG. 3).
Below the operation guarantee voltage, it is not possible to guarantee a reliable voltage monitoring operation. However, in this embodiment, when the boosted voltage becomes 3.7 V or less, the Zener diode 14 is not energized, so that the first transistor 12 is turned off and the magnetic safety valve 8 can be closed. Therefore, even if the voltage of the dry battery 16 becomes 0 to 0.9 V and the microcomputer 10 is in an unstable state and outputs an energization control signal to the transistor 15, the first transistor 12 is reliably turned off.
F, and shut off the power supply to the magnet type safety valve 8 without fail.
The stove can be safely stopped. Moreover, the boosted voltage can be monitored only by providing an inexpensive zener diode 14 without providing an expensive voltage monitoring unit VD130 to monitor.

Next, an example of a specific circuit configuration in the controller 6 of the gas table stove will be described with reference to FIG. In this circuit, a circuit for a stove is provided with a heating chamber, and a circuit for a grill for heating and cooking fish and the like is added.

A microcomputer U1 is provided at the center of the control unit of the controller 6, and controls the combustion of the stove and the grill. The controller 6 has a battery voltage VCC2 of 5
A booster circuit 11 for boosting the voltage to v is provided, and the boosted voltage VDD is supplied as power to the microcomputer U1 and various circuits. The microcomputer U1 has an analog function of reading a voltage level. The input port P1 of the microcomputer U1 is connected to the dry battery 16 via a dividing resistor, and monitors whether the battery voltage VCC2 is higher than a first predetermined voltage level. A battery voltage monitoring circuit 40 is configured. Further, when the microcomputer U1 detects that the battery voltage VCC2 has dropped to 2.1 V or less, a battery replacement lamp 17 that lights up and notifies the user of the battery replacement time is connected to the output port P2 of the microcomputer U1. Furthermore, when the battery voltage VCC2 is 1.
When the battery voltage monitoring circuit 40 detects that the voltage has dropped to 8 V or less, the signal from the output port P5 is turned off,
As will be described later, the transistors Q3 and Q2 are turned off, and the magnetic safety valve 8 provided in the gas flow path is closed to stop combustion.

The booster circuit 11, which is a booster power supply, is connected to the emitter of the transistor Q2 (PNP type), and is connected to the transistor Q1 (PNP type) from the collector of the transistor Q2.
The boosted electric power is supplied to the magnetic safety valve 8 through the magnetic safety valve 8.

The flame detection circuit 41 of the stove comprises a thermocouple 4 for generating a thermoelectromotive force by combustion heat, an operational amplifier U3 for amplifying the thermoelectromotive force, and an amplified thermoelectromotive force and an output port P6 of the microcomputer U1. And a comparator U4 for comparing with the judgment voltage. When the comparator U4 determines that the thermoelectromotive force is equal to or higher than the predetermined voltage, the output side of the comparator U4 is connected to the base of the transistor Q1 so as to turn on the transistor Q1. Further, a Zener diode 14 is connected between the base of the transistor Q1 and the comparator U4, and when the boosted voltage does not exceed the Zener voltage, that is, the boosted voltage VD
When D is equal to or lower than the second predetermined voltage (3.7 V), the boosted voltage monitoring circuit 43 is configured to turn off the transistor Q1 and close the magnetic safety valve 8. On the other hand, the operation assurance voltage of the microcomputer U1 is 2.7 V, and when the battery voltage VCC2 decreases and the boosted voltage VDD becomes 3.7 V, the combustion is stopped as described above, and the battery voltage VCC2 decreases. Also, the microcomputer U1 does not become abnormal.

The thermistor 3 for detecting the bottom temperature of the cooking pot 2 is connected to the input ports P3 and P4 of the microcomputer U1 to form a bottom temperature detection circuit 48. Microcomputer U
1 has an analog function to read the voltage level,
It monitors whether the thermistor 3 detects a temperature within a predetermined temperature range. When the pot bottom temperature of the cooking pot 2 exceeds the predetermined temperature range, the judgment voltage of the comparator U4 output from the output port P6 is increased, the transistor Q1 is turned off, and the magnetic safety valve 8 is closed. Also, in order to prevent forgetting to turn off the burner,
To stop combustion after 2 hours from ignition,
A timer that counts from the time of ignition is set. When the predetermined time has elapsed, the transistor Q1 is turned off and the magnetic safety valve 8 is closed.
Incidentally, the collector of the transistor Q1 is connected to the input port P7 of the microcomputer U1, and the energization state of the magnet type safety valve 8 is pre-checked.

The base of the transistor Q2 is connected to the collector of a transistor Q3 (NPN type) whose emitter is grounded. The base of the transistor Q3 is connected to the output port P5 of the microcomputer U1 via a capacitor. Is configured. When the microcomputer U1 is normal, a pulse signal is output from the microcomputer U1 to turn on the transistor Q3, and the microcomputer U1 goes out of control and becomes Lo.
Alternatively, in the case of continuously outputting Hi, the transistor Q3 is turned off by the capacitor to turn off Q2, and the energizing line to the magnet type safety valve 8 is cut off. Therefore, the pulse detection circuit 46 monitors whether the microcomputer U1 has a failure.

The microcomputer U1 includes an ignition switch 7b.
Is turned on, an initial reset circuit 47 is provided for initializing the microcomputer U1 by generating a rising delay of power-on by a combination of a capacitor and a resistor, and is connected to the input ports VDD and VSS. Further, a clock circuit 49 for operating the microcomputer U1 is connected to the input ports XIN and XOUT.

The grill is subjected to combustion control by the microcomputer U1 as in the case of the stove, but unlike the stove, a pan bottom temperature monitoring circuit is not required. Further, the combustion is stopped after a lapse of 22 minutes from the ignition, and the respective judgment levels are also different. However, since it is the same as a stove in principle,
Components having the same function are denoted by the same reference numerals, and the description of the stove will not be repeated.

As described above, in the stove described in the present embodiment, the dry cell voltage VCC2 is equal to or higher than the first predetermined voltage, the boosted voltage VDD is equal to or higher than the second predetermined voltage, the thermoelectromotive force is equal to or higher than the predetermined level, and the pan bottom temperature is equal to or higher than the predetermined temperature. If all conditions of less than 2 hours after ignition are met, combustion is continued. If any one of these conditions is not satisfied, the magnetic safety valve 8 is immediately closed to stop combustion.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. It is. For example, in this embodiment, the combustion device of the table stove has been described, but the present invention can also be applied to a combustion device such as a water heater, a heater, and a rice cooker. Further, a diode using a forward voltage without using the Zener voltage may be used.

[0030]

As described above in detail, according to the combustion apparatus of the present invention, even if the battery voltage becomes too low, the electromagnetic safety valve is reliably shut off without losing the ability to monitor the battery voltage and the boosted voltage. , Can increase safety. Further, since the boosted voltage can be monitored only by setting the zener voltage and the forward voltage of the diode, there is an excellent effect that the cost is reduced as compared with the case where a boosted voltage monitoring circuit is provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a combustion device as one embodiment.

FIG. 2 is a schematic configuration diagram of a conventional combustion device.

FIG. 3 is a diagram showing a relationship between a dry cell voltage and a boosted voltage.

FIG. 4 is an example of a circuit configuration in a controller as one embodiment.

[Explanation of symbols]

 6 Controller 8 Magnet type safety valve 8a Holding coil 11 Booster circuit 12 First transistor 14 Zener diode 15 Second transistor 16 Dry battery

Claims (1)

[Claims] 1. An electromagnetic safety valve provided in a gas supply path to a burner, a booster for boosting a voltage of a battery as a power supply, and an energization for controlling the energization of the electromagnetic safety valve using the boosted power as a power supply. Control means for monitoring the voltage of the battery using the boosted power as a power source, and outputting a valve closing control signal for the electromagnetic safety valve when the battery voltage is determined to be equal to or lower than a first predetermined voltage. A switching element for interrupting an energizing line to the electromagnetic safety valve in accordance with the valve closing control signal; and the boosted voltage falls below a second predetermined voltage higher than a limit value of a power supply voltage at which the voltage monitoring means can operate. If
A combustion apparatus comprising a diode in which a Zener voltage or a forward voltage is set in a control signal input line of the switching element so as to turn off the switching element.