JPS6339809B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to ignition devices in gas combustion devices, and more particularly to automatic ignition and combustion detection devices in these devices.

In many devices that burn gas, such as boilers, clothes dryers, ovens, etc., heat is added to the gas ejected from the main burner to ignite it. At this time, gas from the main burner is generally supplied near a pilot burner that burns continuously to ignite the main burner.

There is an automatic ignition device that heats a resistive element and ignites the main burner instead of the flame of the pilot burner when it detects that the flame of a continuously burning pilot burner disappears or that there is insufficient combustion.
It is known that such devices use silicon carbide, which has negative resistance-temperature characteristics (the resistivity of silicon carbide decreases as the temperature rises), as an ignition device.

US Pat. No. 3,282,324 is known as such known technology. This patent uses a solenoid operated gas valve and connects the solenoid to the ignition element circuit. Since silicon carbide has a negative resistance-temperature characteristic, when heating is required, the current flowing through the igniter increases due to the decrease in the resistance of the igniter. This increases the circuit current formed with the solenoid winding sufficiently to energize the solenoid and open the gas valve.

In order to close the gas valve in the event of a misfire, the device is provided with a circuit that invites the ignition device after the gas valve has opened. The ignition element also acts as a heat detection element, and the gas valve is closed when the current to the ignition element drops below a value that indicates extinction of the flame.

The above-mentioned US patent describes two methods for ignition and heat detection based on the assumption that the current flowing through the ignition element and its resistance value can be accurately determined from the temperature of the ignition element.
It consists of two modes. However, the above assumption ignores the reality that different silicon carbide ignition elements have different resistance-temperature characteristics. That is, if one ignition element exhibits one temperature at a particular resistance value, another ignition element may exhibit a completely different temperature at the same resistance value. Therefore, simply determining the resistance value of the ignition element in advance to correspond to a temperature sufficient to ignite the gas will result in a potentially less accurate device. Additionally, the time required to open and close the gas valve described in this patent is relatively slow.

In US Pat. No. 3,784,351, the gas flowing through the burner is ignited by an electric ignition device and the ignition element is sufficiently heated. A radiation detector including a bimetallic element is placed in the vicinity of the igniter to identify when the igniter has reached the ignition temperature. When the igniter is activated, the current flowing through the igniter heats it until the transition temperature of the bimetallic element is reached. The bimetallic element then moves from one contact to the other, starting the ignition sequence, supplying gas from the burner and igniting it. Thus, this patent uses a bimetallic element to detect the temperature of the ignition element and to initiate a sequence for ignition when the bimetallic element reaches a predetermined transition temperature.

The present invention provides an improved automatic ignition device for gas-fired devices such as boilers, clothes dryers, ranges, etc. In which, upon energization of the ignition means, a variable resistance ignition element with specific temperature characteristics Ignite the gas from near the burner.

The device of the present invention includes means for repeatedly measuring the resistance value of the ignition means and comparing the measured values, and means for opening the gas valve, and achieves a temperature sufficient for ignition based on the temperature characteristics of the ignition means. When this is detected by the detection means, the gas valve is energized and opened.

In one preferred embodiment, extinguishment detection means are provided and a drop in gas pressure is detected. Furthermore, the operating status of the device, device failures, etc. are displayed by visual means.

In this way, the device of the present invention uses a resistance type ignition element, and also has the ability to determine when the temperature of the ignition element has reached a sufficient temperature to ignite gas, even if the temperature characteristics of the ignition elements are different. have. Preferably, this function is accomplished using a microcomputer device operating in conjunction with the ignition element. This microcomputer device is programmed to repeatedly measure the resistance value of the ignition element at predetermined time intervals and to compare the measured values one after another. In this manner, the microcomputer identifies when the ignition element has reached a plateau region exhibiting a resistance-temperature characteristic that is sufficiently hot to ignite the gas. That is, the microcomputer has 2
It is identified from the two separated measurement values that the resistance-temperature characteristic of the ignition element has become flat.

In a first process described below as a warm test, one threshold value is first set based on the resistance value of the ignition element prior to energizing the ignition element. Next, after the ignition element is energized, the microcomputer measures the resistance value of the ignition element again after a predetermined period of time. If the new measured value is less than or equal to the threshold, the warm test is passed. This indicates that the temperature characteristics of the ignition element are in a relatively steep region, and the resistance value decreases relatively rapidly as the temperature rises. If the warm test does not pass, the microcomputer measures the resistance of the ignition element after a predetermined period of time for comparison with a threshold value. This operation continues until the warm test passes or a predetermined time period elapses. When a predetermined period of time has elapsed, a fault mode described later is entered.

In the second process described as a hot test, the microcomputer continuously performs measurements and continues this operation until the difference between the successively measured values becomes equal to or less than a predetermined maximum value. Once it is confirmed by the above operation that the temperature characteristic has reached a flat region where the resistance value change due to temperature rise is relatively gradual, the ignition element will be sufficiently heated in the flat region of the temperature characteristic as mentioned above. This means that the gas can be ignited.

When it is confirmed that the temperature of the ignition element has reached the ignition temperature, a gas valve is opened by a program in the microcomputer, and the gas passes through a burner in the vicinity of the ignition element and is ignited. The ignition element is then deenergized.

In the preferred device, the microcomputer is programmed to detect extinguishment. This is accomplished by continuously measuring and comparing the resistance values of the ignition elements. Specifically, in the flame detection mode, the microcomputer is programmed to perform two different processes and each process to have the ability to independently detect extinguishment. In the first process, which will be described below as a threshold value or level test, a threshold value of the resistance value is determined based on the resistance value of the ignition element immediately before ignition. After ignition, when the ignition element is deenergized,
A microcomputer continuously monitors the resistance of the ignition element at regular time intervals. Extinction is detected when the resistance of the ignition element exceeds a threshold value, indicating that the plateau area of the ignition element is insufficient to maintain the temperature of the ignition element and the operating point of the ignition element.

In a second process, hereinafter referred to as a late test, the microcomputer compares successively measured resistance values to determine whether the rate of change in resistance of the ignition element exceeds a predetermined value. This predetermined value is selected to ensure that inflammation is extinguished. Upon extinguishing the flame, the microcomputer is preferably programmed to perform correct recovery operations.

Desirable devices include means for verifying that the gas pressure is above the minimum value deemed safe. For this purpose, the device is preferably equipped with two mutually independently operable gas valves arranged in series. One side communicates with the gas flow between the valves, and the other side has an electrically conductive member spaced apart from the contact point, and
These are provided so as to be able to slide inside the guide tube. When the gas valve on the input side of the conduit section is opened, gas flows into the conduit section, and if the gas pressure is sufficient, the conductive member is raised upward to close the electrical circuit between the contacts. The closure of this electrical circuit is detected by a microcomputer connected to the contacts. If the gas pressure is low, the electrical circuit formed by the conductive member will not be closed between the contacts, and this state will be detected by the microcomputer. It is desirable to program the microcomputer to perform correct operation when gas pressure is low.

Furthermore, it is desirable that the microcomputer monitor the gas pressure before and after ignition.

Another feature in the preferred device is to provide a means for indicating the condition of the device and the type of failure. Preferably, such means include a self-powered module with a digital display on top, which is removably mounted on the microcomputer.
When this module is connected to a microcomputer, the presence or absence of a failure in the device and its status, or simply the status of the device, is displayed numerically on the digital display. For example, different numbers on the display may indicate failure of the ignition element, failure of the valve circuit, extinguishing the flame,
It is used to indicate that the ignition element has not reached the ignition temperature. It is contemplated that this module may be used by maintenance personnel to inspect and repair equipment.

Using a microcomputer to control the operation of the device has the effect of shortening the response time of the device while significantly improving overall fuel efficiency and safety.

Also, the reliability of the device is improved by reducing the number of moving parts.

The preferred system preferably includes a means for making programming changes that eliminate the use of specific inputs to the microcomputer for special applications.

The apparatus of a preferred embodiment of the invention described below is described for application to a gas-fired boiler. However, it will be obvious to those skilled in the art that the present invention is widely applicable to the control of gas combustion application devices such as household ranges and dryers.

Next, an apparatus according to an embodiment of the present invention will be described in detail.

In FIG. 1, a device incorporating the present invention for fuel ignition and temperature sensing is designated by the reference numeral 10. As shown, the device 10 includes a microcomputer integrated circuit chip 12, such as a COP411L manufactured by National Semiconductor, which includes input/output devices, read-only memory, random access memory, and a microprocessor on a single chip. Such an integrated circuit chip 12 may be, for example,
It has a built-in control program that can be generally programmed using machine language written in COP assembly language.

Other elements of the apparatus 10 shown in FIG.
4. Ignition element 16, pilot valve assembly 18 and 2
A redundant valve assembly consisting of a secondary valve assembly 20, a pressure sensitive switch 22, a thermostatic control 24, a high limit switch 22, and a plug-in diagnostic module 2.
8 and power supply 30, the functions of each of which will be described in detail below.

In FIG. 1, shown generally, an integrated circuit chip 12 is held within a module or housing 32. As shown in FIG. Housing 32 contains the interface circuitry of integrated circuit chip 12 along with other components of device 10. The housing 32 is provided with an indicator light 34 and a reset switch 36, the interface circuitry of which will be described below in connection with FIGS. 3A and 3B, which generally illustrate the apparatus 10. These are each connected to an integrated circuit chip 12. A power supply 30, which includes a standard 117V AC power supply, provides power to the housing 32 and various other elements of the device 10. The housing 32 is mounted on a control panel near a controlled device, such as a boiler, with screws or the like.

Burner 14 is conventional, for example of the type used in gas-fired boilers. This typically includes a cylindrical member 38 with a plurality of apertures 40 provided therein. Referring to FIGS. 1 and 2, ignition system 16 includes an ignition element 17 secured to one end of an insulating block 42 mounted by screws 44 on a bracket 46 extending from burner 14. In this state, the ignition element 17 is connected to the burner 14.
is supported in the vicinity of the burner 14 to accomplish both the functions of igniting the gas flow from the burner 14 and detecting the temperature of the flame resulting from ignition. A pair of lead wires 48 extending from the other end of the insulating block 42 connects the housing 32 and the ignition element 17.

Ignition element 17 suitable for configuration with device 10
is commercially available. The ignition element 17 is made of silicon carbide, which has a negative resistance-temperature characteristic, and utilizes the fact that the resistance value of silicon carbide decreases as the temperature rises. Generally, the ignition element 17 is commercially available as a package including an insulating block and lead wires.

For example, a type 767A silicon carbide ignition element manufactured by the White Rogers Division of Emerson Electric Company is suitable for use with device 10.

Those skilled in the art understand that each ignition element has different temperature characteristics. That is, if one ignition element exhibits a certain resistance value at 100°, the other ignition element will exhibit a different resistance value even at the same temperature. Therefore, an automatic ignition system that is compatible with different ignition elements must be able to compensate for these differences. As will be described in detail later, the device 10 is fully capable of such operations.

Before gas is supplied to burner 14, it passes through a redundant valve arrangement consisting of a pilot valve assembly 18 and a secondary valve assembly 20. An example of such a valve is model number 36c84 manufactured by the White-Rodiers Division of Emerson Electric Company. As shown, the valve assemblies 18, 20 are preferably of the solenoid operated type, with cores 50, 52 and drive coils 54, 5.
6 respectively. As further seen in FIG. 3, integrated circuit chip 1 is retained within housing 32 and
The coil 54 is connected to the relay 55 connected to the coil 5 through the interface, and the coil 5 is connected to the coil 5 by the relay 57.
6 is operated. The valves 58, 60 are connected to the core 50, respectively.
52. valve seat 62 for valves 58, 60;
64 is preferably formed within a chamber 66 of the casting forming a passage for the supplied gas. As is clear from FIG. 1, two gases are supplied to the burner 14.
It must pass through the opening defined by the two valve seats 62,64. In FIG. 1, valves 58, 60 are shown in the closed position. In this state, the flow of gas from chamber 66 toward burner 14 is blocked. valve 5
8 and 60 are opened, gas enters the burner 14 through the dimensioned orifice 68.

The pressure sensitive switch 22 has a conduit section 7 in communication with the gas flow defined by the chamber 66 between the valve seats 62 and 64.
Contains 0. Conduit portion 70 communicates with a large chamber 72 in which a diaphragm 74 is slidably supported.
When the diaphragm 74 is in its maximum displacement position, a conductive member 76 fixed on the diaphragm 74 contacts the contacts 78,80. The meaning of this will be explained in detail later. Suffice it to say at this point that valve 58 is open and the gas pressure is above the minimum considered safe to ensure that diaphragm 74 is in the uppermost position.

Thermostat 24 is conventional such as those used to control the operation of gas fired boilers or similar equipment. As will be discussed in more detail below, when heat is required at thermostat 24, device 10 is activated and an ignition sequence is initiated. High limit switch 26 is one of the safety devices, preferably including a temperature sensitive switch arranged to sense the temperature in the boiler room.

As will be described in detail later, when the room heats up due to a fan failure, for example, the upper limit switch 26 opens and the integrated circuit chip 12 automatically switches on the relays 55 and 57.
is opened, thereby closing valves 58 and 60 and blocking the supply of gas to burner 14.

Plug-in diagnostic module 28 connectable to housing 32 via receptacle 82 includes a digital display 84 . A plug-in diagnostic module 28 is connected to the housing 3 as described in detail below.
2, the display device 84 provides information indicating the status of the device 10, including the status and presence of faults. Failures, defects, etc. in the device 10 are indicated by lighting of the indicator light 34.

3rd section along with typical component constants and circuit components.
Figures A and 3B show circuit diagrams of the device 10. A detailed explanation of each circuit element will be omitted. The operation of each circuit element will be sufficiently clear to those skilled in the art. Regarding the integrated chip 12, as mentioned above, generally
It is recommended to use the general-purpose COP411L microcomputer manufactured by National Semiconductor, which can be programmed using the COP assembly language.

The operation of apparatus 10 will be described with particular reference to the flowcharts shown in FIGS. 4-9.

To explain the operation of the device 10, it is assumed that there is no flame at first. In this state, the integrated circuit chip 12
holds the device 10 in idle mode (fourth
figure). Integrated circuit chip 1 in idle mode
2 continuously monitors each input of the upper limit switch 26, thermostat 24, and pilot valve relay driver 55. As shown in FIG. 3, the thermostat 24 and the upper limit switch 26 are connected in series and input to the L5 input of the integrated circuit chip 12 via the IC 3a.

As is clear from FIG. 4, the integrated circuit chip 12
The device 10 is held in idle mode until the D1 output drives the pilot valve relay driver 55 via Q2 or until a thermostat/high limit switch input signal is applied for heating. If pilot relay 55 is shorted, integrated circuit chip 12 enters a fault mode. The operation of device 10 in fault mode will be described in detail below.

As shown in FIG. 4, integrated circuit chip 12 is programmed to not ignite unless the current in ignition element 17 exceeds a threshold current. for example,
A current threshold of 100mA is set. This is accomplished by applying the L5 signal via IC 3a so that integrated circuit chip 12 will not be ignited while ignition element 17 does not draw the set current value from the power supply circuit.

Assuming there are no malfunctions, and if a heating request is issued by the thermostat, integrated circuit chip 12 will delay the start of the ignition sequence for, for example, 30 seconds to pre-purge. After a 30 second delay period, integrated circuit chip 12 enters the firing mode shown in FIG.

Once in ignition mode, integrated circuit chip 12 reduces the thermostat threshold current and then tests ignition element 17 by measuring resistance. If the ignition element 17 is short-circuited, the integrated circuit chip 1
2 goes into fault mode. If there is no fault, integrated circuit chip 12 turns on Q2 to drive the pilot valve relay, energizing relay 55 and opening pilot valve 58. Preferably after one second, integrated circuit chip 12 turns thermostat 24 back on.
and monitors the upper limit switch 26 input. If the thermostat 24 and high limit switch 26 inputs are open, the heating request disappears and integrated circuit chip 12 enters the gas-off mode.

As further seen in the flowchart shown in FIG. 8, upon entering the gas-off mode, after 10 seconds the integrated circuit chip 12 enters the idle mode and the pilot valve 58 closes. If the thermostat and high limit switch inputs are closed, integrated circuit chip 12 then checks the gas pressure by monitoring pressure sensitive switch 22. If the gas pressure is normal, the gas flowing through the pilot valve 58 to the conduit section 70 and the connected chamber 72 is directed to the diaphragm 74.
is moved to bring conductive member 76 into contact with contacts 78 and 80 to close the circuit to integrated circuit chip 12.

If the contacts 78 and 80 in the integrated circuit chip 12
When the circuit is detected to be open, integrated circuit chip 12 enters a low voltage mode.

Operation of device 10 in low pressure mode is detailed below. Once gas pressure is confirmed, integrated circuit chip 1
2 enters turn-on mode. At this point, the integrated circuit chip 12 is connected to the device 10 for igniting the gas.
Get ready.

Next, in order to energize the ignition element 17, the transistor Q1 is turned on to drive the ignition element relay 15, and the ignition element relay drive circuit is energized.
When the ignition element 17 is sufficiently heated for gas ignition, it begins supplying gas to the burner 14.

As previously mentioned, in order to identify when a particular ignition element has reached its ignition temperature, integrated circuit chip 12 must overcome the problem of differences in the different temperature characteristics of different elements. As shown in FIG. 6, to identify when the ignition element 17 has reached its ignition temperature, the integrated circuit chip 12 performs two tests: a warm test and a hot test. First, integrated circuit chip 12 operates while ignition element 17 is at a low temperature.
That is, before the ignition device 16 is energized, the ignition element 17
A threshold value is formed based on the resistance value of . Next, after the ignition device 16 is energized for, for example, two seconds, the resistance value of the ignition element 17 is measured again. If the read resistance value is less than or equal to the threshold value, the warm test is passed.

If the warm test is not passed, the ignition device 16 is energized, for example for 2 seconds, the resistance of the ignition element 17 is measured, and the newly read value is compared with the cold reference value. This process continues until the warm test is passed or, for example, one minute has elapsed. If the warm test does not pass after one minute, integrated circuit chip 12 enters a fault mode.

If the warm test passes, the integrated circuit chip 12 is then hot tested. In this test, integrated circuit chip 12 compares two consecutive measured resistance values at ignition element 17. If the difference between the read resistance values is less than a predetermined value, this indicates that the hot test has been passed and the ignition element 17 has reached a flat region, that is, a high temperature region in the temperature characteristics of the ignition element 17. If the hot test is not passed, the ignition element 17 is energized for, for example, two seconds and both the warm test and the hot test are performed again. This continues until the hot test passes or one minute has elapsed. If the hot test does not pass within one minute, integrated circuit chip 12 enters a fault mode.

This measured resistance value is input to the integrated circuit chip 12 via the IC 3c. By using the above-described technique to confirm the ignition temperature, ignition can be performed even if the power supply voltage decreases.

Once the ignition temperature is confirmed, the integrated circuit chip 12
enters the IGNOK mode as shown in Figure 7 and enters the second
Transistor Q to drive relay 57 for the valve
3 is turned on, the relay drive circuit for the second valve is energized, and the second valve 60 is opened. At the same time, the ignition element 17 is energized. At this point gas is passed through chamber 66 and defined orifice 68 to burner 1.
4 and further near the opening 4 of the ignition element 17.
It reaches 0 and is ignited. Also, preferably, the ignition element 17 is deenergized after 4 seconds.

At this point, the ignition element 17 functions as a temperature detection element. Finally, integrated circuit chip 12 monitors the resistance of ignition element 17 to identify the presence or absence of a flame.

As explained below, when the flame is extinguished, integrated circuit chip 12 is programmed to perform regenerative operation. Since the integrated circuit chip 12 detects flame extinction based on the resistance value of the ignition element 17, the integrated circuit chip 12 must have the ability to guarantee changes in temperature characteristics in different ignition elements. To determine whether flame extinction has occurred, integrated circuit chip 12 performs two tests: a level test and a ratio test.

Referring to FIGS. 7 and 8, after the igniter is de-energized, e.g. 2 seconds later, the integrated circuit chip 1
At 2, a threshold value is formed based on a measurement of the resistance of the ignition element 17 just before the ignition device heats up. This threshold value is equal to the measured value increased by a predetermined value. In other words, when the resistance value of the ignition element 17 exceeds the threshold value, the resistance value becomes the threshold value, indicating that the temperature in the vicinity of the ignition element 17 has decreased to a value sufficient to confirm that the flame has disappeared. The value is determined.
The ratio test is accomplished by comparing the rate of change in resistance of the ignition element 17 to a predetermined ratio.

As shown in FIG. 8, when the rate of change in the resistance value of the ignition element exceeds twice the preset rate,
A continuous temperature drop in the vicinity of the ignition element 17 is shown and flame extinction occurs.

When the flame disappears, 12 chips will be accumulated after 10 seconds.
returns to idle mode. As thermostat 24 continues to issue a heating request, integrated circuit chip 12 repeats the above-described firing sequence to produce a flame. Integrated circuit chip 12 enters a fault mode when the extinguishment counter indicates that three flame extinguishments have occurred during a single operation.

When integrated circuit chip 12 enters the monitor mode as shown in FIG. 8, in addition to monitoring the flame, integrated circuit chip 12 continuously controls ignition element 17
Thermostat, upper limit input via IC
The input of the pressure sensitive switch 22 is connected to IC3 via 3a.
b and the pilot relay, drive circuit via IC3d.

As shown in FIG. 8, if the ignition element 17 is short-circuited or the pilot valve drive circuit is broken,
Integrated circuit chip 12 enters a fault mode.
When thermostat 24 or high limit switch 26 opens, integrated circuit chip 12 closes and dissipates pilot valve 58 to return the system to an idle mode as shown in FIG. When switch 22 is open, indicating a drop in gas pressure, integrated circuit chip 12 enters a low pressure mode as shown in FIG.

In the low pressure mode, integrated circuit chip 12 closes the pilot valve and second valves 58,60. Fourth
After a delay time of 30 seconds as shown in Figures and Figure 5,
Integrated circuit chip 12 enters the firing mode and the firing sequence as described above occurs.

The sequence ends with a gas pressure check. This sequence is also repeated while the gas pressure is low. As shown, the closure of switch 22 indicates that gas pressure has been restored and integrated circuit chip 12 enters a turn-on mode. The operation of device 10 in turn-on mode is as previously described in detail.

In the event of an abnormality or failure, such as a short circuit or disconnection of the ignition element 17, a short circuit in the pilot valve relay drive circuit, or a failure of the flame three times, the integrated circuit chip 12 enters the fault mode as described above. A flowchart in fault mode is shown in FIG.

As shown in FIG. 9, in the fault mode, the pilot valve 58 and the second valve 60 are closed to prevent gas flow and the ignition element 17 is deenergized. If it is possible to operate with an external power supply, the operation continues until the reset switch 36, which includes a push button, is pressed and the integrated circuit chip 12 returns to the starting state (FIG. 4). Of course, if the failure is not recovered, integrated circuit chip 1
When the device 2 checks the abnormal element again, it enters the fault mode again. When the device reenters fault mode, indicator light 34 visually indicates the presence of a fault. However, if the device 10 completely fails, the indicator light 34 may not light up due to the loss of overall power.

Furthermore, it is desirable to have means for displaying the status of the failure when a failure occurs. This function is available in device 10
Plug-in diagnostic module 2 that displays the status of
This is achieved by 8. Diagnostic module 28 is clearly intended for use by maintenance personnel. As previously mentioned, the diagnostic module 28 is configured with a conventional decoder driver 83 and a seven segment digital display 84. As shown in Figures 1 to 3, the diagnostic module 2 has a built-in power supply.
8 is plugged into receptacle 82 and connected to integrated circuit chip 12. Digital display 84 displays numbers indicating the type of failure or status of a particular device.

For the device 10 described with reference to FIGS. 4-9, a reading of "zero" indicates that the power level is insufficient to operate the device; a reading of "1" indicates that the power level is insufficient to operate the device. Indicates idle mode, “2” indicates thermostat and upper limit switch input, “3” indicates ignition mode, “4” indicates
In IGNOK mode, "5" indicates low gas pressure, "6" indicates improper pilot valve opening in idle mode, and "7" indicates ignition system failure.

To adapt it to a particular application, the device 10 includes an integrated circuit chip 1 for varying the above-mentioned modes of operation.
It is desirable to provide means for changing the function of No. 2. Referring to FIG. 3, this purpose is preferably accomplished by ungrounding a particular input terminal L7 of integrated circuit chip 12. Third
As shown, ungrounding is achieved by providing a removable member (strap "a" in FIG. 3) connecting between the input and ground. This electrically conductive member is preferably installed at the factory and forms part of the interface circuitry within the housing 32. Removal of strap "a" eliminates the 30 second pre-purge period before integrated circuit chip 12 enters ignition mode (see FIG. 4). This modification is used, for example, when rapid heating is required. When strap "a" is removed, integrated circuit chip 12
preferably enters fault mode with a single flame extinguishment, rather than three extinguishments as shown in FIG. This prevents the buildup of gas that occurs when three ignitions occur without 30 second intervals. It will be appreciated that further additional functions can be programmed into integrated circuit chip 12 by removing other straps, not shown, if desired.

In the above detailed description, it has been described that the resistance value of the ignition element 17 is measured in order to determine the temperature characteristics. However, it is clear to those skilled in the art that similar information can be obtained by measuring, for example, the voltage drop across the terminals of the ignition element or the current flowing through the ignition element.

It will therefore be understood that in applying the phrase "resistance measurement" to an ignition element, consideration should be given to voltage or current measurements that yield information determining the temperature characteristics of the ignition element. In the device 10, information for determining the temperature characteristics of the ignition element is obtained by measuring the voltage drop across the terminals of the ignition element.

Although one preferred embodiment of the present invention has been illustrated and described in detail above, it is clear that the embodiment can be modified without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a partial circuit diagram of an embodiment of the automatic ignition and temperature detection device according to the present invention, FIG. 2 is a front view showing a method of holding the ignition element near the burner, FIGS. 3A and 3 B is a circuit diagram of the device shown in FIG. 1, and FIGS. 4 to 9 are flowcharts showing the operation of the device according to an embodiment of the present invention. In the figure, 12... integrated circuit chip, 14... burner, 16... ignition device, 17... ignition element, 2
2...Pressure sensitive switch, 24...Thermostat,
26... Upper limit switch, 28... Diagnostic module.

Claims (1)

[Scope of Claims] 1. A burner having a spout, a power source, a normally closed fuel valve for controlling gas supplied to the burner, a valve opening means for opening the valve, and operably connected to the power source. an automatic ignition device including a resistance ignition means having a specific resistance-temperature characteristic provided near the jet nozzle for igniting the gas passing through the jet nozzle of the burner when the gas is energized. , a detection means for repeatedly measuring the resistance value of the resistance ignition means in a predetermined period and comparing the measured values; and a detection means operably connected to the detection means and the valve opening means, and a measurement value by the detection means. means for enabling said valve opening means to open said valve when the resistance-temperature characteristic of said resistance ignition means is in a region sufficient to ignite said gas due to the difference between said resistance ignition means; Automatic ignition and combustion detection device in equipment. 2. The automatic ignition and combustion detection device in a gas combustion apparatus according to claim 1, wherein the means for enabling the detection means and the valve opening means includes a microcomputer.