CN214750049U - Flame detection circuit of stove - Google Patents
Flame detection circuit of stove Download PDFInfo
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- CN214750049U CN214750049U CN202120225687.4U CN202120225687U CN214750049U CN 214750049 U CN214750049 U CN 214750049U CN 202120225687 U CN202120225687 U CN 202120225687U CN 214750049 U CN214750049 U CN 214750049U
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Abstract
The application relates to a flame detection circuit of a cooking range, which comprises a flame sensing needle detection circuit, a flame sensing needle detection circuit and a control circuit, wherein the flame sensing needle detection circuit is used for detecting a voltage change signal generated by ions in flame under the excitation of an alternating current voltage source; the signal amplification circuit is used for amplifying the voltage change signal detected by the flame sensing needle detection circuit into an amplified voltage signal and outputting the amplified voltage signal; the interference suppression circuit is used for filtering and outputting the amplified voltage signal output by the signal amplification circuit; and the singlechip main control circuit is used for judging whether flames exist according to the filtered amplified voltage signal output by the interference suppression circuit. The utility model discloses a high-efficient accurate detection of flame.
Description
Technical Field
The application relates to the technical field of detection circuits, in particular to a flame detection circuit of a cooking stove.
Background
The flame detection is an important link in production and life, and has the functions of detecting the combustion condition in real time according to the combustion characteristics of flame, and giving a signal in a certain mode once the combustion state of the flame does not meet normal conditions or is flamed out, so that the fuel supply is stopped when the fire is extinguished.
At present, flame detection circuit is various, like an ionic flame detection and gas control circuit for ladle roaster disclosed in application number CN201620013857.1, including a first power circuit, a second power circuit, an ignition and ionic flame detection circuit, an ionic flame processing circuit, a central control circuit and an electromagnetic gas cut-off valve, the input end of the first power circuit inputs the mains supply, the output end of the first power circuit is respectively electrically connected with the second power circuit, the ignition and ionic flame detection circuit and the ionic flame processing circuit, the second power circuit is further electrically connected with the electromagnetic gas cut-off valve, the ignition and ionic flame detection circuit is electrically connected with the ionic flame processing circuit, and the ionic flame processing circuit is electrically connected with the central control circuit.
Although the above documents can realize that the ion flame processing circuit controls the electromagnetic gas cut-off valve to be opened or closed, obviously, the method is the same as most of flame detection technical schemes on the market, and has the problems of inaccurate detection and influence on use.
Disclosure of Invention
In view of the above, it is necessary to provide a flame detection circuit for a range, which can achieve accurate and efficient flame detection.
The technical scheme of the invention is as follows:
a fire detection circuit for a range, comprising:
the flame sensing needle detection circuit is used for detecting a voltage change signal generated by ions in flame under the excitation of an alternating current voltage source;
the signal amplification circuit is used for amplifying the voltage change signal detected by the flame sensing needle detection circuit into an amplified voltage signal and outputting the amplified voltage signal;
the interference suppression circuit is used for filtering and outputting the amplified voltage signal output by the signal amplification circuit;
and the singlechip main control circuit is used for judging whether flames exist according to the filtered amplified voltage signal output by the interference suppression circuit.
Specifically, the signal amplification circuit comprises a small signal amplifier, an input end of the small signal amplifier is connected with an output end of the flame sensing needle detection circuit, and an output end of the small signal amplifier is connected with the interference suppression circuit.
Specifically, the interference suppression circuit comprises a negative pressure filtering circuit and a low-pass filter circuit, the negative pressure filtering circuit is connected with the output end of the small signal amplifier, one end of the low-pass filter circuit is connected with the negative pressure filtering circuit, and the other end of the low-pass filter circuit is connected with the main control circuit of the single chip microcomputer.
Specifically, the negative pressure filtering circuit includes an adder, an input end of the adder is connected to an output end of the small signal amplifier, and an output end of the adder is connected to one end of the low-pass filter circuit.
Specifically, the low-pass filter circuit comprises an active second-order low-pass filter, one end of the active second-order low-pass filter is connected with the output end of the adder, and the other end of the active second-order low-pass filter is connected with the single chip microcomputer main control circuit.
Specifically, the singlechip main control circuit comprises a main control chip, and the main control chip is connected with the active second-order low-pass filter.
Specifically, the flame sensing needle detection circuit comprises a sensing needle circuit and a rectification filter circuit, wherein the sensing needle circuit is connected with an alternating current excitation end, and the rectification filter circuit is connected with the alternating current excitation end.
Specifically, the induction needle circuit comprises a flame induction needle and an equivalent resistor, wherein the equivalent resistor is connected with the flame induction needle, and the equivalent resistor is connected with an alternating current excitation end.
Specifically, the rectifying and filtering circuit comprises a rectifying capacitor, a first diode and a second diode, one end of the rectifying capacitor, one end of the first diode and one end of the second diode are all connected with the alternating current excitation end and the small signal amplifier, and the other end of the rectifying capacitor, the other end of the first diode and the other end of the second diode are also grounded.
Specifically, the equivalent resistor R0 and the ac excitation end are further provided with a protection resistor.
The flame detection circuit of the cooking range has the following technical effects;
the utility model discloses a set up the voltage variation signal that ion produced under the excitation of alternating voltage source in the flame sensing needle detection circuitry detection flame, set up the voltage variation signal amplification that signal amplification circuit detected the flame sensing needle detection circuitry is amplified and is exported for the voltage signal after the amplification; the amplified voltage signal output by the signal amplifying circuit is filtered and output by the interference suppression circuit; and finally, judging whether flame exists or not by the singlechip master control circuit according to the filtered amplified voltage signal output by the interference suppression circuit, thereby realizing efficient and accurate detection of the flame.
Drawings
FIG. 1 is a schematic circuit diagram of a flame detection circuit for a range in one embodiment;
FIG. 2 is a graph of signals at A, B and point C in the stove flame detection circuit in one embodiment.
Reference numerals:
100. a flame sensing pin detection circuit; 110. an inductive pin circuit; 120. a rectification filter circuit; 200. a signal amplification circuit; 300. an interference suppression circuit; 310. a negative pressure filtering circuit; 320. a low-pass filter circuit; 400. the single chip microcomputer controls the circuit.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In one embodiment, as shown in fig. 1, a flame detection circuit of a cooking stove is provided, which includes a flame sensing needle detection circuit 100, a signal amplification circuit 200, an interference suppression circuit 300 and a single chip microcomputer main control circuit 400.
The flame sensing needle detection circuit 100 is used for detecting a voltage change signal generated by ions in flame under the excitation of an alternating-current voltage source; the signal amplification circuit 200 is configured to amplify the voltage change signal detected by the flame sensing probe detection circuit 100 into an amplified voltage signal and output the amplified voltage signal; the interference suppression circuit 300 is configured to filter and output the amplified voltage signal output by the signal amplification circuit 200; the main control circuit 400 of the single chip microcomputer is configured to determine whether there is a flame according to the filtered amplified voltage signal output by the interference suppression circuit 300.
The utility model discloses a set up flame response needle detection circuitry 100 and detect the voltage variation signal that ion produced under the excitation of alternating voltage source in the flame, set up the voltage variation signal amplification that signal amplification circuitry 200 detected flame response needle detection circuitry 100 is amplified to the voltage signal after the amplification and is exported; the amplified voltage signal output by the signal amplification circuit 200 is filtered and output by the interference suppression circuit 300; and finally, judging whether flame exists or not by the singlechip main control circuit 400 according to the filtered amplified voltage signal output by the interference suppression circuit 300, so as to realize efficient and accurate detection of the flame.
In one embodiment, as shown in fig. 1, the signal amplification circuit 200 includes a small signal amplifier a1, an input of the small signal amplifier a1 is connected to an output of the flame-sensing pin detection circuit 100, and an output of the small signal amplifier a1 is connected to the interference suppression circuit 300. Specifically, the small-signal amplifier a1 is a small-signal amplifier powered by positive and negative power supplies, and amplifies weak signals detected by the flame sensing needle detection circuit 100 by several times, and the amplification function is to ensure that signal identification is more reliable.
In one embodiment, as shown in fig. 1, the interference suppression circuit 300 includes a negative pressure filtering circuit 310 and a low pass filter circuit 320, the negative pressure filtering circuit 310 is connected to the output end of the small signal amplifier a1, one end of the low pass filter circuit 320 is connected to the negative pressure filtering circuit 310, and the other end of the low pass filter circuit 320 is connected to the main control circuit 400 of the single chip microcomputer. Specifically, the interference suppression circuit 300 is configured to perform interference filtering on the signal, so as to improve the flame detection accuracy.
In one embodiment, as shown in fig. 1, the negative voltage filtering circuit 310 includes an adder a2, an input terminal of the adder a2 is connected to an output terminal of the small signal amplifier a1, and an output terminal of the adder a2 is connected to one terminal of the low pass filter circuit 320. Specifically, the adder a2 adds a dc reference VREF to the signal output by the small-signal amplifier a1, and the dc reference can ensure that the voltage output by the adder a2 is all 0V high, thereby avoiding the occurrence of negative voltage and improving the determination accuracy.
In one embodiment, as shown in fig. 1, the low pass filter circuit 320 includes an active second-order low pass filter A3, one end of the active second-order low pass filter A3 is connected to the output end of the adder a2, and the other end of the active second-order low pass filter A3 is connected to the mcu 400. Specifically, the active second-order low-pass filter a3 is an active low-pass filter that filters out various medium and high frequency interference signals.
In one embodiment, as shown in fig. 1, the mcu master control circuit 400 includes a master control chip IC1, and the master control chip IC1 is connected to the active second-order low-pass filter A3. The main control chip IC1 is a controller single chip for flame detection, and the ADC port of the main control chip converts all input analog signals into digital signals and judges whether flames exist or not according to the digital signals.
In one embodiment, as shown in fig. 1, the flame sensing pin detection circuit 100 includes a sensing pin circuit 110 and a rectifying and filtering circuit 120, the sensing pin circuit 110 is connected to an ac excitation terminal, and the rectifying and filtering circuit 120 is connected to the ac excitation terminal. Specifically, the ac excitation terminal connection is realized by an excitation device M1 in the prior art.
In one embodiment, as shown in fig. 1, the sensing pin circuit 110 includes a flame sensing pin and an equivalent resistor R0, the equivalent resistor R0 is connected to the flame sensing pin, and the equivalent resistor R0 is connected to the ac excitation terminal. Specifically, the equivalent resistor R0 is connected to the excitation device M1.
In one embodiment, as shown in fig. 1, the rectifying and filtering circuit 120 includes a rectifying capacitor C1, a first diode D1 and a second diode D2, wherein one end of the rectifying capacitor C1, one end of the first diode D1 and one end of the second diode D2 are connected to the ac excitation terminal and the small signal amplifier a1, and the other end of the rectifying capacitor C1, one end of the first diode D1 and one end of the second diode D2 are further connected to ground. Specifically, the first diode D1 and the second diode D2 can also be used as a limiter circuit to prevent the circuit from being damaged due to an excessive output signal.
In one embodiment, as shown in fig. 1, a protection resistor R1 is further disposed between the equivalent resistor R0 and the ac excitation terminal.
Further, the working principle of the flame detection circuit of the range is explained as follows:
as shown in fig. 2, when the stove flame detection circuit is in use for a period of time, the waveform at A, B and C in fig. 1 is shown.
Specifically, as can be seen from fig. 2, for the flame sensing pin, the voltage ultimately supplied to the ADC port of the main control chip IC1 has a varying voltage Δ V, both in the absence and in the presence of a change in the flame. The main control chip IC1 can easily determine whether a flame is present or not at this varying voltage. The reliability of flame judgment is greatly improved.
Further, a judgment threshold E, for example, 0.2V, may be set by those skilled in the art for the variation of the voltage when the flame exists, and the flame is considered to be changed when the voltage is changed by 0.2V.
In order to improve the reliability of the flame determination, one skilled in the art may also set a number of determinations as to whether the voltage variation is greater than a threshold value. Of course, by adjusting the determination threshold E, the sensitivity of flame determination can be adjusted.
Since the parameters of the flame sensing pin or component change, most of the cases are a slow process, and to accommodate this, the user is unlikely to ignite the device at the initial time of each device turn-on, i.e., about 100ms of start-up, and can therefore be considered to be flameless. The main control chip IC1 records the output voltage V0 of the flame sensing needle at the moment, then the single chip microcomputer continuously reads the output voltage of the flame sensing needle, and when the change of V0 exceeds a judgment threshold E, the fact that flame exists at the moment is indicated. This way, an adaptive decision can be achieved. The reliability of judging the flame is further improved.
The design control part in the above control principle is implemented by applying programming in the prior art by those skilled in the art, and is not described in detail in this application.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A fire detection circuit for a range, comprising:
the flame sensing needle detection circuit is used for detecting a voltage change signal generated by ions in flame under the excitation of an alternating current voltage source;
the signal amplification circuit is used for amplifying the voltage change signal detected by the flame sensing needle detection circuit into an amplified voltage signal and outputting the amplified voltage signal;
the interference suppression circuit is used for filtering and outputting the amplified voltage signal output by the signal amplification circuit;
and the singlechip main control circuit is used for judging whether flames exist according to the filtered amplified voltage signal output by the interference suppression circuit.
2. The range flame detection circuit of claim 1, wherein the signal amplification circuit comprises a small signal amplifier, an input terminal of the small signal amplifier is connected to an output terminal of the flame sensing pin detection circuit, and an output terminal of the small signal amplifier is connected to the interference suppression circuit.
3. The flame detection circuit of the stove according to claim 2, characterized in that the interference suppression circuit comprises a negative pressure filtering circuit and a low pass filter circuit, the negative pressure filtering circuit is connected with the output end of the small signal amplifier, one end of the low pass filter circuit is connected with the negative pressure filtering circuit, and the other end of the low pass filter circuit is connected with the main control circuit of the single chip microcomputer.
4. The range flame detection circuit of claim 3, wherein the negative pressure filtering circuit comprises an adder, an input terminal of the adder is connected to an output terminal of the small signal amplifier, and an output terminal of the adder is connected to one terminal of the low pass filter circuit.
5. The range flame detection circuit of claim 4, wherein the low pass filter circuit comprises an active second-order low pass filter, one end of the active second-order low pass filter is connected with the output end of the adder, and the other end of the active second-order low pass filter is connected with the singlechip main control circuit.
6. The range flame detection circuit of claim 5, wherein the single chip microcomputer master control circuit comprises a master control chip, and the master control chip is connected with the active second-order low pass filter.
7. The fire detection circuit of the range according to any of the claims 2 to 6, wherein the flame sensing pin detection circuit comprises a sensing pin circuit and a rectifying and filtering circuit, the sensing pin circuit is connected with an AC excitation terminal, and the rectifying and filtering circuit is connected with the AC excitation terminal.
8. The range flame detection circuit of claim 7, wherein the sensing pin circuit comprises a flame sensing pin and an equivalent resistor, the equivalent resistor is connected to the flame sensing pin, and the equivalent resistor is connected to the ac excitation terminal.
9. The range flame detection circuit of claim 7, wherein the rectifying and filtering circuit comprises a rectifying capacitor, a first diode and a second diode, one end of the rectifying capacitor, the first diode and the second diode are connected to the ac excitation terminal and the small signal amplifier, and the other end of the rectifying capacitor, the first diode and the second diode are further grounded.
10. The fire detection circuit of the range of claim 8, wherein a protection resistor is further provided between the equivalent resistor R0 and the ac excitation terminal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120225687.4U CN214750049U (en) | 2021-01-27 | 2021-01-27 | Flame detection circuit of stove |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202120225687.4U CN214750049U (en) | 2021-01-27 | 2021-01-27 | Flame detection circuit of stove |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214750049U true CN214750049U (en) | 2021-11-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202120225687.4U Active CN214750049U (en) | 2021-01-27 | 2021-01-27 | Flame detection circuit of stove |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214750049U (en) |
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2021
- 2021-01-27 CN CN202120225687.4U patent/CN214750049U/en active Active
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