CN105841776B - Water level detection circuit and its self checking method and cooking apparatus - Google Patents
Water level detection circuit and its self checking method and cooking apparatus Download PDFInfo
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- CN105841776B CN105841776B CN201510021960.0A CN201510021960A CN105841776B CN 105841776 B CN105841776 B CN 105841776B CN 201510021960 A CN201510021960 A CN 201510021960A CN 105841776 B CN105841776 B CN 105841776B
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Abstract
The present invention provides a kind of water level detection circuit, for the self checking method and its cooking apparatus of water level detection circuit, wherein, the self checking method for water level detection circuit, include: receive power on instruction when, the outputs level signals of the public output of first comparator and the second comparator in water level detection circuit described in real-time detection；If receiving in first predetermined time powered on after instructing, the outputs level signals for detecting the common end are low level signal, and it is instructed and after the second predetermined time by being greater than first predetermined time receiving described power on, the outputs level signals for detecting the common end are high level signal, it is determined that the water level detection circuit is normal.Technical solution of the present invention can be avoided water level detection circuit faults itself cause cannot accurately in cooking apparatus water level or bubble detect the problem of.
Description
Technical field
The present invention relates to water level detecting technical fields, are used for water level in particular to a kind of water level detection circuit, one kind
The self checking method of detection circuit and a kind of cooking apparatus.
Background technique
Existing cooking apparatus, such as electric pressure cooking saucepan, electric cooker, cause to overflow in order to avoid heating power is excessive, need
Water level detection circuit is set in cooking apparatus, in cooking apparatus water level or the bubble that generates of when boiling examine
It surveys.And existing water level detection circuit causes water level detection circuit itself cannot be accurate when breaking down without self-checking function
Effectively in cooking apparatus water level or bubble detect.
Therefore, the self-test for how realizing water level detection circuit, avoiding water level detection circuit faults itself from causing cannot
Accurately in cooking apparatus water level or bubble carry out detection become technical problem urgently to be resolved.
Summary of the invention
The present invention is directed to solve at least one of the technical problems existing in the prior art or related technologies.
For this purpose, can be avoided water level detecting an object of the present invention is to provide a kind of new water level detection circuit
Circuit faults itself cause cannot accurately in cooking apparatus water level or bubble detect the problem of.
It is another object of the present invention to propose a kind of self checking method for water level detection circuit and a kind of culinary art
Utensil.
To achieve the above object, according to the embodiment of the first aspect of the invention, a kind of water level detection circuit is proposed, is wrapped
Include: probe circuit, including the first probe and the second probe, first probe pass through the first sectional pressure element and the second sectional pressure element
It is connected to the first DC power supply, the second probe ground connection；The third sectional pressure element and the 4th sectional pressure element of series connection, it is described
It is connected between first DC power supply and ground after third sectional pressure element and the 4th sectional pressure element series connection；5th partial pressure
Element is connected in parallel between first probe and second probe；First comparator, the first input of the first comparator
End is connected between first sectional pressure element and second sectional pressure element, the second input terminal connection of the first comparator
To between the third sectional pressure element and the 4th sectional pressure element；The 6th sectional pressure element being connected in series and the 7th partial pressure member
Part, the 6th sectional pressure element are connected to first DC power supply, the 7th sectional pressure element ground connection；Electrolytic capacitor, with institute
The 7th sectional pressure element is stated to be connected in parallel；Second comparator, the first input end of second comparator are connected to described 6th point
It presses between element and the 7th sectional pressure element, the second input terminal of second comparator is connected to the first comparator
First input end, the output end of second comparator are connected as common end with the output end of the first comparator；Detection
Circuit, is connected to the common end, and the detection circuit determines whether circuit is abnormal according to the output signal of the common end.
The water level detection circuit of embodiment according to the present invention, by be arranged the 5th sectional pressure element be connected in parallel on the first probe and
Between second probe, the first input end of first comparator is connected between the first sectional pressure element and the second sectional pressure element, and first
Second input terminal of comparator is connected between third sectional pressure element and the 4th sectional pressure element, the first input end of first comparator
It is connected with the second input terminal of the second comparator, and electrolytic capacitor is set and is connected in parallel with the 7th sectional pressure element, so that in circuit
When powering on, the first input end voltage of first comparator is greater than the second input terminal voltage of first comparator, and the second comparator
The second input terminal voltage be greater than the second comparator first input end voltage, and then common end export the first level signal；And
With the saturation of electrolytic capacitor, the voltage at the 7th sectional pressure element both ends is increased, and leads to the second input terminal voltage of the second comparator
Less than the first input end voltage of the second comparator, and then common end exports second electrical level signal, therefore can pass through detection electricity
Whether just whether the level signal of common end output occur reversion to determine water level detection circuit in certain time after the electricity of road
Often.Specifically, it if water level detection circuit is abnormal, if probe circuit occurs that open circuit occurs with other parts, then the 5th divides
Element cannot access circuit, and the first input end voltage of first comparator is caused to be always more than the first input end of the second comparator
Voltage, and then be not in the reversion of level.
And after self-checking circuit is normal, if water level is not detected in probe circuit, i.e. the first probe and the second probe do not lead to
When crossing water connection, the first input end voltage of first comparator is greater than the second input terminal voltage of first comparator, and in probe
When circuit detects water level, the first probe and the second probe are connected by water, and the first input end voltage of first comparator is less than
Second input terminal voltage of first comparator, and then the outputs level signals of first comparator invert, therefore can pass through
The output signal of detection first comparator accurately determines whether probe circuit detects water level.
Water level detection circuit according to the abovementioned embodiments of the present invention can also have following technical characteristic:
According to one embodiment of present invention, the of the first input end of the first comparator and second comparator
One input terminal is positive input terminal, and the second input terminal of the second input terminal of the first comparator and second comparator is negative
Input terminal.
The water level detection circuit of embodiment according to the present invention, if the first input end of first comparator and the second comparator
First input end be positive input terminal, the second input terminal of the second input terminal of first comparator and the second comparator is negative input
End, then when circuit just powers on, first comparator exports high level, and the second comparator exports low level, with electrolytic capacitor
The first input end voltage of saturation, the second comparator increases, and then the second comparator also exports high level, therefore can pass through inspection
The level for surveying common end exports determine whether water level detection circuit is normal.
According to one embodiment of present invention, the detection circuit includes: photo-coupler, and the first of the photo-coupler is defeated
Enter end and be connected to first DC power supply, the second input terminal of the photo-coupler is connected to the common end, the optocoupler
First output end of clutch is connected to the second DC power supply by the 8th sectional pressure element, and the second output terminal of the photo-coupler connects
Ground；Microprocessor, the sampled signal input of the microprocessor are connected to the 8th sectional pressure element and the photo-coupler
The first output end between, the microprocessor determines whether circuit different according to the input signal of the sampled signal input
Often.
The water level detection circuit of embodiment according to the present invention, by the way that photo-coupler is arranged, so that defeated in first comparator
High level out, when the second comparator exports low level, photo-coupler conducting, microprocessor detects low level signal；And
When one comparator and the second comparator all export high level signal, photo-coupler cut-off, microprocessor detects high level signal.
Embodiment according to a second aspect of the present invention, it is also proposed that a kind of self checking method for water level detection circuit is used
It is detected according to the outputs level signals of above-mentioned common end, the self checking method for water level detection circuit, comprising:
It receives when powering on instruction, the outputs level signals of common end described in real-time detection；If receive it is described power on instruction after
In first predetermined time, detect that the outputs level signals of the common end are low level signal, and receiving described power on
After instruction and the second predetermined time by being greater than first predetermined time, the output level letter of the common end is detected
Number be high level signal, it is determined that the water level detection circuit is normal.
The self checking method for water level detection circuit of embodiment according to the present invention, due to when circuit powers on, first
The first input end voltage of comparator is greater than the second input terminal voltage of first comparator, and the second input terminal of the second comparator
Voltage is greater than the first input end voltage of the second comparator, and then common end exports low level signal；And with electrolytic capacitor
The voltage of saturation, the 7th sectional pressure element both ends increases, and causes the second input terminal voltage of the second comparator less than the second comparator
First input end voltage, and then common end exports high level signal, therefore a timing after being powered on by detection circuit
Whether the level signal of interior common end output occurs reversion to determine whether water level detection circuit is normal.Specifically, if water level
Detection circuit is abnormal, and if probe circuit occurs that open circuit occurs with other parts, then the 5th sectional pressure element cannot access circuit,
Cause the first input end voltage of first comparator to be always more than the first input end voltage of the second comparator, and then is not in
The reversion of level.
According to one embodiment of present invention, after determining that the water level detection circuit is normal, further includes: if any
Moment detects that the outputs level signals of the common end are low level signal, it is determined that the water level detection circuit detects water
Position.
The self checking method for water level detection circuit of embodiment according to the present invention is determining the water level detection circuit
After normal, the second comparator exports high level signal, if water level, i.e. the first probe and the second probe is not detected in probe circuit
When not connected by water, the first input end voltage of first comparator is greater than the second input terminal voltage of first comparator, and first
Comparator exports high level signal, then common end is high level signal；And when probe circuit detects water level, the first probe and
Second probe is connected by water, and the first input end voltage of first comparator is less than the second input terminal voltage of first comparator,
First comparator exports low level signal, and then common end exports low level signal, therefore can pass through the defeated of detection common end
Signal accurately determines whether probe circuit detects water level out.
Embodiment according to a third aspect of the present invention, it is also proposed that a kind of self checking method for water level detection circuit is used
It is detected in the signal of the sampled signal input according to microprocessor, comprising: power on instruction and the probe receiving
When water level is not detected in circuit, the incoming level signal of sampled signal input described in real-time detection；If receiving on described
In the first predetermined time after electricity instruction, detect that the incoming level signal of the sampled signal input is low level signal,
And receive it is described power on instruction and the second predetermined time by being greater than first predetermined time after, detect described
The incoming level signal of sampled signal input is high level signal, it is determined that the water level detection circuit is normal, otherwise, it determines
The water level detection circuit breaks down.
The self checking method for water level detection circuit of embodiment according to the present invention, due to when circuit powers on, first
The first input end voltage of comparator is greater than the second input terminal voltage of first comparator, and the second input terminal of the second comparator
Voltage is greater than the first input end voltage of the second comparator, and then common end exports low level signal, photo-coupler conducting, micro- place
The sampled signal input of reason device collects low level signal；And with the saturation of electrolytic capacitor, the 7th sectional pressure element both ends
Voltage increases, and causes the second input terminal voltage of the second comparator less than the first input end voltage of the second comparator, Jin Ergong
End output high level signal altogether, photo-coupler cut-off, the sampled signal input of microprocessor collect high level signal, therefore
Whether the level signal of the sampled signal input of microprocessor occurs in certain time after being powered on by detection circuit
Reversion is to determine whether water level detection circuit is normal.Specifically, if water level detection circuit is abnormal, as probe circuit occur with
Open circuit occurs for other parts, then the 5th sectional pressure element cannot access circuit, lead to the first input end voltage one of first comparator
The straight first input end voltage for being greater than the second comparator, and then be not in the reversion of level.
According to one embodiment of present invention, after determining that the water level detection circuit is normal, further includes: if any
Moment detects that the incoming level signal of the sampled signal input is low level signal, it is determined that the water level detection circuit
Detect water level.
The self checking method for water level detection circuit of embodiment according to the present invention is determining the water level detection circuit
After normal, the second comparator exports high level signal, if water level, i.e. the first probe and the second probe is not detected in probe circuit
When not connected by water, the first input end voltage of first comparator is greater than the second input terminal voltage of first comparator, and first
Comparator exports high level signal, then common end is high level signal, photo-coupler cut-off, the sampled signal input of microprocessor
The input signal at end is high level signal；And when probe circuit detects water level, the first probe and the second probe are connected by water
It connects, the first input end voltage of first comparator is less than the second input terminal voltage of first comparator, and first comparator output is low
Level signal, and then common end exports low level signal, photo-coupler conducting, the input of the sampled signal input of microprocessor
Signal is low level signal, therefore can accurately determine whether probe circuit detects by detecting the output signal of common end
Water level.
According to one embodiment of present invention, further includes: according to the voltage value of first DC power supply and the electrolysis
The parameter value of capacitor determines first predetermined time and second predetermined time.
According to one embodiment of present invention, further includes: according to the voltage value of first DC power supply, electrolysis electricity
The parameter value of appearance and scheduled error time determine first predetermined time and second predetermined time.In the embodiment
Consider the error in element device specification, it is thus determined that the first predetermined time and the second predetermined time it is more accurate.
According to one embodiment of present invention, the water level detection circuit is arranged in cooking apparatus.
Embodiment according to the fourth aspect of the invention, it is also proposed that a kind of cooking apparatus, comprising: any of the above-described is implemented
Water level detection circuit described in example.
Additional aspect and advantage of the invention will be set forth in part in the description, and will partially become from the following description
Obviously, or practice through the invention is recognized.
Detailed description of the invention
Above-mentioned and/or additional aspect of the invention and advantage will become from the description of the embodiment in conjunction with the following figures
Obviously and it is readily appreciated that, in which:
Fig. 1 shows the structural schematic diagram of water level detection circuit according to first embodiment of the invention；
Fig. 2 shows the structural schematic diagrams of the water level detection circuit of second embodiment according to the present invention；
Fig. 3 shows the structural schematic diagram of the water level detection circuit of third embodiment according to the present invention；
Fig. 4 shows the signal stream of the self checking method for water level detection circuit according to first embodiment of the invention
Cheng Tu；
Fig. 5 shows the signal stream of the self checking method for water level detection circuit of second embodiment according to the present invention
Cheng Tu；
Fig. 6 show the input terminal voltage of two comparators in the water level detection circuit of embodiment according to the present invention when
Sequence schematic diagram.
Specific embodiment
To better understand the objects, features and advantages of the present invention, with reference to the accompanying drawing and specific real
Applying mode, the present invention is further described in detail.It should be noted that in the absence of conflict, the reality of the application
The feature applied in example and embodiment can be combined with each other.
In the following description, numerous specific details are set forth in order to facilitate a full understanding of the present invention, still, the present invention may be used also
To be implemented using other than the one described here other modes, therefore, protection scope of the present invention is not by described below
Specific embodiment limitation.
As shown in Figures 1 to 3, the water level detection circuit of embodiment according to the present invention, comprising: probe circuit 1, including first
Probe 11 and the second probe 12, first probe 11 are connected to first by the first sectional pressure element 21 and the second sectional pressure element 22
DC power supply (VCC i.e. shown in figure), second probe 12 are grounded；The third sectional pressure element 23 of series connection and the 4th point
Press element 24, the third sectional pressure element 23 and the 4th sectional pressure element 24 series connection after be connected to first DC power supply and
Between ground；5th sectional pressure element 25 is connected in parallel between first probe 11 and second probe 12；First comparator 3, institute
The first input end for stating first comparator 3 is connected between first sectional pressure element 21 and second sectional pressure element 22, institute
The second input terminal for stating first comparator 3 is connected between the third sectional pressure element 23 and the 4th sectional pressure element 24；String
Join the 6th sectional pressure element 26 and the 7th sectional pressure element 27 of connection, the 6th sectional pressure element 26 is connected to first direct current
Source, the 7th sectional pressure element 27 ground connection；Electrolytic capacitor 4 is connected in parallel with the 7th sectional pressure element 27；Second comparator 5,
The first input end of second comparator 5 is connected between the 6th sectional pressure element 26 and the 7th sectional pressure element 27,
Second input terminal of second comparator 5 is connected to the first input end of the first comparator 3, second comparator 5
Output end be connected with the output end of the first comparator 3 as common end；Detection circuit 6 is connected to the common end, institute
It states detection circuit 6 and determines whether circuit is abnormal according to the output signal of the common end.
It is connected in parallel between the first probe 11 and the second probe 12 by the way that the 5th sectional pressure element 25 is arranged, first comparator 3
First input end is connected between the first sectional pressure element 21 and the second sectional pressure element 22, and the second input terminal of first comparator 3 connects
It is connected between third sectional pressure element 23 and the 4th sectional pressure element 24, the first input end of first comparator 3 and the second comparator 5
Second input terminal is connected, and electrolytic capacitor 4 is arranged and is connected in parallel with the 7th sectional pressure element 27, so that when circuit powers on, first
The first input end voltage of comparator 3 is greater than the second input terminal voltage of first comparator 3, and the second of the second comparator 5 is defeated
Enter to hold voltage to be greater than the first input end voltage of the second comparator 5, and then common end exports the first level signal；And with electrolysis
The voltage of the saturation of capacitor 4,27 both ends of the 7th sectional pressure element increases, and the second input terminal voltage of the second comparator 5 is caused to be less than
The first input end voltage of second comparator 5, and then common end exports second electrical level signal, therefore can pass through detection circuit
Whether the level signal that common end exports in certain time after powering on occurs reversion to determine whether water level detection circuit is normal.
Specifically, if water level detection circuit is abnormal, if probe circuit 1 occurs that open circuit occurs with other parts, then the 5th member is divided
Part 25 cannot access circuit, and the first input end voltage of first comparator 3 is caused to be always more than the first input of the second comparator 5
Voltage is held, and then is not in the reversion of level.
And after self-checking circuit is normal, if water level, i.e. the first probe 11 and the second probe 12 is not detected in probe circuit 1
When not connected by water, the first input end voltage of first comparator 3 is greater than the second input terminal voltage of first comparator 3, and
When probe circuit 1 detects water level, the first probe 11 is connected with the second probe 12 by water, and the first of first comparator 3 is defeated
Enter to hold voltage to be less than the second input terminal voltage of first comparator 3, and then the outputs level signals of first comparator 3 occur instead
Turn, therefore can accurately determine whether probe circuit 1 detects water level by detecting the output signal of first comparator 3.
Water level detection circuit according to the abovementioned embodiments of the present invention can also have following technical characteristic:
According to one embodiment of present invention, the first input end of the first comparator 3 and second comparator 5
First input end is positive input terminal, the second input terminal of the second input terminal of the first comparator 3 and second comparator 5
For negative input end.
If the first input end of the first input end of first comparator 3 and the second comparator 5 is positive input terminal, first compares
Second input terminal of the second input terminal of device 3 and the second comparator 5 is negative input end, then when circuit just powers on, first compares
Device 3 exports high level, and the second comparator 5 exports low level, with the saturation of electrolytic capacitor 4, the first input of the second comparator 5
Voltage is held to increase, and then the second comparator 5 also exports high level, therefore can export determining water by detecting the level of common end
Whether position detection circuit is normal.
According to one embodiment of present invention, the detection circuit 6 includes: photo-coupler 61, the photo-coupler 61
First input end is connected to first DC power supply, and the second input terminal of the photo-coupler 61 is connected to the common end,
To be connected to the second DC power supply (i.e. shown in figure by the 8th sectional pressure element 28 for first output end of the photo-coupler 61
VDD), the second output terminal ground connection of the photo-coupler 61；Microprocessor 62, the sampled signal input of the microprocessor 62
It is connected between the 8th sectional pressure element 28 and the first output end of the photo-coupler 61,62 basis of microprocessor
The input signal of the sampled signal input determines whether circuit is abnormal.
By the way that photo-coupler 61 is arranged, so that exporting high level in first comparator 3, the second comparator 5 exports low level
When, photo-coupler 61 is connected, and microprocessor 62 detects low level signal；And it is all defeated in first comparator 3 and the second comparator 5
Out when high level signal, photo-coupler 61 ends, and microprocessor 62 detects high level signal.
According to one embodiment of present invention, microprocessor 62 is connected to 61 He of photo-coupler by the 9th sectional pressure element 29
Between 8th sectional pressure element 28, the tenth sectional pressure element 210, optocoupler are also connected between photo-coupler 61 and the 8th sectional pressure element 28
The first input end of clutch 61 is connected to the first DC power supply by the 11st sectional pressure element 211, and first comparator 3 passes through the tenth
Two sectional pressure elements 212 are connected between the first sectional pressure element 21 and the second sectional pressure element 22, and the second probe 12 passes through the 13rd point
Pressure element 213 is connected to the ground.
In order to realize isolated detection, probe circuit 1 and other circuits can be separately provided, in order to circuit board
Design, following two embodiment can be used:
Embodiment one:
According to one embodiment of present invention, as shown in Figure 2, further includes: first terminal row 7, the first terminal row's 7
First wiring position is connected to first probe 11, and the second wiring position of the first terminal row 7 is connected to second probe
12, the both ends of the 5th sectional pressure element 25 be respectively connected to first terminal row 7 the first wiring position and the first end
The second wiring position of son row 7；Second terminal row 8, the first wiring position of the Second terminal row 8 are connected to the second partial pressure member
Part 22, the second wiring position ground connection of the Second terminal row 8, the first wiring position of the Second terminal row 8 and the first end
The first wiring position of son row 7 is connected, the second wiring position of the Second terminal row 8 and the second wiring of first terminal row 7
Position, which is connected, (, convenient for expression first terminal row 7 and Second terminal row 8, is not shown first terminal row 7 and Second terminal row 8 in figure
Between connection relationship).
Embodiment two:
According to one embodiment of present invention, as shown in Figure 3, further includes: first terminal row 7, the first terminal row's 7
First wiring position is connected to first probe 11, and the second wiring position of the first terminal row 7 is connected to the first terminal
The third wiring position of the first wiring position of row 7, the first terminal row 7 is connected to second probe 12, the first terminal
The 4th wiring position of row 7 is connected to the third wiring position of the first terminal row 7；Second terminal row 8, the Second terminal row 8
The first wiring position be connected to second sectional pressure element 22, the both ends of the 5th sectional pressure element 25 are respectively connected to described
The second wiring position of two-terminal row 8 and the third wiring position of Second terminal row 8, the 4th wiring of the Second terminal row 8
First wiring position of position ground connection, the Second terminal row 8 is connected with the first wiring position of first terminal row 7, and described second
Second wiring position of terminal block 8 is connected with the second wiring position of first terminal row 7, and the third of the Second terminal row 8 connects
Line position is connected with the third wiring position of first terminal row 7, the 4th wiring position of the Second terminal row 8 and the first end
The 4th wiring position of son row 7 is connected.
Fig. 4 shows the signal stream of the self checking method for water level detection circuit according to first embodiment of the invention
Cheng Tu.
Self checking method in the embodiment is mainly used for being detected according to the outputs level signals of above-mentioned common end.
Specifically, as shown in figure 4, according to first embodiment of the invention for water level detection circuit from procuratorial organ
Method, comprising: step 402, receive power on instruction when, the outputs level signals of common end described in real-time detection；Step 404,
If detecting that the outputs level signals of the common end are low electricity receiving in first predetermined time powered on after instructing
Ordinary mail number, and receive it is described power on instruction and the second predetermined time by being greater than first predetermined time after, detection
Outputs level signals to the common end are high level signal, it is determined that the water level detection circuit is normal.
Since when circuit powers on, the first input end voltage of first comparator is greater than the second input terminal of first comparator
Voltage, and the second input terminal voltage of the second comparator is greater than the first input end voltage of the second comparator, and then common end is defeated
Low level signal out；And as the saturation of electrolytic capacitor, the voltage at the 7th sectional pressure element both ends increase, lead to the second comparator
Second input terminal voltage is less than the first input end voltage of the second comparator, and then common end exports high level signal, therefore can
Determine that water level is examined so that whether the level signal of common end output in certain time after powering on by detection circuit occurs reversion
Whether slowdown monitoring circuit is normal.Specifically, if water level detection circuit is abnormal, as probe circuit occurs to occur to break with other parts
Road, then the 5th sectional pressure element cannot access circuit, cause the first input end voltage of first comparator to be always more than second and compare
The first input end voltage of device, and then be not in the reversion of level.
According to one embodiment of present invention, after determining that the water level detection circuit is normal, further includes: if any
Moment detects that the outputs level signals of the common end are low level signal, it is determined that the water level detection circuit detects
Water level.
After determining that the water level detection circuit is normal, the second comparator exports high level signal, if probe circuit is not
Detect water level, i.e. when the first probe and the second probe are not connected by water, the first input end voltage of first comparator is greater than
Second input terminal voltage of first comparator, first comparator export high level signal, then common end is high level signal；And
When probe circuit detects water level, the first probe and the second probe are connected by water, the first input end voltage of first comparator
Less than the second input terminal voltage of first comparator, first comparator exports low level signal, and then common end exports low level
Signal, therefore can accurately determine whether probe circuit detects water level by detecting the output signal of common end.
Fig. 5 shows the signal stream of the self checking method for water level detection circuit of second embodiment according to the present invention
Cheng Tu.
Self checking method in the embodiment is mainly used for being carried out according to the signal of the sampled signal input of microprocessor
Detection.
As shown in figure 5, the self checking method for water level detection circuit of embodiment according to the present invention, comprising: step
502, instruction is powered on and when water level is not detected in the probe circuit receiving, sampled signal input described in real-time detection
Incoming level signal；Step 504, if detecting the sampling receiving in first predetermined time powered on after instructing
The incoming level signal of signal input part is low level signal, and described powers on instruction and by being greater than described first receiving
After the second predetermined time of predetermined time, detect that the incoming level signal of the sampled signal input is high level signal,
Then determine that the water level detection circuit is normal, otherwise, it determines the water level detection circuit breaks down.
Since when circuit powers on, the first input end voltage of first comparator is greater than the second input terminal of first comparator
Voltage, and the second input terminal voltage of the second comparator is greater than the first input end voltage of the second comparator, and then common end is defeated
Low level signal out, photo-coupler conducting, the sampled signal input of microprocessor collect low level signal；And with electrolysis
The voltage of the saturation of capacitor, the 7th sectional pressure element both ends increases, and causes the second input terminal voltage of the second comparator less than second
The first input end voltage of comparator, and then common end exports high level signal, photo-coupler cut-off, the sampling letter of microprocessor
Number input terminal collects high level signal, thus after being powered on by detection circuit in certain time microprocessor sampling
Whether the level signal of signal input part occurs reversion to determine whether water level detection circuit is normal.Specifically, if water level detecting
Circuit abnormal, if probe circuit occurs that open circuit occurs with other parts, then the 5th sectional pressure element cannot access circuit, lead
It causes the first input end voltage of first comparator to be always more than the first input end voltage of the second comparator, and then is not in electricity
Flat reversion.
Specifically, as shown in fig. 6, waveform 602 is the voltage waveform of the first input end of the second comparator, waveform 604 is
The voltage waveform of the first input end of first comparator when probe circuit detects water level, waveform 606 are the of first comparator
The voltage waveform of two input terminals, waveform 608 are the electricity of the first input end of first comparator when water level is not detected in probe circuit
Corrugating.
As it can be seen that when circuit powers on, if water level is being not detected in probe circuit, in time < t, the second comparator
The first input end voltage of second the second comparator of input terminal voltage >, the second comparator export low level, and photo-coupler is connected,
Microprocessor detects low level, in time > t, the first of second the second comparator of input terminal voltage < of the second comparator
Input terminal voltage, the second comparator export high level, photo-coupler cut-off, and microprocessor detects high level.Due to element device
Specification have certain error, therefore, detect program setting t0, t1 and t2, t0 < t1 < t, t2 > t, after powering on, t0≤when
Between≤t1, and microprocessor detects low level, time >=t2, and microprocessor detects high level, then it can determine that circuit is normal,
Otherwise it determines that circuit is faulty, causes the spillage-proof function of cooking apparatus to fail so as to avoid circuit from breaking down.
According to one embodiment of present invention, after determining that the water level detection circuit is normal, further includes: if any
Moment detects that the incoming level signal of the sampled signal input is low level signal, it is determined that the water level detection circuit
Detect water level.
After determining that the water level detection circuit is normal, the second comparator exports high level signal, if probe circuit is not
Detect water level, i.e. when the first probe and the second probe are not connected by water, the first input end voltage of first comparator is greater than
Second input terminal voltage of first comparator, first comparator export high level signal, then common end is high level signal, optocoupler
Clutch cut-off, the input signal of the sampled signal input of microprocessor are high level signal；And water is detected in probe circuit
When position, the first probe and the second probe are connected by water, and the first input end voltage of first comparator is less than first comparator
Second input terminal voltage, first comparator exports low level signal, and then common end exports low level signal, and photo-coupler is led
Logical, the input signal of the sampled signal input of microprocessor is low level signal, therefore can pass through the defeated of detection common end
Signal accurately determines whether probe circuit detects water level out.
According to one embodiment of present invention, further includes: according to the voltage value of first DC power supply and the electrolysis
The parameter value of capacitor determines first predetermined time and second predetermined time.
According to one embodiment of present invention, further includes: according to the voltage value of first DC power supply, electrolysis electricity
The parameter value of appearance and scheduled error time determine first predetermined time and second predetermined time.In the embodiment
Consider the error in element device specification, it is thus determined that the first predetermined time and the second predetermined time it is more accurate.
According to one embodiment of present invention, the water level detection circuit is arranged in cooking apparatus.
The invention also provides a kind of cooking apparatus, comprising: Fig. 1 water level detection circuit shown in any figure into Fig. 3.
The technical scheme of the present invention has been explained in detail above with reference to the attached drawings, and the invention proposes a kind of new water level detecting electricity
Road and its self checking method, can be avoided water level detection circuit faults itself cause cannot accurately in cooking apparatus water level or
The problem of bubble is detected.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (10)
1. a kind of water level detection circuit characterized by comprising
Probe circuit, including the first probe and the second probe, first probe pass through the first sectional pressure element and the second partial pressure member
Part is connected to the first DC power supply, the second probe ground connection；
The third sectional pressure element and the 4th sectional pressure element of series connection, the third sectional pressure element and the 4th sectional pressure element string
It is connected to after connection between first DC power supply and ground；
5th sectional pressure element is connected in parallel between first probe and second probe；
First comparator, the first input end of the first comparator are connected to first sectional pressure element and second partial pressure
Between element, the second input terminal of the first comparator be connected to the third sectional pressure element and the 4th sectional pressure element it
Between；
The 6th sectional pressure element and the 7th sectional pressure element being connected in series, the 6th sectional pressure element are connected to first direct current
Source, the 7th sectional pressure element ground connection；
Electrolytic capacitor is connected in parallel with the 7th sectional pressure element；
Second comparator, the first input end of second comparator are connected to the 6th sectional pressure element and the 7th partial pressure
Between element, the second input terminal of second comparator is connected to the first input end of the first comparator, and described second
The output end of comparator is connected as common end with the output end of the first comparator；
Detection circuit, is connected to the common end, and the detection circuit determines that circuit is according to the output signal of the common end
No exception；
The detection circuit includes:
Photo-coupler, the first input end of the photo-coupler are connected to first DC power supply, and the of the photo-coupler
Two input terminals are connected to the common end, and the first output end of the photo-coupler is connected to second directly by the 8th sectional pressure element
Galvanic electricity source, the second output terminal ground connection of the photo-coupler；
Microprocessor, the sampled signal input of the microprocessor are connected to the 8th sectional pressure element and the photo-coupler
The first output end between, the microprocessor determines whether circuit different according to the input signal of the sampled signal input
Often.
2. water level detection circuit according to claim 1, which is characterized in that the first input end of the first comparator and
The first input end of second comparator is positive input terminal, and the second input terminal of the first comparator and described second compares
Second input terminal of device is negative input end.
3. a kind of self checking method for water level detection circuit, for being carried out to water level detection circuit as claimed in claim 2
Detection characterized by comprising
Receive power on instruction when, the outputs level signals of common end described in real-time detection；
If detecting that the outputs level signals of the common end are receiving in first predetermined time powered on after instructing
Low level signal, and receive it is described power on instruction and the second predetermined time by being greater than first predetermined time after,
The outputs level signals for detecting the common end are high level signal, it is determined that the water level detection circuit is normal.
4. the self checking method according to claim 3 for water level detection circuit, which is characterized in that determining the water level
After detection circuit is normal, further includes:
If detecting at any one time, the outputs level signals of the common end are low level signal, it is determined that the water level detecting
Circuit detects water level.
5. a kind of self checking method for water level detection circuit, for being carried out to water level detection circuit as described in claim 1
Detection characterized by comprising
Instruction is powered on and when water level is not detected in the probe circuit receiving, sampled signal input described in real-time detection
Incoming level signal；
If detecting the input electricity of the sampled signal input receiving in first predetermined time powered on after instructing
Ordinary mail number is low level signal, and described powers on instruction and second by being greater than first predetermined time is predetermined receiving
After time, detect that the incoming level signal of the sampled signal input is high level signal, it is determined that the water level detecting
Circuit is normal, otherwise, it determines the water level detection circuit breaks down.
6. the self checking method according to claim 5 for water level detection circuit, which is characterized in that determining the water level
After detection circuit is normal, further includes:
If detecting at any one time, the incoming level signal of the sampled signal input is low level signal, it is determined that described
Water level detection circuit detects water level.
7. the self checking method according to any one of claim 3 to 6 for water level detection circuit, which is characterized in that also
Include:
According to the parameter value of the voltage value of first DC power supply and the electrolytic capacitor determine first predetermined time and
Second predetermined time.
8. the self checking method according to any one of claim 3 to 6 for water level detection circuit, which is characterized in that also
Include:
According to the voltage value of first DC power supply, the parameter value and scheduled error time of the electrolytic capacitor, institute is determined
State the first predetermined time and second predetermined time.
9. the self checking method according to any one of claim 3 to 6 for water level detection circuit, which is characterized in that institute
Water level detection circuit is stated to be arranged in cooking apparatus.
10. a kind of cooking apparatus characterized by comprising water level detection circuit as claimed in claim 1 or 2.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201510021960.0A CN105841776B (en) | 2015-01-15 | 2015-01-15 | Water level detection circuit and its self checking method and cooking apparatus |
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| CN201510021960.0A CN105841776B (en) | 2015-01-15 | 2015-01-15 | Water level detection circuit and its self checking method and cooking apparatus |
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| CN105841776A CN105841776A (en) | 2016-08-10 |
| CN105841776B true CN105841776B (en) | 2019-03-12 |
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Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106706073A (en) * | 2017-03-07 | 2017-05-24 | 佛山市人百金贸易有限公司 | Intelligent quantometer |
| CN109700309B (en) * | 2017-10-25 | 2021-05-11 | 佛山市顺德区美的电热电器制造有限公司 | Fault detection method, fault detection device, cooking appliance and computer-readable storage medium |
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| CN105841776A (en) | 2016-08-10 |
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