CN108228010A - Capacitance touch induced key detection circuit and method and household electrical appliance - Google Patents
Capacitance touch induced key detection circuit and method and household electrical appliance Download PDFInfo
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- CN108228010A CN108228010A CN201611145661.9A CN201611145661A CN108228010A CN 108228010 A CN108228010 A CN 108228010A CN 201611145661 A CN201611145661 A CN 201611145661A CN 108228010 A CN108228010 A CN 108228010A
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- 238000001514 detection method Methods 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 title abstract description 11
- 239000003990 capacitor Substances 0.000 claims abstract description 31
- 238000012545 processing Methods 0.000 claims abstract description 24
- 238000001914 filtration Methods 0.000 claims description 8
- 230000005611 electricity Effects 0.000 claims description 6
- 230000003068 static effect Effects 0.000 abstract description 5
- 238000005516 engineering process Methods 0.000 abstract description 3
- 239000002699 waste material Substances 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 2
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M11/00—Coding in connection with keyboards or like devices, i.e. coding of the position of operated keys
- H03M11/26—Coding in connection with keyboards or like devices, i.e. coding of the position of operated keys using opto-electronic means
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Abstract
The present invention relates to field of circuit technology, disclose a kind of capacitance touch induced key detection circuit and method and household electrical appliance, and there are chip pin wastes for the capacitance touch induced key for solving the problems, such as negligible amounts.The detection circuit includes：Touch sensible capacitance, high-pass filter, voltage doubling rectifing circuit and MCU processing circuits, wherein, high-frequency signal source is connect with high-pass filter, and touch sensible capacitance is in parallel with the capacitance in high-pass filter, and high-pass filter, voltage doubling rectifing circuit and MCU processing circuits are sequentially connected；Touch sensible capacitance obtains Static Electro perhaps coupled capacitor；High-pass filter obtains the low level amplitude or high level of the voltage signal of high-frequency signal source；Voltage doubling rectifing circuit exports level magnitude according to specified multiple；MCU processing circuits judge the operation of capacitance touch induced key according to the output level of voltage doubling rectifing circuit.The embodiment of the present invention is applied to the detection of capacitance touch induced key.
Description
Technical field
The present invention relates to field of circuit technology more particularly to a kind of capacitance touch induced key detection circuit and method,
And household electrical appliance.
Background technology
Compared with traditional mechanical key, capacitive induction touch key-press does not need to direct body contact's metal, can be with
It thoroughly eliminates safe hidden trouble, even if with gloves uses, and not by the shadows such as dry weather humidity, human body resistance variation
It rings, it is more convenient to use.There is no any mechanical part, will not wear, infinite life, reduce later maintenance cost.Its detecting part
Dividing can be placed into behind any insulating layer (being usually glass or plastic material), it is easy to be made and mutually be sealed with ambient enviroment
Keyboard.
Capacitance touch induced key has been widely used for sound equipment panel, telephone set control keyboard, instrument and meter at present
Control panel, washer control panel, intelligent access control system control panel, various small household appliances, for example, it is electromagnetic oven, disinfection cabinet, micro-
Wave stove etc., has covered that household electrical appliance, handheld device, Industry Control, automotive electronics, military use product etc. are nearly all to be related to controlling
The application field of button operation panel processed.
For capacitance touch induced key detection generally using it is special touch chip detection after with MCU
The method of (Microcontroller Unit, also known as micro-control unit, microcontroller) communication uses integrated touch controlled key
Detect tailored version MCU.Capacitance touch induced key for negligible amounts or the control button for being used as main MCU by MCU
Operation panel, there are the problem of chip pin waste or weak versatility.
Invention content
The embodiment of the present invention provides a kind of capacitance touch induced key detection circuit and method and household electrical appliance,
Solve the control button operation panel for being used as main MCU for the capacitance touch induced key of negligible amounts or by MCU,
There are the problem of chip pin waste or weak versatility.
In order to achieve the above objectives, the embodiment of the present invention adopts the following technical scheme that：
The present invention provides a kind of capacitance touch induced key detection circuit, including：
Touch sensible capacitance, high-pass filter, voltage doubling rectifing circuit and single-chip microprocessor MCU processing circuit, wherein, high-frequency signal
Source is connect with the high-pass filter, and the touch sensible capacitance is in parallel with the capacitance in the high-pass filter, the high pass
Wave filter, the voltage doubling rectifing circuit and the MCU processing circuits are sequentially connected；
The touch sensible capacitance, for when capacitance touch induced key does not have push, obtaining direct capacitance,
When the capacitance touch induced key push, coupled capacitor is obtained, and the coupled capacitor is more than the Static Electro
Hold；
The high-pass filter, for when the touch sensible capacitance is the direct capacitance, obtaining the high frequency letter
The low level amplitude in number source when the touch sensible capacitance is the coupled capacitor, obtains the height electricity of the high-frequency signal source
Open width value；
The voltage doubling rectifing circuit, for the low level amplitude or the high level of the voltage signal is defeated according to specified multiple
Go out, obtain the low level amplitude of specified multiple or the high level of the voltage signal of specified multiple；
The MCU processing circuits for the output level according to the voltage doubling rectifing circuit, judge the capacitance touch
The operation of induced key, wherein, the output level is the low level amplitude of the specified multiple or the height of the specified multiple
Level magnitude.
Optionally, the high-pass filter is additionally operable to, when the touch sensible capacitance is the direct capacitance, obtain institute
The first cutoff frequency of high-pass filter is stated, when the touch sensible capacitance is the coupled capacitor, obtains the high pass filter
Second cutoff frequency of wave device, and first cutoff frequency is more than second cutoff frequency.
Optionally, the voltage doubling rectifing circuit is additionally operable to the ac high frequency signal for exporting the high-pass filter and converts
For direct current signal.
Optionally, the MCU processing circuits are additionally operable to detect that the output level is from the low of the specified multiple
When level magnitude becomes the high level of the voltage signal of the specified multiple, the capacitance touch induced key is judged for push,
Or work as and detect that the output level is the low level for becoming the specified multiple from the high level of the voltage signal of the specified multiple
During amplitude, judge that the capacitance touch induced key is operated for release.
Optionally, the high-pass filter is single order high-pass filter or bivalent high-pass filter.
Optionally, when the high-pass filter is bivalent high-pass filter, the touch sensible capacitance and the second order
Capacitance in any one section high-pass filtering circuit in high-pass filter is in parallel.
Optionally, the high-pass filter is active high-pass filter or passive high three-way filter.
The present invention also provides a kind of families for including above-mentioned capacitance touch induced key detection circuit provided by the present invention
Electrical appliance.
The present invention also provides a kind of capacitance touch induced key detection method, including：
When capacitance touch induced key does not have push, direct capacitance is obtained, when the capacitance touch senses
During button push, coupled capacitor is obtained, and the coupled capacitor is more than the direct capacitance；
When the touch sensible capacitance is the direct capacitance, the low level amplitude of the high-frequency signal source is obtained, when
When the touch sensible capacitance is the coupled capacitor, the high level of the voltage signal of the high-frequency signal source is obtained；
The low level amplitude or the high level of the voltage signal according to specified multiple are exported, obtain the low level of specified multiple
The high level of the voltage signal of amplitude or specified multiple；
According to the output level of the voltage doubling rectifing circuit detected, the operation of the capacitance touch induced key is judged,
Wherein, the output level is the low level amplitude of the specified multiple or the high level of the voltage signal of the specified multiple.
Optionally, it is described when the touch sensible capacitance is the direct capacitance, obtain the low of the high-frequency signal source
Level magnitude when the touch sensible capacitance is the coupled capacitor, obtains the high level of the voltage signal packet of the high-frequency signal source
It includes：
When the touch sensible capacitance is the direct capacitance, the first cutoff frequency of the high-pass filter is obtained,
And the low level amplitude of the high-frequency signal source is obtained, when the touch sensible capacitance is the coupled capacitor, obtain described
Second cutoff frequency of high-pass filter, and the high level of the voltage signal of the high-frequency signal source is obtained, and first cutoff frequency
More than second cutoff frequency.
Optionally, the output level for the voltage doubling rectifing circuit that the basis detects judges the capacitance touch sensing
The operation of button includes：
When detecting that the output level is the height that becomes the specified multiple from the low level amplitude of the specified multiple
During level magnitude, judge the capacitance touch induced key for push or when detect the output level be from
When the high level of the voltage signal of the specified multiple becomes the low level amplitude of the specified multiple, the capacitance touch sensing is judged
Button is operated for release.
By foregoing circuit, according to the cutoff frequency of the high-pass filter follow the touch sensible capacitance variation and
Variation, so as to determine the ac high frequency of fixed frequency by the amplitude size after the high frequency filter, then via described
The processing of voltage doubling rectifing circuit exports the stable output level for MCU processing circuit processes.Design electricity of the embodiment of the present invention
Road is simple, and it is convenient to realize, can be used for the capacitance touch induced key detection of lesser amt environment, and is not limited to specific
MCU has certain versatility.
Other features and advantages of the present invention will be described in detail in subsequent specific embodiment part.
Description of the drawings
Attached drawing is to be used to provide further understanding of the present invention, and a part for constitution instruction, with following tool
Body embodiment is used to explain the present invention, but be not construed as limiting the invention together.In the accompanying drawings：
Fig. 1 is a kind of schematic diagram of capacitance touch induced key detection circuit provided in an embodiment of the present invention；
Fig. 2 is a kind of circuit diagram of capacitance touch induced key detection circuit provided in an embodiment of the present invention；
Fig. 3 is the circuit diagram of another capacitance touch induced key detection circuit provided in an embodiment of the present invention；
Fig. 4 is a kind of flow chart of capacitance touch induced key detection method provided in an embodiment of the present invention.
Specific embodiment
The specific embodiment of the present invention is described in detail below in conjunction with attached drawing.It should be understood that this place is retouched
The specific embodiment stated is merely to illustrate and explain the present invention, and is not intended to restrict the invention.
The embodiment of the present invention is the detection for capacitance touch induced key, wherein, the capacitance touch sensing is pressed
The principle of key is to be detected whether using the inductance capacitance of human body with the presence of finger, when the finger down of people or close to the electricity
During appearance formula touch sensible button, the parasitic capacitance of human body will be coupled into this direct capacitance, make the final capacitance of the button
Become larger, judge that the button is pressed or discharged by detecting the variable quantity of capacitance.An embodiment of the present invention provides one kind
Capacitance touch induced key detection circuit, as shown in Figure 1, the circuit includes：
Touch sensible capacitance 11, high-pass filter 12, voltage doubling rectifing circuit 13 and single-chip microprocessor MCU processing circuit 14, wherein,
High-frequency signal source (not indicated in Fig. 1) is connect with the high-pass filter 12, and the touch sensible capacitance 11 is filtered with the high pass
Capacitance 15 in wave device 12 is in parallel, the high-pass filter 12, the voltage doubling rectifing circuit 13 and the MCU processing circuits 14 according to
Secondary connection；
The touch sensible capacitance 11, for when capacitance touch induced key does not have push, obtaining Static Electro
Hold, when the capacitance touch induced key push, obtain coupled capacitor, and the coupled capacitor is more than the static state
Capacitance.
When the capacitance touch induced key does not have push, the touch sensible capacitance be direct capacitance, phase
It is disconnected when in the touch sensible capacitance, it is not in parallel with the capacitance in the high-pass filter；When the capacitance touch senses
During button push, coupled capacitor is obtained, the obtained coupled capacitor is more than the direct capacitance.
The high-pass filter 12, for when the touch sensible capacitance is the direct capacitance, obtaining the high frequency
The low level amplitude of signal source when the touch sensible capacitance is the coupled capacitor, obtains the height of the high-frequency signal source
Level magnitude.
That is, when the touch sensible capacitance is the direct capacitance, the first cutoff frequency of the high-pass filter is obtained
Rate when the touch sensible capacitance is the coupled capacitor, obtains the second cutoff frequency of the high-pass filter, and described
First cutoff frequency is more than second cutoff frequency.
As shown in Fig. 2, by the high-pass filter to be illustrated for single order passive high three-way filter, capacitance in Fig. 2
C101 and resistance R101 composition CR high-pass filters, C102 are the touch sensible capacitance.
When the capacitance touch induced key does not have push, the touch sensible capacitance C102 is Static Electro
Hold, be equivalent to disconnecting circuit, not in parallel with capacitance C101, then the component for forming the high-pass filter is capacitance C101 and resistance
R101, so at this point, the cutoff frequency of the high-pass filter is
When the capacitance touch induced key push, the touch sensible capacitance C102 is in parallel with C101, then
The component of the high-pass filter is formed as capacitance C101, touch sensible capacitance C102 and resistance R101, at this time the high pass filter
The cutoff frequency of wave device is
For high-frequency signal source 101 by the level magnitude after the high-pass filter, when the capacitance touch senses
When button does not have push, the cutoff frequency of the high-pass filter isSince the high pass is filtered
The effect of wave device, the high-frequency signal of the high-frequency signal source 101 will decay seriously, obtain low level amplitude；When the capacitance
During formula touch sensible button push, the cutoff frequency of the high-pass filter is
The high-frequency signal of the high-frequency signal source 101 will it is undamped or attenuation very little pass through, obtained high level of the voltage signal.
For example, when the capacitance touch induced key does not have push, the cutoff frequency of the high-pass filter
For 300KHz, the output signal frequency of the high-frequency signal source 101 is 150KHz, and level virtual value is 1V, the high-pass filtering
The level virtual value of the output signal of device will be less than 0.5V to get low level amplitude has been arrived；When the capacitance touch senses
During button push, the cutoff frequency becomes smaller, and less than 75KHz, the level of the output signal of the high-pass filter is effective
Value will be managed in 1V or so substantially to get having arrived high level of the voltage signal.
Above-mentioned illustrated by taking single order passive high three-way filter as an example, and the high-pass filter is not limited to this, institute
It can be single order high-pass filter or bivalent high-pass filter or active high-pass filter or passive high pass to state high-pass filter
Wave filter, as shown in figure 3, when the high-pass filter is single order active high-pass filter, the circuit diagram of the detection circuit.
When the high-pass filter is bivalent high-pass filter, the touch sensible capacitance and the second order high-pass filtering
Capacitance in any one section high-pass filtering circuit in device is in parallel.
The voltage doubling rectifing circuit 13, for the low level amplitude or the high level of the voltage signal is defeated according to specified multiple
Go out, obtain the low level amplitude of specified multiple or the high level of the voltage signal of specified multiple.
Since the MCU processing circuits 14 can only handle direct current signal, by the voltage doubling rectifing circuit 13, by institute
The ac high frequency signal for stating high-pass filter output is converted into direct current signal.
The voltage doubling rectifing circuit 13 can use two voltage doubling rectifying circuit, voltage tripler rectifier circuit or even more times of repoussages
Current circuit, due to the level magnitude ranging from [3.3V, 5V] of the MCU processing circuits 14 processing, as long as ensureing times repoussage
The level magnitude that current circuit 13 exports is in underrange.
As shown in Figure 2 or Figure 3, the voltage doubling rectifing circuit 13 provided is voltage tripler rectifier circuit, includes the one or two pole
Pipe D201 and the first capacitance C201, the second diode D202 and the second capacitance C202, third diode D203 and third capacitance
C203 and load R201.According to voltage tripler rectifier circuit operation principle, the ac high frequency that the high-pass filter is exported is believed
Direct current signal number is converted into, and the level magnitude exported isTimes.So the output signal frequency of high-frequency signal source 101 is
150KHz, level virtual value is 1V, when the capacitance touch induced key does not have push, the high-pass filter
The level virtual value of output signal is less than 0.5V, then the voltage tripler rectifier circuit output voltage will be less than 3V；When the capacitance
During formula touch sensible button push, the level virtual value of the output signal of the high-pass filter is in 1V or so, then described
Voltage tripler rectifier circuit output voltage will be greater than 4V.
The MCU processing circuits 14 for the output level according to the voltage doubling rectifing circuit, judge the capacitive touch
The operation of induced key is touched, wherein, the output level is the low level amplitude of the specified multiple or the specified multiple
High level of the voltage signal.
Wherein, the MCU processing circuits 14, when detecting that the output level is from the low level width of the specified multiple
When value becomes the high level of the voltage signal of the specified multiple, the capacitance touch induced key is judged for push or is worked as
When detecting the output level to become the low level amplitude of the specified multiple from the high level of the voltage signal of the specified multiple,
Judge that the capacitance touch induced key is operated for release.
By foregoing circuit, according to the cutoff frequency of the high-pass filter follow the touch sensible capacitance variation and
Variation, so as to determine the ac high frequency of fixed frequency by the amplitude size after the high frequency filter, then via described
The processing of voltage doubling rectifing circuit exports the stable output level for MCU processing circuit processes.Design electricity of the embodiment of the present invention
Road is simple, and it is convenient to realize, can be used for the capacitance touch induced key detection of lesser amt environment, and is not limited to specific
MCU has certain versatility.
Above-mentioned capacitance touch induced key detection circuit, applies also for the household electric with capacitance touch induced key
Device.
The embodiment of the present invention also provides a kind of capacitance touch induced key detection method, as shown in figure 4, the method packet
Include following steps：
401st, when capacitance touch induced key does not have push, direct capacitance is obtained, when the capacitance touch
During induced key push, coupled capacitor is obtained, and the coupled capacitor is more than the direct capacitance；
402nd, when the touch sensible capacitance is the direct capacitance, the low level width of the high-frequency signal source is obtained
Value when the touch sensible capacitance is the coupled capacitor, obtains the high level of the voltage signal of the high-frequency signal source.
Wherein, when the touch sensible capacitance is the direct capacitance, the first cut-off of the high-pass filter is obtained
Frequency, and the low level amplitude of the high-frequency signal source is obtained, when the touch sensible capacitance is the coupled capacitor, obtain
Second cutoff frequency of the high-pass filter, and the high level of the voltage signal of the high-frequency signal source is obtained, and first cut-off
Frequency is more than second cutoff frequency.
Using the output signal frequency of the high-frequency signal source as 150KHz, virtual value is 1V for example, when the capacitance
When formula touch sensible button does not have push, due to the effect of the high-pass filter, high-frequency signal will decay seriously, defeated
Go out for low level amplitude；When the capacitance touch induced key push, due to the variation of the touch sensible capacitance,
Coupled capacitor is become, and the coupled capacitor is more than the cut-off of the direct capacitance, the then high-pass filter from direct capacitance
Frequency will decline, the high-frequency signal source will undamped or attenuation very little pass through, it is defeated so as to the high-pass filter
Go out for high level of the voltage signal.
403rd, the low level amplitude or the high level of the voltage signal according to specified multiple are exported, obtains the low of specified multiple
The high level of the voltage signal of level magnitude or specified multiple；
404th, according to the output level of voltage doubling rectifing circuit detected, judge the behaviour of the capacitance touch induced key
Make, wherein, the output level is the low level amplitude of the specified multiple or the high level of the voltage signal of the specified multiple.
Wherein, when detecting that the output level is to become the specified multiple from the low level amplitude of the specified multiple
High level of the voltage signal when, judge the capacitance touch induced key for push or when detecting the output level
During low level amplitude to become the specified multiple from the high level of the voltage signal of the specified multiple, the capacitance touch is judged
Induced key is operated for release.
Optionally, the output level of the voltage doubling rectifing circuit can be detected according to preset time, and judge the capacitance
The operation of formula touch sensible button, the preset time can be set as 10ms, not be limited herein.
The physical circuit realization method of the capacitance touch induced key detection method, can participate in above-mentioned capacitance touch
The embodiment of induced key detection circuit.
By above-mentioned detection method, the change of the touch sensible capacitance is followed according to the cutoff frequency of the high-pass filter
Change and change, so as to determine the ac high frequency of fixed frequency by the amplitude size after the high frequency filter, then via
The processing of the voltage doubling rectifing circuit exports the stable output level for MCU processing circuit processes.The embodiment of the present invention is set
It is simple to count circuit, it is convenient to realize, can be used for the capacitance touch induced key detection of lesser amt environment, and is not limited to spy
Determine MCU, there is certain versatility.
The preferred embodiment of the present invention is described in detail above in association with attached drawing, still, the present invention is not limited to above-mentioned realities
The detail in mode is applied, within the scope of the technical concept of the present invention, a variety of letters can be carried out to technical scheme of the present invention
Monotropic type, these simple variants all belong to the scope of protection of the present invention.
It is further to note that specific technical features described in the above specific embodiments, in not lance
In the case of shield, it can be combined by any suitable means.In order to avoid unnecessary repetition, the present invention to it is various can
The combination of energy no longer separately illustrates.
In addition, various embodiments of the present invention can be combined randomly, as long as it is without prejudice to originally
The thought of invention, it should also be regarded as the disclosure of the present invention.
Claims (11)
1. a kind of capacitance touch induced key detection circuit, which is characterized in that including：
Touch sensible capacitance, high-pass filter, voltage doubling rectifing circuit and single-chip microprocessor MCU processing circuit, wherein, high-frequency signal source with
The high-pass filter connection, the touch sensible capacitance is in parallel with the capacitance in the high-pass filter, the high-pass filtering
Device, the voltage doubling rectifing circuit and the MCU processing circuits are sequentially connected；
The touch sensible capacitance, for when capacitance touch induced key does not have push, obtaining direct capacitance, working as institute
When stating capacitance touch induced key push, coupled capacitor is obtained, and the coupled capacitor is more than the direct capacitance；
The high-pass filter, for when the touch sensible capacitance is the direct capacitance, obtaining the high-frequency signal source
Low level amplitude, when the touch sensible capacitance is the coupled capacitor, obtain the high level width of the high-frequency signal source
Value；
The voltage doubling rectifing circuit for the low level amplitude or the high level of the voltage signal to be exported according to specified multiple, obtains
To the low level amplitude of specified multiple or the high level of the voltage signal of specified multiple；
The MCU processing circuits for the output level according to the voltage doubling rectifing circuit, judge the capacitance touch sensing
The operation of button, wherein, the output level is the low level amplitude of the specified multiple or the high level of the specified multiple
Amplitude.
2. capacitance touch induced key detection circuit according to claim 1, which is characterized in that the high-pass filtering
Device is additionally operable to, when the touch sensible capacitance is the direct capacitance, obtain the first cutoff frequency of the high-pass filter,
When the touch sensible capacitance is the coupled capacitor, the second cutoff frequency of the high-pass filter is obtained, and described the
One cutoff frequency is more than second cutoff frequency.
3. capacitance touch induced key detection circuit according to claim 1, which is characterized in that the voltage multiplying rectifier electricity
Road is additionally operable to the ac high frequency signal that the high-pass filter exports being converted into direct current signal.
4. capacitance touch induced key detection circuit according to claim 1, which is characterized in that the MCU processing electricity
Road is additionally operable to when the height for detecting the output level to become the specified multiple from the low level amplitude of the specified multiple
During level magnitude, judge the capacitance touch induced key for push or when detect the output level be from
When the high level of the voltage signal of the specified multiple becomes the low level amplitude of the specified multiple, the capacitance touch sensing is judged
Button is operated for release.
5. capacitance touch induced key detection circuit according to claim 1, which is characterized in that the high-pass filter
For single order high-pass filter or bivalent high-pass filter.
6. capacitance touch induced key detection circuit according to claim 5, which is characterized in that when the high-pass filtering
When device is bivalent high-pass filter, the touch sensible capacitance and any one section high-pass filtering in the bivalent high-pass filter
Capacitance in circuit is in parallel.
7. capacitance touch induced key detection circuit according to claim 1, which is characterized in that the high-pass filter
For active high-pass filter or passive high three-way filter.
8. a kind of household electrical appliance, which is characterized in that include the capacitance touch sense described in any one of claim 1-7 claims
Answer key press detecting circuit.
9. a kind of capacitance touch induced key detection method, which is characterized in that including：
When capacitance touch induced key does not have push, direct capacitance is obtained, when the capacitance touch induced key
During push, coupled capacitor is obtained, and the coupled capacitor is more than the direct capacitance；
When the touch sensible capacitance is the direct capacitance, the low level amplitude of the high-frequency signal source is obtained, when described
When touch sensible capacitance is the coupled capacitor, the high level of the voltage signal of the high-frequency signal source is obtained；
The low level amplitude or the high level of the voltage signal according to specified multiple are exported, obtain the low level amplitude of specified multiple
Or the high level of the voltage signal of specified multiple；
According to the output level of the voltage doubling rectifing circuit detected, the operation of the capacitance touch induced key is judged, wherein,
The output level is the low level amplitude of the specified multiple or the high level of the voltage signal of the specified multiple.
10. capacitance touch induced key detection method according to claim 9, which is characterized in that described to be touched when described
When touching inductance capacitance as the direct capacitance, the low level amplitude of the high-frequency signal source is obtained, when the touch sensible capacitance
During for the coupled capacitor, the high level of the voltage signal for obtaining the high-frequency signal source includes：
When the touch sensible capacitance is the direct capacitance, the first cutoff frequency of the high-pass filter is obtained, and obtain
The low level amplitude of the high-frequency signal source is obtained, when the touch sensible capacitance is the coupled capacitor, obtains the high pass
Second cutoff frequency of wave filter, and the high level of the voltage signal of the high-frequency signal source is obtained, and first cutoff frequency is more than
Second cutoff frequency.
11. capacitance touch induced key detection method according to claim 9, which is characterized in that described according to detection
The output level of the voltage doubling rectifing circuit arrived judges that the operation of the capacitance touch induced key includes：
When detecting that the output level is the high level that becomes the specified multiple from the low level amplitude of the specified multiple
During amplitude, the capacitance touch induced key is judged for push or ought detect that the output level is from described
When the high level of the voltage signal of specified multiple becomes the low level amplitude of the specified multiple, the capacitance touch induced key is judged
It is operated for release.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201611145661.9A CN108228010A (en) | 2016-12-13 | 2016-12-13 | Capacitance touch induced key detection circuit and method and household electrical appliance |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611145661.9A CN108228010A (en) | 2016-12-13 | 2016-12-13 | Capacitance touch induced key detection circuit and method and household electrical appliance |
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| CN108228010A true CN108228010A (en) | 2018-06-29 |
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| CN201611145661.9A Pending CN108228010A (en) | 2016-12-13 | 2016-12-13 | Capacitance touch induced key detection circuit and method and household electrical appliance |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110806523A (en) * | 2019-11-18 | 2020-02-18 | 珠海格力智能装备有限公司 | Method and device for detecting key performance |
| CN111103488A (en) * | 2019-12-25 | 2020-05-05 | 心核心科技(北京)有限公司 | Touch detection circuit, touch sensor and ring receiver |
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| CN111103488A (en) * | 2019-12-25 | 2020-05-05 | 心核心科技(北京)有限公司 | Touch detection circuit, touch sensor and ring receiver |
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