CN201319593Y - Capacitive induction key circuit - Google Patents
Capacitive induction key circuit Download PDFInfo
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- CN201319593Y CN201319593Y CNU2008201733531U CN200820173353U CN201319593Y CN 201319593 Y CN201319593 Y CN 201319593Y CN U2008201733531 U CNU2008201733531 U CN U2008201733531U CN 200820173353 U CN200820173353 U CN 200820173353U CN 201319593 Y CN201319593 Y CN 201319593Y
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- circuit
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- induction key
- capacitive induction
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- 230000006698 induction Effects 0.000 title claims abstract description 28
- 238000001914 filtration Methods 0.000 claims description 6
- 230000000630 rising effect Effects 0.000 claims description 2
- 230000003071 parasitic effect Effects 0.000 description 3
- 239000003990 capacitor Substances 0.000 description 2
- 230000007812 deficiency Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000024241 parasitism Effects 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
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Abstract
The utility model relates to a capacitive induction key circuit which comprises a singlechip controller, a drive control circuit, an induction key electrode and a signal filter partial pressure processing circuit; the capacitive induction key circuit also comprises a pulse transformer used for increasing ground voltage of the induction key electrode. Compared with prior art, the level fluctuation amplitude of the key trigger signal generated by the capacitive induction key circuit can reach certain volt and can be identified directly by control circuit without the processing of amplifier circuit. Besides, compared with the key trigger signal, the generated interference weak signal can be ignored, the anti-interference performance is greatly improved and the performance of induction key is more stable.
Description
Technical field
The utility model relates to tame electro-technical field, particularly a kind of capacitive induction key circuit that is applied on the household electrical appliances.
Background technology
The application of capacitive induction button in electronic product is extensive gradually, and it is ripe that technology also is tending towards.But because the electric capacity of induction parasitism is very faint, the driving voltage of induced key signal processing circuit generally also has only about 5 volts at present, this makes and finally is converted into the variation amplitude of level signal only about the hundreds of millivolt, it is not high that Direct Recognition is handled so faint level variation amplitude reliability, disturbed by external environment condition, influence the performance of induced key.Signal amplifies or the employing special chip is handled if will be undertaken by amplifier, and this can make and design become complexity and cost increase, has reduced the advantage of comparing with the traditional mechanical button.
On April 16th, 2008, disclosed Chinese utility model patent disclosed a kind of capacitive induction button for CN201048368Y number, it is very little that but this induced key finally is converted into the variation amplitude of level signal, need carry out signal by amplifying circuit and amplify and just can make the button operate as normal.Make and design become complexity and cost increase, reduced the advantage of comparing with the traditional mechanical button.
Summary of the invention
The purpose of this utility model is at the deficiencies in the prior art, and a kind of capacitive induction key circuit is provided.
To achieve these goals, the utility model capacitive induction key circuit is reached by the following technical programs:
A kind of capacitive induction key circuit, it comprises singlechip controller, Drive and Control Circuit, induced key electrode, signal filtering voltage division processing circuit, and this capacitive induction key circuit also includes the pulse transformer of the voltage to earth rising that can make the induced key electrode.
Compared with prior art, the level of the button triggering signal that the utility model directly produces changes amplitude can reach several volts, need not to handle through amplifying circuit, can supply the control circuit Direct Recognition.And the small-signal that disturb to produce will be left in the basket by comparison, greatly must improve anti-interference, make the induced key performance more stable.
Description of drawings
The utility model is described in further detail below in conjunction with drawings and Examples:
Fig. 1 is the utility model embodiment principle schematic.
Fig. 2 is the utility model embodiment circuit diagram.
Embodiment
Further specify the technical solution of the utility model below in conjunction with drawings and Examples.
The utility model capacitive induction key circuit adopts high-voltage high-frequency signal to drive, and the voltage to earth of human body sensing electrode is brought up to tens volts even to several hectovolts by general 5V.Because the capacitive induction button necessarily requires at the separator that low-dielectric height withstand voltage (more than the withstand voltage 1000V voltage) is arranged between human body and the induction electrode,, meet the safety requirements index so adopt high-voltage high-frequency signal to drive the human body that can not shock by electricity.The employing high-voltage high-frequency signal drives, and makes to form a stronger electric field between human body and the electrode, strengthens induced signal thus to improve the level signal changing value, is convenient to the detection of control circuit.
Concrete principle as depicted in figs. 1 and 2.The utility model capacitive induction key circuit comprises singlechip controller, Drive and Control Circuit, pulse transformer, induced key electrode, signal dividing potential drop Filtering Processing circuit, button channel selecting control circuit.Single-chip microcomputer at first sends a high-frequency modulation signal, amplify the former limit that pulse transformer is exported in driving through triode Q1, again by the boosting of pulse transformer, make the secondary of pulse transformer produce the driving voltage of tens volts even several hectovolts, realize the high-frequency and high-voltage driving on the induction electrode.The high-frequency high-voltage signal of pulse transformer secondary passes through the dividing potential drop and capacitor C 1 filtering of voltage-stabiliser tube D1 and resistance R 2 again through the parasitic capacitance filtering of resistance R 1 and induction electrode, and finally being output as can be for the direct level signal that detects of singlechip controller.When finger is pressed, the parasitic capacitance of induction electrode can increase, make the time that the discharges and recharges lengthening of parasitic capacitance of R1 and induction electrode, the amplitude that causes signal to discharge and recharge reduces, pass through resistance R 2 and capacitor C 1 filtering again, the level value of final output can diminish, and singlechip controller can reduce to be worth according to level to be judged and have or not key to press.
In this embodiment, the utility model capacitive induction key circuit has also comprised button channel selecting control circuit, is in order to select when having a plurality of button, and certainly, in the embodiment that has only a button, this circuit will not need.
Through experiment test, the level of the button triggering signal that this circuit directly produces changes amplitude can reach several volts, need not to handle through amplifying circuit, can supply the control circuit Direct Recognition.The more important thing is that the small-signal that disturb to produce will be left in the basket by comparison, greatly must improve anti-interference, make the induced key performance more stable, circuit is also very simplified.
Claims (2)
1, a kind of capacitive induction key circuit, Drive and Control Circuit, induced key electrode, signal filtering voltage division processing circuit that it comprises the singlechip controller that can send modulation signal, scalable this modulation signal of driving is characterized in that: this capacitive induction key circuit also includes the pulse transformer of the voltage to earth rising that can make the induced key electrode.
2, capacitive induction key circuit according to claim 1 is characterized in that: described modulation signal amplifies the former limit that pulse transformer is exported in driving through Drive and Control Circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201733531U CN201319593Y (en) | 2008-10-22 | 2008-10-22 | Capacitive induction key circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNU2008201733531U CN201319593Y (en) | 2008-10-22 | 2008-10-22 | Capacitive induction key circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201319593Y true CN201319593Y (en) | 2009-09-30 |
Family
ID=41198351
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNU2008201733531U Expired - Fee Related CN201319593Y (en) | 2008-10-22 | 2008-10-22 | Capacitive induction key circuit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201319593Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012040947A1 (en) * | 2010-09-30 | 2012-04-05 | 江苏惠通集团有限责任公司 | Anti-interference key detection system and method |
| CN102104374B (en) * | 2009-12-22 | 2015-04-22 | 康佳集团股份有限公司 | Keying device and system |
| CN111025956A (en) * | 2019-10-30 | 2020-04-17 | 九阳股份有限公司 | Food preparation machine's button identification circuit |
-
2008
- 2008-10-22 CN CNU2008201733531U patent/CN201319593Y/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102104374B (en) * | 2009-12-22 | 2015-04-22 | 康佳集团股份有限公司 | Keying device and system |
| WO2012040947A1 (en) * | 2010-09-30 | 2012-04-05 | 江苏惠通集团有限责任公司 | Anti-interference key detection system and method |
| CN111025956A (en) * | 2019-10-30 | 2020-04-17 | 九阳股份有限公司 | Food preparation machine's button identification circuit |
| CN111025956B (en) * | 2019-10-30 | 2023-12-08 | 九阳股份有限公司 | Key recognition circuit of food processor |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090930 Termination date: 20131022 |