CN104868901B - Signal deteching circuit - Google Patents
Signal deteching circuit Download PDFInfo
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- CN104868901B CN104868901B CN201410061854.0A CN201410061854A CN104868901B CN 104868901 B CN104868901 B CN 104868901B CN 201410061854 A CN201410061854 A CN 201410061854A CN 104868901 B CN104868901 B CN 104868901B
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Abstract
The invention discloses a kind of signal deteching circuit, including：First circuit part, it is electrically connected to reference voltage source, input and detection circuit part, and when input has low level signal input, the electric current that input is flowed to from reference voltage source is produced, while produce the electric current from reference voltage source flow detection circuit part；Second circuit part, it is electrically connected to input, the first circuit part and detection circuit part, and when input has high level signal input, produces the electric current from input flow detection circuit part；Circuit part is detected, it exports detection signal according to the input current from the first circuit part or second circuit part in output end；When input has low level signal input, the operation of second circuit part is suppressed；And when input has high level signal input, the operation of the first circuit part is suppressed.From regardless of whether input whether input high level or low level signal, output end can detect the input signal.
Description
Technical field
The present invention relates to circuit field, and in particular to a kind of signal deteching circuit.
Background technology
The typical structure of signal deteching circuit of the prior art is cut as shown in figure 1, during input input high level signal
Change switch SW1 and be switched to low level, two-way optocoupler PC1 conductings, output end detects input signal；Input input low level is believed
Number when, switching switch SW1 is switched to high level, and two-way optocoupler PC1 conductings, output end detects input signal.
However, in the signal deteching circuit of prior art as shown in Figure 1, the circuit part of input and output end
Circuit part needs to use different power supplys respectively（VCC power supplys and VDD power supplys shown in figure）；And this circuit is being applied
When, it is also necessary to the switching of switching device, therefore its service life and accuracy of detection are also influenceed by switching device.
The content of the invention
It is an object of the invention to provide a kind of signal deteching circuit for overcoming above-mentioned at least one shortcoming.
A kind of signal deteching circuit provided by the present invention, it has input and output end, and in its output end
Detect whether its input has input signal, including：First circuit part, it is electrically connected to reference voltage source, the input
And detection circuit part, and be configured to when the input has low level signal input, produce and flowed to from reference voltage source
The electric current of the input, and the electric current from the reference voltage source flow detection circuit part is produced simultaneously；Second circuit portion
Point, it is electrically connected to the input, first circuit part and the detection circuit part, and is configured in the input
When there is high level signal input at end, the electric current that the detection circuit part is flowed to from the input is produced；And the detection
Circuit part, it includes the output end, and is configured to basis and comes from first circuit part or the second circuit part
Input current come the output end export detection signal；Wherein, it is described when the input has low level signal input
The operation of second circuit part is suppressed；And when the input has high level signal input, first circuit part
Operation be suppressed.
Preferably, first circuit part includes：The first transistor, its first end are connected to the reference voltage source,
Its second end is connected with its first end by first resistor and second end be connected to via the first one way conducting device it is described defeated
Enter end, and its 3rd end is connected to the detection circuit part via the 3rd one way conducting device, wherein, in the input
When having low level signal input, first one way conducting device conducting, the first end of the first transistor and the 3rd end it
Between turn on, and the 3rd one way conducting device turn on.
Preferably, the second circuit part includes：The second one way conducting device and the 4th conduction device of series connection, and
Wherein, when the input has high level signal input, the second one way conducting device conducting, and the 4th conducting
Device reverse-conducting when the high level signal that the input inputs is higher than its breakdown voltage.
Preferably, the detection circuit part includes：Second transistor, its first end are the output end, its second end
It is connected with its 3rd end by second resistance and second end is connected to first circuit part and the second circuit part
Output par, c to receive the input current, its 3rd end ground connection, and wherein, when receiving the input current, institute
State conducting between the first end of second transistor and the 3rd end and its first end exports the detection signal.
Preferably, first one way conducting device and the 3rd one way conducting device are diode.
Preferably, second one way conducting device is diode, and the 4th conduction device is Zener diode.
Preferably, the first end of the second transistor is connected to the reference voltage source through resistance.
Preferably, the first resistor is embedded in the first transistor.
Preferably, the second resistance is embedded in the second transistor.
Signal deteching circuit provided by the invention, no matter input whether input high level signal or low level signal,
End can be output to detect, and switch switching need not be carried out, it is easy to operate.
Brief description of the drawings
Fig. 1 is the exemplary block diagram of the signal deteching circuit of prior art.
Fig. 2 is the structural representation of the signal deteching circuit of the embodiment of the present invention.
Fig. 3 is the structural representation of the deformation of the signal deteching circuit of the embodiment of the present invention.
Embodiment
To make those skilled in the art more fully understand the present invention, embodiments of the invention are carried out with reference to the accompanying drawings detailed
Describe in detail bright.
Signal deteching circuit provided in an embodiment of the present invention, it has input and output end, and in its output end
Detect whether its input has input signal, including：First circuit part, its be electrically connected to reference voltage source, input and
Circuit part is detected, and is configured to, when input has low level signal input, produce from reference voltage source VCC and flow to input
Electric current, and produce the electric current from reference voltage source VCC flow detection circuit parts simultaneously；Second circuit part, it is electrically connected
To input, the first circuit part and detection circuit part, and be configured to when input has high level signal input, produce from
The electric current of input flow detection circuit part；And detection circuit part, it includes output end, and is configured to according to coming from the
One circuit part or the input current of second circuit part to export detection signal in output end；Wherein, there is low electricity in input
When ordinary mail number inputs, the operation of second circuit part is suppressed；And when input has high level signal input, the first circuit
Partial operation is suppressed.
Signal deteching circuit provided in an embodiment of the present invention, no matter input whether input high level signal or low level
Signal, end can be output and detected, and switch switching need not be carried out, it is easy to operate.
With reference to figure 2, Fig. 2 is the structural representation of the signal deteching circuit of the embodiment of the present invention.As shown in Fig. 2 the first electricity
Road part can include：The first transistor Q1, its first end are connected to reference voltage source VCC, and its second end leads to its first end
Cross resistance connection and second end is connected to input via the first one way conducting device D1, and its 3rd end is single via the 3rd
Detection circuit part is connected to conduction device D3, from the figure, it can be seen that when input has low level signal input, first
One way conducting device D1 is turned on, and is turned between the first transistor Q1 first end and the 3rd end, and the 3rd one way conducting device D3
Conducting.
From the figure, it can be seen that resistance is embedded with the first transistor Q1, to ensure that circuit stability is run.The first transistor
Q1 can be PNP transistor or P-channel field-effect transistor (PEFT) pipe.Also, diode may be used as the first one way conducting device
D1 and the 3rd one way conducting device D3.What deserves to be explained is the diode that " diode " designated herein is known in the art, its
There is one-way conduction characteristic under normal conditions, in the detection circuit that the embodiment of the present invention is provided, refer in particular to only with above-mentioned
One-way conduction characteristic and it will not be hit in the case of the normal use detection circuit because the backward voltage being applied in is excessive
" diode " worn.
Specifically, second circuit part can include：The the second one way conducting device D2 and the 4th conduction device of series connection
D4, and wherein, when input has high level signal input, the second one way conducting device D2 conductings, and the 4th conduction device
Part D4 reverse-conductings when the high level signal that input inputs is higher than its breakdown voltage.
Typically, the second one way conducting device can be diode, and the 4th conduction device D4 can be Zener diode.Together
Diode of receiving is the device for having reverse-conducting characteristic, and according to the breakdown voltage of Zener diode, the detection circuit can also be true
Determine the minimum voltage of input high level signal.
In the signal deteching circuit of the embodiment of the present invention, detection circuit part can include：Second transistor Q2, it
One end is output end, and its second end is connected with its 3rd end by resistance and second end is connected to the first circuit part and second
The output par, c of circuit part is to receive input current, its 3rd end ground connection, and wherein, when receiving input current, the
Conducting and its first end output detection signal between two-transistor Q2 first end and the 3rd end.
From the figure, it can be seen that resistance is embedded with second transistor Q2, to ensure that circuit stability is run.Second transistor
Q2 can be NPN transistor or N-channel FET.
In addition, second transistor Q2 first end is set to be connected to reference voltage source VCC through resistance R1, so as in input
When not having signal input, because Q2 ends, output end is high level signal, and when input has signal input, then output end
Low level signal is exported, so as to distinguish the situation that input whether there is input signal well.Now, low level signal detects letter
Number.Also, same reference voltage source VCC can be used in inlet circuit part and circuit of output terminal part, simplifies setting for circuit
Meter.
Obviously, detection circuit part is also not necessarily limited to above-mentioned concrete structure, for example, it is also possible to utilize device as such as optocoupler
Part, when its input have input signal, its output end can also export detection signal.Those skilled in the art can be according to this hair
Bright spirit and essence makes a change to physical circuit part, but these changes belong to the guarantor that the claims in the present invention are limited
Within the scope of shield.
Current direction by the specific embodiment shown in labor figure in practical application below.
When input have input low level signal, transistor Q1 BE knot conducting, electric current by VCC by Q1 BE knots,
D1 flows to input；Due to D2, D4 presence, this branch road（Second circuit part）It is not turned on；Q1 CE knot conductings simultaneously, electric current
Q2 B poles are flowed to by Q1 CE knots, D3 by VCC, Q2 BE is tied conducting, then Q2 CE knot conductings, output end output are low
Level signal（Low level signal is the detection signal having been explained above）；Due to D2 presence, this branch road of R2, D4, D2（Second
Circuit part）It is not turned on, electric current can only flow to Q2 B poles.When input input high level signal, due to D1 presence, D1
The branch road at place（A part in first circuit part）It is not turned on, electric current flows to D2 by input, and Q2 B is flowed to through D4, R2
Pole, Q2 BE is set to tie conducting, then Q2 CE knot conductings, export low level signal；Wherein due to D3 presence, this branch road of D3
（Another part in first circuit part）It is not turned on.
Fig. 3 is the structural representation of the deformation of the signal deteching circuit of the embodiment of the present invention.In figure 3, the first transistor
It is discrete component between Q1 and R5, R6, you can to understand the first transistor Q1 as the transistor without embedded resistance.Equally
Ground, between second transistor Q2 and R3, R4 and discrete component, i.e. second transistor Q2 are the crystal without embedded resistance
Pipe.
It should be appreciated that the present invention is not limited to above-mentioned specific embodiment, without departing substantially from spirit of the invention and its real situation
Under, those skilled in the art can make various corresponding changes and deformation according to the present invention, but these accordingly change and become
Shape should all belong within the protection domain of appended claims of the present invention.
Claims (7)
1. a kind of signal deteching circuit, it has input and output end, and for whether detecting its input in its output end
There is input signal, including：
First circuit part, it is electrically connected to reference voltage source, the input and detection circuit part, and is configured in institute
When stating input has low level signal input, produce the electric current that the input is flowed to from reference voltage source, and produce simultaneously from
The electric current of the reference voltage source flow detection circuit part；
Second circuit part, it is electrically connected to the input, first circuit part and the detection circuit part, and matches somebody with somebody
It is set to the electricity for when the input has high level signal input, producing and the detection circuit part being flowed to from the input
Stream；And
The detection circuit part, it includes the output end, and is configured to basis and comes from first circuit part or described
The input current of second circuit part to export detection signal in the output end；
Wherein
First circuit part includes：
The first transistor, its first end are connected to the reference voltage source, and its second end is connected with its first end by first resistor
Connect and second end is connected to the input via the first one way conducting device, and its 3rd end is via the 3rd one-way conduction
Device is connected to the detection circuit part,
When the input has low level signal input, turned between the first end of the first transistor and the second end, institute
The conducting of the first one way conducting device is stated, is turned between the first end of the first transistor and the 3rd end, and it is described 3rd unidirectional
Conduction device is turned on, and when the input has high level signal input, first one way conducting device is not turned on；
The second circuit part includes：
The second one way conducting device and the 4th conduction device of series connection, and wherein,
When the input has high level signal input, the second one way conducting device conducting, and the 4th conducting
Device reverse-conducting when the high level signal that the input inputs is higher than its breakdown voltage, has low level in the input
When signal inputs, second one way conducting device and the 4th conduction device are not turned on.
2. signal deteching circuit as claimed in claim 1, wherein the detection circuit part includes：
Second transistor, its first end are the output end, its second end be connected with its 3rd end by second resistance and this
Two ends are connected to the output par, c of first circuit part and the second circuit part to receive the input current, and it
Three ends are grounded, and wherein,
When receiving the input current, conducting and its first end between the first end of the second transistor and the 3rd end
Export the detection signal.
3. signal deteching circuit as claimed in claim 1, wherein
First one way conducting device and the 3rd one way conducting device are diode.
4. signal deteching circuit as claimed in claim 1, wherein second one way conducting device is diode, the described 4th
Conduction device is Zener diode.
5. signal deteching circuit as claimed in claim 2, wherein the first end of the second transistor is connected to institute through resistance
State reference voltage source.
6. signal deteching circuit as claimed in claim 1, wherein the first resistor is embedded in the first transistor.
7. signal deteching circuit as claimed in claim 2, wherein the second resistance is embedded in the second transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410061854.0A CN104868901B (en) | 2014-02-24 | 2014-02-24 | Signal deteching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410061854.0A CN104868901B (en) | 2014-02-24 | 2014-02-24 | Signal deteching circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104868901A CN104868901A (en) | 2015-08-26 |
| CN104868901B true CN104868901B (en) | 2018-02-06 |
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ID=53914464
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410061854.0A Active CN104868901B (en) | 2014-02-24 | 2014-02-24 | Signal deteching circuit |
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| Country | Link |
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Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109445424B (en) * | 2018-12-25 | 2024-06-11 | 珠海格力电器股份有限公司 | Detection circuit and detection device |
| CN116243328B (en) * | 2023-01-20 | 2024-06-25 | 松下神视电子（苏州）有限公司 | Sensor for detecting a position of a body |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0661750A (en) * | 1992-08-10 | 1994-03-04 | Mitsubishi Electric Corp | High frequency amplifier device |
| JPH06269029A (en) * | 1993-03-15 | 1994-09-22 | Fujitsu Ltd | Ringing signal detection circuit |
| US5942942A (en) * | 1997-08-28 | 1999-08-24 | Holtek Semiconductor, Inc. | Differential amplifier with double output stages |
| JP2002072952A (en) * | 2000-08-25 | 2002-03-12 | Sharp Corp | Signal detention circuit and picture display device using the same |
| CN202421285U (en) * | 2011-12-30 | 2012-09-05 | 上海博泰悦臻电子设备制造有限公司 | Automobile collision signal detection circuit |
| CN103167316A (en) * | 2010-05-26 | 2013-06-19 | 友达光电股份有限公司 | Input signal detection circuit and related liquid crystal television |
-
2014
- 2014-02-24 CN CN201410061854.0A patent/CN104868901B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0661750A (en) * | 1992-08-10 | 1994-03-04 | Mitsubishi Electric Corp | High frequency amplifier device |
| JPH06269029A (en) * | 1993-03-15 | 1994-09-22 | Fujitsu Ltd | Ringing signal detection circuit |
| US5942942A (en) * | 1997-08-28 | 1999-08-24 | Holtek Semiconductor, Inc. | Differential amplifier with double output stages |
| JP2002072952A (en) * | 2000-08-25 | 2002-03-12 | Sharp Corp | Signal detention circuit and picture display device using the same |
| CN103167316A (en) * | 2010-05-26 | 2013-06-19 | 友达光电股份有限公司 | Input signal detection circuit and related liquid crystal television |
| CN202421285U (en) * | 2011-12-30 | 2012-09-05 | 上海博泰悦臻电子设备制造有限公司 | Automobile collision signal detection circuit |
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| Publication number | Publication date |
|---|---|
| CN104868901A (en) | 2015-08-26 |
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