CN205679688U - A kind of high accuracy frequency meter - Google Patents
A kind of high accuracy frequency meter Download PDFInfo
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- CN205679688U CN205679688U CN201620569311.4U CN201620569311U CN205679688U CN 205679688 U CN205679688 U CN 205679688U CN 201620569311 U CN201620569311 U CN 201620569311U CN 205679688 U CN205679688 U CN 205679688U
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- resistance
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- operational amplifier
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Abstract
The utility model discloses a kind of high accuracy frequency meter, comprising: signal amplifies and shaping unit, microprocessor unit, warning LED lamp unit, display circuit unit；Signal amplifies the square-wave signal input being connected microprocessor unit with the shaping unit output of shaping unit；First signal output part of microprocessor unit connects the control port of warning LED lamp unit；The secondary signal output of microprocessor unit connects the data-in port of display circuit unit；3rd signal output part of microprocessor unit connects the control input port of display circuit unit.The utility model based on operational amplifier chip, uses two-stage amplifying circuit to be amplified signal source, and gain is big, can the frequency of Validity Test ac small signal.Meanwhile, the utility model circuit is simple, low cost of manufacture, and system reliability is strong.
Description
Technical field
The utility model relates to signal measurement field, particularly relates to a kind of frequency meter.
Background technology
With development and the application of scientific and technological level, Measurement and Control System is also growing.Measurement signal includes simulation
Signal, data signal, also include the information such as amplitude, frequency of signal simultaneously.Additionally, there is also by being converted into physical signalling
Frequency information, is gone other physical characteristics of measurement system further by testing frequency information.Such as test rotating speed, flow etc..
So, frequency measurement is also industry, requisite measurement parameter in scientific research.
In existing frequency meter technology, mainly application transistor amplifier circuit carries out one stage signal amplification simultaneously to signal source
Carrying out shaping, this method hard wires is more complicated, signal is easily disturbed, and reliability is poor.Meanwhile, existing frequency meter one
As use one-level to amplify signal source, for exchange weak signal, its amplifying power is not enough, it is impossible to realize high-precision frequency
Test.
Utility model content
Because the drawbacks described above of prior art, technical problem to be solved in the utility model is to provide a kind of high accuracy
Frequency meter, it amplifies based on two-stage calculation and exchanges weak signal and is amplified.
For achieving the above object, the utility model provides a kind of high accuracy frequency meter, comprising: signal amplifies and shaping list
Unit, microprocessor unit, warning LED lamp unit, display circuit unit；
Signal amplifies the square-wave signal input being connected microprocessor unit with the shaping unit output of shaping unit；Micro-
First signal output part of processor unit connects the control port of warning LED lamp unit；The secondary signal of microprocessor unit
Output connects the data-in port of display circuit unit；3rd signal output part of microprocessor unit connects display circuit
The control input port of unit；
Signal amplification includes with shaping unit: one-level amplifying circuit, second amplifying circuit and voltage comparator circuit；One-level is put
Big circuit comprises measured signal interface, the first polar capacitor, the first resistance, the second polar capacitor, the second resistance, the first computing are put
Big device chip, the 3rd electric capacity, the 3rd resistance, the 4th resistance；Second amplifying circuit comprise polarity the 4th electric capacity, the 5th resistance,
Five polar capacitors, the 6th resistance, the second operational amplifier chip, the 6th electric capacity, the 7th resistance, the 8th resistance；Voltage ratio is more electric
Road comprises the 7th electric capacity, the 9th adjustable resistance, the tenth resistance, the 11st resistance, voltage comparator chip；
Measured signal interface is used for accessing measured signal；One is simultaneously terminated by the first polar capacitor and the first resistant series
Ground, the other end connects the in-phase input end of the first operational amplifier chip；Second polar capacitor and the second resistant series by it
Signaling interface is surveyed in one end reception, and the other end connects the in-phase input end of the first operational amplifier chip；3rd electric capacity and the 3rd electricity
One end is simultaneously grounded by resistance series connection, the inverting input of its another termination the first operational amplifier chip；4th resistance one end is even
Connecing the inverting input of the first operational amplifier chip, the other end connects the output of the first operational amplifier chip；
5th polar capacitor and the 6th resistant series the output that its one end is connected the first operational amplifier chip, separately
One end connects the in-phase input end of the second operational amplifier chip；One is simultaneously terminated by polarity the 4th electric capacity and the 5th resistant series
Ground, the other end connects the in-phase input end of the second operational amplifier chip；6th electric capacity and the 7th resistant series by its one end
Ground connection, its another termination the second operational amplifier chip inverting input.8th resistance one end connects the second operational amplifier
The inverting input of chip, the other end connects the output of the second operational amplifier chip；
7th electric capacity and the 11st resistant series the output that its one end is connected the second operational amplifier chip, another
End connects the in-phase input end of voltage comparator chip；9th adjustable resistance one end ground connection, the other end connects voltage comparator core
The inverting input of piece；Tenth resistance one end connects power supply, and the other end connects the inverting input of voltage comparator chip；Voltage
The output of comparator chip is the output of shaping unit.
The utility model passes through two-stage signal amplifying circuit and voltage comparator chip circuit, is amplified signal source
Shaping, can improve the discriminating power of exchange weak signal, contribute to the mensuration of subsequent frequencies.
Furthermore, the first signal output part of microprocessor unit is P3.3 port；The second of microprocessor unit
Signal output part is P1 port；The data-in port of display circuit unit is 7 pin～14 pin of display module；Microprocessor list
3rd signal output part of unit is P3.4, P3.5, P3.7 port, and the control input port of display circuit unit is display module
4 pin～6 pin；1 pin that display circuit unit also comprises to pull up the first resistance the 4, the 14th pull-up resistor connects power supply, on the 14th
2 pin～9 pin of pull-up resistor connect 7 pin～14 pin of display module.
The utility model using P1 port as the FPDP of display module, using P3.4, P3.5, P3.7 port as display
The control port of module, contributes to circuit board trace.
Furthermore, warning LED lamp unit comprises the 13rd resistance, LED, and the anode of LED connects power supply, LED
Negative electrode series connection the 13rd resistance of lamp, the other end of the 13rd resistance is the control port of warning LED unit, and connects micro-process
The P3.3 port of device unit.The utility model is also equipped with warning LED, and when frequency is higher than the upper limit or is less than lower limit, alarm lamp dodges
Bright signal.
The beneficial effects of the utility model are: the utility model, based on operational amplifier chip, uses two-stage amplifying circuit
Being amplified signal source, gain is big, can the frequency of Validity Test ac small signal.Meanwhile, the utility model circuit is simple, system
Making low cost, system reliability is strong.
Brief description
Fig. 1 is the circuit theory schematic diagram of the utility model one detailed description of the invention；
Fig. 2 is the circuit diagram that in the utility model one embodiment, signal amplifies with shaping unit；
Fig. 3 is that the utility model one implements microprocessor unit circuit figure.
Detailed description of the invention
The utility model is described in further detail with embodiment below in conjunction with the accompanying drawings:
As it is shown in figure 1, the present embodiment provides a kind of high accuracy frequency meter, comprising:
Signal amplifies and shaping unit, microprocessor unit, warning LED lamp unit, display circuit unit；
Signal amplifies the square-wave signal input being connected microprocessor unit 2 with the shaping unit output of shaping unit 1；
First signal output part of microprocessor unit 2 connects the control port of warning LED lamp unit 3；The second of microprocessor unit 2
Signal output part connects the data-in port of display circuit unit 4；3rd signal output part of microprocessor unit 2 connects aobvious
Show the control input port of circuit unit 4；
As in figure 2 it is shown, in the present embodiment, signal amplification includes with shaping unit 1: one-level amplifying circuit, two grades of amplifications
Circuit and voltage comparator circuit；One-level amplifying circuit comprise measured signal interface the 11st, the first polar capacitor C1, the first resistance R1,
Second polar capacitor C2, the second resistance R2, the first operational amplifier chip U1, the 3rd electric capacity C3, the 3rd resistance R3, the 4th resistance
R4；Second amplifying circuit comprises quadripolarity electric capacity C4, the 5th resistance R5, the 5th polar capacitor C5, the 6th resistance R6, the second fortune
Calculate amplifier chip U2, the 6th electric capacity C6, the 7th resistance R7, the 8th resistance R8；Voltage comparator circuit comprise the 7th electric capacity C7, can
Adjust the 9th resistance R9, the tenth resistance R10, the 11st resistance R11, voltage comparator chip U3；
In the present embodiment, measured signal interface 11 is used for receiving measured signal；First polar capacitor C1 and the first resistance
One end is simultaneously grounded by R1 series connection, and the other end connects the in-phase input end of the first operational amplifier chip U1；Second polar capacitor
One is simultaneously terminated measured signal interface measured signal port 11 by C2 and the second resistance R2 series connection, and the other end connects the first computing and puts
The in-phase input end of big device chip U1；One end is simultaneously grounded by the 3rd electric capacity C3 and the 3rd resistance R3 series connection, its another termination the
The inverting input of one operational amplifier chip U1；4th resistance R4 one end connects the anti-phase defeated of the first operational amplifier chip U1
Entering end, the other end connects the output of the first operational amplifier chip U1；
In the present embodiment, the 5th polar capacitor C5 and the 6th resistance R6 connects and its one end is connected the first operation amplifier
The output of device chip U1, the other end connects the in-phase input end of the second operational amplifier chip U2；Quadripolarity electric capacity C4 and
One end is simultaneously grounded by the 5th resistance R5 series connection, and the other end connects the in-phase input end of the second operational amplifier chip U2；6th
One end is simultaneously grounded by electric capacity C6 and the 7th resistance R7 series connection, the anti-phase input of its another termination the second operational amplifier chip U2
End.8th resistance R8 one end connects the inverting input of the second operational amplifier chip U2, and the other end connects the second operation amplifier
The output of device chip U2；In the present embodiment, it is will to exchange small signals amplification by two-stage amplifying circuit, to facilitate follow-up ripple
Shape converts.
In the present embodiment, the 7th electric capacity C7 and the 11st resistance R11 connects and its one end is connected the second operation amplifier
The output of device chip U2, the other end connects the in-phase input end of voltage comparator chip U3；Adjustable 9th resistance R9 mono-terminates
Ground, the other end connects the inverting input of voltage comparator chip U3；10th the tenth resistance R10 mono-terminates 5V, and the other end connects
The inverting input of voltage comparator chip U3；The output of voltage comparator chip U3 is the output of shaping unit.At this
It in embodiment, is to use voltage comparator chip, AC signal is converted to square-wave signal.
As it is shown on figure 3, in the present embodiment, the first signal output part of microprocessor unit 2 is P3.3 port；Micro-process
The secondary signal output of device unit 2 is P1 port；The data-in port of display circuit unit 4 is 7 pin of display module 41
～14 pin；3rd signal output part of microprocessor unit 2 is P3.4, P3.5, P3.7 port, the control of display circuit unit 4
Input port is 4 pin～6 pin of display module 41；Display circuit unit 4 also comprises the 14th pull-up resistor R14, on the 14th
1 pin of pull-up resistor R14 meets 5V, and 2 pin～9 pin of the 14th pull-up resistor R14 connect 7 pin～14 pin of display module 41.
The utility model using P1 port as the FPDP of display module, using P3.4, P3.5, P3.7 port as display
The control port of module, contributes to circuit board trace.
In the present embodiment, warning LED lamp unit 3 comprises the 13rd resistance R13, LED L1, and the anode of LED L1 connects
5V, negative electrode series connection the 13rd resistance R13 of LED L1, the other end of the 13rd resistance R13 is the control end of warning LED unit 3
Mouthful, and connect the P3.3 port of microprocessor unit 2.
In the present embodiment, the first polar capacitor C1 be 220uF, the first resistance R1 be that 200 Ω, the second polar capacitor C2 are
22uF, the second resistance R2 be 10k Ω, the first operational amplifier chip U1 be chip AD8051, the 3rd electric capacity C3 be 22uF, the 3rd
Resistance R3 be 500 Ω, the 4th resistance R4 be 5k Ω；Quadripolarity electric capacity C4 be 220uF, the 5th resistance R5 be 2.2k Ω, the 5th
Polar capacitor C5 be 220uF, the 6th resistance R6 be 100k Ω, the second operational amplifier chip U2 be chip AD8051, the 6th electricity
Hold C6 be 220uF, the 7th resistance R7 be 5k Ω, the 8th resistance R8 be 100k Ω；7th electric capacity C7 is 100pF, adjustable 9th electricity
Resistance R9 be 20k Ω, the tenth resistance R10 be 20k Ω, the 11st resistance R11 be 10k Ω, voltage comparator chip U3 be chip
LM339。
In the present embodiment, the 8th electric capacity C8, the 9th electric capacity C9 are 33pF, and crystal oscillator Y1 is 12Mhz, and the tenth electric capacity C10 is
10uF, the 12nd resistance R12, the 13rd resistance R13 are 4.7k Ω, and the 14th pull-up resistor R14 is 10k Ω.Pull-up resistor has
Help improve the driving force of single-chip microcomputer P0 mouth.
In the present embodiment, the main control chip of microprocessor unit 2 is AT89C2051, and display module 41 is LCD1602.
In the present embodiment, square-wave signal input connects the P3.0 port of AT89C2051.It is noted that AT89C2051 is
8015 series monolithics simplify version, and structure is more simplified.
Additionally, in the present embodiment, microprocessor unit is used for receiving input signal and sends control signal, warning LED
Unit is used for underfrequency or too high warning, and display circuit unit is used for display frequency information.
To sum up, the utility model uses two-stage amplifying circuit to be amplified to measured signal, uses voltage comparator chip
AC signal being converted into square-wave signal, and being sent to microprocessor unit, frequency information is shown by display unit, reports to the police
Dangerous Frequency is reported to the police by LED.Measured signal gain amplifier is big, can the frequency of Validity Test ac small signal.Meanwhile, originally
Utility model circuit is simple, low cost of manufacture, and system reliability is strong.
Preferred embodiment of the present utility model described in detail above.It should be appreciated that the ordinary skill people of this area
Member just can make many modifications and variations according to design of the present utility model without creative work.Therefore, all technology neck
In territory, technical staff passes through logic analysis, reasoning or limited reality on the basis of existing technology according to design of the present utility model
Test available technical scheme, all should be in the protection domain being defined in the patent claims.
Claims (3)
1. one kind high accuracy frequency meter, it is characterised in that include: signal amplify with shaping unit (1), microprocessor unit (2),
Warning LED lamp unit (3), display circuit unit (4)；
Described signal amplifies the square wave letter being connected described microprocessor unit (2) with the shaping unit output of shaping unit (1)
Number input；First signal output part of described microprocessor unit (2) connects the control port of warning LED lamp unit (3)；Institute
The secondary signal output stating microprocessor unit (2) connects the data-in port of described display circuit unit (4)；Described micro-
3rd signal output part of processor unit (2) connects the control input port of described display circuit unit (4)；
The amplification of described signal includes with shaping unit (1): one-level amplifying circuit, second amplifying circuit and voltage comparator circuit；Institute
State one-level amplifying circuit and comprise measured signal interface (11), the first polar capacitor (C1), the first resistance (R1), the second polar capacitor
(C2), the second resistance (R2), the first operational amplifier chip (U1), the 3rd electric capacity (C3), the 3rd resistance (R3), the 4th resistance
(R4)；Described second amplifying circuit comprise quadripolarity electric capacity (C4), the 5th resistance (R5), the 5th polar capacitor (C5), the 6th
Resistance (R6), the second operational amplifier chip (U2), the 6th electric capacity (C6), the 7th resistance (R7), the 8th resistance (R8)；Described electricity
Pressure comparison circuit comprises the 7th electric capacity (C7), the 9th adjustable resistance (R9), the tenth resistance (R10), the 11st resistance (R11), electricity
Pressure comparator chip (U3)；
Described measured signal interface (11) is used for accessing measured signal；Described first polar capacitor (C1) and the first resistance (R1) string
One end is simultaneously grounded by connection, and the other end connects the in-phase input end of described first operational amplifier chip (U1)；Described second pole
Property electric capacity (C2) and the second resistance (R2) series connection and by one termination measured signal interface (11), the other end connect described first fortune
Calculate the in-phase input end of amplifier chip (U1)；3rd electric capacity (C3) is connected with the 3rd resistance (R3) and is grounded one end, its
The inverting input of another termination the first operational amplifier chip (U1)；Described 4th resistance (R4) one end connects the first computing
The inverting input of amplifier chip (U1), the other end connects the output of the first operational amplifier chip (U1)；
Described 5th polar capacitor (C5) and the 6th resistance (R6) are connected and its one end are connected described first operational amplifier core
The output of piece (U1), the other end connects the in-phase input end of described second operational amplifier chip (U2)；Described quadripolarity
Electric capacity (C4) and the 5th resistance (R5) are connected and are grounded one end, and the other end connects described second operational amplifier chip (U2)
In-phase input end；6th electric capacity (C6) connect with the 7th resistance (R7) and by one end be grounded, its another termination the second computing
The inverting input of amplifier chip (U2)；Described 8th resistance (R8) one end connects the anti-of the second operational amplifier chip (U2)
Phase input, the other end connects the output of the second operational amplifier chip (U2)；
Described 7th electric capacity (C7) and the 11st resistance (R11) are connected and its one end are connected described second operational amplifier chip
(U2) output, the other end connects the in-phase input end of described voltage comparator chip (U3)；9th adjustable resistance (R9)
End ground connection, the other end connects the inverting input of voltage comparator chip (U3)；Tenth resistance (R10) one end connects power supply, separately
One end connects the inverting input of voltage comparator chip (U3)；The output of described voltage comparator chip (U3) is described whole
The output of shape unit.
2. a kind of high accuracy frequency meter as claimed in claim 1, it is characterised in that the first of described microprocessor unit (2)
Signal output part is P3.3 port；The secondary signal output of described microprocessor unit (2) is P1 port；Described display circuit
The data-in port of unit (4) is 7 pin～14 pin of display module (41)；3rd signal of described microprocessor unit (2)
Output is P3.4, P3.5, P3.7 port, and the control input port of described display circuit unit (4) is the 4 of display module (41)
Pin～6 pin；Described display circuit unit (4) also comprises the 14th pull-up resistor (R14), described 14th pull-up resistor (R14)
1 pin connect power supply, 2 pin～9 pin of described 14th pull-up resistor (R14) connect 7 pin～14 of described display module (41)
Pin.
3. high accuracy frequency meter as claimed in claim 2 a kind of, it is characterised in that described warning LED lamp unit (3) comprises the
13 resistance (R13), LED (L1), the anode of described LED (L1) connects power supply, the negative electrode series connection institute of described LED (L1)
Stating the 13rd resistance (R13), the other end of described 13rd resistance (R13) is the control port of described warning LED unit (3),
And connect the P3.3 port of described microprocessor unit (2).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620569311.4U CN205679688U (en) | 2016-06-13 | 2016-06-13 | A kind of high accuracy frequency meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201620569311.4U CN205679688U (en) | 2016-06-13 | 2016-06-13 | A kind of high accuracy frequency meter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205679688U true CN205679688U (en) | 2016-11-09 |
Family
ID=57431933
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201620569311.4U Expired - Fee Related CN205679688U (en) | 2016-06-13 | 2016-06-13 | A kind of high accuracy frequency meter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205679688U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114325077A (en) * | 2021-12-28 | 2022-04-12 | 南京济拓信息系统有限公司 | Data emission and acquisition system based on characteristic current |
-
2016
- 2016-06-13 CN CN201620569311.4U patent/CN205679688U/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114325077A (en) * | 2021-12-28 | 2022-04-12 | 南京济拓信息系统有限公司 | Data emission and acquisition system based on characteristic current |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20161109 Termination date: 20170613 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |