CN204373736U - Based on the detecting liquid level circuit of phaselocked loop - Google Patents
Based on the detecting liquid level circuit of phaselocked loop Download PDFInfo
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- CN204373736U CN204373736U CN201520032866.0U CN201520032866U CN204373736U CN 204373736 U CN204373736 U CN 204373736U CN 201520032866 U CN201520032866 U CN 201520032866U CN 204373736 U CN204373736 U CN 204373736U
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Abstract
The utility model discloses a kind of detecting liquid level circuit based on phaselocked loop, and this circuit comprises liquid level detection circuit, waveform modulated circuit module; The reference voltage of detecting liquid level circuit is by vibrate and frequency dividing circuit provides, and by the sample needle of capacitance type structure as level sensing mode, the output terminal of liquid level detection circuit is connected to the input end of waveform modulated circuit, and the output terminal of waveform modulated circuit is connected to the look-at-me end of MCU.The utility model has the advantage of: sample needle selects high reliability capacitance level transducer, and adopt phaselocked loop CD4046 circuit to complete the output of detection to capacitance type sensor capacitance variations, signal filtering and control signal, achieve the target reducing cross pollution, improve instrument performance, and the utility model structure is simple, good stability, solves the faults such as ever-present in conventional biochemical analyser " striker " and " suction ".
Description
Technical field
The utility model belongs to the electronic circuit of Medical Devices, mainly realizes the detecting liquid level function of automatic clinical chemistry analyzer.
Background technology
Detecting liquid level (LLD) function is that clinical full-automatic testing instruments are requisite, it probes into the degree of depth of liquid to be transferred by controlling sample needle, thus farthest solves the problem that instrument cross pollution is high and loading errors is large because sample needle outside surface attaching liq causes.Residual contamination rate is the important indicator weighing Biochemical Analyzer analytical performance, and sample needle outside surface liquid carrying amount is the principal element causing instrument Residual contamination, the liquid carrying amount therefore reducing sample needle outside surface is the important method reducing residual contamination rate, improve analysis precision.
At present, detecting liquid level circuit senses mode mainly contains resistance-type and condenser type two kinds, and traditional system generally adopts resistance-type sensing mode, and this mode detects liquid level according to air resistance from the different of liquid resistance.But in actual applications, because the conductance of different liquids is different, and resistance-type sensing sensitivity is poor, is therefore difficult to accurately control the degree of depth that sampling needle probes into liquid to be transferred, often occurs the fault such as " suction " and " striker " clinically.
Summary of the invention
The purpose of this utility model is to provide a kind of frame mode be combined with phase-locked loop circuit by condenser type suction needle, to overcome the deficiency of detecting liquid level function in prior art.
The technical solution of the utility model is: a kind of detecting liquid level circuit based on phaselocked loop, and this circuit comprises liquid level detection circuit, waveform modulated circuit module; The reference voltage of detecting liquid level circuit is by vibrate and frequency dividing circuit provides, and by the sample needle of capacitance type structure as level sensing mode, the output terminal of liquid level detection circuit is connected to the input end of waveform modulated circuit, and the output terminal of waveform modulated circuit is connected to the look-at-me end of MCU.
Described liquid level detection circuit comprises switch chip and CD4046 typical chip, V
inthe output terminal of signal access vibration and frequency dividing circuit, as the reference voltage of phase-locked loop circuit, Probe signal is connected to condenser type suction needle, and output voltage signal VCO_OUT is connected to the input end of waveform modulated circuit.
Described waveform modulated circuit comprises two amplifiers and peripheral circuit thereof, and VCO_OUT is connected to the output terminal of liquid level detection circuit, and No. 7 pins of amplifier IC205B are connected to the look-at-me input end of MCU.
Thinking of the present utility model is: when sample needle touches liquid, its capacitance changes, and cause the phase place of phaselocked loop input voltage signal to change, now the change of phase place is converted to a deviation voltage by phase-locked loop circuit, again after low-pass filter filtering, signal shaping and voltage amplification, detecting liquid level system exports positive pulse signal, and triggers corresponding MCU generation interruption, is finally completed the start and stop controlling sample needle action by central processing unit.
Vibration and frequency dividing circuit can be liquid level detection circuit provides a fixed frequency to be f
0output voltage V
in, this voltage makes the benchmark of whole phaselocked loop phase comparator.Sample needle is an external capacitor sensor, is connected to 6, No. 7 pins of CD4046 typical chip, and form RC oscillatory circuit, oscillation frequency is f
1.When sample needle does not touch liquid, by regulating the voltage V of vibration and frequency dividing circuit
in, satisfy condition f
1=f
0, now, in CD4046 typical chip, the output voltage of phase comparator II is 0.When sample needle touches liquid, the capacitance of sample needle changes, voltage controlled oscillator output voltage signal V
ofrequency change, now, f
1≠ f
0, i.e. V
owith reference signal V
inthere is phase differential, therefore phase comparator will obtain a deviation voltage Δ U, this voltage, through forming low-pass filter circuit filtering high fdrequency component by R213, R214, R215, R216, C208, C209, C210, finally exports a burning voltage signal VCO_OUT.VCO_OUT outputs to the look-at-me input end of MCU through the amplification of waveform modulated circuit, Shape correction.
The utility model has the advantage of: sample needle selects high reliability capacitance level transducer, and adopt phaselocked loop CD4046 circuit to complete the output of detection to capacitance type sensor capacitance variations, signal filtering and control signal, achieve the target reducing cross pollution, improve instrument performance, and the utility model structure is simple, good stability, solves the faults such as ever-present in conventional biochemical analyser " striker " and " suction ".
Accompanying drawing explanation
Fig. 1 is the schematic diagram of liquid level detection circuit;
Fig. 2 is the schematic diagram of waveform modulated circuit.
Embodiment
The utility model will by reference to the accompanying drawings, is described further by following examples.
Embodiment.
Accompanying drawing 1 is the schematic diagram of liquid level detection circuit.Probe signal is connected to condenser type suction needle, V
insignal is connected to the output terminal of vibration and frequency dividing circuit, and VCO_OUT is connected to the input end of waveform modulated circuit.Wherein IC203 is CD4046 typical chip, and SW201 is that toggle switch MK13C01, Probe are connected to condenser type suction needle, V
insignal is connected to the output terminal of vibration and frequency dividing circuit, and VCO_OUT is connected to the input end of waveform modulated circuit.
Accompanying drawing 2 is the schematic diagram of waveform modulated circuit.VCO_OUT is connected to the output terminal of liquid level detection circuit, and No. 7 pins of amplifier IC205B are connected to the signal input part of controller.Wherein IC205A, IC205B are the output terminal that operational amplifier LM358AD, VCO_OUT are connected to liquid level detection circuit, and No. 7 pins of amplifier IC205B are connected to the look-at-me input end of controller.
The concrete connected mode of the present embodiment is: 6, No. 7 pins of CD4046 typical chip IC203 are connected to sample needle by electric capacity C207, No. 12 pins of CD4046 typical chip IC203 are connected to No. 3 pins of switch chip SW201 by resistance R210 and potentiometer RW201,9, No. 13 pins of CD4046 typical chip IC203 are connected to the input end VCO_OUT of waveform modulated circuit by resistance R214, R215, R216 and electric capacity C208, C209, C210.No. 4 pins of switch chip SW201 are connected to No. 2 pins of switch chip SW201 by resistance R202, No. 2 pins of switch chip SW201 are connected to No. 1 pin of switch chip SW201 again by resistance R207, No. 1 pin of switch chip SW201 is again by resistance R208 ground connection.No. 3 pins of amplifier IC205A are connected to the output terminal VCO_OUT of liquid level detection circuit by resistance R220,1, No. 2 pin of amplifier IC205A is by electric capacity C212, resistance R219, R217, R218, R219 ground connection, No. 8 pins of amplifier IC205A are connected to power end VCC_5V, No. 4 pin ground connection of amplifier IC205A.No. 5 pins of amplifier IC205B are connected to No. 1 pin of amplifier IC205A by resistance R221, No. 6 pins of amplifier IC205B are connected to power supply VCC_5V by R222 and by resistance R233 ground connection, No. 7 pins of amplifier IC205B are connected to the look-at-me input end of MCU.
The course of work of the present embodiment is: vibration and frequency dividing circuit can be liquid level detection circuit provides a fixed frequency to be f
0output voltage V
in, this voltage makes the benchmark of whole phaselocked loop phase comparator.Sample needle is an external capacitor sensor, is connected to 6, No. 7 pins of CD4046 typical chip IC203, and form RC oscillatory circuit, oscillation frequency is f
1.When sample needle does not touch liquid, by regulating the voltage V of vibration and frequency dividing circuit
in, satisfy condition f
1=f
0, now, in CD4046 typical chip IC203, the output voltage of phase comparator II is 0.When sample needle touches liquid, the capacitance of sample needle changes, voltage controlled oscillator output voltage signal V
ofrequency change, now, f
1≠ f
0, i.e. V
owith reference signal V
inthere is phase differential, therefore phase comparator will obtain a deviation voltage Δ U, this voltage, through forming low-pass filter circuit filtering high fdrequency component by R213, R214, R215, R216, C208, C209, C210, finally exports a burning voltage signal VCO_OUT.VCO_OUT outputs to the look-at-me input end of MCU through the amplification of waveform modulated circuit, Shape correction.Owing to adopting capacitive sensing mode to detect liquid level, highly sensitive, reliability strong, reduces the frequency that the fault of Biochemical Analyzer in application of sample process occurs.
Claims (3)
1. based on a detecting liquid level circuit for phaselocked loop, it is characterized in that: this circuit comprises liquid level detection circuit, waveform modulated circuit module; The reference voltage of detecting liquid level circuit is by vibrate and frequency dividing circuit provides, and by the sample needle of capacitance type structure as level sensing mode, the output terminal of liquid level detection circuit is connected to the input end of waveform modulated circuit, and the output terminal of waveform modulated circuit is connected to the look-at-me end of MCU.
2. according to claim 1 based on the detecting liquid level circuit of phaselocked loop, it is characterized in that: described liquid level detection circuit comprises switch chip SW201 and CD4046 typical chip IC203, V
inthe output terminal of signal access vibration and frequency dividing circuit, as the reference voltage of phase-locked loop circuit, Probe signal is connected to condenser type suction needle, and output voltage signal VCO_OUT is connected to the input end of waveform modulated circuit.
3. according to claim 1 based on the detecting liquid level circuit of phaselocked loop, it is characterized in that: described waveform modulated circuit comprises two amplifiers IC205A, IC205B and peripheral circuit thereof, VCO_OUT is connected to the output terminal of liquid level detection circuit, and No. 7 pins of amplifier IC205B are connected to the look-at-me input end of MCU.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520032866.0U CN204373736U (en) | 2015-01-19 | 2015-01-19 | Based on the detecting liquid level circuit of phaselocked loop |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520032866.0U CN204373736U (en) | 2015-01-19 | 2015-01-19 | Based on the detecting liquid level circuit of phaselocked loop |
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|---|---|
| CN204373736U true CN204373736U (en) | 2015-06-03 |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110221090A (en) * | 2019-06-21 | 2019-09-10 | 苏州长光华医生物医学工程有限公司 | A kind of anti-suction of applied chemistry luminescence analyzer, idle discharge system and method |
| CN111077819A (en) * | 2019-12-06 | 2020-04-28 | 武汉航空仪表有限责任公司 | Frequency starting circuit |
| CN113514129A (en) * | 2021-06-28 | 2021-10-19 | 安徽伊普诺康生物技术股份有限公司 | Liquid level detection system and method |
| CN115790777A (en) * | 2023-01-05 | 2023-03-14 | 山东康华生物医疗科技股份有限公司 | Liquid level detection device |
-
2015
- 2015-01-19 CN CN201520032866.0U patent/CN204373736U/en active Active
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110221090A (en) * | 2019-06-21 | 2019-09-10 | 苏州长光华医生物医学工程有限公司 | A kind of anti-suction of applied chemistry luminescence analyzer, idle discharge system and method |
| CN110221090B (en) * | 2019-06-21 | 2021-03-23 | 苏州长光华医生物医学工程有限公司 | Air suction and air discharge preventing system and method applying chemiluminescence analyzer |
| CN111077819A (en) * | 2019-12-06 | 2020-04-28 | 武汉航空仪表有限责任公司 | Frequency starting circuit |
| CN111077819B (en) * | 2019-12-06 | 2021-06-01 | 武汉航空仪表有限责任公司 | Frequency starting circuit |
| CN113514129A (en) * | 2021-06-28 | 2021-10-19 | 安徽伊普诺康生物技术股份有限公司 | Liquid level detection system and method |
| CN115790777A (en) * | 2023-01-05 | 2023-03-14 | 山东康华生物医疗科技股份有限公司 | Liquid level detection device |
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