CN204557241U - A kind of digital pressure switch - Google Patents
A kind of digital pressure switch Download PDFInfo
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- CN204557241U CN204557241U CN201520213837.4U CN201520213837U CN204557241U CN 204557241 U CN204557241 U CN 204557241U CN 201520213837 U CN201520213837 U CN 201520213837U CN 204557241 U CN204557241 U CN 204557241U
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Abstract
A kind of digital pressure switch, belongs to pressure control equipment field.Comprise shell and be fixed on the control circuit in shell, control circuit at least comprises the pressure transducer, amplifier unit, AD conversion unit, the CPU (central processing unit) that connect successively, and the power supply unit of directly or indirectly to power for pressure transducer, amplifier unit, AD conversion unit, CPU (central processing unit), it is characterized in that: be connected with can be triggered and the signal output unit of output switching signal by CPU (central processing unit) at the signal output part of described CPU (central processing unit).The utility model, by circuit output switching signal, avoids mechanical pressure switch and there is mechanical wear, the defect that contact is easily aging.Signal output unit adopts digital switch, and fast response time, long service life, be provided with reverse fly-wheel diode simultaneously, ensures circuit board not by the impact of inverse electromotive force during switch motion.
Description
Technical field
A kind of digital pressure switch, belongs to pressure control equipment field.
Background technology
Pressure switch is a kind of pressure control device, reaches setting value timer can occur report to the police or send control signal at pressure.Traditional pressure switch is mechanical type, and mechanical pressure switch adopts mechanical type movable member, and its precision is low, bad response and there is alarm setting value dead band.When triggering, by exporting corresponding switching signal after the physical construction action in it.Owing to there is mechanical wear when switch motion, long-term work can make contact aging, causes switching effect undesirable, and serviceable life is shorter.
Summary of the invention
The technical problems to be solved in the utility model is: overcome the deficiencies in the prior art, provides a kind of by circuit output switching signal, avoids mechanical pressure switch and there is mechanical wear, the digital pressure switch that contact is easily aging.
The utility model solves the technical scheme that its technical matters adopts: this digital pressure switch, comprise shell and be fixed on the control circuit in shell, control circuit at least comprises the pressure transducer connected successively, amplifier unit, AD conversion unit, CPU (central processing unit) and be pressure transducer, amplifier unit, AD conversion unit, the power supply unit that CPU (central processing unit) is directly or indirectly powered, it is characterized in that: be connected with can be triggered and the signal output unit of output switching signal by CPU (central processing unit) at the signal output part of described CPU (central processing unit).
Preferably, be connected with at the signal output part of described CPU (central processing unit) and powered by power supply unit, for the display unit shown.
Preferably, be also provided with the signal input output end mouth of described CPU (central processing unit) interconnected, for carrying out the communication unit of communication with CPU (central processing unit).
Preferably, described signal output unit comprises the optocoupler OC1 that model is PC817, a termination power V of resistance R4
cCthe other end connects 1 pin of optocoupler OC1 in succession, 2 pin of optocoupler OC1 connect the signal output part of CPU (central processing unit), the one termination external power source 24VDC+ of resistance R5,4 pin of another termination optocoupler OC1, the 3 pin ground connection of optocoupler OC1,4 pin of the one termination optocoupler OC1 of resistance R6, the base stage of another termination triode Q1 of resistance R6, the emitter of triode Q1 meets external power source 24VDC+, the collector of triode Q1 connects the negative electrode of diode D3, the plus earth of diode D3 and external power source 24VDC-, the current collection very output switch parameter end of triode Q1.
Preferably, be also provided with and be connected with described power supply unit, to the constant-current source circuit that described pressure transducer is powered.
Preferably, described constant-current source circuit comprises the voltage stabilizing diode D1 that operational amplifier U1 that model is TLV2631 and model are LM385, a termination power V of resistance R1
cC, the other end connects the negative electrode of voltage stabilizing diode D1 and the in-phase input end V of operational amplifier U1 simultaneously
iN+, the plus earth of voltage stabilizing diode D1, the inverting input V of a termination operational amplifier U1 of resistance R2
iN-, other end ground connection; The V of operational amplifier U1
oUTfor the output cathode of constant-current source circuit, be connected with the power supply positive pole of pressure transducer U8, the V of operational amplifier U1
iN-for the output negative pole of constant current source, be connected with the power supply negative pole of pressure transducer U8.
Preferably, described pressure transducer adopts diffused silicon piezoresistive pressure sensor.
Compared with prior art, the beneficial effect that the utility model has is:
1, the utility model is by circuit output switching signal, avoids mechanical pressure switch and there is mechanical wear, the defect that contact is easily aging;
2, signal output unit adopts digital switch, and fast response time, long service life, be provided with reverse fly-wheel diode simultaneously, ensures circuit board not by the impact of inverse electromotive force during switch motion;
3, amplifier unit adopts the integrated instrument amplifier of typical three amplifier, while ensure that high cmrr, solves the problem that zero crossings settings exist dead band;
4, adopt diffused silicon piezoresistive pressure sensor, ensure that tonometric high precision, be that pressure transducer is powered by constant current source simultaneously, improves the accuracy of detection of pressure transducer, stablize, the serviceable life of raising switch;
5, analog to digital converter model is MCP3425, adopts 16 analog to digital converters, ensure that very high switch resolution;
6, can be modified to relative alarm parameter by USB interface, parameter configuration is very convenient.
Accompanying drawing explanation
Fig. 1 is digital pressure ON-OFF control circuit functional-block diagram.
Fig. 2 is digital pressure ON-OFF control circuit schematic diagram.
Embodiment
Fig. 1 ~ 2 are most preferred embodiments of the present utility model, are described further below in conjunction with accompanying drawing 1 ~ 2 pair of the utility model.
The control circuit that digital pressure switch comprises shell and arranges in the enclosure, as shown in Figure 1, control circuit comprises: pressure transducer, amplifier unit, AD conversion unit, CPU (central processing unit), display unit, communication unit and signal output unit.The signal output part of pressure transducer is connected with the signal input part of amplifier unit, the signal output part of amplifier module is connected with the signal input part of AD conversion unit, and amplifier module is delivered in AD conversion unit after being amplified by the pressure signal that pressure transducer exports.The output terminal of AD conversion unit is connected with the signal input part of CPU (central processing unit), delivers to CPU (central processing unit) and process after the signal that amplifier exports is carried out analog to digital conversion.The output terminal of CPU (central processing unit) is connected with display unit, the display of data is carried out by display unit, the output terminal of CPU (central processing unit) is connected with signal output unit, by signal output unit to follow-up equipment output switching signal, the input/output port of CPU (central processing unit) is connected with communication unit simultaneously, is realized the communication of data by communication unit.Pressure transducer adopts diffused silicon piezoresistive pressure sensor.
Power supply unit (not drawing in Fig. 1) is also provided with in control circuit, power supply unit is connected with amplifier unit, AD conversion unit, CPU (central processing unit), display unit, control module simultaneously and directly powers for it, be provided with constant-current source circuit simultaneously, power supply unit is that constant-current source circuit is powered, and constant-current source circuit is that pressure transducer is powered.
As shown in Figure 2, power supply unit comprises: model is power conversion chip U7, inductance L 1, the diode D2 of LM2596.The power input pin V of power conversion chip U7
iNmeet external power source 24VDC+, ON/OFF, GND pin ground connection respectively of power conversion chip U7, the power supply output pin V of power conversion chip U7
oUTconnect one end of inductance L 1 and the negative electrode of diode D2 respectively, the plus earth of diode D2, the other end of inductance L 1 is connected with the feedback pin Feedback of power conversion chip U7, the V of power conversion chip U7
oUTpin is voltage output pin, out-put supply V
cC.The model of diode D2 is 1N5824.
Constant-current source circuit comprises: model is the operational amplifier U1 of TLV2631, and model is voltage stabilizing diode D1 and the resistance R1 ~ R2 of LM385.The one termination power V of resistance R1
cC, the other end connects the negative electrode of voltage stabilizing diode D1 and the in-phase input end V of operational amplifier U1 simultaneously
iN+, the plus earth of voltage stabilizing diode D1, the inverting input V of a termination operational amplifier U1 of resistance R2
iN-, other end ground connection.The V of operational amplifier U1
oUTfor the output cathode of constant-current source circuit, be connected with the power supply positive pole of pressure transducer U8, the V of operational amplifier U1
iN-for the output negative pole of constant current source, be connected with the power supply negative pole of pressure transducer U8.
Amplifier unit comprises the instrument amplifier U2 and resistance R3 that model is AD8227.The output cathode of pressure transducer U8 and output negative pole respectively with the V of instrument amplifier U2
iN+pin and V
iN-pin is connected.+ the V of instrument amplifier U2
spin connects power supply V
cC, two R of instrument amplifier U2
gthe indirect gain resistor R3 of pin, the output pin V of instrument amplifier U2
oUTmeet the input end V of modulus conversion chip U3
iN+, REF pin and the-V of instrument amplifier U2
spin is ground connection simultaneously.Amplifier unit adopts the integrated instrument amplifier of typical three amplifier, while ensure that high cmrr, solves the problem that zero crossings settings exist dead band
AD conversion unit comprises the modulus conversion chip U3 that model is MCP3425, and the SCL pin of analog to digital converter U3, SDA pin are connected with 2 pin of central processing unit U4,3 pin respectively, the V of modulus conversion chip U3
iN-pin and V
sSpin short circuit ground connection.The V of modulus conversion chip U3
dDpin connects power supply V
cC-----.Central processing unit U4 is above-mentioned CPU (central processing unit), and employing model is the single-chip microcomputer of PIC18F2XK80 series.
Display unit comprises the LCD MODULE U5 that model is SMS0403A2, and the VDD pin of LCD MODULE U5 is connected power supply V
cC, the DI pin of LCD MODULE U5, CLK pin are connected with 4 pin of central processing unit U4,5 pin respectively, the GND pin ground connection of LCD MODULE U5.
Communication unit comprises the USB communication chip U6 that model is FT245RL and the USB interface be connected with USB communication chip U6.+ 5V the terminal of USB interface is connected after the VCCIO pin of USB communication chip U6, VCC pin short circuit, the USBDM pin of USB communication chip U6, USBDP pin connect UD-, UD+ terminal of USB interface respectively, the GND terminal ground connection simultaneously of the AGND pin of USB communication unit U6, GND pin, TEST pin and USB interface.D0 ~ D7 pin of USB communication chip U6 is connected with 11 ~ 18 pins of central processing unit U4 respectively, and the WR pin of USB communication chip U6, RD pin, TXE pin, RXF pin are connected with 21 ~ 24 pins of central processing unit U4 respectively.
Signal output unit comprises: model is the optocoupler OC1 of PC817, resistance R4 ~ R6, and model is the triode Q1 of PMBT2907A, diode D3.The one termination power VCC of resistance R4, 1 pin of another termination optocoupler OC1, 2 pin of optocoupler OC1 connect 25 pin of central processing unit U4, the one termination external power source 24VDC+ of resistance R5, 4 pin of another termination optocoupler OC1, the 3 pin ground connection of optocoupler OC1, 4 pin of the one termination optocoupler OC1 of resistance R6, the base stage of another termination triode Q1 of resistance R6, the emitter of triode Q1 meets external power source 24VDC+, the collector of triode Q1 connects the negative electrode of diode D3, the plus earth of diode D3 and external power source 24VDC-(and earth terminal), the current collection very output switch parameter end of triode Q1.
By circuit output switching signal, avoid mechanical pressure switch and there is mechanical wear, the defect that contact is easily aging.Signal output unit adopts digital switch, and fast response time, long service life, be provided with reverse sustained diode 3 simultaneously, ensures circuit board not by the impact of inverse electromotive force during switch motion.
Specific works process and principle as follows:
Outside 24VDC power supply is that power supply unit is powered, the output voltage V of power supply unit
cCbe respectively constant-current source circuit, instrument amplifier U2, modulus conversion chip U3, central processing unit U4, LCD MODULE U5 power, constant-current source circuit is that pressure transducer is powered, and USB communication unit is then powered by USB interface by host computer.The output signal of pressure transducer is after instrument amplifier U2 amplifies, enter modulus conversion chip U3 and carry out A/D conversion, data after conversion are sent into central processing unit U4 and are calculated, and the data calculated and alarm setting value compare, and send into LCD MODULE U5 and carry out scene and show.If the data after calculating have exceeded alarm setting value, then central processing unit U4 has sent control signal, and control signal delivers to the base stage of triode Q1 through optocoupler OC1, and makes triode Q1 conducting.After triode Q1 conducting, the output switch parameter end being connected in parallel on its collector exports corresponding on-off model.USB communication unit is responsible for the communication of host computer and intelligent digital pressure switch, and host computer is modified by the correlation parameter of USB interface to intelligent digital pressure switch.
The above, it is only preferred embodiment of the present utility model, be not restriction the utility model being made to other form, any those skilled in the art may utilize the technology contents of above-mentioned announcement to be changed or be modified as the Equivalent embodiments of equivalent variations.But everyly do not depart from technical solutions of the utility model content, any simple modification, equivalent variations and the remodeling done above embodiment according to technical spirit of the present utility model, still belong to the protection domain of technical solutions of the utility model.
Claims (7)
1. a digital pressure switch, comprise shell and be fixed on the control circuit in shell, control circuit at least comprises the pressure transducer, amplifier unit, AD conversion unit, CPU (central processing unit) and the power supply unit of directly or indirectly powering for pressure transducer, amplifier unit, AD conversion unit, CPU (central processing unit) that connect successively, it is characterized in that: be connected with can be triggered and the signal output unit of output switching signal by CPU (central processing unit) at the signal output part of described CPU (central processing unit).
2. digital pressure switch according to claim 1, is characterized in that: be connected with at the signal output part of described CPU (central processing unit) and powered by power supply unit, for the display unit shown.
3. digital pressure switch according to claim 1, is characterized in that: be also provided with the signal input output end mouth of described CPU (central processing unit) interconnected, for carrying out the communication unit of communication with CPU (central processing unit).
4. digital pressure switch according to claim 1, is characterized in that: described signal output unit comprises the optocoupler OC1 that model is PC817, a termination power V of resistance R4
cCthe other end connects 1 pin of optocoupler OC1 in succession, 2 pin of optocoupler OC1 connect the signal output part of CPU (central processing unit), the one termination external power source 24VDC+ of resistance R5,4 pin of another termination optocoupler OC1, the 3 pin ground connection of optocoupler OC1,4 pin of the one termination optocoupler OC1 of resistance R6, the base stage of another termination triode Q1 of resistance R6, the emitter of triode Q1 meets external power source 24VDC+, the collector of triode Q1 connects the negative electrode of diode D3, the plus earth of diode D3 and external power source 24VDC-, the current collection very output switch parameter end of triode Q1.
5. digital pressure switch according to claim 1, is characterized in that: be also provided with and be connected with described power supply unit, to the constant-current source circuit that described pressure transducer is powered.
6. digital pressure switch according to claim 5, is characterized in that: described constant-current source circuit comprises the voltage stabilizing diode D1 that operational amplifier U1 that model is TLV2631 and model are LM385, a termination power V of resistance R1
cC, the other end connects the negative electrode of voltage stabilizing diode D1 and the in-phase input end V of operational amplifier U1 simultaneously
iN+, the plus earth of voltage stabilizing diode D1, the inverting input V of a termination operational amplifier U1 of resistance R2
iN-, other end ground connection; The V of operational amplifier U1
oUTfor the output cathode of constant-current source circuit, be connected with the power supply positive pole of pressure transducer U8, the V of operational amplifier U1
iN-for the output negative pole of constant current source, be connected with the power supply negative pole of pressure transducer U8.
7. digital pressure switch according to claim 1 or 5, is characterized in that: described pressure transducer adopts diffused silicon piezoresistive pressure sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520213837.4U CN204557241U (en) | 2015-04-10 | 2015-04-10 | A kind of digital pressure switch |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520213837.4U CN204557241U (en) | 2015-04-10 | 2015-04-10 | A kind of digital pressure switch |
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| Publication Number | Publication Date |
|---|---|
| CN204557241U true CN204557241U (en) | 2015-08-12 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201520213837.4U Expired - Fee Related CN204557241U (en) | 2015-04-10 | 2015-04-10 | A kind of digital pressure switch |
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| Country | Link |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107478377A (en) * | 2016-06-08 | 2017-12-15 | 深圳市艾而特工业自动化设备有限公司 | The digital air gauge that a kind of double pictures are shown |
| WO2022000739A1 (en) * | 2020-07-02 | 2022-01-06 | 深圳市鹰硕教育服务有限公司 | Smart pen pressure sensor drive circuit |
-
2015
- 2015-04-10 CN CN201520213837.4U patent/CN204557241U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107478377A (en) * | 2016-06-08 | 2017-12-15 | 深圳市艾而特工业自动化设备有限公司 | The digital air gauge that a kind of double pictures are shown |
| CN107478377B (en) * | 2016-06-08 | 2023-06-06 | 深圳市艾而特传感器精密有限公司 | Double-picture display digital barometer |
| WO2022000739A1 (en) * | 2020-07-02 | 2022-01-06 | 深圳市鹰硕教育服务有限公司 | Smart pen pressure sensor drive circuit |
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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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150812 Termination date: 20160410 |