CN102944259B - Wireless passive measuring device - Google Patents

Abstract

A wireless passive measurement device, the first microcontroller controls the input of the power supply through the voltage doubler power drive module; the power supply supplies power to the wireless passive measurement circuit through the voltage doubler power drive module and the primary coil in turn; A wireless module realizes the communication with the wireless passive measurement circuit; the secondary coil couples the electric energy into the rectification and charging management module, and stores it in the farad capacitor; supplies power to the second microcontroller and the sensor module through the voltage stabilizing circuit; the second The second micro-controller detects the charging and discharging voltage of the farad capacitor in real time through the voltage monitoring module, and charges it through the external control circuit; the sensor module obtains the measured physical quantity, and transmits it to the external control through the second wireless module under the control of the second micro-controller The circuit realizes the wireless passive measurement of the physical quantity. The invention is applied in some occasions where wires cannot be used for energy transmission and signal reading; and it can measure multiple analog or digital physical quantities.

Description

A wireless passive measuring device

technical field

The invention relates to the wireless passive field, in particular to a wireless passive measuring device.

Background technique

The development of modern measurement technology has made it possible to measure many physical quantities intuitively, such as pressure, temperature, humidity and flow. But a big limitation is that it needs to supply energy and read data through wires, which is very unfavorable for the application of measuring some physical quantities inside containers, animals or certain parts inside the human body.

The Chinese utility model patent "A Wireless Passive Measurement Circuit" (public number: CN201629035U, publication date: November 10, 2010) provides a wireless passive measurement circuit, which realizes the measurement of physical quantities through controllable capacitance or inductance. However, this measurement method can measure fewer physical quantities, only one physical quantity can be measured at a time, and it is difficult to achieve continuous measurement.

Chinese utility model patent "A wireless passive measurement device" (publication number: CN201964897U, publication date: September 7, 2011) proposes an optimization scheme for wireless passive measurement, which is realized by regularly refreshing the display data Energy saving can improve the working time of the system, but the specific energy source and the realization method of energy conversion cannot be given.

Contents of the invention

The invention provides a wireless passive measurement device, which solves the limitation of the application range due to the connecting wire; at the same time, it can continuously measure multiple physical quantities and provides a specific energy source and energy conversion implementation. See the following description for details:

A wireless passive measurement device, comprising: an external control circuit and a wireless passive measurement circuit,

The external control circuit includes: a first micro-controller, the first micro-controller controls the input of the power supply through the voltage doubling power drive module; The passive measurement circuit is powered; the first microcontroller implements communication with the wireless passive measurement circuit through the first wireless module;

The wireless passive measurement circuit includes: a secondary coil, the secondary coil couples electric energy into the rectification and charging management module, and stores it in a farad capacitor; supplies power to the second microcontroller and the sensor module through a voltage stabilizing circuit; The second micro-controller detects the charging and discharging voltage of the farad capacitor in real time through the voltage monitoring module, and charges through the external control circuit; the sensor module obtains the measured physical quantity, and is controlled by the second micro-controller The second wireless module transmits to the external control circuit to realize wireless passive measurement of physical quantities.

The second micro-controller detects the charge and discharge voltage of the farad capacitor in real time through the voltage monitoring module, and charges through the external control circuit as follows:

The second microcontroller detects the charging and discharging voltage of the Farah capacitor in real time through the voltage monitoring module, when the charging voltage of the Farad capacitor is higher than the first preset value or the discharging voltage is lower than the second preset value , the second microcontroller sends control information to the first wireless module through the second wireless module, and the first wireless module transmits the control information to the first microcontroller; the first microcontroller The controller stops or charges the farad capacitor by controlling the voltage doubler power drive module.

The voltage doubling power drive module uses a full-bridge H-bridge drive circuit to convert the pulse level output by the first microcontroller into a high-voltage pulse level.

The H-bridge driving circuit of the full bridge uses four N-type MOS transistors.

The voltage stabilizing circuit includes: a conversion circuit for converting pulse signals into voltage signals,

The conversion circuit transmits the voltage signal to the voltage feedback module, and the positive polarity terminal of the voltage feedback module is connected to the reference voltage through a controllable single-pole double-throw switch; the negative polarity terminal is connected to the divided voltage of the voltage stabilized by the Buck-Boost circuit; The output terminal of the voltage feedback module is connected to the PWM driving module, and the PWM driving module outputs a pulse waveform with a certain frequency and duty cycle and adds it to the Buck-Boost circuit, and the Buck-Boost circuit outputs a stable voltage.

The reference voltage connected to the controllable single-pole double-throw switch is specifically:

The controllable SPDT switch is connected to a fixed reference voltage VREF, or,

The controllable single-pole double-throw switch is connected to the pulse waveform output by the second microcontroller.

The first microcontroller and the second microcontroller are low-power microcontrollers.

The first micro-controller and the second micro-controller are CC430 series, which are integrated with radio frequency transceiver modules.

When the output of the sensor module is an analog signal, it is directly input to the AD conversion interface of the second microcontroller after being amplified or followed; if the output of the sensor module is a digital signal, it is passed through the second microcontroller The IO interface reads the output signal of the sensor module.

The beneficial effects of the technical solution provided by the invention are:

1) The problem of electromagnetic wave interference to the wireless module during the charging process is solved by using a Farad capacitor, that is, the data transmission and reception can be suspended during the charging process and the data transmission and reception process can be continued after the charging process is completed; at the same time, because the Farad capacitor can be charged repeatedly and Does not affect its ability to charge and discharge, thereby increasing the service life and applicability of the wireless passive measuring device;

2) By using the external control circuit and the wireless passive measurement circuit, it can be used in some occasions where the wires cannot be used for energy transmission and signal reading; and through the design of the sensor module and the second microcontroller, when actually working, Can measure multiple analog or digital physical quantities;

3) When the voltage doubler power drive module adopts the full-bridge H-bridge drive circuit, the efficiency of energy transmission is improved, the charging time is shortened, and the interference caused by high-frequency electromagnetic signals during charging is reduced; and when the selected four N When the type MOS tube is used, the efficiency of the circuit is further improved;

4) When the voltage stabilizing circuit provided by the present invention is used, the stable power supply to the sensor module and the second microcontroller is realized; when the controllable single-pole double-throw switch inputs the pulse waveform output by the second microcontroller, the voltage is enlarged The output range can better provide a stable working voltage for the sensor module.

Description of drawings

Fig. 1 is the circuit diagram of wireless passive measuring device;

FIG. 2 is a schematic circuit diagram of a voltage doubling power drive module;

FIG. 3 is a schematic circuit diagram of a rectification and charging management module;

FIG. 4 is a schematic circuit diagram of a voltage stabilizing circuit module.

In the accompanying drawings, the list of parts represented by each label is as follows:

1: Power supply; 2: The first microcontroller;

3: Double voltage power drive module; 4: The first wireless module;

5: primary coil; 6: secondary coil;

7: Rectifier charging management module; 8: Farah capacitor;

9: Regulator circuit; 10: Second wireless module;

11: Second microcontroller; 12: Sensor module;

13: Voltage monitoring module; 14: Full bridge diode rectifier circuit;

15: Zener tube; 16: Buck-Boost circuit;

17: PWM drive module; 18: Voltage feedback module;

19: conversion circuit; 20: controllable single-pole double-throw switch.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the implementation manner of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Farad capacitor is a new type of energy storage device developed in the 1970s and 1980s. It has many advantages such as high power density, short charge and discharge time, long cycle life, wide operating temperature range, green environmental protection and no pollution. Its The application can further improve the application range and usage time of the wireless passive measurement equipment.

In order to solve the limitation of the application range due to the connecting wire; at the same time, multiple physical quantities can be continuously measured and the specific energy source and energy conversion are given. See Figure 1 and Figure 2, a wireless passive measurement device, including: external control circuit and wireless passive measurement circuit,

The external control circuit includes: the first microcontroller 2, the first microcontroller 2 controls the input of the power supply 1 through the voltage doubler power drive module 3; the power supply 1 passes through the voltage doubler power drive module 3 and the primary coil 5 in turn for wireless passive measurement Circuit power supply; the first microcontroller 2 realizes the communication with the wireless passive measurement circuit through the first wireless module 4;

The wireless passive measurement circuit includes: a secondary coil 6, the secondary coil 6 couples the electric energy into the rectification and charging management module 7, and stores it in the farad capacitor 8; the second microcontroller 11 and the sensor module 12 pass through the voltage stabilizing circuit 9 Power supply; the second micro-controller 11 detects the charging and discharging voltage of the farad capacitor 8 in real time through the voltage monitoring module 13, and charges through an external control circuit; the sensor module 12 obtains the measured physical quantity, and passes through under the control of the second micro-controller 11 The second wireless module 10 transmits to the external control circuit to realize the wireless passive measurement of the physical quantity.

Wherein, the second micro-controller 11 detects the charge and discharge voltage of the farad capacitor 8 in real time through the voltage monitoring module 13, and charges through the external control circuit as follows:

The second microcontroller 11 detects the charging and discharging voltage of the farad capacitor 8 in real time through the voltage monitoring module 13. When the charging voltage of the farad capacitor 8 is higher than the first preset value or the discharge voltage is lower than the second preset value, the second microcontroller The controller 11 sends control information to the first wireless module 4 through the second wireless module 10, and the first wireless module 4 transmits the control information to the first microcontroller 2; the first microcontroller 2 controls the voltage doubler power drive module 3 Stop or charge the farad capacitor 8.

During specific implementation, the first preset value and the second preset value are set according to requirements in practical applications, which is not limited in this embodiment of the present invention during specific implementation.

Among them, the external control circuit generates a high-frequency pulse signal of a certain amplitude through the voltage doubler power drive module 3 and generates a high-frequency resonant electromagnetic field through the primary coil 5. The high-frequency resonant electromagnetic field is coupled to the wireless passive measurement circuit for power supply. The primary coil 5 and the secondary coil 6 form a loosely coupled transformer.

Referring to FIG. 2, the voltage doubler power drive module 3 uses a full-bridge H-bridge drive circuit, thereby converting the pulse level output by the first microcontroller 2 into a high-voltage pulse level to improve energy transmission efficiency. Shorten the charging time and reduce the interference caused by high-frequency electromagnetic signals during charging.

At the same time, in order to reduce the quiescent current when the MOS tube is working and reduce the overall power consumption, the H-bridge drive circuit of the full bridge uses four N-type MOS tubes. At any time, there is always a pair of MOS tubes with zero voltage drop. ("ON"), a pair of MOS tubes are in a state of zero current ("OFF"), theoretically no energy will be lost, thus greatly improving the efficiency of the circuit.

Referring to Fig. 3, the rectification and charging management module 7 is composed of a full-bridge diode rectifier circuit 14 and a voltage regulator tube 15. The full-bridge diode rectifier circuit 14 rectifies the alternating current coupled with the secondary coil 6 into a direct current; the voltage regulator tube 15 stabilizes the direct current , to prevent the DC voltage from exceeding the rated voltage upper limit of the farad capacitor 8 and damage the farad capacitor 8 .

Referring to FIG. 4, the input voltage of the voltage stabilizing circuit 9 is the output voltage of the farad capacitor 8. According to the discharge curve of the farad capacitor 8, the input voltage of the voltage stabilizing circuit 9 is not a stable voltage and may be lower than the second microcontroller 11 and The voltage required for the sensor module 12 to work normally.

In order to provide a stable power supply for the second microcontroller 11 and the sensor module 12, the voltage stabilizing circuit 9 includes: a conversion circuit 19 that converts the pulse signal into a voltage signal, and the conversion circuit 19 transmits the voltage signal to the voltage feedback module 18, and the voltage The positive polarity end of the feedback module 18 is connected to the reference voltage through the controllable single-pole double-throw switch 20; Connected to a PWM (Pulse Width Modulation) drive module, the PWM drive module outputs a pulse waveform with a certain frequency and duty cycle and adds it to the Buck-Boost circuit 16, and the Buck-Boost circuit 16 outputs a stable voltage.

Wherein, the controllable SPDT switch 20 is connected to the reference voltage specifically: the controllable SPDT switch 20 is connected to the fixed reference voltage VREF, or connected to the pulse waveform output by the second microcontroller 11 .

In actual application, the controllable SPDT switch 20 is closed at the reference voltage VREF terminal by default, but can be closed to the VIO terminal through the second micro-controller 11, and the VIO terminal inputs the pulse waveform output by the second micro-controller 11, through conversion The circuit 19 can be converted into a voltage signal and then control the PWM drive module 17 to output a certain waveform through the voltage feedback module 18 to make the Buck-Boost circuit 16 output a stable voltage, so that while ensuring power supply for the second microcontroller 11, the sensor module A better power supply is carried out, and the range of the output voltage is expanded.

In order to reduce the power consumption of the device, the first microcontroller 2 and the second microcontroller 11 are preferably low-power microcontrollers.

When the models of the first microcontroller 2 and the second microcontroller 11 are CC430 series, 1) you can choose to supply power to each module in the microcontroller, which achieves the purpose of low power consumption; 2) because the CC430 series The low-power microcontroller has a large flash storage space, so the data measured by the wireless passive detection circuit can be temporarily stored in the internal flash, so that CC1101 can be selected by software for a long period of time. The wireless radio frequency module supplies power, and then supplies power and transmits data after storing a certain amount of data, which shortens the power-on time of the wireless radio frequency module and reduces overall power consumption; 3) the first microcontroller 2 and the second microcontroller 11 are integrated with The wireless radio frequency transceiver module does not need to separately install the first wireless module 4 and the second wireless module 10, which saves the cost. For example: the first micro-controller 2 and the second micro-controller 11 are preferably CC430F5137 in the CC430 series ultra-low-power single-chip microcomputer, which has its own DA and AD conversion modules; and a CC1101 radio frequency module is integrated inside.

Since there is a stable power supply 1 for power supply and the wireless passive detection circuit has a second microcontroller 11, the sensor module 12 can be an electrical sensor for measuring any physical quantity. If the output of the sensor module 12 is an analog signal, it can be directly amplified or followed. Input to the AD conversion interface of the first microcontroller 11 so as to realize the measurement of the physical quantity; if the output of the sensor module 12 is a digital signal, then the digital IO port of the second microcontroller 11 can be used to read the sensor module 12. The output signal realizes the function of measurement.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred embodiment, and the serial numbers of the above-mentioned embodiments of the present invention are for description only, and do not represent the advantages and disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (8)

1. a wireless and passive measurement mechanism, comprising: external control circuit and wireless and passive metering circuit, is characterized in that,

Described external control circuit comprises: the first microcontroller, and described first microcontroller controls the input of power supply by multiplication of voltage power driver module; Described power supply is that described wireless and passive metering circuit is powered through described multiplication of voltage power driver module and primary coil successively; Described first microcontroller realizes the communication between described wireless and passive metering circuit by the first wireless module;

Described wireless and passive metering circuit comprises: secondary coil, and couple electrical energy is entered rectification charging administration module by described secondary coil, and is stored in farad capacitor; Be that the second microcontroller and sensor assembly are powered through mu balanced circuit; Described second microcontroller detects the charging/discharging voltage of described farad capacitor in real time by voltage monitoring module, and is charged by described external control circuit; Described sensor assembly obtains the physical quantity measured, and is transferred to described external control circuit, realizes measuring the wireless and passive of physical quantity under the control of described second microcontroller by the second wireless module;

Wherein, described mu balanced circuit comprises: change-over circuit pulse signal being converted to voltage signal,

Voltage signal is transferred to voltage feedback module by described change-over circuit, and the positive ends of described voltage feedback module connects reference voltage by controlled single-pole double-throw switch (SPDT); The dividing potential drop of voltage after the voltage stabilizing of negative polarity termination Buck-Boost circuit; The output termination PWM driver module of described voltage feedback module, described PWM driver module exports the pulse waveform of certain frequency and dutycycle and is added on described Buck-Boost circuit, controls the voltage of described Buck-Boost circuit stable output.

2. a kind of wireless and passive measurement mechanism according to claim 1, is characterized in that, described second microcontroller detects the charging/discharging voltage of described farad capacitor in real time by voltage monitoring module, and carries out charging by described external control circuit and be specially:

Described second microcontroller detects the charging/discharging voltage of described farad capacitor in real time by described voltage monitoring module, when the charging voltage of described farad capacitor higher than the first preset value or sparking voltage lower than the second preset value time, described second microcontroller sends control information to described first wireless module by described second wireless module, and described control information is transferred to the first microcontroller by described first wireless module; Described first microcontroller stops the charging of described farad capacitor by controlling described multiplication of voltage power driver module or charges.

3. a kind of wireless and passive measurement mechanism according to claim 1, is characterized in that, described multiplication of voltage power driver module adopts the H-bridge drive circuit of full-bridge, and the impulse level that described first microcontroller exports is converted to high-tension impulse level.

4. a kind of wireless and passive measurement mechanism according to claim 3, is characterized in that, the H-bridge drive circuit of described full-bridge selects the metal-oxide-semiconductor of four N-types.

5. a kind of wireless and passive measurement mechanism according to claim 1, is characterized in that, described controlled single-pole double-throw switch (SPDT) connects reference voltage and is specially:

Described controlled single-pole double-throw switch (SPDT) meets fixed reference potential VREF, or,

Described controlled single-pole double-throw switch (SPDT) connects the pulse waveform that described second microcontroller exports.

6. a kind of wireless and passive measurement mechanism according to claim 1 and 2, is characterized in that, described first microcontroller and the second microcontroller are low-power consumption microcontroller.

7. a kind of wireless and passive measurement mechanism according to claim 1 and 2, is characterized in that, described first microcontroller and the second microcontroller are CC430 series, are integrated with radio frequency transceiving module.

8. a kind of wireless and passive measurement mechanism according to claim 1 and 2, is characterized in that, when described sensor assembly exports as simulating signal, then by amplifying or be directly inputted to after following the AD conversion interface of described second microcontroller; If described sensor assembly exports as digital signal, then read the output signal of described sensor assembly by the I/O port of described second microcontroller.