CN110632371B - A non-contact detection device and method for charged surface of an object - Google Patents

Abstract

The invention provides a charged non-contact detection device and method for the surface of an object, which comprises the following steps: a transparent housing; the electric field sensor is arranged in the shell, and the signal conditioning circuit, the control processing unit, the display unit and the power supply unit are connected with the electric field sensor; transparent epoxy resin is filled and sealed between the transparent shell and each part in the transparent shell, and the control processing unit is further connected with an alarm buzzer and an infrared inductor. By implementing the invention, the charged state of an object, particularly a metal plane surface can be accurately identified in the actual use process, and a guarantee means is provided for the safe development of production and life.

Description

A non-contact detection device and method for charged surface of an object

technical field

The invention relates to the technical field of electric power safety, and in particular, to a non-contact monitoring device and method for electrification on the surface of an object.

Background technique

There is a huge safety hazard in the electrification of the surface of the object. Accidents caused in production and life are often reported. Usually, the electric pen is used to measure by direct contact with the human body. However, there is no mature, simple and reliable identification method in the existing technology.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a non-contact monitoring device and method for surface electrification of objects, so as to realize the indication of electrification state of object surfaces, provide warning and guarantee functions for the safe operation of equipment and ensure the personal safety of operators.

In order to solve the above-mentioned technical problem, the present invention provides a kind of object surface charged non-contact monitoring device, it is characterized in that, comprises:

transparent shell;

A non-contact electric field sensor arranged in the housing, and a signal conditioning circuit, a control processing unit, a display unit and a power supply unit connected to the electric field sensor; wherein the electric field sensor is used for sensing the power frequency of the surface of the object The size of the electric field, the main function of the signal conditioning circuit is to amplify the output signal of the sensor; the control processing unit is used to analyze and process the amplified information output by the signal conditioning circuit; the display unit is used to display the charged state of the surface of the object And for low battery indication, the power supply unit provides working power for the entire device;

Transparent epoxy resin is potted between the transparent casing and its internal components;

Wherein, the control processing unit is further connected with an alarm buzzer and an infrared sensor.

Preferably, the object surface electric field sensor is composed of two printed PCBs that are orthogonal in space. The PCB material is FR4, the dielectric constant is about 4.2, and the board thickness is 1.6 mm. One of them is printed on the top layer with a looped wire, and the width of the wire is 1 mm. , the radius of gyration is 3mm, and the total length is 2450mm. The other piece is printed with the same looped wire, which is staggered from the first piece. There is a matching circuit at the end of the wire. The resistance size is 1M, and the capacitance size is nF. Two pieces of PCB form an electric field resonant cavity , under the excitation of the power frequency electromagnetic field, a voltage proportional to the excitation source is generated at the output end.

Preferably, the signal conditioning circuit includes:

The first resonant circuit is composed of a parallel resistor R6 and a capacitor C3, which is arranged at one end of the electric field sensor;

The second resonance circuit is composed of a resistor R7 and a capacitor C4, which is arranged at the other end of the electric field sensor;

The first stage amplifier, associated with the first resonant circuit and the second resonant circuit, is composed of resistor R3, resistor R9, resistor R2, resistor R10, capacitor C4 and comparator U12B, and is used to convert the electric field of the sensor output Amplify the signal;

The second-stage amplifier is connected to the back end of the first-stage amplifier, and is composed of a capacitor C5, a resistor R1, a resistor R42, a resistor R52, a capacitor C6, a resistor R5 and a comparator U12A;

The models of the comparator U12B and the comparator U12A are both OPA2379AID.

Preferably, the control and processing unit is composed of a capacitor C1, a capacitor C9, a resistor R11, a processing chip U1 and a second chip J1. The model of the processing chip U1 is PIC16F1518-E/SS. After the input electric field of the third pin is amplified The signal UAD1, the 4th pin inputs the infrared signal, the 23rd pin outputs the alarm control signal to the shutter.

Preferably, the display includes an alarm indicator and a low battery indicator, and the alarm indicator and the low battery indicator adopt an LCD display screen, and the LCD display screen is composed of a liquid crystal shutter, which is used to reduce the power consumption of the alarm indication.

Preferably, the infrared sensor is used to identify the characteristic infrared signal of 30-100 Hz, and start a buzzer to give an alarm.

Preferably, the power supply unit is composed of a battery and a power detection circuit. The battery output voltage is 3.6V and the power is 0.5Ah. When the battery power, that is, the output voltage, is less than the threshold, the power detection circuit outputs a signal to control the LCD display to display.

Correspondingly, the present invention also provides a method for detecting a charged surface of an object, which is completed by using the aforementioned device, and the method includes the following steps:

Step S1, performing effective value calculation, wherein the number of sampling points is 32, and the reference voltage is 2.5V;

Step S2, calculate the signal frequency, and calculate the frequency of the input signal according to the multiple zero-crossing points of the signal;

Step S3, according to the effective value and frequency of the signal to determine whether the signal is a power frequency signal;

Step S4, according to the judgment result, confirm whether to output the LCD flicker control signal; if the judgment result is yes, it is determined that the surface of the signal is charged, and the LCD flicker control signal is output to control the LCD display screen to flicker.

Preferably, it further includes:

Step S5, if the infrared sensor recognizes a characteristic infrared signal of 30-100 Hz, it is determined that someone is approaching, a buzzer alarm is activated, and an LCD flashing control signal is output to control the LCD display to flash.

Implementing the embodiment of the present invention, its beneficial effects are:

By arranging an electric field sensor, a signal conditioning circuit, a control processing unit, a display unit and a power supply unit connected to the electric field sensor in a transparent casing, the accurate indication of the charged state of the surface of the object can be realized, which is convenient for equipment and operators. Safety provides warning and assurance.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a circuit frame structure of a non-contact monitoring device for charged surface of an object provided by the present invention;

Fig. 2 is the circuit schematic diagram of the signal conditioning circuit in Fig. 1;

Fig. 3 is the circuit schematic diagram of the control processing unit in Fig. 1;

Fig. 4 is the circuit schematic diagram of the interface circuit involved in Fig. 1;

FIG. 5 is a schematic diagram of a wire routing structure in a PCB board in the electric field sensor;

FIG. 6 is a schematic main flow diagram of a non-contact monitoring method for charged surface of an object provided by the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

The following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the invention may be practiced.

Please refer to FIG. 1, which shows a schematic diagram of the circuit frame structure of a non-contact monitoring device for a charged surface of an object provided by the present invention; as shown in FIG. 2 to FIG. 5 together, in this embodiment, the object Surface electrification monitoring devices include:

transparent shell;

The electric field sensor 10 disposed in the housing, and the signal conditioning circuit 11, the control processing unit 12, the display unit 14 and the power supply unit 13 connected to the electric field sensor 10; wherein the electric field sensor 10 is used for sensing objects The size of the electric field on the surface, especially the power frequency electric field, the main function of the signal conditioning circuit 11 is to amplify the output signal of the sensor; the control processing unit 12 is used to analyze and process the amplified information output by the signal conditioning circuit 11, Output a drive signal for driving the display unit 14; the display unit 14 is used to display the charged state of the surface of the object and to perform low battery indication, the power supply unit 13 provides working power for the entire device, and monitors its own voltage at the same time. alarm information;

Wherein, the control processing unit 12 is further connected with an alarm buzzer 15 and an infrared sensor 15 .

Transparent epoxy resin is potted between the transparent casing and its internal components;

As shown in Figure 2, a schematic diagram of the induction circuit in a PCB board is shown. The electric field sensor is used to sense the magnitude of the electric field on the surface of the object, and the electric field sensor includes two PCB boards that are orthogonal in space, and sensing circuits are printed on the opposite surfaces of the two PCB boards. In a practical example, the surface electric field sensor of the object consists of two printed PCBs that are orthogonal in space. The PCB material is FR4, the dielectric constant is about 4.2, and the board thickness is 1.6 mm. One of them is printed on the top layer. The width is 1mm, the radius of gyration is 3mm, and the total length is 2450mm. The other piece is printed with the same looped wire, which is staggered from the first piece. There is a matching circuit at the end of the wire. The resistance size is 1M, and the capacitance size is nF. Two pieces of PCB form an electric field The resonant cavity generates a voltage proportional to the excitation source at the output end under the excitation of the power frequency electromagnetic field.

In a specific example, the electric field sensor, the signal conditioning circuit, the control processing unit, the display unit, the power supply are installed in a 50*45*5mm transparent casing, and the interior is potted with transparent epoxy resin, and the protection level is better than IP67, Adapt to a variety of different use environments.

As shown in FIG. 3 to FIG. 5 , a circuit schematic diagram of a non-contact detection device for charged surface of an object is shown. specifically,

The signal conditioning circuit includes:

The first resonant circuit is composed of a parallel resistor R6 and a capacitor C3, which is arranged at one end of the electric field sensor;

The second resonance circuit is composed of a resistor R7 and a capacitor C4, which is arranged at the other end of the electric field sensor;

The first-stage amplifier, which is associated with the first resonant circuit and the second resonant circuit, is composed of a resistor R3, a resistor R9, a resistor R2, a resistor R10, a capacitor C4 and a comparator U12B, wherein the amplifier cut-off frequency is 5Hz, and the gain is 2500, which is used to amplify the electric field signal output by the sensor; among them, the model of U12B is OPA2379AID;

The second-stage amplifier, connected to the back end of the first-stage amplifier, is composed of a capacitor C5, a resistor R1, a resistor R42, a resistor R52, a capacitor C6, a resistor R5 and a comparator U12A, and its gain is 2, which is used to convert the signal The total magnification is 5000; among them, the model of U12A is OPA2379AID;

Among them, the control processing unit is composed of capacitor C1, capacitor C9, resistor R11, processing chips U1 and J1. The model of the processing chip U1 is PIC16F1518-E/SS. Pin input infrared signal, pin 23 output alarm control signal to the shutter.

The power supply circuit is composed of a battery and a power detection circuit. The battery output voltage is 3.6V and the power is 0.5Ah. When the battery power, that is, the output voltage, is less than the threshold, the power detection circuit outputs a signal to control the LCD indication.

Further, the display includes an alarm indicator and a low battery indicator, and the alarm indicator and the low battery indicator adopt an LCD display screen, and the LCD display screen is composed of a liquid crystal shutter, which is used to reduce the power consumption of the alarm indication. Further, the alarm indicator is used to indicate the charged state of the surface of the object, the low battery indicator is used to indicate the battery level, the working voltage is 3.3v, and the frequency of the control signal is 5Hz.

Further referring to the interface circuit in FIG. 5 , P1 is the battery interface, P2 is the live alarm shutter interface, U2 is the battery power monitoring chip, P3 is the battery power alarm shutter interface, and P4 is the infrared sensor interface.

Correspondingly, as shown in FIG. 6 , it is a schematic diagram of the main flow of an object surface electrification detection method provided by the present invention. In the present embodiment, the non-contact detection method for the charged surface of the object is completed by using the device shown in FIG. 1 to FIG. 5 , and the method includes the following steps:

Step S1, performing effective value calculation, wherein the number of sampling points is 32, and the reference voltage is 2.5V;

Step S2, calculate the signal frequency, and calculate the frequency of the input signal according to the multiple zero-crossing points of the signal;

Step S3, according to the effective value and frequency of the signal to determine whether the signal is a power frequency signal;

Step S4, according to the judgment result, confirm whether to output the LCD flicker control signal; if the judgment result is yes, it is determined that the surface of the signal is charged, and the LCD flicker control signal is output to control the LCD display screen to flicker.

In some specific examples, it further includes:

Step S5, if the infrared sensor recognizes a characteristic infrared signal of 30-100 Hz, it is determined that someone is approaching, a buzzer alarm is activated, and an LCD flashing control signal is output to control the LCD display to flash.

Implementing the embodiment of the present invention, its beneficial effects are:

By arranging a non-contact electric field sensor, a signal conditioning circuit, a control processing unit, a display unit, and a power supply unit connected to the electric field sensor in a transparent casing, the accurate indication of the charged state of the surface of the object can be realized, which is helpful for equipment and Operator safety provides warning and assurance.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (8)

1. An object surface charged non-contact monitoring device, comprising:

a transparent housing;

the electric field sensor is arranged in the shell, and the signal conditioning circuit, the control processing unit, the display unit and the power supply unit are connected with the electric field sensor; the signal conditioning circuit is mainly used for amplifying an output signal of the electric field sensor; the control processing unit is used for analyzing and processing the amplified information output by the signal conditioning circuit and outputting a driving signal for driving the display unit; the display unit is used for displaying the charged state of the surface of an object and indicating low electric quantity, and the power supply unit provides a working power supply for the whole device;

transparent epoxy resin is encapsulated between the transparent shell and each part in the transparent shell;

the control processing unit is further connected with an alarm buzzer and an infrared sensor;

the electric field sensor consists of two printed PCBs (printed circuit boards) which are orthogonal in space, wherein one printed square-wave conductor is printed on the top layer, the other printed square-wave conductor is printed on the top layer, the printed square-wave conductor and the first printed square-wave conductor are arranged in a staggered mode, and the two PCBs form an electric field resonant cavity which is used for generating a voltage which is proportional to an excitation source at an output end under the excitation of a power frequency electromagnetic field;

wherein the signal conditioning circuit comprises:

the first resonant circuit consists of a resistor R6 and a capacitor C3 which are connected in parallel and is arranged at one end of the electric field sensor;

the second resonant circuit consists of a resistor R7 and a capacitor C4 and is arranged at the other end of the electric field sensor;

a first stage amplifier, associated with the first and second resonant circuits, consisting of a resistor R3, a resistor R9, a resistor R2, a resistor R10, a capacitor C4 and a comparator U12B, for amplifying the electric field signal output by the sensor;

and the second-stage amplifier is connected at the rear end of the first-stage amplifier and consists of a capacitor C5, a resistor R1, a resistor R42, a resistor R52, a capacitor C6, a resistor R5 and a comparator U12A.

2. The apparatus of claim 1,

the comparator U12B and the comparator U12A are OPA2379AID in model.

3. The device as claimed in claim 2, wherein the control processing unit is composed of a capacitor C1, a capacitor C9, a resistor R11, a processing chip U1 and a second chip J1, the model of the processing chip U1 is PIC16F1518-E/SS, the third pin inputs the signal UAD1 after electric field amplification, the 4 th pin inputs an infrared signal, and the 23 rd pin outputs an alarm control signal to the shutter.

4. The apparatus of claim 3, wherein the display unit includes an alarm indicator and a low-power indicator, the alarm indicator and the low-power indicator using an LCD display screen, the LCD display screen being composed of liquid crystal shutters for reducing alarm indication power consumption.

5. The device as claimed in claim 4, wherein the infrared sensor is used for identifying a characteristic infrared signal of 30-100 Hz and starting a buzzer to alarm.

6. The apparatus of claim 5, wherein the power supply unit comprises a battery and a power detection circuit, the battery has an output voltage of 3.6V and a power of 0.5Ah, and when the battery power, i.e. the output voltage, is less than a threshold, the power detection circuit outputs a signal to control the LCD display to display.

7. A method for non-contact detection of charged surfaces of objects, characterized in that it is carried out with a device as provided in any one of claims 1 to 6, said method comprising the steps of:

step S1, calculating an effective value, wherein the number of sampling points is 32, and the reference voltage is 2.5V;

step S2, calculating the frequency of the signal, and calculating the frequency of the input signal according to the multiple zero-crossing points of the signal;

step S3, judging whether the signal is a power frequency signal according to the effective value and the frequency of the signal;

step S4, confirming whether to output LCD flicker control signal according to the judgment result; and if so, determining that the signal surface is electrified, outputting an LCD flicker control signal, and controlling an LCD display screen to flicker.

8. The method of claim 7, further comprising:

and step S5, if the infrared sensor recognizes a characteristic infrared signal of 30-100 Hz, determining that a person approaches, starting a buzzer to give an alarm, outputting an LCD flicker control signal, and controlling an LCD display screen to flicker.

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