WO2015143707A1

WO2015143707A1 - Proximity sensing switch

Info

Publication number: WO2015143707A1
Application number: PCT/CN2014/074275
Authority: WO
Inventors: 肖锴
Original assignee: 肖锴
Priority date: 2014-03-28
Filing date: 2014-03-28
Publication date: 2015-10-01

Abstract

A proximity sensing switch comprises: a conductive sensing module (100), used for receiving electrostatic charges of a human body when the human body approaches; a capacitor control module (200), used for controlling charging and discharging of a capacitor according to the electrostatic charges so as to generate a valve drive signal; and a valve drive module (300), used for controlling opening and closing of a valve module (400) according to the valve drive signal. Because the conductive sensing module itself is used as a sensor, proximity sensing can be implemented without mounting an independent sensor and the problem of the service life of the independent sensor does not need to be considered. Because the electrostatic charges of the human body are sensed, the proximity sensing switch has no directivity and the switch can be triggered to switch on and switch off as long as the switch approaches an inductor. In addition, charging and discharging of a capacitor is controlled according to the electrostatic charges, so that different sensing distances can be set according to users.

Description

Proximity sensor switch

Technical field

The present invention relates to the field of inductive switches, and more particularly to a proximity inductive switch.

Background technique

Existing inductive switches typically use an infrared proximity sensor or a conventional capacitive sensor to generate a switch control signal. The drive circuit controls the solenoid valve switch based on the switch control signal. However, infrared sensor switches require independent or integrated installation of infrared proximity sensors. Since the infrared proximity sensor is in operation for a long time, the service life is limited. And the infrared proximity sensor has directivity, and the sensing area is relatively small, so when in use, the user has to enter the area specified by the infrared proximity sensor to trigger the switch. The sensing distance of a conventional capacitive sensing switch is very short and cannot be changed.

Therefore, there is a need for a proximity sensor switch that does not require an additional proximity sensor, a large sensing area, and a sensing distance that can be set.

Summary of the invention

The technical problem to be solved by the present invention is that the proximity sensing switch of the prior art requires an additional proximity sensor, a small sensing area and a fixed sensing distance, and provides a large proximity sensing sensor without additional installation of the proximity sensor. A proximity proximity switch that can be set.

The technical solution adopted by the present invention to solve the technical problem is to construct a proximity sensor switch, including:

a conductive sensing module for receiving an electrostatic charge of the human body when the human body approaches;

a capacitance control module for controlling a charging discharge of the capacitor based on the electrostatic charge to generate a valve driving signal;

A valve drive module for controlling opening and closing of the valve module based on the valve drive signal.

In the proximity sensor switch of the present invention, the capacitor controller further includes:

a capacitor charging and discharging module, configured to charge and discharge the capacitor based on the electrostatic charge;

a pulse width modulation module for generating a duty cycle signal according to a predetermined setting;

a bit stream signal generating module, configured to generate a bit stream signal based on the charging discharge;

a counting module, configured to generate a count based on the duty cycle signal and the bit stream signal;

A processing module for generating a valve drive signal based on the count.

In the proximity sensor switch of the present invention, the capacitor charging and discharging module includes a sensing capacitor, an external modulation capacitor, and a discharge resistor, and the first end of the sensing capacitor is connected to a power source via the first control switch, and the sensing capacitor The second end of the external modulation capacitor is connected to the power source via the second control switch and the first control switch, and the second end of the external modulation capacitor is grounded, and the first end of the discharge resistor is connected The first end of the external modulation capacitor and the bit stream signal generating module and the second end of the discharging resistor are grounded via a third control switch.

In the proximity sensor switch of the present invention, the bit stream signal generating module includes a comparator and a latch, and the first input end of the comparator is connected to the capacitor charging and discharging module, and the comparator The input terminal is connected to the input terminal of the latch, and the output of the latch is connected to the counting module and the capacitor charging and discharging module.

In the proximity sensor switch of the present invention, the counting module includes an AND gate and a counter, and the first input end of the AND gate is connected to the pulse width modulation module, and the second input end of the AND gate is connected The bit stream signal generating module and the output end of the AND gate are connected to an input end of the counter.

In the proximity sensor switch of the present invention, the capacitance controller further includes a clock module for generating a clock signal.

In the proximity sensor switch of the present invention, the clock module includes a clock source, an oscillating module, and a branching module, and the clock source is connected to an input end of the oscillating module, and an output end of the oscillating module is connected to the The input end of the branching module is connected to the pulse width modulation module, the bit stream signal generating module and the clock end of the counting module.

Another technical solution adopted by the present invention to solve the technical problem is to construct a proximity sensing switch, including: a conductive sensing module, Inductive capacitor, external modulation capacitor, discharge resistor, comparator, latch, AND gate, pulse width modulation module, counter, processing module, valve drive module and valve module; wherein the conductive sensing module is used to receive when the human body approaches An electrostatic charge of the human body, the induced capacitance sensing the electrostatic charge, the first end of the sensing capacitor is connected to the power source via a first control switch, the second end of the sensing capacitor is grounded, and the first externally modulated capacitor The terminal is connected to the power source via the second control switch and the first control switch, and the second end of the external modulation capacitor is grounded, the first end of the discharge resistor is connected to the first end of the external modulation capacitor and the comparison a first input end of the device, a second end of the discharge resistor is grounded via a third control switch, a second input of the comparator is coupled to a reference voltage signal, and an output of the comparator is coupled to the latch Input end, the output end of the latch is connected to the third control switch and the second input end of the AND gate, and the first input end of the AND gate is connected to the pulse width a modulation module, an output end of the AND gate connected to an input end of the counter, an output end of the counter connected to the processing module to output a count, the processing module generating a valve driving signal based on the counting, the valve driving The module controls the opening and closing of the valve module based on the valve drive signal.

In the proximity sensor switch of the present invention, the clock module includes a clock source, an oscillating module, and a branching module, and the clock source is connected to an input end of the oscillating module, and an output end of the oscillating module is connected to the The input end of the branching module is connected to the pulse width modulation module, the latch, and the clock end of the counter.

By implementing the proximity sensor switch of the present invention, since the conductive sensing module itself is used as the sensor, proximity sensing can be realized without installing a separate sensor. And because there are no separate sensors, there is no problem with sensor life. Since the electrostatic charge is sensed by the human body, there is no directivity, and the proximity and proximity of the body can be triggered to turn on and off. Further, since the control is based on the charge discharge of the electrostatic charge control capacitor, different sensing distances can be set according to the user.

DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a schematic block diagram of a first embodiment of a proximity sensor switch of the present invention;

Figure 2 is a schematic block diagram of a second embodiment of the proximity sensor switch of the present invention;

Figure 3 is a circuit schematic diagram of a third embodiment of the proximity sensor switch of the present invention;

4 is an equivalent circuit diagram of a modulation mode of the proximity type inductive switch shown in FIG. 3;

5 is a voltage output waveform diagram of a charging and discharging process of the proximity type inductive switch shown in FIG. 3;

6 is a waveform diagram of a comparator output of a charge and discharge process of the proximity type inductive switch shown in FIG. 3;

FIG. 7 is a schematic diagram showing the principle of the counting process of the charging and discharging process of the proximity type inductive switch shown in FIG.

detailed description

The above is only the specific embodiment of the present invention, and the scope of the present invention is not limited thereto, and the average variation made by those skilled in the art according to the present creation, as well as the changes well known to those skilled in the art, should still be The scope covered by the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic block diagram of a first embodiment of a proximity sensor switch of the present invention. As shown in FIG. 1 , the proximity sensor switch includes a conductive sensing module 100 , a capacitor control module 200 , a valve driving module 300 , and a valve module 400 . The conductive sensing module 100 is configured to receive an electrostatic charge of a human body when the human body approaches. For example, the conductive sensing module 100 can be any metal inductor, graphite conductor, polymer inductor or other conductive material inductor. In a preferred embodiment of the present invention, the conductive sensing module 100 may be, for example, a metal faucet, a metal button for controlling a household appliance such as an electric lamp, a television, a refrigerator, or the like. The capacitance control module 200 is configured to control a charge discharge of the capacitor based on the electrostatic charge to generate a valve drive signal. The capacitance control module 200 receives an electrostatic charge from the conductive sensing module 100. Since the amount of electrostatic charge received is different when people approach and leave, this will result in different charging and discharging times of the capacitor. The capacitance control module 200 can generate a valve drive signal based on this difference. The valve drive module 300 receives the valve drive signal from the capacitance control module 200 and controls opening and closing of the valve module 400 based on the valve drive signal. In one embodiment of the invention, the valve module 400 can be a solenoid valve, and the valve actuation module 300 can be a solenoid valve drive circuit. In other embodiments of the invention, the valve module can be other switching devices such as transistors, transistors, and the like. The valve driving module 300 may be a triode driving circuit or a transistor driving circuit or the like.

2 is a schematic block diagram of a second embodiment of the proximity sensor switch of the present invention. As shown in FIG. 2, the proximity sensor switch includes a conductive sensing module 100, a capacitor control module 200, a valve driving module 300, and a valve module 400. In this embodiment, the conductive sensing module 100, the valve driving module 300, and the valve module 400 can be constructed according to the embodiment shown in FIG. 1, and will not be described here.

In this embodiment, the capacitance control module 200 includes a capacitor charging and discharging module 210, a pulse width modulation module 220, a bit stream signal generating module 230, a counting module 240, and a processing module 250. In this embodiment, the capacitor charging and discharging module 210 is configured to charge and discharge the capacitor based on the electrostatic charge. For example, the capacitor charging and discharging module 210 can be any LC charging and discharging circuit, or an LRC charging and discharging circuit. The pulse width modulation module 220 is configured to generate a duty cycle signal in accordance with a predetermined setting. For example, the pulse width modulation module 220 can be any pulse width modulation circuit, chip or program module. The bit stream signal generation module 230 is configured to generate a bit stream signal based on the charge discharge. For example, the bitstream signal generation module 230 can generate a bitstream signal based on the charge and discharge time and the magnitude of the voltage. The counting module 240 is configured to generate a count based on the duty cycle signal and the bit stream signal. For example, the counting module 240 can count using any counter. The processing module 250 can generate a valve drive signal based on the count. For example, when the count is greater than the set value, an open valve drive signal is generated. When the count is less than the set value, a closed valve drive signal is generated.

Figure 3 is a circuit schematic diagram of a third embodiment of the proximity sensor switch of the present invention. The configuration of the capacitance control module 200 is mainly shown in FIG. As shown in FIG. 3, the capacitance control module 200 includes a sensing capacitor Cx, an external modulation capacitor Cmod, a discharge resistor RB, a comparator F1, a latch L1, an AND gate Y1, a pulse width modulation module PWM, a counter CN1, and a processing module 250. The sensing capacitor Cx, the external modulation capacitor Cmod, and the discharging resistor RB constitute the capacitor charging and discharging module 210 shown in FIG. 2. The pulse width modulation module PWM constitutes the pulse width modulation module 220 shown in FIG. The comparator F1 and the latch L1 constitute the bit stream signal generating module 230 shown in FIG. 2. The AND gate Y1 and the counter CN1 constitute the counting module 240 shown in FIG. 2.

As shown in FIG. 3, the first end of the sensing capacitor Cx is connected to the power supply VDD via the first control switch φ1, and the second end of the sensing capacitor Cx is grounded. The first end of the external modulation capacitor Cmod is sequentially connected to the power supply VDD via the second control switch φ2 and the first control switch φ1. The second end of the external modulation capacitor Cmod is grounded. A first end of the discharge resistor RB is coupled to a first end of the external modulation capacitor Cmod and a first input of the comparator F1. The second end of the discharge resistor RB is grounded via a third control switch φ3, and the second input of the comparator F1 is connected to the reference voltage signal VREF. The output of the comparator F1 is connected to the input of the latch L1. An output end of the latch L1 is connected to the third control switch φ3 and a second input terminal of the AND gate Y1. The first input of the AND gate Y1 is coupled to the pulse width modulation module PWM. The output of the AND gate Y1 is connected to the input of the counter CN1 to output a count. The processing module 250 generates a valve drive signal based on the count.

4 is an equivalent circuit diagram of a modulation mode of the proximity type inductive switch shown in FIG. Fig. 5 is a diagram showing voltage output waveforms of a charge and discharge process of the proximity type inductive switch shown in Fig. 3. Fig. 6 is a diagram showing a comparator output waveform of a charge and discharge process of the proximity type inductive switch shown in Fig. 3. FIG. 7 is a schematic diagram showing the principle of the counting process of the charging and discharging process of the proximity type inductive switch shown in FIG. The principle of the proximity sensor switch shown in Fig. 3 will be described below with reference to Figs. 4-7.

As shown in FIG. 3-4, when the first control switch φ1 is closed, the sensing capacitor Cx is charged by the power source VDD. When the first control switch φ1 is turned off and the second control switch φ2 is turned off, the external modulation capacitor Cmod is charged by the sense capacitor Cx. When the Cmod charging voltage reaches the reference voltage Vref, the comparator F1 outputs a high level. Latch L1 will latch high. The high level of the latch L1 controls the third control switch φ3 to be closed, thereby discharging by the discharge resistor RB. Latch L1 enables the PWM modulation module PWM output to AND gate Y1; until latch L1 has a new status update. The duty ratio of the pulse width modulation module PWM output and the bit stream signal output from the latch L1 are combined with the gate Y1 and supplied to the input terminal of the counter CN1. Counter CN1 outputs a count to processing module 250. The processing module 250 finally processes the value of the counter CN1 to determine if there is a finger touch.

3 and FIG. 5, the sensing capacitor Cx can be converted into an equivalent resistor Rcx. The resistor Vdd charges the external modulation capacitor Cmod through the equivalent resistor Rcx, knowing that the charge reaches the reference voltage Vref. The comparator F1 outputs a high level, the latch L1 latches a high level, the discharge resistor RB accesses the ground, and discharges the external modulation capacitor Cmod. When the external modulation capacitor Cmod voltage is lower than the reference voltage Vref, the comparator F1 outputs Low level, the discharge resistor RB is disconnected to ground, and the power supply Vdd again charges the external modulation capacitor Cmod. During charging and discharging, the external modulation capacitor Cmod voltage V (Cmod) and the output of the comparator F1 are as shown in Figure 5-6.

When a person approaches or touches the conductive sensing module 100, the conductive sensing module 100 is configured to receive an electrostatic charge of the human body when the human body approaches or touches. At this time, the sense capacitance Cx increases, and the equivalent resistance Rcx becomes small. The equivalent resistance Rcx becomes smaller, the charging current becomes larger, and the charging time of the external modulation capacitor Cmod becomes shorter. When the external modulation capacitor Cmod is charged, the charging time becomes shorter and the discharge time does not change. At this time, after the AND gate Y1 sums the duty signal from the pulse width modulation module PWM and the bit stream signal from the latch L1, the obtained duty ratio becomes large, and the counter CN1 can be turned on for a longer time. . Since the time for turning on the counter CN1 is longer, the counter CN1 counts more, as shown in FIG. The value of the counter can be calculated by employing the processing module 250, and then it is determined whether someone is approaching or touching the conductive sensing module 100. For example, when the count is greater than the set value, it is determined that a person approaches or touches the conductive sensing module 100 to generate an open valve drive signal. When the count is less than the set value, it is determined that no one approaches or touches the conductive sensing module 100 to generate an open valve drive signal.

In the embodiment shown in FIG. 3, the capacitor control module 200 further includes a clock module composed of a clock source PRS, an oscillation module OS1, and a branching module r. As shown in FIG. 3, the clock source PRS is connected to an input end of the oscillation module OS1. The output of the oscillation module OS1 is connected to the input of the branching module r. The output ends of the splitting module r are respectively connected to the clock widths of the pulse width modulation module PWM, the latch L1 and the counter CN1. As shown in FIG. 3, the clock source PRS simultaneously controls the first control switch φ1 and the second control switch φ2. In other embodiments of the present invention, a person skilled in the art may separately set a clock in the pulse width modulation module PWM, the latch L1 and the counter CN1, or may have a clock built in the processing module 250, or adopt a clock. The processing module 250 controls the first control switch φ1 and the second control switch φ2.

By implementing the proximity sensor switch of the present invention, since the conductive sensing module itself is used as the sensor, proximity sensing can be realized without installing a separate sensor. And because there are no separate sensors, there is no problem with sensor life. Since the electrostatic charge is sensed by the human body, there is no directivity, and the proximity and proximity of the body can be triggered to turn on and off. Further, since the control is based on the charge discharge of the electrostatic charge control capacitor, different sensing distances can be set according to the user. Further, since the present invention does not measure the capacitance voltage to determine whether someone is approaching or touching, as in the conventional method, but by determining whether the charging voltage is greater than the reference voltage, the accuracy problem caused by the voltage conversion is minimized. Therefore, the sensitivity is better.

While the invention has been described by way of specific embodiments, the embodiments of the invention Therefore, the invention is not limited to the specific embodiments disclosed, but all the embodiments falling within the scope of the appended claims.

Claims

A proximity sensor switch, comprising:

2. The proximity sensor switch of claim 1, wherein the capacitance controller further comprises:

A processing module for generating a valve drive signal based on the count.

The proximity sensor of claim 2, wherein the capacitor charging and discharging module comprises an inductive capacitor, an external modulation capacitor and a discharge resistor, and the first end of the inductive capacitor is connected to the first control switch The second end of the external modulation capacitor is grounded, the first end of the external modulation capacitor is sequentially connected to the power source via the second control switch and the first control switch, and the second end of the external modulation capacitor is grounded, the discharge A first end of the resistor is coupled to the first end of the external modulation capacitor and the bit stream signal generating module, and the second end of the discharge resistor is grounded via a third control switch.

The proximity sensor switch according to claim 2, wherein the bit stream signal generating module comprises a comparator and a latch, and the first input end of the comparator is connected to the capacitor charging and discharging module, a second input end of the comparator is connected to a reference voltage signal, an output end of the comparator is connected to an input end of the latch, an output end of the latch is connected to the counting module, and the capacitor is charged and discharged. Module.

The proximity sensor switch according to claim 2, wherein the counting module comprises an AND gate and a counter, the first input end of the AND gate is connected to the pulse width modulation module, the AND gate The second input is coupled to the bitstream signal generation module, and the output of the AND gate is coupled to the input of the counter.

6. A proximity sensor switch according to any of claims 1-5, wherein the capacitance controller further comprises a clock module for generating a clock signal.

The proximity sensor switch according to claim 6, wherein the clock module comprises a clock source, an oscillating module, and a branching module, wherein the clock source is connected to an input end of the oscillating module, and the oscillating An output end of the module is connected to an input end of the branching module, and an output end of the branching module is respectively connected to the pulse width modulation module, the bit stream signal generating module and a clock end of the counting module.

8. A proximity sensor switch, comprising: a conductive sensing module, Inductive capacitor, external modulation capacitor, discharge resistor, comparator, latch, AND gate, pulse width modulation module, counter, processing module, valve drive module and valve module; wherein the conductive sensing module is used to receive when the human body approaches An electrostatic charge of the human body, the induced capacitance sensing the electrostatic charge, the first end of the sensing capacitor is connected to the power source via a first control switch, the second end of the sensing capacitor is grounded, and the first externally modulated capacitor The terminal is connected to the power source via the second control switch and the first control switch, and the second end of the external modulation capacitor is grounded, the first end of the discharge resistor is connected to the first end of the external modulation capacitor and the comparison a first input end of the device, a second end of the discharge resistor is grounded via a third control switch, a second input of the comparator is coupled to a reference voltage signal, and an output of the comparator is coupled to the latch Input end, the output end of the latch is connected to the third control switch and the second input end of the AND gate, and the first input end of the AND gate is connected to the pulse width a modulation module, an output of the AND gate connected to an input end of the counter, an output of the counter being connected to the processing module to output a count, the processing module generating a valve driving signal based on the counting, the valve The drive module controls opening and closing of the valve module based on the valve drive signal.

9. The proximity sensor switch of claim 8 wherein said capacitance controller further comprises a clock module for generating a clock signal.

The proximity sensor switch according to claim 9, wherein the clock module comprises a clock source, an oscillating module, and a branching module, wherein the clock source is connected to an input end of the oscillating module, and the oscillating An output end of the module is connected to an input end of the branching module, and an output end of the branching module is respectively connected to the pulse width modulation module, the latch, and a clock end of the counter.