CN102640250B - Human body electromagnetic induction switchgear and method for starting electrical equipment - Google Patents

Abstract

A human body electromagnetic induction switch device (100) and a method for starting electrical equipment. The human body electromagnetic induction switch device (100) includes a detector circuit (101) for detecting human body electromagnetic induction signals and a drive circuit (102) connected to the detector circuit (101). The drive circuit (102) generates a drive signal based on the output of the detector circuit (101) to connect the power supply of the electrical equipment or start the main circuit (120) of the electrical equipment.

Description

Human body electromagnetic induction switch device and method for starting electrical equipment

technical field

The invention relates to electrical equipment, more specifically, to a human body electromagnetic induction switch device for starting electrical equipment.

Background technique

In existing human body induction switches such as infrared and voice-activated switches, the power supply to the sensor circuit and the main circuit is usually a normal power supply or an interval power supply. The normal power supply method has a large waste of electric energy due to the continuous power supply. Interval power supply has a time gap between two power supplies. When the switch needs to be turned on during the time gap, it will take a while to start the switch main circuit, so there is a long delay. And this delay will cause inconvenience to people. For example, for the lighting lamps used in the corridor, it is expected that the human body induction switch can turn on the power supply of the lighting lamps with the minimum delay. Other application places, such as corridors, warehouses, underground passages, toilets and other places that automatically turn on and off lights, also have similar requirements.

In addition, cities or places with human activities are already full of electromagnetic waves, especially the fluctuations of 50/60HZ power frequency waves are particularly huge (the peak-to-peak value can reach about 220V), and there are also other electromagnetic waves such as GSM signals. In such an environment, electromagnetic induction signals will be generated on the human body.

Contents of the invention

The technical problem to be solved by the present invention is to provide a switch device that activates electrical equipment only when a human body touches or approaches it, aiming at the above-mentioned defects of high power consumption and delayed response time in the prior art.

The technical solution adopted by the present invention to solve the technical problem is: to construct a human body electromagnetic induction switch device for starting electrical equipment, including a detection circuit for detecting human body electromagnetic induction signals; a drive circuit connected to the detection circuit, It generates a driving signal based on the output of the detection circuit, and is used to turn on the power supply of the electrical equipment or wake up the circuit board of the electrical equipment.

In the human body electromagnetic induction switch device of the present invention, the detection circuit outputs a voltage or current signal when the human body touches or approaches the human body.

In the human body electromagnetic induction switch device according to the present invention, the detection circuit includes a diode, a capacitor, and a conductive contact piece and/or a contact point; wherein, one end of the diode is connected to the conductive contact piece and/or contact point, The other end is connected to one end of the capacitor, and the other end of the capacitor is grounded or VCC.

In the human body electromagnetic induction switch device according to the present invention, a resistor is connected in parallel at both ends of the capacitor.

In the human body electromagnetic induction switch device according to the present invention, the driving circuit includes a controllable level conversion circuit module, an analog switch or S3.

In the human body electromagnetic induction switch device according to the present invention, the detection circuit includes a field effect transistor and a capacitor connected thereto, a first resistor, a second resistor, and a conductive contact piece and/or a contact point, and the drive circuit can be control level conversion circuit module.

In the human body electromagnetic induction switch device according to the present invention, the field effect transistor is a P-channel field effect transistor, and its source is grounded through the capacitor and connected to the enable terminal of the controllable level conversion circuit module, The drain is connected to VCC, the gate is connected to the conductive contact sheet and/or the contact point, the first resistor is connected between the gate of the P-channel field effect transistor and ground, the second resistor is connected to the capacitor in parallel.

In the human body electromagnetic induction switch device according to the present invention, the field effect transistor is an N-channel field effect transistor, its source is connected to VCC, and its drain is grounded through the capacitor and connected to the controllable level conversion circuit module The enabling terminal and the grid are connected to the conductive contact sheet and/or the contact point, the first resistor is connected between the grid of the P-channel field effect transistor and VCC, the second resistor is connected to the capacitor in parallel.

The technical solution adopted by the present invention to solve the technical problem is to provide a method for starting electrical equipment, including:

Detecting the electromagnetic induction signal of the human body, and outputting the induction signal;

generating a driving signal based on the sensing signal; and

In response to the drive signal, power on the electrical equipment or wake up the circuit board of the electrical equipment.

In the method for starting an electrical device according to the present invention, it is characterized in that the induction signal includes a voltage or current signal generated when a human body touches or approaches it.

The implementation of the present invention has the following beneficial effects: since the human body electromagnetic induction signal detection circuit can detect the voltage change caused by the human body electromagnetic induction signal without power consumption, and transmit the voltage to the drive circuit, it can save electric energy and has no Delays due to interval power supply. In addition, the scheme of using the electromagnetic induction signal of the human body to start the electrical equipment can detect whether the user is close to or touching the sensor position, so it can also be used as a reference for the electronic system to judge whether the user has illegal operation behavior. And because this solution needs to rely on the large capacitance effect produced by the human body, it can well overcome the interference of humidity such as water droplets and fog, and can better overcome the sudden change of the external electric field. At the same time, since the sensor can be non-exposed, wear and corrosion can be avoided, and the service life can be improved.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the structural representation of human body electromagnetic induction switch device of the present invention;

Fig. 2 is the flow chart of the method for starting electrical equipment of the present invention;

3A is a schematic circuit diagram of the first embodiment of the human body electromagnetic induction switch device of the present invention;

3B is a schematic circuit diagram of the second embodiment of the human body electromagnetic induction switch device of the present invention;

3C is a schematic circuit diagram of the third embodiment of the human body electromagnetic induction switch device of the present invention;

3D is a schematic circuit diagram of a fourth embodiment of the human body electromagnetic induction switch device of the present invention;

Fig. 3E is a schematic circuit diagram of the fifth embodiment of the human body electromagnetic induction switch device of the present invention;

Fig. 3F is a schematic circuit diagram of the sixth embodiment of the human body electromagnetic induction switch device of the present invention;

Fig. 4A is a schematic diagram of the voltage of the human body relative to the earth when there is a power frequency alternating current around;

4B is a schematic diagram of the output voltage after the human body electromagnetic induction signal is detected by the diode capacitance detection circuit according to an embodiment of the human body electromagnetic induction switch device;

4C is a schematic diagram of the electrical signal output by the driving circuit according to an embodiment of the human body electromagnetic induction switch device of the present invention.

Detailed ways

As shown in FIG. 1 , the human body electromagnetic induction switch device 100 includes a detection circuit 101 and a driving circuit 102 . The detection circuit 101 can detect the voltage change (that is, the human body electromagnetic induction signal) caused by the induction electromagnetic wave of the human body without power consumption, and transmit the voltage signal to the driving circuit 102, and the driving circuit 102 generates a driving signal to start the electrical appliance The device main circuit 120 is, for example, turning on the power of the electrical device main circuit 120 or waking up the circuit board of the electrical device main circuit 120 .

In operation, the method for starting electrical equipment is as shown in Figure 2. In step 210, the detection circuit 101 detects the electromagnetic induction signal of the human body, and outputs the induction signal; in step 220, the driving circuit 102 generates a driving signal based on the induction signal; Step 230, responding to the drive signal to turn on the power of the electrical equipment or wake up the circuit board of the electrical equipment.

In various embodiments of the present invention, diodes, capacitors, and conductive contact pieces and/or contact points are used to form an AC detection circuit to convert an AC signal into a fluctuating DC signal. And the use of resistors is used to accelerate the discharge speed of the capacitor after the human body leaves, and to maintain the stability of the electric signal output by the detection circuit when no human body is approaching or touching. The role of the resistor is to accelerate the discharge of the capacitor and stabilize the level. As shown in Fig. 3A-Fig. 3D, design a detection circuit composed of a simple diode, capacitor and conductive contact point/sheet, cooperate with an attached large resistor to prevent the accumulation of floating charge, conductive contact point/sheet 124( Directly exposed or covered) is used to detect the voltage change caused by the human body touching or approaching.

Its working principle is: when no one touches, the output signal is a stable level; when someone (represented by finger 110) touches or approaches, a varying voltage will be generated. When the voltage exceeds the threshold, the detection circuit will drive the power supply behind it to turn on or wake up the circuit board. The driving circuit can be, for example, a controllable switch, an analog switch or a field effect tube circuit.

As shown in FIG. 3A, the detection circuit includes a diode D1, a capacitor C1, and a conductive contact piece and/or a contact point 124, wherein the negative end of the diode D1 is connected to the conductive contact piece and/or the contact point 124, and the positive end is connected to the capacitor C1. One end of the capacitor is connected, and the other end of the capacitor is connected to VCC. A resistor R1 is connected in parallel with both ends of the capacitor C1. The drive circuit is a controllable switch or electronic switch S1.

As shown in Figure 3B, the detection circuit includes a diode D2, a capacitor C2, and a conductive contact piece and/or a contact point 124, wherein the positive end of the diode D2 is connected to the conductive contact piece and/or the contact point 124, and the negative end is connected to the capacitor C2 One end of the capacitor is connected, and the other end of the capacitor is grounded. A resistor R2 is connected in parallel with both ends of the capacitor C2. The drive circuit is a controllable switch or electronic switch S2.

As shown in Figure 3C, the detection circuit includes a diode D3, a capacitor C3, and a conductive contact piece and/or a contact point 124, wherein the positive end of the diode D3 is connected to the conductive contact piece and/or the contact point 124, and the negative end is connected to the capacitor C3 One end of the capacitor is connected, and the other end of the capacitor is grounded. A resistor R3 is connected in parallel with both ends of the capacitor C3. The driving circuit is a controllable level conversion circuit module U1.

As shown in Figure 3D, the detection circuit includes a diode D4, a capacitor C4, and a conductive contact piece and/or a contact point 124, wherein the positive end of the diode D4 is connected to the conductive contact piece and/or the contact point 124, and the negative end is connected to the capacitor C4 One end of the capacitor is connected, and the other end of the capacitor is grounded. A resistor R4 is connected in parallel with both ends of the capacitor C4. The driving circuit is an analog switch S3.

Wherein the controllable switch or electronic switch S1, S2 is a kind of circuit. The analog switch S3 is a chip.

In other embodiments of the present invention, a detection circuit is formed by using a field effect transistor, a capacitor, two resistors, and a conductive contact piece and/or a contact point.

As shown in Figure 3E, the detection circuit includes a field effect transistor M1, a capacitor C5, a first resistor R7, a second resistor R6, and a conductive contact piece and/or a contact point 124, and the drive circuit is a controllable level conversion circuit module U2 . Wherein, the field effect transistor M1 is a P-channel field effect transistor, its source is grounded through the capacitor C5 and connected to the enable terminal of the controllable level conversion circuit module U2, the drain is connected to VCC, and the gate is connected to the conductive contact piece and/or At the contact point 124, the first resistor R7 is connected between the gate of the P-channel field effect transistor M1 and the ground, and the second resistor R6 is connected in parallel with the capacitor C5.

As shown in FIG. 3F , the detection circuit includes a field effect transistor M2 , a capacitor C6 , a first resistor R9 , a second resistor R8 , a conductive contact piece and/or a contact point 124 , and the driving circuit is a controllable level conversion circuit module U3 . Wherein, the field effect transistor M2 is an N-channel field effect transistor, its source is connected to VCC, its drain is grounded through the capacitor C6 and connected to the enable end of the controllable level conversion circuit module U3, and its gate is connected to the conductive contact piece and /or the contact point 124, the first resistor R9 is connected between the gate of the P-channel field effect transistor M2 and VCC, and the second resistor R8 is connected in parallel with the capacitor C6.

Its working principle is: through the electromagnetic induction signal of the human body, drive the field effect transistor to turn on and off, charge the capacitor when it is turned on, keep the charge when it is turned off, and output a stable high-level signal. The function of the first resistors R7 and R9 is to keep the gate of the field effect transistor at a fixed level, such as GND or VCC, when there is no human body induction signal. The function of the second resistors R6 and R8 is to enable the capacitor to quickly discharge the capacitor after the human body induction signal disappears, so as to restore it to a stable level.

In the embodiments shown in FIG. 3E and FIG. 3F , the controllable level conversion circuit modules U2 and U3 are set to be enabled at a high level, so the capacitor is at the GND level before being charged. If the controllable level conversion circuit modules U2 and U3 need to be enabled with a low level, you can refer to the previous Figures 3A to 3D, swap the positions of the capacitor and its discharge resistor, connect to VCC, and form a discharge circuit output.

The human body electromagnetic induction switch device of the present invention is installed in a position that the user will inevitably approach and touch when using the equipment, such as around the fingerprint collection sensor or the vein collection sensor, the handle or the key of the electromechanical equipment.

4A-4C are respectively the voltage of the human body relative to the ground, the voltage output by the detection circuit, and the electrical signal output by the drive circuit.

As shown in FIG. 4A , in a power frequency alternating current environment, the voltage of the human body relative to the ground also changes in a sine wave with time T. When the human body approaches or touches, the detection circuit generates an induced voltage, the waveform of which is shown in Figure 4B. As mentioned above, when the induced voltage exceeds the threshold, the driving circuit generates a driving signal to turn on the driving power or wake up the circuit board. As shown in FIG. 4C , the driving circuit starts to output a high level at time T0.

Table 1 shows the performance comparison between the human body electromagnetic induction switch device of the present invention and existing mechanical keys or active detection (such as infrared).

Table I:

mechanical button Active detection (infrared) Electromagnetic induction of human body speed 100us-10ms 0.5-2s 10ms Working power consumption 0 Above 10uA 0 volume middle big Small Easy to install middle Disaster easy life 10000 times 0.3-2 years over 10 years system cost 0.1-0.8 yuan 0.3-5 yuan 0.05-0.07 yuan Anti-human interference middle weak powerful water proof no weak yes temperature effect not affected influential not affected Environmental friendly no no yes

Rely on external electromagnetic no no yes

The human body electromagnetic induction switch device of the present invention can be applied to user identification equipment such as fingerprint door locks, vein detection locks, computer and mobile phone activation, factory equipment activation such as numerical control lathes and hydraulic equipment, household appliances such as electric lights, air conditioner activation, etc.

Claims (5)

1. A human body electromagnetic induction switch device, used to start electrical equipment, is characterized in that it includes a detection circuit for detecting human body electromagnetic induction signals; a drive circuit connected to the detection circuit, which is based on the output of the detection circuit Generate a drive signal to turn on the power of the electrical equipment or wake up the circuit board of the electrical equipment. The detection circuit includes a capacitor and a resistor. The resistor is used to accelerate the discharge of the capacitor and stabilize the level when there is no human body electromagnetic induction signal. The detection circuit outputs a voltage or current signal when the human body touches or approaches, wherein: The resistor is composed of a first resistor and a second resistor, and the detection circuit also includes a field effect transistor connected to the capacitor and a conductive contact piece and/or a contact point, and the second resistor is connected in parallel with the capacitor, so The driving circuit is a controllable level conversion circuit module, the function of the first resistor is to keep the grid of the field effect transistor at a fixed level when there is no human body induction signal, and the function of the second resistor is to After the human body induction signal of the capacitor disappears, the second resistor quickly discharges the capacitor to restore the capacitor to a stable level. 2. The human body electromagnetic induction switch device according to claim 1, wherein the field effect transistor is a P-channel field effect transistor, and its source is grounded through the capacitor and connected to the controllable level conversion circuit The enable end of the module, the drain is connected to VCC, the gate is connected to the conductive contact piece and/or the contact point, the first resistor is connected between the gate of the P-channel field effect transistor and the ground, and the first resistor is connected to the ground. Two resistors are connected in parallel with the capacitor. 3. The human body electromagnetic induction switch device according to claim 1, wherein the field effect transistor is an N-channel field effect transistor, its source is connected to VCC, and its drain is grounded through the capacitor and connected to the The enable terminal and the gate of the control level conversion circuit module are connected to the conductive contact piece and/or the contact point, the first resistor is connected between the gate of the N-channel field effect transistor and VCC, and the first resistor is connected to the VCC. Two resistors are connected in parallel with the capacitor. 4. A method of using the human body electromagnetic induction switch device as claimed in claim 1 to start electrical equipment, characterized in that it comprises: Detecting the electromagnetic induction signal of the human body, and outputting the induction signal; generating a driving signal based on the sensing signal; and In response to the driving signal, power on the electrical equipment or wake up the circuit board of the electrical equipment. 5. The method for starting an electrical device according to claim 4, wherein the induction signal includes a voltage or current signal generated when a human body touches or approaches it.