阅读说明：本技术 一种低功耗红外反射检测电路 (Low-power consumption infrared reflection detection circuit ) 是由 王旭东 于 2021-09-17 设计创作，主要内容包括：本发明提供了一种低功耗红外反射检测电路,包括恒流电路模块、红外发射管、红外接收管、反馈电路模块和供电电源；恒流电路电源输入端连接所述供电电源,红外发射管与恒流电流输出端串联,红外接收管的供电端与恒流电流输出端连接,红外接收管的输出端与反馈电路的输入端连接,反馈电路的输出端连接恒流电路反馈信号输入端。本发明当无人体或无物体靠近红外发射管时,可以使整个电路的电流及流过红外发生管的电流维持在很小的静态电流范围内,当有人体或物体靠近红外发射管又可使静态电流迅速变大,确保人或物体被可靠感应到,这样就可以在不影响检测效果的情况下,将静态工作电流降到最低,然后再增加间歇工作模式,把平均电流按比例减小,最终达到降低功耗的目的。(The invention provides a low-power consumption infrared reflection detection circuit, which comprises a constant current circuit module, an infrared transmitting tube, an infrared receiving tube, a feedback circuit module and a power supply; the input end of the power supply of the constant current circuit is connected with the power supply, the infrared transmitting tube is connected with the output end of the constant current in series, the power supply end of the infrared receiving tube is connected with the output end of the constant current, the output end of the infrared receiving tube is connected with the input end of the feedback circuit, and the output end of the feedback circuit is connected with the feedback signal input end of the constant current circuit. When no human body or object is close to the infrared emission tube, the current of the whole circuit and the current flowing through the infrared generation tube can be maintained in a small static current range, and when a human body or object is close to the infrared emission tube, the static current can be rapidly increased, so that the human body or the object can be reliably sensed, the static working current can be reduced to the minimum under the condition of not influencing the detection effect, then the intermittent working mode is increased, the average current is reduced in proportion, and the purpose of reducing the power consumption is finally achieved.)

1. A low-power consumption infrared reflection detection circuit is characterized in that: the infrared emission and feedback circuit comprises a constant current circuit module, an infrared emission tube, an infrared receiving tube, a feedback circuit module and a power supply;

the constant current circuit module is used for converting a power supply into constant current output and comprises a constant current circuit power supply input end, a constant current output end and a constant current circuit feedback signal input end, and the feedback circuit module comprises an input end of a feedback circuit module and an output end of the feedback circuit module;

the infrared emission tube is connected with the constant current output end in series, the power supply end of the infrared receiving tube is connected with the constant current output end, the output end of the infrared receiving tube is connected with the input end of the feedback circuit, the output end of the feedback circuit is connected with the feedback signal input end of the constant current circuit, the constant current circuit is used for providing low-power constant current for the infrared emission tube when no person or no object approaches, and the constant current circuit is also used for increasing output current after receiving a feedback signal of the feedback circuit when a person or an object approaches so as to improve the emission power of the infrared emission tube and improve the detection reliability.

2. The low power consumption infrared reflectance detection circuit of claim 1, wherein: the controller is used for outputting control signals and controlling the opening and closing of the constant current circuit and the duration of the opening and closing of the constant current circuit.

3. The low power consumption infrared reflectance detection circuit of claim 2, wherein: the power supply input end of the constant current circuit and the input end of the infrared emission tube are connected with the power supply through a third switching tube Q3, wherein the switch control end of the third switching tube Q3 is connected with a controller, and the controller controls the opening, closing and the duration of the opening and closing.

4. A low power consumption infrared reflectance detection circuit as defined in claim 3, wherein: the constant current circuit module comprises a first resistor R1, a second resistor R2, a third resistor R3, a first switch tube Q1 and a second switch tube Q2, wherein a first end of the first resistor R1 is connected with an output end of a third switch tube Q3, namely, a first end of the first resistor R1 is a constant current circuit power supply input end, a second end of the first resistor R1 is connected with an input end of the first switch tube Q1, a control end of the first switch tube Q1 is connected with an input end of the second switch tube Q2, an emission end of the first switch tube Q1 is connected with a first end of the second resistor R2, a second end of the second resistor R2 is grounded, a control end of the first switch tube Q1 is also connected with a first end of the third resistor R3, a first end of the second resistor R2 is a feedback signal input end of the constant current circuit, a second end of the third resistor R3 is grounded, and a second end of the second switch tube Q2 is connected with a control end of the second switch tube Q1, the output end of the second switch tube Q2 is connected with the cathode of the infrared emission tube, the output end of the second switch tube Q2 is the constant current output end, the anode of the infrared emission tube is connected with the power supply through the third switch tube Q3, and the power supply supplies power to the infrared emission tube under the control of the controller.

5. The low power consumption infrared reflectance detection circuit of claim 4, wherein: the second switching tube Q2 adopts a field effect MOS tube.

6. The low power consumption infrared reflectance detection circuit of claim 4, wherein: the first switch tube adopts a triode.

7. The low power consumption infrared reflectance detection circuit of claim 1, wherein: the feedback circuit module adopts a fourth resistor R4, a first end of the fourth resistor R4 is connected with the output end of the infrared receiving tube, and a second end of the fourth resistor R4 is connected with the feedback signal input end of the constant current circuit.

8. A low power consumption infrared reflectance detection circuit as defined in claim 3, wherein: the controller is used for providing high and low level signals for the third switching tube Q3, and controlling the conduction and the closing of the constant current circuit, the infrared emission tube and the power supply through the high and low level signals so as to control the opening and the closing of the constant current circuit and the infrared emission tube.

9. The low power consumption infrared reflectance detection circuit of claim 2, wherein: and a first capacitor C1 is also connected between the input end of the feedback circuit and the ground and is used for filtering and interference identification.

Technical Field

The utility model relates to an infrared detection technology field especially relates to a low-power consumption infrared reflection detection circuitry.

Background

In infrared detection application, there is the application of a reflection signal detection, the circuit comprises infrared transmitting tube and infrared receiving tube, infrared pipe is under the standby condition, need outwards emit the infrared light always, when someone or there is the object to be close to infrared probe, because of there being light reflection, infrared receiving tube switches on because of sensing the infrared light, thereby trigger relevant circuit or singlechip IO mouth, when the circuit uses battery power supply, the live time of battery and detection circuitry's power consumption has very big relation, if do not adopt the power saving technique, under certain time of endurance requirement (such as a year), the capacity of required battery (such as 35AH) will lead to the volume too big, the price is too high, finally lead to the unable smooth volume production of product.

Disclosure of Invention

Based on the defects of the prior art, the invention provides the low-power-consumption infrared reflection detection circuit, which reduces the power consumption as much as possible and prolongs the battery endurance time on the premise of ensuring the stability and reliability of infrared detection.

A low-power consumption infrared reflection detection circuit is characterized in that: the infrared emission and feedback circuit comprises a constant current circuit module, an infrared emission tube, an infrared receiving tube, a feedback circuit module and a power supply;

the constant current circuit module is used for converting a power supply into constant current output and comprises a constant current circuit power supply input end, a constant current output end and a constant current circuit feedback signal input end, and the feedback circuit module comprises an input end of a feedback circuit module and an output end of the feedback circuit module.

The infrared emission tube is connected with the constant current output end in series, the power supply end of the infrared receiving tube is connected with the constant current output end, the output end of the infrared receiving tube is connected with the input end of the feedback circuit, the output end of the feedback circuit is connected with the feedback signal input end of the constant current circuit, the constant current circuit is used for providing low-power constant current for the infrared emission tube when no person or no object approaches, and the constant current circuit is also used for increasing the output current after receiving the feedback signal of the feedback circuit when a person or an object approaches so as to improve the emission power of the infrared emission tube and improve the detection reliability.

The controller is used for outputting control signals and controlling the opening, closing and the duration of the opening and closing of the constant current circuit and the infrared emission tube.

Furthermore, the power supply input end of the constant current circuit and the input end of the infrared emission tube are connected with the power supply through a third switching tube Q3, wherein the switch control end of the third switching tube Q3 is connected with a controller, and the controller controls the on/off and the duration of the on/off.

Further, the constant current circuit module includes a first resistor R1, a second resistor R2, a third resistor R3, a first switch tube Q1 and a second switch tube Q2, a first end of the first resistor R1 is connected to an output end of a third switch tube Q3, that is, the first end of the first resistor R1 is a power input end of the constant current circuit, a second end of the first resistor R1 is connected to an input end of the first switch tube Q1, a control end of the first switch tube Q1 is connected to an input end of the second switch tube Q2, an emitter end of the first switch tube Q1 is connected to a first end of the second resistor R2, a second end of the second resistor R2 is grounded, a control end of the first switch tube Q1 is further connected to a first end of the third resistor R3, a first end of the second resistor R2 is a feedback signal input end of the constant current circuit, and a second end of the third resistor R3 is grounded, the control end of the second switch tube Q2 is connected with the second end of the first resistor R1, the output end of the second switch tube Q2 is connected with the negative electrode of the infrared emission tube, the output end of the second switch tube Q2 is the constant current output end, the positive electrode of the infrared emission tube is connected with the power supply through the third switch tube Q3, and the power supply supplies power to the infrared emission tube under the control of the controller.

Further, the second switching tube Q2 is a field effect MOS tube.

Furthermore, the first switch tube adopts a triode.

Further, the feedback circuit module adopts a fourth resistor R4, a first end of the fourth resistor R4 is connected with the output end of the infrared receiving tube, and a second end of the fourth resistor R4 is connected with the feedback signal input end of the constant current circuit.

Further, the controller is configured to provide a high-low level signal for the third switching tube Q3, and control the conduction and the shutdown of the constant current circuit, the infrared emission tube, and the power supply through the high-low level signal, so as to control the on and the off of the constant current circuit and the infrared emission tube.

Further, a first capacitor C1 is connected between the input end of the feedback circuit and the ground for filtering and interference identification.

Has the advantages that: when no human body or object is close to the infrared transmitting tube, the current of the whole circuit and the current flowing through the infrared generating tube can be maintained in a very small static current range due to the action of the constant current circuit, and when a human body or an object is close to the infrared transmitting tube, the static current can be rapidly increased, so that the object is ensured to be reliably sensed, and the static working current of the circuit can be obviously reduced.

In addition, the controller can provide an opening or closing control signal for the whole circuit by combining a time-sharing principle, so that the whole circuit can work intermittently, and the purpose of reducing power consumption is further achieved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings needed to be used in the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic circuit diagram according to an embodiment of the present invention.

Detailed Description

The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure in the specification. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be embodied or carried out in various other specific embodiments, and various modifications and changes may be made in the details within the description without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

As shown in fig. 1, the low power consumption infrared reflection detection circuit includes a constant current circuit module 1, an infrared transmitting tube D1, an infrared receiving tube Q01, a feedback circuit module 2, and a power supply VCC.

Specifically, the constant current circuit module 1 is configured to convert a voltage of a power supply VCC into a constant current and output the constant current, and includes a power supply receiving terminal, a constant current output terminal, and a constant current circuit feedback signal input terminal, where the feedback circuit includes an input terminal of a feedback circuit module and an output terminal of the feedback circuit module.

The power receiving end is connected to the power supply VCC through a third switching tube Q3, the third switching tube Q3 of this embodiment employs a field effect MOS transistor, specifically, the third switching tube Q3 may employ an NMOS field effect transistor, certainly, under the condition that the concept of the present invention is not violated, the third switching tube Q3 may employ a PMOS field effect transistor, when a PMOS field effect transistor is employed, the connection mode and level polarity of the corresponding circuit need to be changed properly, but such a change is that a person skilled in the art can easily modify and transform without creative work, and thus, no further description is given here. The infrared transmitting tube D1 is connected in series with the constant current output end, the power supply end of the infrared receiving tube Q01 is connected with the output end of the infrared transmitting tube D1, the output end of the infrared receiving tube Q01 is connected with the input end of the feedback circuit, the output end of the feedback circuit is connected with the feedback signal input end of the constant current circuit, the constant current circuit 1 is used for providing low-power constant current for the infrared transmitting tube D1 when no person or no object approaches, and the constant current circuit 1 is also used for increasing the output current after receiving the feedback signal of the feedback circuit 2 when a person or an object approaches so as to improve the transmitting power of the infrared transmitting tube D1 and improve the detection reliability.

The low-power-consumption infrared reflection detection circuit further comprises a controller, the constant current circuit module further comprises a constant current circuit switch control end, the constant current circuit switch control end is indirectly connected with the controller through a switch tube, the controller is used for outputting control signals, opening and closing of the constant current circuit and duration time of opening and closing are controlled by controlling opening and closing of the switch tube, and an infrared emission tube is an energy consumption device of the whole circuit and is controlled by the constant current circuit and also synchronously opened or closed.

It should be noted that, in this embodiment, a controller is not shown in fig. 1, but no specific requirements are made on the structure, the specific model, and the like of the controller, as long as a high-low level signal can be provided, and particularly, a PWM-adjustable control signal can be output, and a single chip microcomputer is adopted in the controller of this embodiment.

The following is a constant current circuit module provided in this embodiment, and includes a first resistor R1, a second resistor R2, a third resistor R3, a first switch Q1, and a second switch Q2, where the first switch Q1 is a triode, the second switch Q2 is a field effect MOS transistor, a first end of the first resistor R1 is connected to a source of the third switch Q3, a drain of the third switch Q3 is connected to the power supply VCC, a gate of the third switch Q3 is connected to a controller, a first end of the first resistor R1 is a power receiving end of a constant current circuit, a second end of the first resistor R1 is connected to an input end of the first switch Q1, a control end of the first switch Q1 is connected to a gate of the second switch Q2, an emitter end of the first switch Q1 is connected to a first end of the second resistor R2, and a second end of the second switch Q2 is grounded, the control end of the first switch tube Q1 is further connected to the first end of the third resistor R3, the first end of the second resistor R2 is the constant current circuit feedback signal input end, the second end of the third resistor R3 is grounded, the first end of the fourth resistor R4 is the input end of the feedback circuit module, the second end of the fourth resistor R4 is the output end of the feedback circuit module, the gate of the second switch tube Q2 is connected to the second end of the first resistor R1, the source of the second switch tube Q2 is connected to the negative electrode of the infrared emitting tube D1, the source of the second switch tube Q2 is the constant current output end, the positive electrode of the infrared emitting tube D1 is connected to the drain of the third switch tube Q3, and the source of the third switch tube Q3 is connected to the power supply VCC.

The first switch tube Q1 may be a triode, specifically, an NPN triode may be used, and the second switch tube Q2 may be an NMOS tube. Similarly, the first switch tube Q1 of this embodiment may also use a PNP type triode instead, but the PNP type triode is used, so the connection mode of the circuit also needs to be changed properly, and the second switch tube Q2 may also use a PMOS tube.

Specifically, the feedback circuit module 2 adopts a fourth resistor R4, a first end of the fourth resistor R4 is connected to an output end of the infrared receiving tube Q01, a second end of the fourth resistor R4 is connected to a first end of the second resistor R2, a first end of the fourth resistor R4 is an input end of the feedback circuit module 2, a second end of the fourth resistor R4 is connected to a feedback signal input end of the constant current circuit, and a second end of the fourth resistor R4 is an output end of the feedback circuit module 2.

The working principle of the circuit is as follows:

the constant current circuit comprises a first resistor R1, a second resistor R2, a third resistor R3, a first switch tube Q1 and a second switch tube Q2, and aims to ensure that the static current passing through an infrared emission tube D1 is kept constant when a power supply VCC (voltage supply) changes, and the specific working process of the constant current circuit is as follows: in the constant current circuit, at the moment of power-up, the first resistor R1 provides a turn-on voltage for the second switch tube Q2, the second switch tube Q2 is turned on, a current flows through the third resistor R3, when the voltage across the third resistor R3 is higher than 0.7V, the second switch tube Q1 is turned on, the current through the first resistor R1 rapidly increases, so as to pull down the gate voltage of the second switch tube Q2, until the third resistor R3 is stabilized at a value slightly less than 0.7V, at this time, the current through the third resistor R3 (assuming that the resistance value thereof is 1.8K) is constant at 0.7/1.8 ═ 0.39(mA), the current through the base of the first switch tube Q1 is negligible, so that the current flowing through the infrared emitter D1 is also stabilized at 0.39 mA.

When a human body or an object approaches the sensor infrared transmitting tube D1, the current of the Q01 increases due to receiving infrared rays diffusely reflected by the infrared transmitting tube D1, the infrared rays are loaded onto the second resistor R2 through the fourth resistor R4 of the feedback circuit module 2, the voltage of the second resistor R2 increases, and the voltage of the emitting junction of the first switch tube Q1 is relatively stable, so the voltage of the third resistor R3 also increases, and the current passing through the infrared transmitting tube D1 increases until the second switch tube Q2 enters a saturation region through the positive feedback path of the feedback circuit module 2, and at this time, the current flowing through the infrared transmitting tube D1 is equal to the current flowing through the second switch tube Q2 plus the current flowing through the first switch tube Q1, which is much larger than 0.38 mA-0.39 mA in a static state, thereby ensuring that the object is reliably sensed.

Through the embodiment, when no human body or no object is close to the circuit, the static current of the circuit is maintained to be about 0.38 mA-0.39 mA, when a human body or an object is close to the circuit, the current is rapidly increased to about 4mA, and the circuit is standby by using a small current instead of a large current, so that the static working current of the circuit can be obviously reduced.

As a further optimization of the technical solution in the above embodiment, the constant current circuit switch control end is further indirectly connected to a controller, the controller is configured to output a high-low level signal, and also may output a PWM pulse modulation signal according to needs, in this embodiment, a single chip of the controller generates a PWM pulse signal with a duration Th high level and a duration Tl low level, and a duty ratio d being Th/(Th + Tl), where Th randomly jitters within a range of ± 10% of an upper and lower deviation of a standard value (a jitter ratio may be adjusted according to actual application), and the constant current circuit is controlled to be turned on and off by the PWM signal.

The controller can intermittently control the constant current circuit 1 to be switched on and off, and the purpose of reducing power consumption is achieved through intermittent work.

Through experiments, in terms of reducing the standby current, when the duty ratio is 2% (ratio of high level time to full period), the average current can be reduced from 0.39mA to 0.39 × 2% — 0.0078(mA), i.e., 7.8 uA. When the parameters of each element are adjusted reasonably, the duty ratio can be adjusted to 1%, and then the average current at the moment is only 3.9 uA.

In this embodiment, the controller sends a turn-on signal to the fet Q3, and similarly, the fet Q3 determines the connection and disconnection between the ir transmitting tube D1 and the power supply under the control of the controller.

Specifically, the purpose of saving power is achieved by enabling the IREN through the enable signal output by the controller, when the IREN is grounded, the third field-effect tube Q3 is connected, the whole constant-current circuit module and the infrared emission tube work, when the IREN is connected with a high level, the third field-effect tube Q3 is not connected, the whole circuit is closed, and the current is close to 0.

It should be noted that the output terminal IRST of the infrared receiving tube Q01 outputs a high level when a human body or an object approaches, or outputs a low level when the human body or the object approaches, and may be connected to an IO port of a controller to control peripheral devices such as an electromagnetic valve or a motor.

Whether a person or an object is close to the infrared pair tubes (the infrared transmitting tube and the infrared receiving tube) can be judged by detecting the level, so that an external controlled circuit can indicate, open or close some equipment, count times and other practical applications.

As a further optimization of the above scheme, a first capacitor C1 may be further connected between the input terminal of the feedback circuit module 2 and ground, and due to the existence of C1, a delay may be generated when IRST outputs a high level, when IREN is grounded and an object approaches, there is a delay Td of a fixed time from when IREN is grounded to when IRST goes high, and when the actual delay deviates from Td by more than a certain proportion (for example, ± 10%), it indicates that there is other infrared light or strong light interference outside.

The anti-interference detection strategy can also judge the time length of the circuit starting pulse and the deviation of the received high-level time length, and when the deviation exceeds a certain proportion (such as +/-5 percent), other infrared or strong light interference can also be indicated.

And finally, in the aspect of comprehensively judging whether the interference exists, pulses with delay and output pulse width not exceeding a set proportion are regarded as qualified pulses, the number of continuous qualified pulses is counted, and when the number is larger than a set value (such as 3), the fact that people or objects approach the pulses can be judged instead of false alarm generated by an interference source.

The policy-free reflection-type infrared induction switch has the advantages that the current can reach 5mA or even higher when the policy-free reflection-type infrared induction switch works, the power consumption per month can reach 3.6AH when the policy-free reflection-type infrared induction switch is used for supplying power to a battery, the average current can be reduced to 5uA by adopting the power saving policy in the embodiment, the power consumption per year can not reach 50mAH, and the power saving effect is very obvious.

In the above embodiments, the controller may be a microprocessor MCU or other processor with control function, and the main control chip of the controller is not limited.

The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present disclosure should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.