An infrared emitting tube working state detection circuit

Abstract

This invention provides an infrared emitting diode (IRD) operating status detection circuit, relating to the field of electronic device detection technology. It includes: an IRD driving module comprising an IRD, a first switch, and a first resistor; the input terminal of the first switch is connected to a first power supply terminal, the output terminal of the first switch is connected to the positive terminal of the IRD, and the negative terminal of the IRD is connected to one end of the first resistor; and a detection module comprising a light-emitting diode (LED), a second switch, a second resistor, a third resistor, and a capacitor; the control terminal of the second switch is connected to one end of the second resistor, the other end of the second resistor is connected to the negative terminal of the IRD, and the input terminal of the second switch is connected to the negative terminal of the LED and one end of the capacitor. The advantage of this invention is that the operating status of the IRD is determined by visually observing the light-emitting state of the LED; there is a one-to-one correspondence between the LED and the IRD, allowing for accurate detection of the IRD's operating status.

Description

Technical Field

[0001] This invention relates to the field of electronic device testing technology, and more specifically to an infrared emitting diode operating status detection circuit. Background Technology

[0002] Since infrared light is invisible to the naked eye, infrared emitters and similar products can only be tested during the production and testing phase by using infrared receivers to detect the working status of the infrared emitters. However, when two or more infrared emitters are being tested simultaneously, their emitted infrared signals overlap, making it impossible for the infrared receiver to detect whether each emitter is functioning correctly, resulting in inaccurate detection.

[0003] Therefore, how to accurately detect the working status of infrared emitting diodes is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an infrared emitting tube working status detection circuit that accurately detects the working status of the infrared emitting tube.

[0005] This invention is implemented as follows: an infrared emitting diode operating status detection circuit, comprising:

[0006] An infrared emitting diode driving module includes an infrared emitting diode, a first switch, and a first resistor. The input terminal of the first switch is connected to a first power supply terminal, the output terminal of the first switch is connected to the positive terminal of the infrared emitting diode, the control terminal of the first switch is connected to a drive signal terminal, the negative terminal of the infrared emitting diode is connected to one end of the first resistor, and the other end of the first resistor is grounded.

[0007] The detection module includes a light-emitting diode (LED), a second switch, a second resistor, a third resistor, and a capacitor. The control terminal of the second switch is connected to one end of the second resistor, and the other end of the second resistor is connected to the negative terminal of the infrared LED. The input terminal of the second switch is connected to the negative terminal of the LED and one end of the capacitor. The output terminal of the second switch and the other end of the capacitor are both grounded. The positive terminal of the LED is connected to one end of the third resistor, and the other end of the third resistor is connected to a second power supply terminal.

[0008] Furthermore, the first switch is a PNP transistor, the emitter of which is connected to the first power supply terminal, the collector of which is connected to the positive terminal of the infrared emitting diode, and the base of which is connected to the drive signal terminal.

[0009] Furthermore, the second switch is an NPN transistor, with its emitter grounded, its collector connected to the negative terminal of the light-emitting diode, and its base connected to one end of the second resistor.

[0010] Furthermore, it also includes a microcontroller, one of which has an I / O pin that serves as the drive signal terminal.

[0011] Furthermore, the infrared emitting tube driving module also includes a first connector, which is connected to the negative terminal of the infrared emitting tube;

[0012] The detection module also includes a second connector, which is connected to the other end of the second resistor;

[0013] The first connector is paired with the second connector.

[0014] The advantages of this invention are: the working state of the infrared emitting diode is determined by observing the light emission state of the light-emitting diode with the naked eye; the light-emitting diode and the infrared emitting diode are in one-to-one correspondence, and the working state of the infrared emitting diode is accurately detected; the infrared receiver is eliminated, and when two or more external emitting diodes are detected at the same time, even if the emitted infrared signals overlap, it will not affect the light-emitting diode. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0016] Figure 1 This is a schematic diagram of an embodiment of the infrared emitting tube operating status detection circuit of the present invention.

[0017] Figure 2 This is a schematic diagram of the working process of the infrared emitting tube working status detection circuit of the present invention.

[0018] Figure 3 This is a schematic diagram of a second embodiment of the infrared emitting tube working status detection circuit of the present invention. Detailed Implementation

[0019] This invention provides an infrared LED operating status detection circuit to overcome the shortcomings of the prior art where infrared receivers cannot simultaneously detect the operating status of more than two infrared LEDs. It achieves the technical effect of accurately detecting the operating status of infrared LEDs by observing the light emission status of LEDs with the naked eye.

[0020] The technical solution in this invention aims to overcome the above-mentioned shortcomings, and the overall approach is as follows:

[0021] An infrared LED is essentially a diode that emits infrared light. The negative terminal of the infrared LED is grounded through a resistor. During normal operation, the negative terminal of the infrared LED will inevitably generate a voltage level fluctuation. That is, when the infrared LED is powered on, the negative terminal is at a high level, and when the infrared LED is powered off, the negative terminal is at a low level. This voltage level fluctuation is used to light up an ordinary LED. The lighting time of the LED is extended by the charging and discharging characteristics of the capacitor. The working status of the infrared LED can be detected by observing the light emission status of the LED, thus eliminating the need to use an infrared receiver to detect the working status of the infrared LED.

[0022] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0023] See Figure 1 and Figure 2 Embodiment 1 of the present invention.

[0024] An infrared emitting diode operating status detection circuit includes:

[0025] The infrared LED driver module includes an infrared LED1, a first switch Q1, and a first resistor R1. The input terminal of the first switch Q1 is connected to a first power supply terminal, the output terminal of the first switch Q1 is connected to the positive terminal of the infrared LED1, the control terminal of the first switch Q1 is connected to the drive signal terminal IR_CONTROL, the negative terminal of the infrared LED1 is connected to one end of the first resistor R1, and the other end of the first resistor R1 is grounded. The switching between the input and output terminals of the first switch Q1 is controlled by the level of the control terminal of the first switch Q1. The first power supply terminal is connected to 3.3V DC.

[0026] The detection module includes a light-emitting diode (LED2), a second switch (Q2), a second resistor (R2), a third resistor (R3), and a capacitor (C1). The control terminal of the second switch (Q2) is connected to one end of the second resistor (R2), and the other end of the second resistor (R2) is connected to the negative terminal of the infrared emitting diode (LED1). The input terminal of the second switch (Q2) is connected to the negative terminal of the LED2 and one end of the capacitor (C1). The output terminal of the second switch (Q2) and the other end of the capacitor (C1) are both grounded. The positive terminal of the LED2 is connected to one end of the third resistor (R3), and the other end of the third resistor (R3) is connected to a second power supply terminal. The on / off state between the input and output terminals of the second switch (Q2) is controlled by the voltage level of the control terminal of the second switch (Q2). The second power supply terminal is connected to 5V DC.

[0027] In the initial stage, when the first switch Q1 is open, the infrared LED1 does not work. At this time, the control terminal of the second switch Q2 is at a low level, the second switch Q2 is open, and during the charging process of capacitor C1, the light-emitting diode LED2 lights up. The voltage across capacitor C1 gradually increases, that is, the negative potential of the light-emitting diode LED2 gradually increases. When the voltage difference between the positive and negative terminals of the light-emitting diode LED2 does not meet the forward voltage drop of the light-emitting diode LED2, the light-emitting diode LED2 turns off. During the testing phase, the IR_CONTROL drive signal turns on the first switch Q1, activating the infrared LED1. The negative terminal of LED1 is at a high level, and the control terminal of the second switch Q2 is also at a high level, turning on Q2. This causes capacitor C1 to rapidly generate electricity, quickly reducing the negative voltage of the LED2 and illuminating it. Next, the IR_CONTROL drive signal turns off the first switch Q1, stopping LED1. The control terminal of the second switch Q2 then goes low, turning off Q2. As capacitor C1 begins charging, LED2 continues to illuminate. Once capacitor C1 has finished charging, LED2 turns off. This utilizes the charging and discharging characteristics of a capacitor to extend the visible light duration of LED2, facilitating visual observation by the tester.

[0028] An infrared emitter is paired with a light-emitting diode (LED2) in a one-to-one manner. When two or more infrared emitters are detected simultaneously, a corresponding number of detection modules are configured. The working status of each infrared emitter is then confirmed by observing the light emission status of the corresponding LED2. Even if two or more infrared emitters are working at the same time and the emitted infrared signals overlap, it will not affect the LED2, thus effectively improving the detection accuracy.

[0029] In this embodiment, the first switch Q1 is a PNP transistor. The emitter of the PNP transistor is connected to the first power supply terminal, the collector is connected to the positive terminal of the infrared emitting diode LED1, and the base is connected to the drive signal terminal IR_CONTROL. The characteristic of a PNP transistor is that it is in the off state when the base is high and in the on state when the base is low.

[0030] The second switch Q2 is an NPN transistor. The emitter of the NPN transistor is grounded, the collector is connected to the negative terminal of the light-emitting diode LED2, and the base is connected to one end of the second resistor R2. The characteristic of an NPN transistor is that it is in the conducting state when the base is high and in the cutoff state when the base is low.

[0031] It also includes a microcontroller M1, one of whose I / O pins is the drive signal terminal IR_CONTROL. According to actual testing, the microcontroller M1 controls the high and low levels of the drive signal terminal IR_CONTROL, thereby controlling whether the infrared emitting diode LED1 works.

[0032] The operation mode of the infrared emitting tube operating status detection circuit of the present invention is as follows:

[0033] (1) Combination Figure 1 The left side of the diagram shows the infrared LED driver module. Under normal conditions, the driver signal terminal IR_CONTROL is high, the PNP transistor Q1 is cut off, and the infrared LED1 is not working. The right side shows the detection module. When the infrared LED1 is not working, the negative terminal of the infrared LED1 is low, and the NPN transistor Q2 is cut off. When the second power supply is powered on, if capacitor C1 is charging, the LED2 lights up, and capacitor C1 charges slowly. When the voltage across capacitor C1 is higher than the voltage of the second power supply, the voltage drop across the third resistor R3, and the difference between the conduction voltage drop of the LED2, i.e., U... C1 >5V-U R3 -U VR U R3 It is the voltage drop across the third resistor, U VR This is the on-state voltage drop of LED2, at which point LED2 is off. As capacitor C1 charges, the voltage across C1 increases, and the current flowing through the third resistor R3 decreases. When capacitor C1 is nearly fully charged, the current flowing through the third resistor R3 is very small, and the voltage drop across R3 can be approximated as zero. Compared to 3.3V, choosing a 5V power supply for the second power supply can also extend the lighting time of LED2.

[0034] (2) When the microcontroller M1 switches the drive signal terminal IR_CONTROL to a low level, the PNP transistor Q1 turns on, and the infrared emitting diode LED1 works. At this time, the negative voltage of the infrared emitting diode LED1 is about 2V, which is a high level, causing the NPN transistor Q2 to turn on. Then the capacitor C1 discharges quickly, and the light-emitting diode LED2 lights up.

[0035] (3) The duration of a single infrared signal is approximately 120ms. After 120ms, the microcontroller M1 restores the drive signal terminal IR_CONTROL to a high level, the infrared emitting diode LED1 stops working, causing the NPN transistor Q2 to turn off, and capacitor C1 to recharge. In the detection module, the second power supply terminal is 5V, and the forward voltage drop of the light-emitting diode LED2 is V0. RFThe voltage across capacitor C1 is approximately 2.2V, so LED2 will remain lit until the voltage across C1 rises to 2.8V. In the charging circuit, the third resistor R3 has a resistance of 1K ohms, and the time constant τ is approximately 0.47. In summary, LED2 will remain lit for about 1 second (this can be adjusted by the capacitance of capacitor C1; a larger capacitance results in a longer lighting time).

[0036] The infrared emitting diode (LED) operating status detection circuit of this invention is simple and practical. It converts the detection of invisible infrared light into the visible emission status of a regular light-emitting diode (LED2), while extending the duration of visible light. This allows testers to determine the operating status of the infrared emitting diode (LED1) by visually observing the state of the LED2, optimizing the production and testing scheme for infrared emitter products and saving production and testing costs.

[0037] See Figure 2 Embodiment 2 of the present invention.

[0038] The infrared emitting diode driving module further includes a first connector A1, which is connected to the negative terminal of the infrared emitting diode LED1; the detection module further includes a second connector A2, which is connected to the other end of the second resistor R2; the first connector A1 and the second connector A2 are paired and connected. Thus, when detection is required, the infrared emitting diode driving module and the detection module are connected via connectors; after detection, the connectors are disconnected; this facilitates one detection module to be connected sequentially to multiple infrared emitting diode driving modules for detection. For other parts not described herein, please refer to Embodiment 1 of the present invention.

[0039] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An infrared emitting diode operating status detection circuit, characterized in that, include: An infrared emitting diode driving module includes an infrared emitting diode, a first switch, and a first resistor. The input terminal of the first switch is connected to a first power supply terminal, the output terminal of the first switch is connected to the positive terminal of the infrared emitting diode, the control terminal of the first switch is connected to a drive signal terminal, the negative terminal of the infrared emitting diode is connected to one end of the first resistor, and the other end of the first resistor is grounded. The detection module includes a light-emitting diode (LED), a second switch, a second resistor, a third resistor, and a capacitor. The control terminal of the second switch is connected to one end of the second resistor, and the other end of the second resistor is connected to the negative terminal of the infrared LED. The input terminal of the second switch is connected to the negative terminal of the LED and one end of the capacitor. The output terminal of the second switch and the other end of the capacitor are both grounded. The positive terminal of the LED is connected to one end of the third resistor, and the other end of the third resistor is connected to a second power supply terminal.

2. The infrared emitting diode operating status detection circuit according to claim 1, characterized in that, The first switch is a PNP transistor. The emitter of the PNP transistor is connected to the first power supply terminal, the collector is connected to the positive terminal of the infrared emitting diode, and the base is connected to the drive signal terminal.

3. The infrared emitting diode operating status detection circuit according to claim 2, characterized in that, The second switch is an NPN transistor, with its emitter grounded, its collector connected to the negative terminal of the light-emitting diode, and its base connected to one end of the second resistor.

4. The infrared emitting diode operating status detection circuit according to claim 1, characterized in that, It also includes a microcontroller, one of the microcontroller's I / O pins being the drive signal terminal.

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