CN109991521B - Light emitting diode detection circuit and device - Google Patents
Light emitting diode detection circuit and device Download PDFInfo
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- CN109991521B CN109991521B CN201910269203.3A CN201910269203A CN109991521B CN 109991521 B CN109991521 B CN 109991521B CN 201910269203 A CN201910269203 A CN 201910269203A CN 109991521 B CN109991521 B CN 109991521B
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- G01R31/2632—Circuits therefor for testing diodes
- G01R31/2635—Testing light-emitting diodes, laser diodes or photodiodes
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
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Abstract
The invention relates to a light emitting diode detection circuit and a device, wherein the light emitting diode detection circuit is characterized in that a sampling resistor is connected with a power supply through a first switch module, the sampling resistor is grounded through a second switch module, the sampling resistor is connected with the anode of a light emitting diode to be detected, a third switch module is connected with the power supply, the third switch module is connected with the cathode of the light emitting diode to be detected, a fourth switch module is used for grounding, the fourth switch module is connected with the cathode of the light emitting diode to be detected, the first input ends of a first comparator, a second comparator and a third comparator are respectively connected with the sampling resistor and the second input end of the first comparator, the output end of the second comparator and the output end of the third comparator are respectively connected with an indication module, and the comparators output ends output corresponding detection signals are output by forward energizing and backward energizing the light emitting diode, the LED chip testing device realizes the electrical performance test of the LED and is suitable for detecting the LED chip on a COB board.
Description
Technical Field
The invention relates to the technical field of diodes, in particular to a light-emitting diode detection circuit and a light-emitting diode detection device.
Background
With the continuous development of the modern science and technology, the application market of the LED (Light-Emitting Diode) is gradually mature, wherein a COB (chip on Board) Light source is a high-Light-efficiency integrated surface Light source technology for directly attaching an LED chip to a mirror metal substrate with high Light reflection rate, the technology eliminates the concept of a bracket, and has no processes of electroless plating, reflow soldering and chip mounting, so that the production cost is reduced, the personalized design can be performed, and the heat dissipation performance of the COB is good, so that the application of the COB in illumination becomes a trend and trend.
Because the LED wafer is easy to leak the solid crystal, leak the bonding wire and the wafer leaks electricity when encapsulating in COB cell board, lead to the LED wafer to appear the abnormal conditions such as reverse electric leakage and short circuit, consequently, the LED wafer in the COB after the encapsulation needs performance detection, at present, adopt LED to divide the optical machine or adopt LED automatic lighting machine to detect LED wafer in the COB after the encapsulation usually, but adopt LED to divide the optical machine and can't test many LED wafers, adopt LED automatic lighting machine equipment with high costs, influenced by camera performance, appear leaking to survey or misjudge easily, and can't detect whether LED wafer has the electric leakage phenomenon.
Disclosure of Invention
Therefore, it is necessary to provide a light emitting diode detection circuit and device for solving the problems that the conventional detection equipment is easy to have the leakage detection or the misjudgment, and cannot detect the leakage of the LED chip.
A light emitting diode detection circuit comprising: the circuit comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a first comparator U1, a second comparator U2, a third comparator U3, a sampling resistor R1 and at least one indication module; the first end of the sampling resistor R1 is used for being connected with a power supply through the first switch module, the first end of the sampling resistor R1 is also used for being connected with the ground of the second switch module, the second end of the sampling resistor R1 is used for being connected with the anode of the light-emitting diode to be tested, the first end of the third switch module is used for being connected with the power supply, the second end of the third switch module is used for being connected with the cathode of the light-emitting diode to be tested, the first end of the fourth switch module is used for being connected with the ground, the second end of the fourth switch module is used for being connected with the cathode of the light-emitting diode to be tested, the second end of the sampling resistor R1 is also respectively connected with the first input end of the first comparator U1, the first input end of the second comparator U2 and the first input end of the third comparator U3, the second input end of the first comparator U1 is used for being connected with a first reference power supply, a second input terminal of the second comparator U2 is configured to be connected to a second reference power supply, a second input terminal of the third comparator U3 is configured to be connected to a third reference power supply, and an output terminal of the first comparator U1, an output terminal of the second comparator U2, and an output terminal of the third comparator U3 are respectively connected to the at least one indication module.
In one embodiment, the operating state of the first switch module is the same as the operating state of the fourth switch module, the operating state of the second switch module is the same as the operating state of the third switch module, and the operating state of the first switch module is different from the operating state of the second switch module.
In one embodiment, the second terminal of the sampling resistor R1 is connected to the non-inverting input terminal of the first comparator U1, the inverting input terminal of the second comparator U2 and the non-inverting input terminal of the third comparator U3, respectively, the inverting input terminal of the first comparator U1 is connected to the first reference power supply, the non-inverting input terminal of the second comparator U2 is connected to the second reference power supply, and the inverting input terminal of the third comparator U3 is connected to the third reference power supply.
In one embodiment, the led detection circuit further includes a control module, and the control module is respectively connected to the control terminal of the first switch module, the control terminal of the second switch module, the control terminal of the third switch module, and the control terminal of the fourth switch module.
In one embodiment, at least one of the first switch module, the second switch module, the third switch module and the fourth switch module is a field effect transistor, and a gate of the field effect transistor is connected to the control module.
In one embodiment, the first switch module and the third switch module are both PMOS transistors, and the second switch module and the fourth switch module are both NMOS transistors.
In one embodiment, the led detection circuit further includes a processing module, wherein the output terminal of the first comparator U1, the output terminal of the second comparator U2, and the output terminal of the third comparator U3 are respectively connected to the input terminal of the processing module, and the output terminal of the processing module is connected to the indication module.
In one embodiment, the indication module comprises a display screen, and the display screen is connected with the output end of the processing module.
In one embodiment, the first comparator U1, the second comparator U2, and the third comparator U3 are all voltage comparators.
The utility model provides a light emitting diode detection device, includes two probes, support frame and the above-mentioned LED detection circuitry in any embodiment, the probe set up in on the support frame, sampling resistance R1's second end be used for through one the probe with the positive pole of the light emitting diode that awaits measuring is connected, the second end of third switch module is used for through another the probe with the negative pole of the light emitting diode that awaits measuring is connected.
When the first switch module and the fourth switch module are in a conducting state and the second switch module and the third switch module are in a disconnecting state, the LED to be detected is in a forward conducting state, the indication module sends out corresponding indication signals through the corresponding detection signals output by the first comparator and the second comparator, the detection of the normal lighting state and the electric leakage state of the light-emitting diode can be realized, when the first switch module and the fourth switch module are in the off state and the second switch module and the third switch module are in the on state, the diode is in the reverse power-on state, the third comparator outputs a corresponding detection signal to enable the indication module to send a corresponding indication signal so as to detect whether the light emitting diode has the electric leakage phenomenon or not, therefore, the light emitting diode is inspected, and the detection circuit is suitable for detecting the LED wafer on the COB board.
Drawings
FIG. 1 is a schematic circuit diagram of an LED detection circuit in one embodiment;
FIG. 2 is a schematic circuit diagram of an LED detection circuit in another embodiment;
fig. 3 is a schematic circuit diagram of an led detection apparatus according to an embodiment.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
For example, there is provided a light emitting diode detection circuit comprising: the circuit comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a first comparator U1, a second comparator U2, a third comparator U3, a sampling resistor R1 and at least one indication module; the first end of the sampling resistor R1 is used for being connected with a power supply through the first switch module, the first end of the sampling resistor R1 is also used for being connected with the ground of the second switch module, the second end of the sampling resistor R1 is used for being connected with the anode of the light-emitting diode to be tested, the first end of the third switch module is used for being connected with the power supply, the second end of the third switch module is used for being connected with the cathode of the light-emitting diode to be tested, the first end of the fourth switch module is used for being connected with the ground, the second end of the fourth switch module is used for being connected with the cathode of the light-emitting diode to be tested, the second end of the sampling resistor R1 is also respectively connected with the first input end of the first comparator U1, the first input end of the second comparator U2 and the first input end of the third comparator U3, the second input end of the first comparator U1 is used for being connected with a first reference power supply, a second input terminal of the second comparator U2 is configured to be connected to a second reference power supply, a second input terminal of the third comparator U3 is configured to be connected to a third reference power supply, and an output terminal of the first comparator U1, an output terminal of the second comparator U2, and an output terminal of the third comparator U3 are respectively connected to the at least one indication module.
When the first switch module and the fourth switch module are in a conducting state and the second switch module and the third switch module are in a disconnecting state, the LED to be detected is in a forward conducting state, the corresponding detection signals output by the first comparator U1 and the second comparator U2 enable the indication module to send out corresponding indication signals, the detection of the normal lighting state and the electric leakage state of the light-emitting diode can be realized, when the first switch module and the fourth switch module are in the off state and the second switch module and the third switch module are in the on state, the diode is in the reverse power-on state, the third comparator U3 outputs a corresponding detection signal to make the indication module send a corresponding indication signal to detect whether the led has a leakage phenomenon, therefore, the light emitting diode is inspected, and the detection circuit is suitable for detecting the LED wafer on the COB board.
In one embodiment, referring to fig. 1, an led detection circuit 10 includes: a first switching module 100, a second switching module 200, a third switching module 300, a fourth switching module 400, a first comparator U1, a second comparator U2, a third comparator U3, a sampling resistor R1, and at least one indicator module 500; the first end of the sampling resistor R1 is used for being connected with a power supply through the first switch module 100, the first end of the sampling resistor R1 is also used for being connected with the ground through the second switch module 200, the second end of the sampling resistor R1 is used for being connected with the anode of the light emitting diode to be tested, the first end of the third switch module 300 is used for being connected with the power supply, the second end of the third switch module 300 is used for being connected with the cathode of the light emitting diode to be tested, the first end of the fourth switch module 400 is used for being connected with the ground, the second end of the fourth switch module 400 is used for being connected with the cathode of the light emitting diode to be tested, the second end of the sampling resistor R1 is also respectively connected with the first input end of the first comparator U1, the first input end of the second comparator U2 and the first input end of the third comparator U3, the second input end of the first comparator U1 is used for being connected with a first reference power supply, a second input terminal of the second comparator U2 is configured to be connected to a second reference power supply, a second input terminal of the third comparator U3 is configured to be connected to a third reference power supply, and an output terminal of the first comparator U1, an output terminal of the second comparator U2, and an output terminal of the third comparator U3 are respectively connected to the at least one indication module 500.
Specifically, the comparator has a positive phase input terminal and an inverse phase input terminal, the first input terminal of the comparator may be a positive phase input terminal or an inverse phase input terminal, and the second input terminal of the comparator may be a positive phase input terminal or an inverse phase input terminal. For example, the second terminal of the sampling resistor R1 is connected to the non-inverting input terminal of the first comparator U1, the inverting input terminal of the second comparator U2, and the non-inverting input terminal of the third comparator U3, respectively, the inverting input terminal of the first comparator U1 is connected to the first reference power supply, the non-inverting input terminal of the second comparator U2 is connected to the second reference power supply, and the inverting input terminal of the third comparator U3 is connected to the third reference power supply. For another example, the second terminal of the sampling resistor R1 is connected to the inverting input terminal of the first comparator U1, the non-inverting input terminal of the second comparator U2, and the non-inverting input terminal of the third comparator U3, respectively, the non-inverting input terminal of the first comparator U1 is connected to the first reference power supply, the inverting input terminal of the second comparator U2 is connected to the second reference power supply, and the inverting input terminal of the third comparator U3 is connected to the third reference power supply. Specifically, the connection between the non-inverting input terminal and the inverting input terminal of the first comparator U1, the second comparator U2, and the third comparator U3 using the resistor and the reference power source may be arranged in a permutation and combination manner, which is not illustrated in this embodiment.
In one embodiment, the sampling resistor R1 is an adjustable resistor.
In one embodiment, the first reference power supply is 1.5 volts dc, the second reference power supply is 3.8 volts dc, and the third reference power supply is 10 mV.
In the light emitting diode detection circuit, the first reference voltage is greater than and less than the second reference voltage, when a user detects the light emitting diode, the first switch module and the fourth switch module are in a conducting state, the second switch module and the third switch module are in a disconnecting state, the diode to be detected is in a forward conducting state at the moment, the voltage collected by the sampling resistor R1 is compared with the reference voltage through the first comparator U1 and the second comparator U2, when the sampling voltage is less than the first reference voltage, the light emitting diode is in an open-circuit state, when the sampling voltage is greater than the first reference voltage and less than the second reference voltage, the light emitting diode is in a normal lighting state, when the sampling voltage is greater than the second reference voltage, the light emitting diode is in a short-circuit state, the first comparator U1 and the second comparator U2 output corresponding detection signals, so that the indicating module sends corresponding indicating signals, the detection of normal work, open circuit and short circuit of the light-emitting diode is realized; the second switch module and the third switch module are placed in a conducting state, the first switch module and the fourth switch module are placed in a disconnecting state, the diode to be detected is in a reverse power-on state at the moment, when the sampling voltage is larger than a third reference voltage, the light-emitting diode has a leakage condition, the third comparator U3 outputs a corresponding detection signal, so that the indication module sends a corresponding indication signal, the reverse leakage detection of the light-emitting diode is realized, and the detection circuit is suitable for the detection of an LED chip on a COB board.
In one embodiment, the led detection circuit includes a first indication module, a second indication module, and a third indication module, wherein the first indication module, the second indication module, and the third indication module are indication lamps, an output terminal of the first comparator U1 is connected to the first indication module, an output terminal of the second comparator U2 is connected to the second indication module, and an output terminal of the third comparator U3 is connected to the third indication module. In one embodiment, the first indication module comprises a first LED lamp, the second indication module comprises a second LED lamp, the third indication module comprises a third LED lamp, the positive pole of the first LED lamp is respectively connected with the output terminal of the first comparator U1 and the power supply, the negative pole of the first LED lamp is used for grounding, the positive pole of the second LED lamp is respectively connected with the output terminal of the second comparator U2 and the power supply, the negative pole of the second LED lamp is used for grounding, the positive pole of the third LED lamp is respectively connected with the output terminal of the third comparator U3 and the power supply, the negative pole of the third LED lamp is used for grounding, for example, the second terminal of the sampling resistor R1 is respectively connected with the positive phase input terminal of the first comparator U1, the negative phase input terminal of the second comparator U2 and the positive phase input terminal of the third comparator U3, the negative phase input terminal of the first comparator U1 is used for connecting with the first power supply, the positive phase input end of the second comparator U2 is used for being connected with the second reference power supply, and the negative phase input end of the third comparator U3 is used for being connected with the third reference power supply, so that when the first indicator light and the second indicator light are both in a lighting state, the light-emitting diode to be tested is in a normal lighting state; when the first indicator light is in an off state and the second indicator light is in an on state, the light emitting diode to be tested has an electric leakage phenomenon; when the first indicator light is in a lighting state and the second indicator light is in a extinguishing state, the light-emitting diode to be tested is in an open circuit state; when the third indicator light is in the lighting state, the light-emitting diode to be detected is in the electric leakage state, and a user can judge whether the light-emitting diode is qualified or not according to the lighting and extinguishing conditions of the indicator light by arranging the three indicator lights.
In one embodiment, the first indication module includes a first control switch and a first LED lamp, the second indication module includes a second control switch and a second LED lamp, the third indication module includes a third control switch and a third LED lamp, an output terminal of the first comparator is connected to a control terminal of the first control switch, a first terminal of the first control switch is used for connecting a power supply, a second terminal of the first control switch is connected to an anode of the first LED lamp, a cathode of the first LED lamp is used for grounding, an output terminal of the second comparator is connected to a control terminal of the second control switch, a first terminal of the second control switch is used for connecting a power supply, a second terminal of the second control switch is connected to an anode of the second LED lamp, a cathode of the second LED lamp is used for grounding, an output terminal of the third comparator is connected to a control terminal of the third control switch, the first end of the third control switch is used for being connected with a power supply, the second end of the third control switch is connected with the anode of the second LED lamp, the cathode of the third LED lamp is grounded, and the comparator enables the comparator to send out a corresponding detection signal to enable the LED lamp to shine according to the received sampling voltage through the indication module, so that a user can conveniently check a detection result.
In one embodiment, the indicating module includes a nand and an indicator light, the output of the first comparator U1 is connected to the first input of the nand, the output of the second comparator U2 is connected to the second input of the nand, the output of the nand is connected to the indicator light, the output of the third comparator U3 is connected to the indicator light, specifically, the second terminal of the sampling resistor R1 is connected to the non-inverting input of the first comparator U1, the inverting input of the second comparator U2 and the non-inverting input of the third comparator U3, the inverting input of the first comparator U1 is connected to the first reference power supply, the non-inverting input of the second comparator U2 is connected to the second reference power supply, and the inverting input of the third comparator U3 is connected to the third reference power supply, during detection, when the indicator light is on, the LED to be detected is in a short circuit, electric leakage or disconnection state, and when the indicator light is off, the LED to be detected is normally on, so that a user can check a detection result conveniently.
In one embodiment, the indication module is a buzzer. The principle of the feedback detection result is the same as that of the LED lamp, and the description in the embodiment is not redundant.
In order to enable the detection circuit to work normally, in one embodiment, the working state of the first switch module is the same as that of the fourth switch module, the working state of the second switch module is the same as that of the third switch module, the working state of the first switch module is different from that of the second switch module, and the working state of the third switch module is different from that of the fourth switch module. The working states of the switch modules comprise a conducting state and a disconnecting state, specifically, when the first switch module is in the disconnecting state, the fourth switch module is in the disconnecting state, and the second switch module and the third switch module are in the conducting state; when the first switch module is in a conducting state, the fourth switch module is in a conducting state, and the second switch module and the third switch module are in a disconnecting state, so that forward voltage or reverse voltage is applied to the light emitting diode to be detected, and the detection circuit can work normally.
In order to facilitate the indication module to send out the corresponding indication signal according to the received corresponding detection signal, in one embodiment, referring to fig. 1, the second terminal of the sampling resistor R1 is respectively connected to the non-inverting input terminal of the first comparator U1, the inverting input terminal of the second comparator U2, and the non-inverting input terminal of the third comparator U3, the inverting input terminal of the first comparator U1 is configured to be connected to the first reference power supply, the non-inverting input terminal of the second comparator U2 is configured to be connected to the second reference power supply, and the inverting input terminal of the third comparator U3 is configured to be connected to the third reference power supply. Thus, when the first comparator U1 and the second comparator U2 output high level signals, the light emitting diode is in a normal working state, and when the first comparator U1 outputs high level signals and the second comparator U2 outputs low level signals, the light emitting diode is in an open circuit state; when the first comparator U1 outputs a low level signal and the second comparator U2 outputs a high level signal, the light emitting diode is in an off state, and when the third comparator U3 outputs a high level signal, the light emitting diode is in a leakage state, so that the indication module sends out a corresponding indication signal according to the received corresponding detection signal.
In order to facilitate a user to control the on/off of the switch module, in one embodiment, referring to fig. 2, the led detection circuit 10 further includes a control module 620, and the control module 620 is respectively connected to the control terminal of the first switch module 100, the control terminal of the second switch module 200, the control terminal of the third switch module 300, and the control terminal of the fourth switch module 400. Through setting up control module, then the user can be through operation control module to realize switching of switch module operating condition, be convenient for the user to control switch module's switching on or disconnection.
In order to facilitate a user to control the switching of the operating states of the switch modules, in one embodiment, at least one of the first switch module, the second switch module, the third switch module, and the fourth switch module is a field effect transistor, and a gate of the field effect transistor is connected to the control module. In one embodiment, referring to fig. 2, the first switch module includes a fet Q1, the second switch module includes a fet Q2, the third switch module includes a fet Q3, the fourth switch module includes a fet Q4, a source of the fet Q1 is used for connecting a power supply, a drain of the fet Q1 is connected to the first end of the sampling resistor R1, a gate of the fet Q1 is connected to the control module, a source of the fet Q2 is used for grounding, a drain of the fet Q2 is connected to the first end of the sampling resistor R1, a gate of the fet Q2 is connected to the control module, a source of the fet Q3 is used for connecting a power supply, a drain of the fet Q3 is used for connecting to a cathode of the led to be tested, and a gate of the fet Q3 is connected to the control module, the source electrode of the field effect transistor Q4 is used for grounding, the drain electrode of the field effect transistor Q4 is used for connecting with the cathode of the light emitting diode to be tested, the grid electrode of the field effect transistor Q4 is electrically connected with the microcontroller, specifically, the grid electrode of the field effect transistor is connected with the control module, when the control module sends control signals to the grid electrodes of the four field effect transistors respectively, the source electrode and the drain electrode of the corresponding field effect transistor are switched on or off, the effect of the switch is realized, and therefore the switching of the working state of the switch module is controlled by a user conveniently.
In one embodiment, the control module has four control signal outputs, including a first control signal output, a second control signal output, a third control signal output and a fourth control signal output, wherein the first control signal output is connected to the gate of the fet Q1, the second control signal output is connected to the gate of the fet Q2, the third control signal output is connected to the gate of the fet Q3, and the fourth control signal output is connected to the gate of the fet Q4, such that when the first control signal output and the fourth control signal output high level signals and the second control signal output and the third control signal output low level signals, the fets Q1 and Q4 are turned on, and the fets Q2 and Q3 are turned off; when the first control signal output end and the fourth control signal output end output low level signals and the second control signal output end and the third control signal output end output high level signals, the field effect transistor Q1 and the field effect transistor Q4 are cut off, and the field effect transistor Q2 and the field effect transistor Q3 are switched on, so that the control module respectively controls the four field effect transistors.
In one embodiment, the control module has two control signal outputs, the two control signal outputs include a first control signal output and a second control signal output, wherein the level signals output by the first control signal output and the second control signal output are different, the first control signal output is respectively connected with the gate of the fet Q1 and the gate of the fet Q4, the second control signal output is respectively connected with the gate of the fet Q2 and the gate of the fet Q3, when the first control signal output outputs a high level signal and the second control signal output outputs a low level signal, the fets Q1 and Q4 are turned on, and the fets Q2 and Q3 are turned off; when the first control signal output end outputs a low level signal and the second control signal output end outputs a high level signal, the field effect transistor Q1 and the field effect transistor Q4 are cut off, and the field effect transistor Q2 and the field effect transistor Q3 are switched on, so that the control module only needs to be provided with two control signal output ends to control the working states of the four field effect transistors because the level signals output by the first control signal output end and the second control signal output end are different, so that the working states of the field effect transistor Q1 and the field effect transistor Q4 are the same, the working states of the field effect transistor Q2 and the field effect transistor Q3 are the same, and the working states of the field effect transistor Q1 and the field effect transistor Q are different.
In one embodiment, at least one of the first switch module, the second switch module, the third switch module and the fourth switch module is a metal-oxide-semiconductor field effect transistor (MOS), and a gate of the MOS is connected to the control module.
In order to further facilitate the switching of the operating states of the user-controlled switch modules, in one embodiment, the first switch module and the third switch module are both PMOS (positive channel Metal Oxide Semiconductor) transistors, and the second switch module and the fourth switch module are both NMOS (N-Metal-Oxide-Semiconductor) transistors. Because first switch module and third switch module are connected with the power, the PMOS pipe is applicable to the control and switches on with between the power, and second switch module and fourth switch module are connected with ground, and the NMOS pipe is applicable to the control and switches on with between the ground, consequently, through setting first switch module and third switch module to the PMOS pipe, second switch module and fourth switch module set to the NMOS pipe, can further be convenient for user control switch module operating condition's switching.
In one embodiment, the first switch module, the second switch module, the third switch module and the fourth switch module are all triodes.
In order to facilitate the user to view the detection result, in one embodiment, referring to fig. 2, the led detection circuit 10 further includes a processing module 610, an output terminal of the first comparator U1, an output terminal of the second comparator U2, and an output terminal of the third comparator U3 are respectively connected to an input terminal of the processing module 610, and an output terminal of the processing module 610 is connected to the indication module 500. In one embodiment, the indication module comprises a display screen, and the display screen is connected with the output end of the processing module. The results output by the processing module can be displayed through the display screen.
In order to save costs and reduce circuit volume, in one embodiment, a micro control unit is further included, the processing module and the control module being integrated within the micro control unit. It should be noted that the processing module and the control module may belong to the same component or different components, and specifically, the processing module and the control module are integrated in a micro control unit, and the micro control unit is a single chip microcomputer. Through setting up processing module, with better the sending to instruction module of the detected signal of first comparator U1, second comparator U2 and third comparator U3, further, processing module sends the detected signal who corresponds to the display screen to make the display screen display correspond the testing result, thereby be convenient for the user look over the testing result, and through with processing module and control module integrate in for the control unit, can save the cost to reduce the circuit volume.
In one embodiment, the first comparator U1, the second comparator U2, and the third comparator U3 are all voltage comparators. Specifically, the operating principle of the voltage comparator is that when the voltage signal received by the positive phase input terminal is greater than the voltage signal received by the negative phase input terminal, the output terminal of the voltage comparator is a high-level signal, and the first comparator U1, the second comparator U2 and the third comparator U3 are all set as the voltage comparator, and the detection signal of the sampling resistor R1 is received, so that the corresponding check signal is sent out, and the electrical performance detection of the light emitting diode is realized.
In one embodiment, please refer to fig. 3, a light emitting diode detection apparatus 20 includes two probes 710, a support frame 700 and the light emitting diode detection circuit described in any of the above embodiments, the probes 710 are disposed on the support frame 700, a second end of the sampling resistor R1 is used for being connected to an anode of the light emitting diode to be detected through one of the probes, and a second end of the third switch module 300 is used for being connected to a cathode of the light emitting diode to be detected through the other probe. Specifically, the light emitting diode to be measured is disposed on the COB unit panel 800.
When the first switch module and the fourth switch module are in a conducting state and the second switch module and the third switch module are in a disconnecting state, the diode to be detected is in a forward conducting state at the moment, the indicating module sends out corresponding indicating signals through corresponding detecting signals output by the first comparator U1 and the second comparator U2, the detection of the normal lighting state and the electric leakage state of the light emitting diode can be realized, when the first switch module and the fourth switch module are in the disconnecting state and the second switch module and the third switch module are in the conducting state, the diode is in a reverse conducting state at the moment, the corresponding detecting signals are output by the third comparator U3, the indicating module sends out corresponding indicating signals to detect whether the electric leakage phenomenon exists in the light emitting diode or not, the detection of the light emitting diode is realized, and the detection device is suitable for detecting the LED chip on a COB board, in addition, after the detection device detects one light-emitting diode to be detected, the next light-emitting diode to be detected can be detected, so that the electrical performance of a plurality of light-emitting diodes can be detected.
In one embodiment, the light emitting diode detection device further comprises a serial port, the indication module is a computer, the processing module is connected with the computer through the serial port, the processing module sends the corresponding detection signal to the computer, and the detection result is displayed through the computer, so that a detector can conveniently check the detection result.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A light emitting diode detection circuit, comprising: the circuit comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a first comparator U1, a second comparator U2, a third comparator U3, a sampling resistor R1 and at least one indication module;
the first end of the sampling resistor R1 is used for being connected with a power supply through the first switch module, the first end of the sampling resistor R1 is also used for being connected with the ground of the second switch module, the second end of the sampling resistor R1 is used for being connected with the anode of the light-emitting diode to be tested, the first end of the third switch module is used for being connected with the power supply, the second end of the third switch module is used for being connected with the cathode of the light-emitting diode to be tested, the first end of the fourth switch module is used for being connected with the ground, the second end of the fourth switch module is used for being connected with the cathode of the light-emitting diode to be tested, the second end of the sampling resistor R1 is also respectively connected with the first input end of the first comparator U1, the first input end of the second comparator U2 and the first input end of the third comparator U3, the second input end of the first comparator U1 is used for being connected with a first reference power supply, a second input terminal of the second comparator U2 is configured to be connected to a second reference power supply, a second input terminal of the third comparator U3 is configured to be connected to a third reference power supply, and an output terminal of the first comparator U1, an output terminal of the second comparator U2, and an output terminal of the third comparator U3 are respectively connected to the at least one indication module.
2. The led detection circuit of claim 1, wherein the operating state of the first switch module is the same as the operating state of the fourth switch module, the operating state of the second switch module is the same as the operating state of the third switch module, and the operating state of the first switch module is different from the operating state of the second switch module.
3. The LED detection circuit of claim 1, wherein a second terminal of the sampling resistor R1 is connected to a non-inverting input terminal of the first comparator U1, an inverting input terminal of the second comparator U2 and a non-inverting input terminal of the third comparator U3, respectively, the inverting input terminal of the first comparator U1 is configured to be connected to the first reference power supply, the non-inverting input terminal of the second comparator U2 is configured to be connected to the second reference power supply, and the inverting input terminal of the third comparator U3 is configured to be connected to the third reference power supply.
4. The LED detection circuit according to any of claims 1-3, further comprising a control module, wherein the control module is connected to the control terminal of the first switch module, the control terminal of the second switch module, the control terminal of the third switch module, and the control terminal of the fourth switch module, respectively.
5. The LED detection circuit of claim 4, wherein at least one of the first switch module, the second switch module, the third switch module and the fourth switch module is a field effect transistor, and a gate of the field effect transistor is connected to the control module.
6. The LED detection circuit of claim 5, wherein the first switch module and the third switch module are both PMOS transistors, and the second switch module and the fourth switch module are both NMOS transistors.
7. The LED detection circuit of claim 1, further comprising a processing module, wherein the output terminal of the first comparator U1, the output terminal of the second comparator U2 and the output terminal of the third comparator U3 are respectively connected to the input terminal of the processing module, and the output terminal of the processing module is connected to the indication module.
8. The LED detection circuit of claim 7, wherein the indication module comprises a display screen, the display screen being coupled to the output of the processing module.
9. The LED detection circuit of claim 1, wherein the first comparator U1, the second comparator U2 and the third comparator U3 are all voltage comparators.
10. An led testing apparatus, comprising two probes, a supporting frame and an led testing circuit as claimed in any one of claims 1 to 9, wherein the probes are disposed on the supporting frame, the second end of the sampling resistor R1 is used to connect with the anode of the led to be tested through one of the probes, and the second end of the third switch module is used to connect with the cathode of the led to be tested through the other of the probes.
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| CN201910269203.3A CN109991521B (en) | 2019-04-04 | 2019-04-04 | Light emitting diode detection circuit and device |
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| CN201910269203.3A CN109991521B (en) | 2019-04-04 | 2019-04-04 | Light emitting diode detection circuit and device |
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| CN111474458B (en) * | 2020-04-17 | 2022-08-19 | 歌尔微电子有限公司 | LED light source test fixture and LED light source test system |
| CN114113705B (en) * | 2021-11-23 | 2023-09-22 | 中车大连机车车辆有限公司 | Diode terminal strip with self-detection fault state and detection circuit thereof |
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