Detection device for testing photoelectric switch

Abstract

The utility model discloses a detection device for testing a photoelectric switch. The detection device comprises a current source circuit, a relay circuit, an IL test circuit and an ID test circuit. The input end of the current source circuit is externally connected with a 5V power supply, the output end of the current source circuit is connected with the light emitting side of the photoelectric switch U7, and the light receiving side of the photoelectric switch U7 is connected with a common contact of the relay circuit; a normally closed contact of the relay circuit is connected with the IL test circuit, and a normally open contact of the relay circuit is connected with the ID test circuit; the relay circuit comprises a change-over switch S1, when the change-over switch S1 is switched off, the common contact of the relay circuit is communicated with the normally-closed contact, and when the change-over switch S1 is switched on, the common contact of the relay circuit is communicated with the normally-open contact. The utility model relates to the technical field of photoelectric switch test equipment, and can solve the problems that a special detection instrument for a photoelectric switch in the prior art cannot flexibly adapt to the test requirements of the photoelectric switch on an actual production line and is relatively high in price.

Description

Technical Field

[0001] The utility model relates to the technical field of photoelectric switch testing equipment, in particular to a detection device for testing a photoelectric switch. Background Art

[0002] After the photoelectric switch is produced, its photocurrent IL and dark current ID need to be tested. Currently, there are many special detection instruments for photoelectric switches on the market that can be used to measure the current of photoelectric switches, but the cost of special detection instruments for photoelectric switches is generally high.

[0003] Photoelectric switches with different parameters have different test items and other test requirements. Existing photoelectric switch-specific test instruments are unable to flexibly adapt to the test items required for photoelectric switches with different parameters on actual production lines. Switching between different test items is inconvenient, making them unsuitable for batch testing on production lines. Therefore, it is necessary to provide a photoelectric switch testing device that can address the problems of existing photoelectric switch-specific test instruments being unable to flexibly adapt to the test requirements of photoelectric switches on actual production lines and being relatively expensive. Summary of the Invention

[0004] The purpose of the utility model is to provide a detection device for testing photoelectric switches, which can solve the problem that the special detection instruments for photoelectric switches in the prior art cannot flexibly adapt to the photoelectric switch testing needs on the actual production line and are relatively expensive.

[0005] The utility model is achieved in this way:

[0006] A detection device for testing a photoelectric switch includes a current source circuit, a relay circuit, an IL test circuit, and an ID test circuit; the input end of the current source circuit is externally connected to a 5V power supply, the output end of the current source circuit is connected to the light-emitting side of the photoelectric switch, and the light-receiving side of the photoelectric switch is connected to the common contact of the relay circuit; the normally closed contact of the relay circuit is connected to the IL test circuit, and the normally open contact of the relay circuit is connected to the ID test circuit; the relay circuit includes a switching switch; when the switching switch is off, the common contact of the relay circuit is connected to the normally closed contact, and when the switching switch is on, the common contact of the relay circuit is connected to the normally open contact.

[0007] The current source circuit includes a first operational amplifier, a second operational amplifier, a third resistor, a fourth resistor, a sixth resistor, a seventh resistor, and a second potentiometer; the first pin No. 2 of the first operational amplifier is connected to the fourth resistor and then to ground, and is connected to one end of the second potentiometer through the third resistor; the first pin No. 6 of the first operational amplifier is connected to one end of the second potentiometer; the first pin No. 3 of the first operational amplifier is connected to an external 5V power supply through the sixth resistor; the first pin No. 3 of the first operational amplifier is connected to the second pin No. 6 and the second pin No. 2 of the second operational amplifier through the seventh resistor; the second pin No. 3 of the second operational amplifier is connected to the other end of the second potentiometer and serves as the output end of the current source circuit and is connected to the light-emitting side of the photoelectric switch.

[0008] The photoelectric switch includes an LED on the light-emitting side and a PTR on the light-receiving side; the output end of the current source circuit is connected to the positive electrode of the LED on the light-emitting side, and the negative electrode of the LED is grounded; the PTR on the light-receiving side is connected to the common contact of the relay circuit.

[0009] The IL test circuit includes a third op amp, a second resistor, a first resistor, a fourth op amp, a first potentiometer, a fifth resistor, a seventh capacitor, and a first light-emitting diode; the second resistor is connected between the third pin No. 2 and the third pin No. 6 of the third op amp to form a first-stage amplifier circuit, which is a transimpedance amplifier; the third pin No. 2 of the third op amp is connected to the normally closed contact of the relay circuit; the third pin No. 6 of the third op amp is connected to the fourth pin No. 2 of the fourth op amp; the fourth pin No. 3 of the fourth op amp is connected to the seventh capacitor and the first potentiometer; the fourth pin No. 3 of the fourth op amp is connected to the cathode of the first light-emitting diode and the fourth pin No. 6 of the fourth op amp via the fifth resistor; the anode of the first light-emitting diode is connected to the first resistor to form a second-stage amplifier circuit, which is a hysteresis comparator.

[0010] The ID test circuit includes a fifth op amp, an eighth resistor, a third capacitor, a sixth op amp, a tenth resistor, a sixth capacitor, a third potentiometer and a second light-emitting diode; the eighth resistor and the third capacitor are connected in parallel between the fifth pin No. 2 and the fifth pin No. 6 of the fifth op amp to form a first-stage amplification circuit, the fifth pin No. 2 of the fifth op amp is connected to the normally open contact of the relay circuit, and the fifth pin No. 6 of the fifth op amp is connected to the sixth pin No. 2 of the sixth op amp; the sixth pin No. 3 of the sixth op amp is connected to the third potentiometer, the sixth pin No. 3 of the sixth op amp is grounded through the sixth capacitor and connected to one end of the tenth resistor, the sixth pin No. 6 of the sixth op amp is connected to the other end of the tenth resistor and connected to the positive electrode of the second light-emitting diode through the ninth resistor to form a second-stage amplification circuit.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1. The utility model is provided with a relay circuit. The normally closed contact and the normally open contact of the relay circuit are connected to the common contact by pressing the switch, so that the photoelectric switch is connected to the IL test circuit or switched to the ID test circuit, thereby realizing fast switching between different test items of the photocurrent IL and dark current ID of the photoelectric switch. It can be used by the production department to perform batch quality inspection of photoelectric switches, and the operation is convenient and efficient.

[0013] 2. Since the utility model is provided with an IL test circuit and an ID test circuit, the independently designed test circuit has a simple structure and low cost. The test conditions and test items can be flexibly adjusted according to the parameters of the device to be tested. Different photoelectric switches can be connected between the current source circuit and the relay circuit through leads, which has high flexibility in use. The test circuit can be used as an independent detection device and is also easy to be integrated into special detection equipment, with strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The utility model is a circuit principle diagram of a detection device for testing a photoelectric switch.

[0015] In the figure, 1 is a current source circuit, 101 is a first op amp, 102 is a second op amp, 2 is a relay circuit, 3 is an IL test circuit, 301 is a third op amp, 302 is a fourth op amp, 4 is an ID test circuit, 401 is a fifth op amp, and 402 is a sixth op amp. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0017] Please see the attached Figure 1 A detection device for testing a photoelectric switch includes a current source circuit 1, a relay circuit 2, an IL test circuit 3, and an ID test circuit 4; the input end of the current source circuit 1 is connected to an external 5V power supply, the output end of the current source circuit 1 is connected to the light-emitting side of the photoelectric switch U7, and the light-receiving side of the photoelectric switch U7 is connected to the common contact of the relay circuit 2 (i.e., pin 3 and pin 6 of the relay circuit 2); the normally closed contact of the relay circuit 2 (i.e., pin 2 and pin 7 of the relay circuit 2) is connected to the IL test circuit 3, and the normally open contact of the relay circuit 2 (i.e., pin 4 and pin 5 of the relay circuit 2) is connected to the ID test circuit 4; the relay circuit 2 includes a switching switch S1. When the switching switch S1 is disconnected, the common contact of the relay circuit 2 is connected to the normally closed contact. When the switching switch S1 is connected, the common contact of the relay circuit 2 is connected to the normally open contact.

[0018] The current source circuit 1 includes a first operational amplifier 101, a second operational amplifier 102, a third resistor R3, a fourth resistor R4, a sixth resistor R6, a seventh resistor R7 and a second potentiometer VR2; the first pin No. 2 of the first operational amplifier 101 is connected to the fourth resistor R4 and then to ground, and is connected to one end of the second potentiometer VR2 through the third resistor R3, the first pin No. 6 of the first operational amplifier 101 is connected to one end of the second potentiometer VR2, and the first pin No. 3 of the first operational amplifier 101 (i.e., the input end of the current source circuit 1) is externally connected to a 5V power supply through the sixth resistor R6; the first pin No. 3 of the first operational amplifier 101 is connected to the second pin No. 6 and the second pin No. 2 of the second operational amplifier 102 through the seventh resistor R7, the second pin No. 3 of the second operational amplifier 102 is connected to the other end of the second potentiometer VR2, and is connected to the light-emitting side of the photoelectric switch U7 as the output end of the current source circuit 1.

[0019] The current source circuit 1 plays the role of differential amplification, adding the voltage difference 5V at the input end of the first operational amplifier 101 to the second potentiometer VR2, and the second pin 3 of the second operational amplifier 102 outputs a stable driving current IS=5V / VR2.

[0020] Preferably, an ammeter can be connected to the second potentiometer VR2 to test the value of the driving current IS output by the second potentiometer VR2. By adjusting the potential sliding of the second potentiometer VR2, the value of the driving current IS can be adjusted, that is, the first reference current for the photocurrent IL and the second reference current for measuring the dark current ID test, so that they can meet the required test conditions.

[0021] The photoelectric switch U7 includes an LED on the light-emitting side and a PTR (i.e., phototransistor) on the light-receiving side; the output end of the current source circuit 1 is connected to the positive electrode of the LED on the light-emitting side, and the negative electrode of the LED is grounded; the PTR on the light-receiving side is connected to the common contact of the relay circuit 2 (i.e., pins 3 and 6 of the relay circuit 2).

[0022] The driving current IS provides driving current for the LED on one side of the photoelectric switch U7, causing the LED to emit light and the light to be received by the PTR on the other side. The collector of the PTR is connected to the common contact of the relay circuit 2. When the switch S1 is not pressed, the common contact is connected to the IL detection circuit 3 through the normally closed contact. When the switch S1 is pressed, the common contact is switched to be connected to the normally open contact, so that the common contact is connected to the ID detection circuit 4 through the normally open contact.

[0023] By pressing the switch S1 to switch the IL detection circuit 3 and the ID detection circuit 4, the switching operation is convenient and flexible, and can meet the requirements of fast and flexible switching between different test items (ie, photocurrent IL and dark current ID).

[0024] LED and PTR are conventional photoelectric switch structures, and their working principles will not be described in detail here.

[0025] The IL test circuit 3 includes a third op amp 301, a second resistor R2, a first resistor R1, a fourth op amp 302, a first potentiometer VR1, a fifth resistor R5, a seventh capacitor C7, and a first light-emitting diode D1. The second resistor R2 is connected between the third pin 2 and the third pin 6 of the third op amp 301 to form a first-stage amplifier circuit, which is a transimpedance amplifier. The third pin 2 of the third op amp 301 is connected to the normally closed contact of the relay circuit 2, and the third pin 6 of the third op amp 301 is connected to the fourth pin 2 of the fourth op amp 302. The fourth pin 3 of the fourth op amp 302 is connected to the seventh capacitor C7 and the first potentiometer VR1. The fourth pin 3 of the fourth op amp 302 is connected to the cathode of the first light-emitting diode D1 and the fourth pin 6 of the fourth op amp 302 via the fifth resistor R5. The anode of the first light-emitting diode D1 is connected to the first resistor R1, forming a second-stage amplifier circuit, which is a hysteresis comparator.

[0026] The first-stage amplifier circuit composed of the second resistor R2 and the third operational amplifier 301 is a transimpedance amplifier. The third pin 3 (input terminal +IN) of the third operational amplifier 301 provides a 5V bias voltage to the PTR collector of the photoelectric switch U7, and at the same time generates an output voltage higher than the 5V reference voltage Il*R2; the second-stage amplifier circuit composed of the fifth resistor R5, the seventh capacitor C7, the first potentiometer VR1 and the fourth operational amplifier 302 is a hysteresis comparator that can stably output digital signals; when the tested photocurrent IL is greater than the first reference current, the OUT terminal of the fourth operational amplifier 302 outputs -15V, at which time the first light-emitting diode D1 is turned on, that is, the first light-emitting diode D1 is lit, and the test is passed; when the tested photocurrent IL is less than the first reference current, the OUT terminal of the fourth operational amplifier 302 outputs +15V, at which time the first light-emitting diode D1 is not turned on, that is, the first light-emitting diode D1 is not lit, and the test is failed.

[0027] Whether the tested photocurrent IL is qualified can be judged intuitively and quickly by the lighting or non-lighting of the first light emitting diode D1, thereby completing the photocurrent IL test of the photoelectric switch U7.

[0028] The ID test circuit 4 includes a fifth op amp 401, an eighth resistor R8, a third capacitor C3, a sixth op amp 402, a tenth resistor R10, a sixth capacitor C6, a third potentiometer VR3 and a second light-emitting diode D2; the eighth resistor R8 and the third capacitor C3 are connected in parallel between the fifth pin 2 and the fifth pin 6 of the fifth op amp 401 to form a first-stage amplification circuit, the fifth pin 2 of the fifth op amp 401 is connected to the normally open contact of the relay circuit 2, and the fifth pin 6 of the fifth op amp 401 is connected to the sixth pin 2 of the sixth op amp 402; the sixth pin 3 of the sixth op amp 402 is connected to the third potentiometer VR3, the sixth pin 3 of the sixth op amp 402 is grounded through the sixth capacitor C6 and connected to one end of the tenth resistor R10, the sixth pin 6 of the sixth op amp 402 is connected to the other end of the tenth resistor R10, and is connected to the positive electrode of the second light-emitting diode D2 through the ninth resistor R9 to form a second-stage amplification circuit.

[0029] The first-stage amplifier, consisting of the eighth resistor R8, the third capacitor C3, and the fifth op amp 401, is a transimpedance amplifier. Pin 53 (input +IN) of the fifth op amp 401 provides a 5V bias voltage to the PTR collector of the photoelectric switch U7, while also generating an output voltage higher than the 5V reference voltage ID*R8. The third capacitor C3 is a frequency compensation capacitor, which provides filtering and reduces the output noise of the transimpedance amplifier.

[0030] The second-stage amplifier composed of the tenth resistor R10, the sixth capacitor C6, the third potentiometer VR3 and the sixth operational amplifier 402 is a hysteresis comparator that can stably output digital signals; when the tested dark current ID is less than the second reference current, the OUT terminal of the sixth operational amplifier 402 outputs +15V, at which time the second light-emitting diode D2 is turned on, that is, the second light-emitting diode D2 is bright, and the test is qualified; when the tested dark current ID is greater than the second reference current, the OUT terminal of the sixth operational amplifier 402 outputs -15V, at which time the second light-emitting diode D2 is not turned on, that is, the second light-emitting diode D2 is not bright, and the test fails.

[0031] Whether the dark current ID is qualified can be judged intuitively and quickly by the lighting or non-lighting of the second light-emitting diode D2, thereby completing the dark current ID test of the photoelectric switch U7.

[0032] When performing a photocurrent IL test, assuming that the photocurrent IL value to be tested is greater than the first reference current I1 under the specified LED drive current, a pass signal is output, and D1 illuminates. An external auxiliary current source is required and adjusted so that the current flowing from the IL test circuit 3 to the auxiliary current source is I1. The potentiometer of the auxiliary current source is then adjusted to an output current that causes the first light-emitting diode D1 to just turn off from on. The potentiometer position at this point is the reference position for determining whether the photocurrent IL is greater than the first reference current I1. If IL>I1 during the test, D1 illuminates. Furthermore, the bias voltage of IL is the 5V voltage connected to the +IN input terminal of the first op amp 301.

[0033] Similarly, when the shield is present, it is determined whether the dark current ID is less than the second reference current I2.

[0034] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A detection device for testing a photoelectric switch, characterized by: The invention comprises a current source circuit (1), a relay circuit (2), an IL test circuit (3) and an ID test circuit (4); the input end of the current source circuit (1) is connected to an external 5V power supply, the output end of the current source circuit (1) is connected to the light-emitting side of a photoelectric switch U7, and the light-receiving side of the photoelectric switch U7 is connected to the common contact of the relay circuit (2); the normally closed contact of the relay circuit (2) is connected to the IL test circuit (3), and the normally open contact of the relay circuit (2) is connected to the ID test circuit (4); the relay circuit (2) comprises a switching switch S1, and when the switching switch S1 is disconnected, the common contact of the relay circuit (2) is connected to the normally closed contact, and when the switching switch S1 is connected, the common contact of the relay circuit (2) is connected to the normally open contact.

2. The detection device for testing a photoelectric switch according to claim 1, wherein: The current source circuit (1) comprises a first operational amplifier (101), a second operational amplifier (102), a third resistor R3, a fourth resistor R4, a sixth resistor R6, a seventh resistor R7 and a second potentiometer VR2; the first pin No. 2 of the first operational amplifier (101) is connected to the fourth resistor R4 and then to ground, and is connected to one end of the second potentiometer VR2 through the third resistor R3; the first pin No. 6 of the first operational amplifier (101) is connected to one end of the second potentiometer VR2; the first pin No. 3 of the first operational amplifier (101) is connected to an external 5V power supply through the sixth resistor R6; the first pin No. 3 of the first operational amplifier (101) is connected to the second pin No. 6 and the second pin No. 2 of the second operational amplifier (102) through the seventh resistor R7; the second pin No. 3 of the second operational amplifier (102) is connected to the other end of the second potentiometer VR2 and is connected to the light-emitting side of the photoelectric switch U7 as the output end of the current source circuit (1).

3. The detection device for testing a photoelectric switch according to claim 2, wherein: The photoelectric switch U7 comprises an LED on the light-emitting side and a PTR on the light-receiving side; the output end of the current source circuit (1) is connected to the positive electrode of the LED on the light-emitting side, and the negative electrode of the LED is grounded; the PTR on the light-receiving side is connected to the common contact of the relay circuit (2).

4. The detection device for testing a photoelectric switch according to claim 1, wherein: The IL test circuit (3) includes a third operational amplifier (301), a second resistor R2, a first resistor R1, a fourth operational amplifier (302), a first potentiometer VR1, a fifth resistor R5, a seventh capacitor C7, and a first light-emitting diode D1; the second resistor R2 is connected between the third pin No. 2 and the third pin No. 6 of the third operational amplifier (301) to form a first-stage amplifier circuit, which is a transimpedance amplifier; the third pin No. 2 of the third operational amplifier (301) is connected to the normally closed contact of the relay circuit (2). The third pin No. 6 of the third operational amplifier (301) is connected to the fourth pin No. 2 of the fourth operational amplifier (302); the fourth pin No. 3 of the fourth operational amplifier (302) is connected to the seventh capacitor C7 and the first potentiometer VR1; the fourth pin No. 3 of the fourth operational amplifier (302) is connected to the cathode of the first light-emitting diode D1 and the fourth pin No. 6 of the fourth operational amplifier (302) through the fifth resistor R5; the anode of the first light-emitting diode D1 is connected to the first resistor R1, forming a second-stage amplifier circuit, and the second-stage amplifier circuit is a hysteresis comparator.

5. The detection device for testing a photoelectric switch according to claim 1, wherein: The ID test circuit (4) comprises a fifth operational amplifier (401), an eighth resistor R8, a third capacitor C3, a sixth operational amplifier (402), a tenth resistor R10, a sixth capacitor C6, a third potentiometer VR3 and a second light emitting diode D2; the eighth resistor R8 and the third capacitor C3 are connected in parallel between the fifth pin No. 2 and the fifth pin No. 6 of the fifth operational amplifier (401), forming a first-stage amplifier circuit; the fifth pin No. 2 of the fifth operational amplifier (401) is connected to the normally open contact of the relay circuit (2); the fifth pin No. 6 of the fifth operational amplifier (401) is connected to the normally open contact of the relay circuit (2); the eighth resistor R8 and the third capacitor C3 are connected in parallel between the fifth pin No. 2 and the fifth pin No. 6 of the fifth operational amplifier (401), forming a first-stage amplifier circuit; the fifth pin No. 2 ...); the eighth resistor R8 and the third capacitor C3 are connected in parallel between the fifth pin No. 2 and the fifth pin No. 6 of the fifth operational amplifier (401); the eighth resistor R8 and the third capacitor The fifth pin No. 6 of the fifth operational amplifier (401) is connected to the sixth pin No. 2 of the sixth operational amplifier (402); the sixth pin No. 3 of the sixth operational amplifier (402) is connected to the third potentiometer VR3; the sixth pin No. 3 of the sixth operational amplifier (402) is grounded via a sixth capacitor C6 and connected to one end of a tenth resistor R10; the sixth pin No. 6 of the sixth operational amplifier (402) is connected to the other end of the tenth resistor R10 and connected to the positive electrode of the second light emitting diode D2 via a ninth resistor R9, thereby forming a second-stage amplifier circuit.

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