Code scanning circuit used on automobile wire harness test bench

Abstract

The utility model relates to a code scanning circuit used on an automobile wire harness testboard, comprising a DCDC conversion circuit and an infrared induction indicating circuit, the infrared induction indicating circuit comprises a comparator U4B, an infrared emission part and an infrared receiving part, the infrared emission part comprises an infrared emission tube LED1 connected with a resistor R8, and the infrared receiving part comprises an infrared receiving tube LED2 connected with the resistor R8. And the infrared receiving part comprises an infrared receiving tube LED 2. Compared with the prior art, the infrared indicating circuit has the advantages that the structure of the infrared indicating circuit is simplified, the input voltage of the circuit is stable, and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to, especially to a kind of for the code scanning circuit on automobile wiring harness test bench. BACKGROUND

[0002] 2D barcode label is pasted on the multiple branches of automobile wiring harness, different branches are distinguished and identified, and it is also convenient to load vehicle. In the general assembly wiring harness electrical performance test bench, it needs to use code scanning device to identify whether the branch at the position is correct. Infrared circuit can be used to trigger the start of CPU of the code scanning device of general assembly wiring harness electrical performance test bench, but the existing infrared circuit induction is relatively complex, and the infrared circuit needs stable input voltage, and the voltage conversion efficiency of the power supply circuit of the existing infrared circuit is low. UTILITARIAN CONTENT

[0003] The utility model discloses a kind of for the code scanning circuit on automobile wiring harness test bench, which is to simplify the structure of infrared indicating circuit and realize the input voltage stability of circuit.

[0004] The purpose of the utility model can be realized by the following technical solutions.

[0005] A kind of for the code scanning circuit on automobile wiring harness test bench, DCDC conversion circuit, infrared induction indicating circuit and code scanning part, the infrared induction indicating circuit includes comparator U4B, infrared emission part and infrared receiving part, the infrared emission part includes the infrared emission tube LED1 of resistance R8 interconnection, infrared receiving part includes infrared receiving tube LED2;

[0006] Wherein, one end of the infrared emission tube LED1 is grounded, the positive input end of the comparator U4B is connected with the output end of infrared receiving tube LED2, the negative input end of the comparator U4B is connected with one end of variable resistance RL1, the output end of comparator U4B is connected with the cathode of trigger indicator D1, the anode of trigger indicator D1 is connected with voltage input end VDD, the voltage input end VDD is connected with the output end of DCDC conversion circuit;

[0007] The code scanning part includes scanning sensor, the cathode of the trigger indicator D1 of the infrared induction indicating circuit is connected with the scanning sensor, and the scanning sensor is arranged on one side of the barcode label to be detected.

[0008] Further, the anode of the trigger indicator D1 is connected with one end of resistance R20, the other end of resistance R20, one end of resistance R8 and the other end of variable resistance RL1 are connected with voltage input end VDD.

[0009] Further, the positive input end of the comparator U4B is connected with one end of the capacitor C39 and one end of the resistor R21, the other end of the resistor R21 is connected with the voltage input end VDD, the other end of the capacitor C39 is grounded, and the other end of the resistor R21 is connected with one end of the capacitor C38.

[0010] Further, the output end of the comparator U4B is connected with one end of the resistor R22, and the other end of the resistor R22 is connected with the cathode of the voltage stabilizing diode D5.

[0011] Further, the anode of the voltage stabilizing diode D5, one end of the infrared receiving tube LED2 and the other end of the capacitor C38 are all grounded.

[0012] Further, the DCDC conversion circuit comprises a step-down module U2, the voltage input end VIN of the step-down module U2 is connected with the external input voltage DC_IN, and one end of the resistor R2 and one end of the resistor R6 are connected with the enable end EN of the step-down module U2.

[0013] Further, the other end of the resistor R2 and the other end of the resistor R6 are connected with two ends of the capacitor C36 and the capacitor C37.

[0014] Further, one end of the capacitor C32 connected with the boost capacitor pin BOOT of the step-down module U2, the other end of the capacitor C32 is connected with the switch pin SW of the step-down module U2, one end of the inductor L7 is connected with the switch pin SW, the other end of the inductor L7 is connected with one end of the capacitor C34 and the capacitor C33, and the other end of the inductor L7 is connected with the output end of the DCDC conversion circuit.

[0015] Further, the other end of the capacitor C34 and the other end of the capacitor C33 are connected with each other and grounded together.

[0016] Further, the feedback pin FB of the step-down module U2 is connected with one end of the capacitor C35, one end of the resistor R4 and one end of the resistor R7, the other end of the resistor R7 is grounded, the other end of the resistor R4 is connected with one end of the resistor R3, and the other end of the resistor R3 is connected with the output end of the DCDC conversion circuit.

[0017] Compared with the prior art, the power supply circuit has the following beneficial effects:

[0018] The power supply circuit adopts the DC-DC conversion circuit, the voltage feedforward circuit in the DC-DC conversion circuit improves transient response, high conversion efficiency can be realized, the infrared indication circuit works by using the photoelectric effect principle, the infrared emission tube, the infrared receiving sensor and the comparator are used for infrared indication, the structure is simple, the adjustable potentiometer RL1 is used in the circuit, the sensing distance can be adjusted, and the applicability is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a DCDC conversion circuit structure schematic view of the utility model.

[0020] Figure 2 It is an infrared induction indicating circuit structure schematic view of the utility model. DETAILED DESCRIPTION

[0021] The utility model will be explained in detail below in combination with the drawings and specific embodiments. The embodiment is implemented on the premise of the technical scheme of the utility model, and gives detailed implementation modes and specific operation processes, but the protection scope of the utility model is not limited to the following examples.

[0022] It should be noted that: similar signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0023] Some embodiments of the utility model will be explained in detail below in combination with the drawings. In the case of no conflict, the following examples and features in the examples can be combined with each other.

[0024] The utility model proposes a kind of for the code scanning circuit on the test board of automobile wire harness, DCDC conversion circuit, infrared induction indicating circuit and code scanning part, the infrared induction indicating circuit includes comparator U4B, infrared emission part and infrared receiving part, the infrared emission part includes the infrared emission tube LED1 of resistance R8 interconnection, and infrared receiving part includes infrared receiving tube LED2;

[0025] Wherein, one end of the infrared emission tube LED1 is grounded, the positive input end of the comparator U4B is connected with the output end of infrared receiving tube LED2, the negative input end of the comparator U4B is connected with one end of variable resistance RL1, the output end of comparator U4B is connected with the cathode of trigger indicator D1, the anode of trigger indicator D1 is connected with voltage input end VDD, and the voltage input end VDD is connected with the output end of DCDC conversion circuit.

[0026] The code scanning part includes scanning sensor, and the cathode of the trigger indicator D1 of the infrared induction indicating circuit is connected with the scanning sensor.

[0027] The structure diagram of DCDC conversion circuit is as shown in Figure 1 The structure diagram of infrared induction indicating circuit is as shown in Figure 2

[0028] The anode of the trigger indicator D1 is connected with one end of resistance R20, and the other end of resistance R20, one end of resistance R8 and the other end of variable resistance RL1 are connected with voltage input end VDD.

[0029] ​The positive input end of the comparator U4B is connected with one end of the capacitor C39 and one end of the resistor R21, the other end of the resistor R21 is connected with the voltage input end VDD, the other end of the capacitor C39 is grounded, and the other end of the resistor R21 is connected with one end of the capacitor C38.

[0030] The output end of the comparator U4B is connected with one end of the resistor R22, and the other end of the resistor R22 is connected with the cathode of the voltage stabilizing diode D5.

[0031] The anode of the voltage stabilizing diode D5, one end of the infrared receiving tube LED2 and the other end of the capacitor C38 are all grounded.

[0032] The DCDC conversion circuit comprises a step-down module U2, the voltage input end VIN of the step-down module U2 is connected with the external input voltage DC_IN, and the enable end EN of the step-down module U2 is connected with one end of the resistor R2 and one end of the resistor R6.

[0033] The other end of the resistor R2 and the other end of the resistor R6 are connected with two ends of the capacitor C36 and the capacitor C37.

[0034] The boost capacitor pin BOOT of the step-down module U2 is connected with one end of the capacitor C32, the other end of the capacitor C32 is connected with the switch pin SW of the step-down module U2, the switch pin SW is connected with one end of the inductor L7, the other end of the inductor L7 is connected with one end of the capacitor C34 and the capacitor C33, and the other end of the inductor L7 is connected with the output end of the DCDC conversion circuit.

[0035] The other end of the capacitor C34 and the other end of the capacitor C33 are connected with each other and grounded together.

[0036] The feedback pin FB of the step-down module U2 is connected with one end of the capacitor C35, one end of the resistor R4 and one end of the resistor R7, the other end of the resistor R7 is grounded, the other end of the resistor R4 is connected with one end of the resistor R3, and the other end of the resistor R3 is connected with the output end of the DCDC conversion circuit.

[0037] The code scanning part of the utility model discloses a code scanning sensor, the sensor is controlled through CPU or PLC controller, the controller monitors the trigger signal of the sensor, starts the scanning device to read the label information, realizes code scanning.

[0038] The code scanning sensor outputs the scanning result, and based on the 2D bar code information wireless receiving control method, the 2D bar code information storage and comparison method based on a microprocessor and the 2D bar code fault tolerance method, when the code scanning sensor receives the trigger indication signal of the infrared induction indication circuit, scanning is carried out, and the obtained signal can be transmitted to the controller for processing, such as storing bar code data, judging whether the obtained data character is legal, comparing the length of the obtained bar code data and the reference bar code data and the like.

[0039] The working principle of the DCDC conversion circuit is as follows:

[0040] The external input DC voltage is converted into the stable DC 5V voltage required by the module through the PWM mode. U2 is a high output current PWM converter, and the model can adopt the existing SGM61220XTN6G chip. A low resistance, high side N-channel MOSFET is integrated, and a high-performance voltage error amplifier is included on the board, which provides strict voltage regulation accuracy under transient conditions; an under-voltage lockout circuit to prevent start-up until the input voltage reaches 5.5V; an internally set slow start circuit to limit inrush current; and a voltage feedforward circuit to improve transient response. Using the EN pin, the shutdown power supply current is usually reduced to 18uA. Other functions include an active high enable, over-current limit, over-voltage protection and thermal shutdown. The conversion circuit has 5.5V to 36V input, DC 5V output current up to 3A (4A peak), and can achieve up to 95% conversion efficiency.

[0041] The working principle of the infrared induction indication circuit is as follows:

[0042] The infrared emission tube and the infrared receiving sensor are used for two-dimensional bar code label sensing according to the photoelectric effect principle, the infrared emission tube LED1 can emit continuous infrared rays, the rays are reflected on the label, and are received by the infrared receiver LED2, the IR output terminal of the infrared receiver LED2 changes according to the received IR rays, and the output is fed back to the U4B comparator, when the infrared receiver LED2 does not receive the signal, the potential of the inverting input terminal is higher than that of the non-inverting input terminal of the comparator U4. Therefore, the output of the comparator is 0, and the trigger indicator D1 does not emit light. When the infrared receiver LED2 receives the signal, the potential of the inverting input terminal is lower than that of the non-inverting input terminal of the comparator U4, the output of the comparator is 1, the trigger indicator D1 starts to emit light, and the trigger indication signal is emitted. The adjustable potentiometer RL1 is used for sensing distance adjustment.

[0043] The model of the infrared receiver LED2 can be TSOP1738, VS1838, HX1838, IRM-56384, IRM3638 and IRM-H638T, etc. The model of the infrared emitter LED1 can be TSAL6200, TSAL6400, TSAL6100, TSAL5300 and TSAL5300A. The model of the trigger indicator D1 can be LED lamp tube. The model of the voltage stabilizing diode D5 can be 1N4148, 1N4742, 1N5231, 1N5408 and TL431.

[0044] The model of the code scanning sensor can be MK 7120MS-2d PLUS and EP2300, etc.

[0045] With the above circuit, the DCDC conversion circuit supplies power to the infrared induction indicating circuit, and the infrared induction indicating circuit adjusts the output according to the reflected light of each position of the scanned two-dimensional barcode label. The output induction signal can indicate the position of the label, and then trigger the scanner to scan the label.

[0046] The above describes the preferred embodiments of the present application in detail. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the present application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the present application shall be within the protection scope defined by the claims.

Claims

1. A code scanning circuit for use on a harness testing bench for automobiles, characterized in that, The infrared induction indicating circuit comprises a comparator U4B, an infrared emission part and an infrared receiving part, the infrared emission part comprises an infrared emission tube LED1 connected with each other through a resistor R8, and the infrared receiving part comprises an infrared receiving tube LED2; One end of the infrared emission tube LED1 is grounded, a positive input end of the comparator U4B is connected with an output end of the infrared receiving tube LED2, a negative input end of the comparator U4B is connected with one end of a variable resistor RL1, an output end of the comparator U4B is connected with a cathode of a trigger indicating lamp D1, an anode of the trigger indicating lamp D1 is connected with a voltage input end VDD, and the voltage input end VDD is connected with an output end of the DCDC conversion circuit. The cathode of the trigger indicating lamp D1 of the infrared induction indicating circuit is connected with the scanning sensor, and the scanning sensor is arranged on one side of the bar code label to be detected.

2. The code scanning circuit for use in the automobile wire harness test bench according to claim 1, characterized in that, One end of the anode of the trigger indicating lamp D1 is connected with one end of a resistor R20, the other end of the resistor R20, one end of the resistor R8 and the other end of the variable resistor RL1 are connected with the voltage input end VDD.

3. The code scanning circuit for use in the automobile wire harness test bench according to claim 2, characterized in that, The positive input end of the comparator U4B is connected with one end of a capacitor C39 and one end of a resistor R21, the other end of the resistor R21 is connected with the voltage input end VDD, the other end of the capacitor C39 is grounded, and the other end of the resistor R21 is connected with one end of a capacitor C38.

4. The code scanning circuit for use in the automobile wire harness test bench according to claim 3, characterized in that, The output end of the comparator U4B is connected with one end of a resistor R22, and the other end of the resistor R22 is connected with a cathode of a voltage stabilizing diode D5.

5. The code scanning circuit for use in the automotive wiring harness test bench according to claim 4, characterized in that, The anode of the voltage stabilizing diode D5, one end of the infrared receiving tube LED2 and the other end of the capacitor C38 are all grounded.

6. The code scanning circuit for use in the automobile wire harness test bench according to claim 1, characterized in that, The DCDC conversion circuit comprises a step-down module U2, a voltage input end VIN of the step-down module U2 is connected with an external input voltage DC_IN, and an enable end EN of the step-down module U2 is connected with one end of a resistor R2 and one end of a resistor R6.

7. The code scanning circuit for use in the automobile wire harness test bench according to claim 6, characterized in that, The other end of the resistor R2 and the other end of the resistor R6 are connected with both ends of a capacitor C36 and a capacitor C37.

8. The code scanning circuit for use in the automobile wire harness test bench according to claim 6, characterized in that, One end of a boost capacitor pin BOOT of the step-down module U2 is connected with one end of a capacitor C32, the other end of the capacitor C32 is connected with a switch pin SW of the step-down module U2, one end of an inductor L7 connected with the switch pin SW, the other end of the inductor L7 is connected with one end of a capacitor C34 and a capacitor C33, and the other end of the inductor L7 is connected with an output end of the DCDC conversion circuit.

9. The code scanning circuit for use in the automotive wiring harness test bench according to claim 8, characterized in that, The other end of the capacitor C34 and the other end of the capacitor C33 are connected with each other and grounded.

10. The code scanning circuit for use in the automotive wiring harness test bench according to claim 8, characterized in that, One end of a capacitor C35, one end of a resistor R4 and one end of a resistor R7 connected with a feedback pin FB of the step-down module U2, the other end of the resistor R7 is grounded, the other end of the resistor R4 is connected with one end of a resistor R3, and the other end of the resistor R3 is connected with the output end of the DCDC conversion circuit.

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