Windscreen wiper control device of rail transit train

Abstract

The rail transit train windscreen wiper control device comprises an input interface, a starting circuit, a direct current conversion circuit and a main circuit which are connected in sequence, the input interface is connected to a vehicle-mounted direct current 110V power source, in the starting circuit, an emitting electrode of a first PNP triode is connected to the input interface and connected to a base electrode of an NPN triode through a first branch, and an emitting electrode of a second PNP triode is connected to the main circuit through a second branch. The collector electrode of the NPN triode is connected to the base electrode of the second PNP triode through the fifth resistor, the emitter electrode of the NPN triode is grounded, the collector electrode of the NPN triode is connected to the base electrode of the second PNP triode through the fifth resistor, the emitter electrode of the second PNP triode is grounded, and the collector electrode of the second PNP triode is connected to the base electrode of the first PNP triode. Compared with the prior art, the power supply circuit has the advantage that the stability and the reliability are improved.

Description

Technical Field

[0001] The invention relates to the field of rail transit train wiper control, and in particular to a rail transit train wiper control device. Background Art

[0002] In order to ensure driving safety, the front window of the train is generally equipped with a wiper, which is electrically controlled with a rated input voltage of DC110. The wiper controller is a device that removes dirt and dust from the front windshield of the train during driving, keeps the glass bright and clean, and helps the driver see the road conditions ahead to ensure driving safety. The DC110V of the train battery supplies the working voltage to the wiper controller. The wiper controller controls the slow and fast rotation of the wiper motor to drive the fast and slow swing of the wiper arm. When the front windshield needs to be cleaned, the wiper controller controls the water spraying motor to spray water on the glass.

[0003] However, at present, the damage rate of wiper controllers is relatively high. When the wipers work at a high frequency or the liquid level in the wiper water tank is low, the wipers frequently malfunction, resulting in inconvenience in using the wipers and excessive maintenance pressure on the wipers and their accessories. Summary of the invention

[0004] The purpose of the present invention is to provide a rail transit train wiper control device. By designing a multi-stage transistor start-up control and limiting the rated power of the fifth resistor that controls the on and off of the second PNP transistor, the current tolerance capacity of the fifth circuit can be effectively improved, thereby reducing the failure rate of the control device when the wiper works at a high frequency or the liquid level in the wiper water tank is low.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A rail transit train wiper control device comprises an input interface, a start-up circuit, a DC conversion circuit and a main circuit connected in sequence, wherein the input interface is connected to an on-board DC 110V power supply, the start-up circuit comprises a first PNP transistor, a second PNP transistor, an NPN transistor, a second resistor, a fifth resistor and a first branch, the emitter of the first PNP transistor is connected to the input interface, and is connected to the base of the NPN transistor through the first branch, and is connected to the collector of the NPN transistor through the second resistor and the fifth resistor in sequence, the emitter of the NPN transistor is grounded, and the collector is connected to the base of the second PNP transistor through the fifth resistor, the emitter of the second PNP transistor is grounded, and the collector is connected to the base of the first PNP transistor, the collector of the first PNP transistor is connected to the input end of the DC conversion circuit, and the rated power of the fifth resistor is:

[0007] W R5≥110A / (R 2 +R 5 )*1000*1.5

[0008] Where: W R5 is the rated power of the fifth resistor in watts, A is the maximum input voltage deviation ratio, R 2 is the resistance of the second resistor, R 5 is the resistance value of the fifth resistor.

[0009] The rated power of the fifth resistor is 2 watts, and the resistance is 33 kΩ. The resistance of the second resistor is 68 kΩ.

[0010] The first branch includes a first resistor, a sixth diode, a filter capacitor, a fourth resistor and a third resistor. One end of the first resistor is connected to the emitter of the first PNP transistor, and the other end is connected to the anode of the sixth diode and one end of the fourth resistor. The cathode of the sixth diode and the other end of the fourth resistor are both connected to the first end of the third resistor. The second end of the third resistor is connected to the base of the NPN transistor. The positive electrode of the filter capacitor is connected to the first end of the third resistor, and the negative electrode is grounded.

[0011] The filter capacitor is an electrolytic capacitor.

[0012] The first branch further includes a fifth diode and a first voltage regulator tube. The anode of the fifth diode is connected to the anode of the sixth diode, and the cathode is grounded via the first voltage regulator tube.

[0013] A rectifier is provided between the emitter of the first PNP transistor and the input interface, and the rectifier is composed of a first diode and a second diode connected in reverse.

[0014] The control device also includes a first relay, whose contacts are arranged between the emitter of the first PNP transistor and the input interface, and the common contact is connected to the input interface, and the normally open contact is connected to the emitter of the first PNP transistor. The coil of the first relay is connected to the liquid level switch of the wiper water tank. When the liquid level of the wiper water tank is lower than the limited value, the liquid level switch is disconnected, the first relay is disconnected, and the normally open contact is open.

[0015] The emitter of the second PNP transistor is grounded via a second filter capacitor.

[0016] The collector of the first PNP transistor is also grounded via a third diode and a grounding capacitor in sequence.

[0017] The emitter of the NPN transistor is grounded through a fourth diode.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. By designing a multi-stage transistor start-up control and limiting the rated power of the fifth resistor that controls the on and off of the second PNP transistor, the current tolerance of the fifth circuit can be effectively improved, thereby reducing the failure rate of the control device when the wiper works at a high frequency or the liquid level in the wiper water tank is low.

[0020] 2. By setting multi-stage current limiting and filtering in the first DC, the signal quality of the base of the PNP transistor can be improved, avoiding the instability of the output signal of the startup circuit caused by the unstable state of the PNP transistor.

[0021] 3. By designing the first relay, it can be linked to the liquid level of the wiper tank. When the liquid level is low, the startup can be interrupted to avoid the burning of the subsequent devices due to long-term power supply caused by no water. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 is a schematic diagram of the starting circuit;

[0024] Among them: 1. input interface, 2. starting circuit, 3. DC conversion circuit, 4. main circuit, K1, first relay, R1, first resistor, R2, second resistor, R3, third resistor, R4, fourth resistor, R5, fifth resistor, D1, first diode, D2, second diode, D3, third diode, D4, fourth diode, D5, fifth diode, D6, sixth diode, Q1, first PNP transistor, Q2, NPN transistor, Q3, second PNP transistor, EC2, first filter capacitor, C1, second filter capacitor, C2, grounding capacitor. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0026] The inventor analyzed the faulty control device and found that the cause of the fault was mainly concentrated in the starting circuit, resulting in no output in the subsequent stage and inability to work normally.

[0027] A rail transit train wiper control device, such as Figure 1 As shown, it includes an input interface 1, a start-up circuit 2, a DC conversion circuit 3 and a main circuit 4 connected in sequence, and the input interface 1 is connected to a vehicle-mounted DC 110V power supply, such as Figure 2As shown, the start-up circuit 2 includes a first PNP transistor Q1, a second PNP transistor Q3, an NPN transistor Q2, a second resistor R2, a fifth resistor R5 and a first branch. The emitter of the first PNP transistor Q1 is connected to the input interface 1, and is connected to the base of the NPN transistor Q2 through the first branch, and is connected to the collector of the NPN transistor Q2 through the second resistor R2 and the fifth resistor R5 in sequence. The emitter of the NPN transistor Q2 is grounded, and the collector is connected to the base of the second PNP transistor Q3 through the fifth resistor R5. The emitter of the second PNP transistor Q3 is grounded, and the collector is connected to the base of the first PNP transistor Q1. The collector of the first PNP transistor Q1 is connected to the input end of the DC conversion circuit 3. The rated power of the fifth resistor R5 is:

[0028] W R5 ≥110A / (R 2 +R 5 )*1000*1.5

[0029] Where: W R5 is the rated power of the fifth resistor R5, in watts, A is the maximum input voltage deviation ratio, R 2 is the resistance value of the second resistor R2, R 5 is the resistance value of the fifth resistor R5.

[0030] All the above parameters are in international standard units. Generally speaking, a 1W capacitor allows a maximum current of 10mA. Through the above restrictions, it can be ensured that the current passing through the fifth resistor R5 is within a limited range.

[0031] By designing a multi-stage transistor startup control and limiting the rated power of the fifth resistor R5 that controls the on and off of the second PNP transistor Q3, the current tolerance of the fifth circuit can be effectively improved, thereby reducing the failure rate of the control device when the wiper operates at a high frequency or the liquid level in the wiper water tank is low.

[0032] In this embodiment, if Figure 2 As shown, the fifth resistor R5 has a rated power of 2 watts and a resistance of 33 kΩ, and the second resistor R2 has a resistance of 68 kΩ.

[0033] In most embodiments, the first branch includes a first resistor R1, a sixth diode D6, a first filter capacitor EC2, a fourth resistor R4, and a third resistor R3. One end of the first resistor R1 is connected to the emitter of the first PNP transistor Q1, and the other end is connected to the anode of the sixth diode D6 and one end of the fourth resistor R4. The cathode of the sixth diode D6 and the other end of the fourth resistor R4 are both connected to the first end of the third resistor R3. The second end of the third resistor R3 is connected to the base of the NPN transistor Q2. The anode of the first filter capacitor EC2 is connected to the first end of the third resistor R3, and the cathode is grounded.

[0034] Generally, the first filter capacitor EC2 can be selected as an electrolytic capacitor.

[0035] In addition, the first branch also includes a fifth diode D5 and a first voltage regulator. The anode of the fifth diode D5 is connected to the anode of the sixth diode D6, and the cathode is grounded via the first voltage regulator. Overvoltage protection can be performed through the fifth diode D5 and the first voltage regulator.

[0036] In addition, in most embodiments, a rectifier is provided between the emitter of the first PNP transistor Q1 and the input interface 1 , and the rectifier is a bridge rectifier, specifically composed of a first diode D1 and a second diode D2 which are connected inversely.

[0037] In some embodiments, the control device further includes a first relay K1, the contact of the first relay K1 is arranged between the emitter of the first PNP transistor Q1 and the input interface 1, and the common contact is connected to the input interface 1, the normally open contact is connected to the emitter of the first PNP transistor Q1, and the coil of the first relay K1 is connected to the liquid level switch of the wiper water tank. When the liquid level of the wiper water tank is lower than the limit value, the liquid level switch is disconnected, the first relay K1 is disconnected, and the normally open contact is open; when the liquid level of the wiper water tank is higher than the limit value, the liquid level switch is opened, at this time the first relay K1 is in the energized state, the normally open contact is turned on, and the start circuit 2 can work normally. By adding the first relay K1, the problem of the subsequent water pump working for a long time due to the start circuit 2 being turned on for a long time when there is no water spraying, causing the water pump and other devices to burn out easily, etc., is avoided.

[0038] In addition, in most embodiments, the emitter of the second PNP transistor Q3 is grounded through the second filter capacitor C1, the collector of the first PNP transistor Q1 is also grounded through the third diode D3 and the grounding capacitor C2 in sequence, and the emitter of the NPN transistor Q2 is grounded through the fourth diode D4. This can avoid the problem of uneven wiper speed caused by voltage instability or wiper state switching.

[0039] When working normally, such as Figure 2As shown, the second path at point A passes through the second resistor R2 to point D, point D reaches the base of the second PNP transistor Q3, and point D also passes through the fifth resistor R5 to the collector of the NPN transistor Q2. When the input interface 1 is normally input, the NPN transistor Q2, at this time the voltage at point D is pulled low, the second PNP transistor Q3 is turned on, and at this time the first PNP transistor Q1 is turned on, and the output voltage of the first PNP transistor Q1 is output via the DC conversion circuit 3 to power the main circuit 4.

[0040] If the above functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program code.

Claims

1. A rail transit train wiper control device, comprising an input interface, a start-up circuit, a DC conversion circuit and a main circuit connected in sequence, wherein the input interface is connected to a vehicle-mounted DC 110V power supply, characterized in that: The startup circuit includes a first PNP transistor, a second PNP transistor, an NPN transistor, a second resistor, a fifth resistor and a first branch, the emitter of the first PNP transistor is connected to the input interface, and is connected to the base of the NPN transistor through the first branch, and is connected to the collector of the NPN transistor through the second resistor and the fifth resistor in sequence, the emitter of the NPN transistor is grounded, and the collector is connected to the base of the second PNP transistor through the fifth resistor, the emitter of the second PNP transistor is grounded, and the collector is connected to the base of the first PNP transistor, the collector of the first PNP transistor is connected to the input end of the DC conversion circuit, and the rated power of the fifth resistor is: IN R5 ≥110A / (R2+R5)*1000*1.5 Where: W R5 is the rated power of the fifth resistor, in watts, A is the maximum input voltage deviation ratio, R2 is the resistance value of the second resistor, and R5 is the resistance value of the fifth resistor.

2. A rail transit train wiper control device according to claim 1, characterized in that: The rated power of the fifth resistor is 2 watts, and the resistance is 33 kΩ. The resistance of the second resistor is 68 kΩ.

3. A rail transit train wiper control device according to claim 1, characterized in that: The first branch includes a first resistor, a sixth diode, a filter capacitor, a fourth resistor and a third resistor. One end of the first resistor is connected to the emitter of the first PNP transistor, and the other end is connected to the anode of the sixth diode and one end of the fourth resistor. The cathode of the sixth diode and the other end of the fourth resistor are both connected to the first end of the third resistor. The second end of the third resistor is connected to the base of the NPN transistor. The positive electrode of the filter capacitor is connected to the first end of the third resistor, and the negative electrode is grounded.

4. A rail transit train wiper control device according to claim 3, characterized in that: The filter capacitor is an electrolytic capacitor.

5. A rail transit train wiper control device according to claim 3, characterized in that: The first branch further includes a fifth diode and a first voltage regulator tube. The anode of the fifth diode is connected to the anode of the sixth diode, and the cathode is grounded via the first voltage regulator tube.

6. A rail transit train wiper control device according to claim 1, characterized in that: A rectifier is provided between the emitter of the first PNP transistor and the input interface, and the rectifier is composed of a first diode and a second diode connected in reverse.

7. A rail transit train wiper control device according to claim 1, characterized in that: The control device also includes a first relay, whose contacts are arranged between the emitter of the first PNP transistor and the input interface, and the common contact is connected to the input interface, and the normally open contact is connected to the emitter of the first PNP transistor. The coil of the first relay is connected to the liquid level switch of the wiper water tank. When the liquid level of the wiper water tank is lower than the limited value, the liquid level switch is disconnected, the first relay is disconnected, and the normally open contact is open.

8. A rail transit train wiper control device according to claim 1, characterized in that: The emitter of the second PNP transistor is grounded via a second filter capacitor.

9. A rail transit train wiper control device according to claim 1, characterized in that: The collector of the first PNP transistor is also grounded via a third diode and a grounding capacitor in sequence.

10. A rail transit train wiper control device according to claim 1, characterized in that: The emitter of the NPN transistor is grounded through a fourth diode.

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