Traffic signal machine

Abstract

The utility model discloses a traffic signal controller, and belongs to the technical field of electronics. The traffic signal controller comprises a lamp control circuit, a current acquisition circuit and a controller. A power supply end of the lamp control circuit is used for being connected with a lamp control power supply, a control end is connected with a first output end of the controller, an output end is connected with a target signal lamp, the lamp control circuit is used for conducting or disconnecting according to a signal lamp operation scheme so as to lighten or extinguish the target signal lamp, and the target signal lamp is a signal lamp of any color in traffic signal lamps; the acquisition end of the current acquisition circuit is connected with the output end of the lamp control circuit, the output end is connected with the input end of the controller, and the current acquisition circuit is used for acquiring current flowing through the target signal lamp; the controller is used for switching off the lamp control circuit after determining that the target signal lamp breaks down based on the current collected by the current collection circuit. According to the invention, when the target signal lamp breaks down, the power supply line of the target signal lamp can be quickly cut off, so that the traffic signal controller is effectively protected.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a traffic signal. Background Art

[0002] Traffic signals are an important part of modern urban transportation systems, and are mainly used for the control and management of urban road traffic signals. In bad weather or when wiring is misoperated during construction, the power supply line of the traffic signal may experience overvoltage, short circuit, overcurrent and other faults. If the power supply line is not cut off in time, the traffic signal may be damaged.

[0003] The related technology installs a fast-blow fuse in the power supply line. When a fault occurs, the power supply line will be cut off by blowing the fuse, thereby avoiding burning out the components in the traffic signal. However, when a transient short circuit with high current occurs, the above method cannot effectively protect the traffic signal due to its slow reaction speed. Utility Model Content

[0004] In order to quickly cut off the power supply line of the target signal light when a target signal light fails to avoid damaging the traffic signal light, the present application provides a traffic signal light. The technical solution is as follows:

[0005] The present application provides a traffic signal, which includes a light control circuit, a current collection circuit and a controller;

[0006] The power supply end of the light control circuit is used to be connected to the light control power supply, the control end of the light control circuit is connected to the first output end of the controller, the output end of the light control circuit is connected to the target signal light, and the light control circuit is used to be turned on or off according to the signal light operation plan to light up or extinguish the target signal light, and the target signal light is a signal light of any color among traffic lights;

[0007] The collection end of the current collection circuit is connected to the output end of the light control circuit, the output end of the current collection circuit is connected to the input end of the controller, and the current collection circuit is used to collect the current flowing through the target signal light;

[0008] Wherein, the controller is used to disconnect the light control circuit after determining that the target signal light fails based on the current collected by the current collection circuit.

[0009] Optionally, the traffic signal further comprises a state detection circuit;

[0010] The power supply end of the state detection circuit is used to be connected to the light control power supply, the control end of the state detection circuit is connected to the second output end of the controller, the output end of the state detection circuit is connected to the target signal light, and the state detection circuit is used to detect the fault state of the target signal light;

[0011] The controller is further used to control the state detection circuit to be turned on after the light control circuit is disconnected due to a fault in the target signal light, and to determine whether the target signal light has returned to normal through the current collected by the current collection circuit.

[0012] Optionally, the lighting control circuit includes a first switch subcircuit;

[0013] The input end of the first switch subcircuit is used to connect to the light-controlled power supply, the control end of the first switch subcircuit is connected to the first output end of the controller, and the output end of the first switch subcircuit is connected to the target signal light.

[0014] Optionally, the lighting control circuit further includes a photoelectric isolation subcircuit;

[0015] The photoelectric isolation subcircuit is connected in series between the first output terminal of the controller and the control terminal of the first switch subcircuit, and is used to isolate the high-voltage signal on the first switch subcircuit side from the low-voltage signal on the controller side to prevent the controller from being burned out.

[0016] Optionally, the lighting control circuit further includes a reverse protection diode;

[0017] The anode of the anti-reverse protection diode is connected to the output end of the first switch sub-circuit, and the cathode of the anti-reverse protection diode is connected to the target signal light. The anti-reverse protection diode is used to prevent the target signal light side from burning out the first switch sub-circuit due to redundant power caused by incorrect wiring.

[0018] Optionally, the state detection circuit includes a second switch subcircuit and a current limiting resistor;

[0019] The power supply end of the second switch subcircuit is used to connect to the light-controlled power supply, the control end of the second switch subcircuit is connected to the second output end of the controller, the output end of the second switch subcircuit is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the target signal lamp;

[0020] The current limiting resistor is used to ensure that the target signal light will not be lit after the second switch sub-circuit is turned on.

[0021] Optionally, the current acquisition circuit includes a current sensing resistor and a current sampling subcircuit;

[0022] The current sensing resistor is connected in series between the output end of the light control circuit and the target signal light, and the two ends of the current sensing resistor are also respectively connected to the first input end and the second input end of the current sampling subcircuit, and the output end of the current sampling subcircuit is connected to the input end of the controller.

[0023] Optionally, the current sampling subcircuit includes a first resistor, a second resistor, a first amplifier, a first switch tube and a third resistor, and the first resistor and the second resistor have the same resistance value;

[0024] One end of the first resistor is connected to one end of the current-sensing resistor, and the other end of the first resistor is connected to the inverting input end of the first amplifier;

[0025] One end of the second resistor is connected to the other end of the current-sense resistor, and the other end of the second resistor is connected to the non-inverting input end of the first amplifier;

[0026] The output end of the first amplifier is connected to the control end of the first switch tube, the input end of the first switch tube is connected to the non-inverting input end of the first amplifier, the output end of the first switch tube is respectively connected to one end of the third resistor and the input end of the controller, and the other end of the third resistor is grounded.

[0027] Optionally, the current acquisition circuit further includes an amplification and conditioning subcircuit;

[0028] The input end of the amplifying and conditioning subcircuit is connected to the output end of the current sampling subcircuit, the output end of the amplifying and conditioning subcircuit is connected to the input end of the controller, and the amplifying and conditioning subcircuit is used to amplify the output voltage of the current sampling subcircuit.

[0029] Optionally, the amplification and conditioning subcircuit includes a fourth resistor, a second amplifier, a fifth resistor and a sixth resistor, and the resistance of the fourth resistor is equal to the parallel resistance of the fifth resistor and the sixth resistor;

[0030] One end of the fourth resistor is connected to the output end of the current sampling sub-circuit, and the other end of the fourth resistor is connected to the inverting input end of the second amplifier;

[0031] One end of the fifth resistor is respectively connected to the non-inverting input end of the second amplifier and one end of the sixth resistor, and the other end of the fifth resistor is grounded;

[0032] The output end of the second amplifier is connected to the other end of the sixth resistor, and the output end of the second amplifier is also connected to the input end of the controller.

[0033] The beneficial effects of the technical solution provided by this application are:

[0034] The traffic signal includes a light control circuit, a current collection circuit and a controller. The controller can determine whether a target signal light fails based on the current collected by the current collection circuit. When the target signal light fails, the controller can control the light control circuit to quickly disconnect. This process reaches the microsecond level. That is to say, when the target signal light fails, it only takes microseconds to cut off the power supply line of the signal light, while a blowing fuse takes milliseconds. Therefore, compared with the method of protecting the traffic signal by blowing a fuse, the embodiment of the present application can cut off the power supply line of the signal light more quickly, thereby effectively protecting the traffic signal and avoiding damage to the traffic signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the first traffic signal provided in the embodiment of the present application;

[0036] Figure 2 is a structural schematic diagram of a second traffic signal provided in an embodiment of the present application;

[0037] Figure 3 is a structural schematic diagram of a third type of traffic signal provided in an embodiment of the present application;

[0038] Figure 4 is a structural schematic diagram of a fourth type of traffic signal provided in an embodiment of the present application;

[0039] Figure 5 is a structural schematic diagram of a fifth traffic signal provided in an embodiment of the present application;

[0040] Figure 6 is a structural schematic diagram of a sixth type of traffic signal provided in an embodiment of the present application;

[0041] Figure 7 is a structural schematic diagram of a seventh traffic signal provided in an embodiment of the present application;

[0042] Figure 8 is a structural schematic diagram of an eighth type of traffic signal provided in an embodiment of the present application;

[0043] Fig. 9 is a schematic structural diagram of a ninth traffic signal provided in an embodiment of the present application;

[0044] Fig.10 is a structural schematic diagram of the tenth traffic signal provided in an embodiment of the present application;

[0045] Fig.11 is a schematic structural diagram of an eleventh traffic signal provided in an embodiment of the present application;

[0046] Fig.12 is a structural schematic diagram of a twelfth traffic signal provided in an embodiment of the present application;

[0047] Fig.13 This is a workflow diagram of a traffic signal provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0049] Please refer to Figure 1 , Figure 1 It is a structural schematic diagram of a traffic signal provided by an embodiment of the present application, and the traffic signal includes a light control circuit 1, a current collection circuit 2 and a controller 3. The power supply terminal d1 of the light control circuit 1 is used to connect to the light control power supply, the control terminal d2 of the light control circuit 1 is connected to the first output terminal k1 of the controller 3, the output terminal d3 of the light control circuit 1 is connected to the target signal light, and the light control circuit 1 is used to conduct or disconnect according to the signal light operation plan to light up or extinguish the target signal light, and the target signal light is a signal light of any color in the traffic light; the collection terminal c1 of the current collection circuit 2 is connected to the output terminal d3 of the light control circuit 1, the output terminal c2 of the current collection circuit 2 is connected to the input terminal k2 of the controller 3, and the current collection circuit 2 is used to collect the current flowing through the target signal light; wherein the controller 3 is used to disconnect the light control circuit 1 after determining that the target signal light fails based on the current collected by the current collection circuit 2.

[0050] Since the power supply end of the light control circuit is connected to the light control power supply, the control end of the light control circuit is connected to the first output end of the controller, and the output end of the light control circuit is connected to the target signal light, when the controller controls the light control circuit to be turned on, the light control power supply can supply power to the target signal light through the light control circuit to light up the target signal light, and when the controller controls the light control circuit to be disconnected, the light control power supply cannot supply power to the target signal light through the light control circuit, and therefore, the target signal light will go out.

[0051] In some embodiments, the traffic lights may include red, green and yellow lights, and each color of the traffic lights has its own corresponding light control circuit, that is, the lighting or extinguishing of the traffic lights of different colors is realized by their own light control circuits. Therefore, the controller can turn on or off the red light by controlling the conduction or disconnection of the light control circuit corresponding to the red light; the controller can turn on or off the green light by controlling the conduction or disconnection of the light control circuit corresponding to the green light; the controller can turn on or off the yellow light by controlling the conduction or disconnection of the light control circuit corresponding to the yellow light.

[0052] In some embodiments, in order to determine whether a target signal light fails, the collection end of the current collection circuit can be connected to the output end of the light control circuit, so that the current collection circuit can collect the current output by the light control circuit to the target signal light, that is, collect the current flowing through the target signal light.

[0053] Similar to the above-mentioned light control circuit, signal lights of different colors also correspond to current collection circuits respectively, so that the current collection circuit can collect the current flowing through the signal lights of corresponding colors. For example, assuming that the red light corresponds to the first light control circuit and the first current collection circuit, then the collection end of the first current collection circuit can be connected to the output end of the first light control circuit, so that the first current collection circuit can collect the current flowing through the red light; assuming that the green light corresponds to the second light control circuit and the second current collection circuit, then the collection end of the second current collection circuit can be connected to the output end of the second light control circuit, so that the second current collection circuit can collect the current flowing through the green light; assuming that the yellow light corresponds to the third light control circuit and the third current collection circuit, then the collection end of the third current collection circuit can be connected to the output end of the third light control circuit, so that the third current collection circuit can collect the current flowing through the yellow light.

[0054] In addition, in some embodiments, since the output end of the current acquisition circuit is connected to the input end of the controller, the current acquisition circuit can input the acquired current into the controller, so that the controller determines whether the target signal light is faulty based on the current acquired by the current acquisition circuit. When the target signal light is on, that is, the light control circuit is on, if the controller determines that the target signal light is faulty based on the current acquired by the current acquisition circuit, the light control circuit is controlled to be disconnected to extinguish the target signal light, so as to prevent damage to the traffic signal machine due to overvoltage, overcurrent and other faults of the target signal light; if the controller determines that the target signal light is not faulty based on the current acquired by the current acquisition circuit, the light control circuit is controlled to be turned on or off according to the signal light operation plan to light or extinguish the target signal light.

[0055] In some embodiments, the controller can determine whether the target signal light is faulty by determining whether the current collected by the current acquisition circuit is within a first current range. That is, if the controller determines that the current collected by the current acquisition circuit is within the first current range, it determines that the target signal light is not faulty; if the controller determines that the current collected by the current acquisition circuit is not within the first current range, it determines that the target signal light is faulty.

[0056] It should be noted that the size of the first current range can be set according to actual conditions. For example, the first current range can be set according to the current range flowing through the signal lamp when the signal lamp is working normally. For example, when the target signal lamp is working normally, the current range flowing through the signal lamp is X to Y, then the first current range can be set to X to Y. The embodiments of the present application are not limited to this.

[0057] In some embodiments, when the target signal light fails and the target signal light is not a yellow light, the controller can control the yellow light to flash continuously to remind vehicles or pedestrians to slow down. That is, when the red light and / or the green light fails, the above method can be used to ensure the safe passage of vehicles or pedestrians.

[0058] In addition, based on the above description, each color of the signal light corresponds to a light control circuit and a current collection circuit, and the control method of each color of the signal light is similar, so the embodiment of the present application takes a signal light of one color as an example for introduction.

[0059] Since the traffic signal includes a light control circuit, a current collection circuit and a controller, when the light control circuit is turned on, the current collection circuit can collect the current flowing through the target signal light, so that the controller determines whether the target signal light is faulty based on the current collected by the current collection circuit. When the target signal light fails, the controller can control the light control circuit to disconnect quickly, and this process reaches the microsecond level. That is to say, when the target signal light fails, it only takes microseconds to cut off the power supply line of the signal light, while the time for a fuse to blow is milliseconds. Therefore, the embodiment of the present application can cut off the power supply line of the signal light more quickly, thereby effectively protecting the traffic signal.

[0060] In some embodiments, please refer to Figure 2 The traffic signal also includes a state detection circuit 4, a power supply end j1 of the state detection circuit 4 is used to connect to the light control power supply, a control end j2 of the state detection circuit 4 is connected to the second output end k3 of the controller 3, an output end j3 of the state detection circuit 4 is connected to the target signal light, and the state detection circuit 4 is used to detect the fault state of the target signal light; wherein the controller 3 is also used to control the state detection circuit 4 to be turned on after the light control circuit 1 is disconnected due to a fault of the target signal light, and determine whether the target signal light has returned to normal through the current collected by the current collection circuit 2.

[0061] In the embodiment of the present application, in order for the target signal light to automatically resume operation after the target signal light that has failed returns to normal, the traffic signal may further include a state detection circuit. Since the control end of the state detection circuit is connected to the second output end of the controller, the controller can control the state detection circuit to be turned on after the light control circuit is disconnected due to a failure of the target signal light; since the power supply end of the state detection circuit is connected to the power supply, and the output end is connected to the target signal light, when the state detection circuit is turned on, current will flow through the target signal light, so that the current acquisition circuit can acquire the current flowing through the target signal light, so that the controller determines whether the target signal light has returned to normal based on the current acquired by the current acquisition circuit.

[0062] In some embodiments, the controller can determine whether the target signal light has returned to normal by determining whether the current collected by the current collection circuit is within the second current range. That is, if the controller determines that the current collected by the current collection circuit is within the second current range, it is determined that the target signal light has returned to normal; if the controller determines that the current collected by the current collection circuit is not within the second current range, it is determined that the target signal light has not returned to normal.

[0063] In addition, in some embodiments, in order to avoid the situation where the target signal light is incorrectly judged to be restored to normal due to excessive current change, the controller can also determine whether the target signal light is restored to normal based on the current collected multiple times by the current collection circuit. For example, the controller can determine whether the target signal light is restored to normal based on whether the average value of the current collected multiple times by the current collection circuit is within the second current range.

[0064] It should be noted that the size of the second current range can be set according to actual conditions. For example, the second current range can be set according to the current range flowing through the signal light when the state detection circuit is turned on, the light control circuit is turned off, and the signal light is not faulty. For example, when the state detection circuit is turned on, the light control circuit is turned off, and the signal light is not faulty, the current range flowing through the signal light is A to B. That is to say, when the current range flowing through the signal light is between A and B, the signal light returns to normal, so the second current range can be set to A to B. The embodiments of the present application are not limited to this.

[0065] Continuing with the above description, when the controller determines that the target signal light has returned to normal, the control state detection circuit is disconnected, and when the signal light operation plan runs to the point where the target signal light needs to be lit, the control light control circuit is turned on to light the target signal light; when the controller determines that the target signal light has not returned to normal, the state detection circuit is kept turned on and the light control circuit is disconnected, so that the controller can promptly determine whether the target signal light has returned to normal based on the current collected by the current collection circuit.

[0066] In addition, in some embodiments, when the target signal lamp is not faulty, the state detection circuit is in a closed state. After the target signal lamp fails, the controller can control the state detection circuit to be turned on periodically for a short time to determine whether the target signal lamp has returned to normal. For example, the controller can control the state detection circuit to be turned on every time T, and the duration of each turn-on is A, so that the controller can periodically determine whether the target signal lamp has returned to normal, which can save power consumption.

[0067] In some embodiments, please refer to Figure 3 The state detection circuit 4 includes a second switch subcircuit 41 and a current limiting resistor R1. The power supply end e1 of the second switch subcircuit 41 is used to connect to the light control power supply. The control end e2 of the second switch subcircuit 41 is connected to the second output end k3 of the controller 3. The output end e3 of the second switch subcircuit 41 is connected to one end of the current limiting resistor R1, and the other end of the current limiting resistor R1 is connected to the target signal light. The current limiting resistor R1 is used to ensure that the target signal light will not be lit after the second switch subcircuit 41 is turned on.

[0068] Since the control end of the second switch subcircuit is connected to the second output end of the controller, when the target signal light fails, the controller can control the second switch subcircuit to be turned on, thereby turning on the state detection circuit. One end of the current limiting resistor is connected to the second switch subcircuit, and the other end is connected to the target signal light. In this way, it can be ensured that the target signal light will not be lit, and the current collection circuit can collect the current flowing through the target signal light, so that the controller can determine whether the target signal light has returned to normal based on the current collected by the current collection circuit.

[0069] Therefore, when a target signal light fails and the light control circuit of the target signal light is disconnected, the status detection circuit can be turned on, so that the controller can determine whether the target signal light has returned to normal based on the current collected by the current collection circuit. Then, after the fault of the target signal light is repaired, normal operation can be automatically restored without manual replacement of the fuse, thus saving costs.

[0070] In some embodiments, the traffic signal may also include a status recording module, which is used to record faults occurring in the target traffic light and report the faults to the operation and maintenance center so that the operation and maintenance personnel can obtain information about the traffic signal faults in a timely manner; the status recording module is also used to report the working status of the traffic signal to the operation and maintenance center at a regular periodic rate so that the operation and maintenance personnel can obtain the current status of the traffic signal in a timely manner.

[0071] In some embodiments, please refer to Figure 4The lighting control circuit 1 includes a first switch subcircuit 11, an input terminal y1 of the first switch subcircuit 11 is used to connect to the lighting control power supply, a control terminal y2 of the first switch subcircuit 11 is connected to a first output terminal k1 of the controller 3, and an output terminal y3 of the first switch subcircuit 11 is connected to a target signal light.

[0072] In this way, when the controller controls the first switch subcircuit to be turned on, the target signal light can be lit, and when the controller controls the first switch subcircuit to be turned off, the target signal light can be turned off. In other words, the on or off of the light control circuit depends on the on and off of the first switch subcircuit. When the first switch subcircuit is turned off, the light control circuit is also turned off, and when the first switch subcircuit is turned on, the light control circuit is also turned on.

[0073] In some embodiments, please refer to Figure 5 The first switch subcircuit 11 may include a first voltage-dividing resistor R2, a second voltage-dividing resistor R3 and a first MOS transistor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET, Metal-Oxide Semiconductor Field-Effect Transistor) M1. One end of the first voltage-dividing resistor R2 is connected to the first output end k1 of the controller 3, the other end of the first voltage-dividing resistor R2 is respectively connected to one end of the second voltage-dividing resistor R3 and the gate G of the first MOS transistor M1, the drain D of the first MOS transistor M1 is connected to the target signal light, the source S of the first MOS transistor M1 is connected to the light-controlled power supply, and the other end of the second voltage-dividing resistor R3 is also connected to the light-controlled power supply.

[0074] The first voltage-dividing resistor and the second voltage-dividing resistor are used to ensure that the voltage provided by the light-controlled power supply can meet the turn-on condition of the first MOS tube when the target signal lamp has no fault and the target signal lamp should be turned on, so as to turn on the first MOS tube and then turn on the target signal lamp.

[0075] In some embodiments, please refer to Figure 5 The first switch sub-circuit 11 may further include a bidirectional breakdown diode 111, which is connected between the gate G and the source S of the first MOS tube M1 to prevent damage to the first MOS tube when an ESD (Electro-Static discharge) phenomenon occurs.

[0076] In some embodiments, please refer to Figure 5 Due to the structure of the first MOS tube M1, a body diode V1 may be formed between the source S and the drain D, so that leakage between the source S and the drain D of the first MOS tube M1 can be prevented.

[0077] It should be noted that the MOS tube in the embodiment of the present application can be an N-MOS tube (Negative Channel Metal Oxide Semiconductor, N-channel Metal Oxide Semiconductor Field Effect Transistor), or a P-MOS tube (Positive Channel Metal Oxide Semiconductor, P-channel Metal Oxide Semiconductor Field Effect Transistor) or other MOS tubes, and the embodiment of the present application is not limited to this.

[0078] Based on the above description, it can be seen that the conduction or disconnection of the light control circuit depends on the conduction and disconnection of the first switch subcircuit. Therefore, when a target traffic light fails, the controller can quickly disconnect the light control circuit by controlling the conduction or disconnection of the first switch subcircuit, thereby effectively protecting the traffic signal.

[0079] In some embodiments, please refer to Figure 6 The lighting control circuit 1 also includes a photoelectric isolation sub-circuit 12, which is connected in series between the first output terminal k1 of the controller 3 and the control terminal y2 of the first switch sub-circuit 11. The photoelectric isolation sub-circuit 12 is used to isolate the high-voltage signal on the first switch sub-circuit 11 side from the low-voltage signal on the controller 3 side to prevent the controller 3 from being burned out.

[0080] In some embodiments, please refer to Figure 7 The photoelectric isolation subcircuit 12 includes a light emitting diode 121 and a phototransistor 122. The anode of the light emitting diode 121 is connected to an external power supply, the cathode of the light emitting diode 121 is connected to the first output terminal k1 of the controller 3, the base B of the phototransistor 122 is used to determine whether the light emitting diode 121 is lit, the collector C of the phototransistor 122 is connected to one end of the first voltage-dividing resistor R2, and the emitter E of the phototransistor 122 is grounded, wherein the external power supply is used to power the light emitting diode 121.

[0081] When the target signal light has not failed and the signal light operation scheme runs to the point where the target signal light needs to be lit, the controller can send a low-level signal to the light-emitting diode to light the light-emitting diode. When the light-emitting diode is lit, the phototransistor will be turned on, thereby controlling the first MOS tube to be turned on. When the target signal light fails or the target signal light does not need to be lit at present, the controller can send a high-level signal to the light-emitting diode to turn off the light-emitting diode. When the light-emitting diode is turned off, the phototransistor will also be turned off, thereby controlling the first MOS tube to be turned off, thereby cutting off the power supply to the target signal light, and at the same time isolating the high-voltage signal on the first switch sub-circuit side from the low-voltage signal on the controller side to prevent the controller from being burned out.

[0082] In some embodiments, please refer to Figure 7The photoelectric isolation subcircuit may further include a voltage regulating resistor R4, which is connected between the first output terminal k1 of the controller 3 and the cathode of the light emitting diode 121. Compared with ordinary resistors, the voltage regulating resistor has a larger rated power, can withstand the impact of high voltage and current, and is not prone to thermal runaway, so it can ensure signal stability. In addition, the voltage regulating resistor can also reduce the current flowing through the light emitting diode to prevent damage to the light emitting diode.

[0083] In some embodiments, please refer to Figure 8 The light control circuit 1 further includes a non-reverse protection diode 13, the anode of the non-reverse protection diode 13 is connected to the output end y3 of the first switch sub-circuit 11, and the cathode of the non-reverse protection diode 13 is connected to the target signal light. The non-reverse protection diode 13 is used to prevent the target signal light from burning the first switch sub-circuit 11 due to redundant power caused by incorrect wiring. In other words, the unidirectional conductivity of the non-reverse diode can be used to prevent current from flowing back.

[0084] In some embodiments, please refer to Fig. 9 The current acquisition circuit 2 includes a current sensing resistor R5 and a current sampling sub-circuit 21. The current sensing resistor R5 is connected in series between the output terminal d3 of the lighting control circuit 1 and the target signal light. The two ends of the current sensing resistor R5 are also respectively connected to the first input terminal cy1 and the second input terminal cy2 of the current sampling sub-circuit 21. The output terminal cy3 of the current sampling sub-circuit 21 is connected to the input terminal k2 of the controller 3.

[0085] Since the current-sense resistor is connected in series between the output end of the light-control circuit and the target signal light, and the two ends of the current-sense resistor are respectively connected to the first input end and the second input end of the current sampling subcircuit, the current can be sampled by the high-side current sampling method to obtain the sampled current. Among them, the high-side current sampling method refers to the method of placing the current-sense resistor at a high position between the power supply voltage (such as the light-control power supply) and the load (such as the target signal light) to perform current sampling. This placement method not only eliminates the ground interference generated in the low-side current sampling method, but also can realize the current control and protection functions.

[0086] In some embodiments, please refer to Fig.10The current sampling subcircuit 21 includes a first resistor R6, a second resistor R7, a first amplifier 211, a first switch tube 212 and a third resistor R8. The first resistor R6 and the second resistor R7 have the same resistance value; one end of the first resistor R6 is connected to one end of the current sensing resistor R11, and the other end of the first resistor R6 is connected to the inverting input end of the first amplifier 211; one end of the second resistor R7 is connected to the other end of the current sensing resistor R5, and the other end of the second resistor R7 is connected to the non-inverting input end of the first amplifier 211; the output end of the first amplifier 211 is connected to the control end of the first switch tube 212, the input end of the first switch tube 212 is connected to the non-inverting input end of the first amplifier 211, the output end of the first switch tube 212 is respectively connected to one end of the third resistor R8 and the input end k2 of the controller 3, and the other end of the third resistor R8 is grounded.

[0087] Since one end of the first resistor is connected to one end of the current-sensing resistor, one end of the second resistor is also connected to the other end of the current-sensing resistor, and the other end of the first resistor is connected to the inverting input end of the first amplifier, and the other end of the second resistor is connected to the non-inverting input end of the first amplifier, and the current-sensing resistor is also connected in series between the output end of the light-control circuit and the target signal light, the current output from the light-control circuit to the target signal light will pass through the current-sensing resistor to form a cross-voltage between the non-inverting input end and the non-inverting input end of the first amplifier, and the voltage difference between the non-inverting input end and the non-inverting input end of the first amplifier is equal to the sampling current multiplied by the resistance value of the current-sensing resistor. For example, assuming that the resistance value of the current-sensing resistor is Rs, and the current sampled by the current-sensing resistor is Is, then the voltage difference between the non-inverting input end and the non-inverting input end of the first amplifier can be obtained as Rs*Is.

[0088] According to the principle of virtual short of the first amplifier, the voltages of the positive input terminal and the negative input terminal of the first amplifier are equal, that is, the voltage difference between the positive input terminal and the negative input terminal of the first amplifier is 0. However, based on the above description, the voltage difference between the positive input terminal and the negative input terminal of the first amplifier is equal to the sampling current multiplied by the resistance value of the current sensing resistor. Therefore, the voltage drop across the first resistor is the sampling current multiplied by the resistance value of the current sensing resistor. Similarly, the voltage drop across the second resistor is also the sampling current multiplied by the resistance value of the current sensing resistor.

[0089] According to the principle of virtual disconnection of the first amplifier, the current flowing through the first amplifier is 0, so the output current of the first amplifier is equal to the voltage drop across the resistor divided by the resistance value of the resistor. For example, assuming that the resistance value of the first resistor is Rf and the voltage drop across it is Rs*Is, then the output current Iout of the first amplifier is equal to Rs*Is divided by Rf.

[0090] In some embodiments, please refer to Fig.10, the first switch tube 212 is a second MOS tube M2, and the gate G of the second MOS tube M2 is connected to the output end of the first amplifier 211, the drain D is connected to the non-inverting input end of the first amplifier 211, and the source S is respectively connected to one end of the third resistor R8 and the output end k2 of the controller 3. In this way, the second MOS tube M2 can form a source follower, that is, a voltage follower, thereby providing a stable and reliable signal amplification and driving function for the current sampling sub-circuit 21.

[0091] In addition, in some embodiments, the first resistor, the second resistor and the third resistor form a feedback network, and based on the above description, it can be seen that the output current of the first amplifier is equal to the voltage drop across the resistor divided by the resistance value of the resistor, that is, the current input to the third resistor is equal to the voltage drop across the resistor divided by the resistance value of the resistor. Therefore, it can be obtained that the output voltage of the current sampling subcircuit is the product of the current input to the third resistor and the resistance value of the third resistor.

[0092] As an example, the output voltage of the current sampling subcircuit can be expressed according to the following formula (1):

[0093]

[0094] Among them, V OUT Represents the output voltage of the current sampling subcircuit, I out represents the output current of the first amplifier, R L Represents the resistance of the third resistor, R s Represents the resistance of the current-sense resistor, I s Represents the current flowing through the target signal lamp, R f Indicates the resistance values ​​of the first resistor and the second resistor.

[0095] In some embodiments, the controller may determine the current flowing through the target signal lamp according to the output voltage of the current sampling subcircuit.

[0096] Continuing with the above example, based on the above formula (1), the controller can determine the current flowing through the target signal lamp according to the following formula (2);

[0097]

[0098] In some embodiments, please refer to Fig.11 The current acquisition circuit 2 also includes an amplifying and conditioning sub-circuit 22, an input terminal f1 of the amplifying and conditioning sub-circuit 22 is connected to an output terminal cy3 of the current sampling sub-circuit 21, an output terminal f2 of the amplifying and conditioning sub-circuit 22 is connected to an input terminal k2 of the controller 3, and the amplifying and conditioning sub-circuit 22 is used to amplify the output voltage of the current sampling sub-circuit 21.

[0099] In some embodiments, please refer to Fig.12The amplification and conditioning subcircuit 22 includes a fourth resistor R9, a second amplifier 221, a fifth resistor R10 and a sixth resistor R11, and the resistance of the fourth resistor R9 is equal to the parallel resistance of the fifth resistor R10 and the sixth resistor R11; one end of the fourth resistor R9 is connected to the output end cy3 of the current sampling subcircuit 21, and the other end of the fourth resistor R9 is connected to the inverting input end of the second amplifier 221; one end of the fifth resistor R10 is respectively connected to the non-inverting input end of the second amplifier 221 and one end of the sixth resistor R11, and the other end of the fifth resistor R10 is grounded; the output end of the second amplifier 221 is connected to the other end of the sixth resistor R11, and the output end of the second amplifier 221 is also connected to the input end k2 of the controller 3.

[0100] Among them, the fourth resistor is a matching resistor, and its main function is to provide signal transmission between different circuits so that the accuracy and quality of the signal can be guaranteed, and the resistance of the fourth resistor is equal to the parallel resistance of the fifth resistor and the sixth resistor. For example, if the resistance of the fifth resistor and the sixth resistor are both 20Ω, it can be obtained that the parallel resistance of the fifth resistor and the sixth resistor is 10Ω, then a resistor with a resistance of 10Ω can be selected as the fourth resistor.

[0101] In addition, in some embodiments, the voltage output after the amplification and conditioning subcircuit can be expressed according to the following formula (3):

[0102]

[0103] Among them, V o represents the output voltage of the amplifier and conditioning subcircuit, R 6 Represents the resistance value of the sixth resistor, R 5 Represents the resistance value of the fifth resistor, R s Represents the resistance value of the current sensing resistor, V i represents the input voltage to the conditioning amplifier subcircuit.

[0104] Since the input end of the amplifying and conditioning sub-circuit is connected to the output end of the current sampling sub-circuit, the input voltage of the amplifying and conditioning sub-circuit is equal to the output voltage of the current sampling sub-circuit.

[0105] As an example, the output voltage of the current sampling subcircuit after the output voltage of the amplification and conditioning subcircuit can be expressed according to the following formula (4):

[0106]

[0107] Among them, V o represents the output voltage of the amplifier and conditioning subcircuit, R 6 Represents the resistance value of the sixth resistor, R 5 Represents the resistance value of the fifth resistor, V OUTrepresents the output voltage of the current sampling subcircuit, R L Represents the resistance of the third resistor, R s Represents the resistance of the current-sense resistor, I s Represents the current flowing through the target signal lamp, R f Indicates the resistance values ​​of the first resistor and the second resistor.

[0108] Since the output of the amplifying and conditioning subcircuit is connected to the input of the controller, the controller can determine the current flowing through the target signal lamp based on the voltage input by the amplifying and conditioning subcircuit. For example, the controller can determine the current flowing through the target signal lamp according to the following formula (5);

[0109]

[0110] It should be noted that the above description is based on the use of an amplifying and conditioning sub-circuit to amplify the output voltage of the current sampling sub-circuit. Of course, in actual applications, voltage amplification can also be achieved by adjusting the sizes of the first resistor, the second resistor, and the third resistor, or voltage amplification can be achieved by other methods, and the embodiments of the present application are not limited to this.

[0111] Next, the workflow of the traffic signal provided in the embodiment of the present application will be generally introduced.

[0112] Please refer to Fig.13 When the traffic signal starts working, the default controller controls the state detection circuit to be disconnected; the controller controls the conduction or disconnection of the light control circuit according to the configured signal light operation plan to light up or extinguish the target signal light; the current acquisition circuit collects the current flowing through the target signal light in real time; the controller determines whether the current collected by the current acquisition circuit is within the first current range. If the current is within the first current range, the controller continues to control the opening or conduction of the light control circuit according to the configured signal light operation plan to light up or extinguish the target signal light, and the state recording module periodically reports the working state of the traffic signal to the operation and maintenance center. If the current is not within the first current range and the target signal light is not yellow, the controller controls the light control circuit to disconnect and controls the yellow light to flash continuously, and the status recording module reports the fault to the operation and maintenance center; the controller controls the state detection circuit to be turned on in a short-term fixed period so that the current acquisition circuit collects the current flowing through the target signal light at this time, and the controller determines whether the current is within the second current range. If the current is within the second current range, the controller returns to the step of controlling the state detection circuit to disconnect, and the controller controls the light control circuit according to the configured signal light operation plan; if the current is not within the second current range, the controller returns to the step of controlling the light control circuit to disconnect and controls the yellow light to flash continuously, and the status recording module reports the fault to the operation and maintenance center.

[0113] In an embodiment of the present application, a traffic signal includes a light control circuit, a current collection circuit and a controller. The controller can determine whether a target signal light fails based on the current collected by the current collection circuit. When the target signal light fails, the controller can control the light control circuit to quickly disconnect. This process reaches the microsecond level. That is, when the target signal light fails, it only takes microseconds to cut off the power supply line of the signal light, while a blowing fuse takes milliseconds. Therefore, compared with the method of protecting the traffic signal by blowing a fuse, the embodiment of the present application can cut off the power supply line of the signal light more quickly, thereby effectively protecting the traffic signal and avoiding damage to the traffic signal. Moreover, the traffic signal can also include a status detection circuit, so that when a fault occurs in the light control circuit, the controller can control the status detection circuit to open, so that the current detection circuit can collect current, and then the controller determines whether the target signal light has returned to normal based on the current collected by the current collection circuit, so that after the target signal light returns to normal, the controller can control the conduction or disconnection of the light control circuit according to the signal light operation plan, so that the target signal light can automatically resume normal operation. In other words, the traffic signal provided in the embodiment of the present application does not require manual replacement of the fuse after a signal light fails, and can automatically resume operation after the signal light returns to normal, which can save costs.

[0114] It should be understood that the "at least one" mentioned herein refers to one or more, and "multiple" refers to two or more. In the description of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not limit them to be necessarily different.

[0115] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A traffic signal, characterized in that: The traffic signal includes a light control circuit, a current collection circuit and a controller; The power supply end of the light control circuit is used to be connected to the light control power supply, the control end of the light control circuit is connected to the first output end of the controller, the output end of the light control circuit is connected to the target signal light, and the light control circuit is used to be turned on or off according to the signal light operation plan to light up or extinguish the target signal light, and the target signal light is a signal light of any color among traffic lights; The collection end of the current collection circuit is connected to the output end of the light control circuit, the output end of the current collection circuit is connected to the input end of the controller, and the current collection circuit is used to collect the current flowing through the target signal light; Wherein, the controller is used to disconnect the light control circuit after determining that the target signal light fails based on the current collected by the current collection circuit.

2. The traffic signal according to claim 1, characterized in that: The traffic signal also includes a state detection circuit; The power supply end of the state detection circuit is used to be connected to the light control power supply, the control end of the state detection circuit is connected to the second output end of the controller, the output end of the state detection circuit is connected to the target signal light, and the state detection circuit is used to detect the fault state of the target signal light; The controller is further used to control the state detection circuit to be turned on after the light control circuit is disconnected due to a fault in the target signal light, and to determine whether the target signal light has returned to normal through the current collected by the current collection circuit.

3. The traffic signal according to claim 1 or 2, characterized in that: The light control circuit comprises a first switch subcircuit; The input end of the first switch subcircuit is used to connect to the light-controlled power supply, the control end of the first switch subcircuit is connected to the first output end of the controller, and the output end of the first switch subcircuit is connected to the target signal light.

4. The traffic signal according to claim 3, characterized in that: The light control circuit also includes a photoelectric isolation sub-circuit; The photoelectric isolation subcircuit is connected in series between the first output terminal of the controller and the control terminal of the first switch subcircuit, and is used to isolate the high-voltage signal on the first switch subcircuit side from the low-voltage signal on the controller side to prevent the controller from being burned out.

5. The traffic signal according to claim 3, characterized in that: The light control circuit also includes a reverse protection diode; The anode of the anti-reverse protection diode is connected to the output end of the first switch sub-circuit, and the cathode of the anti-reverse protection diode is connected to the target signal light. The anti-reverse protection diode is used to prevent the target signal light side from burning out the first switch sub-circuit due to redundant power caused by incorrect wiring.

6. The traffic signal according to claim 2, characterized in that: The state detection circuit includes a second switch subcircuit and a current limiting resistor; The power supply end of the second switch subcircuit is used to connect to the light-controlled power supply, the control end of the second switch subcircuit is connected to the second output end of the controller, the output end of the second switch subcircuit is connected to one end of the current-limiting resistor, and the other end of the current-limiting resistor is connected to the target signal lamp; The current limiting resistor is used to ensure that the target signal light will not be lit after the second switch sub-circuit is turned on.

7. The traffic signal according to claim 1, characterized in that: The current acquisition circuit includes a current sensing resistor and a current sampling subcircuit; The current sensing resistor is connected in series between the output end of the light control circuit and the target signal light, and the two ends of the current sensing resistor are also respectively connected to the first input end and the second input end of the current sampling subcircuit, and the output end of the current sampling subcircuit is connected to the input end of the controller.

8. The traffic signal according to claim 7, characterized in that: The current sampling subcircuit comprises a first resistor, a second resistor, a first amplifier, a first switch tube and a third resistor, and the first resistor and the second resistor have the same resistance value; One end of the first resistor is connected to one end of the current-sensing resistor, and the other end of the first resistor is connected to the inverting input end of the first amplifier; One end of the second resistor is connected to the other end of the current-sense resistor, and the other end of the second resistor is connected to the non-inverting input end of the first amplifier; The output end of the first amplifier is connected to the control end of the first switch tube, the input end of the first switch tube is connected to the non-inverting input end of the first amplifier, the output end of the first switch tube is respectively connected to one end of the third resistor and the input end of the controller, and the other end of the third resistor is grounded.

9. The traffic signal according to claim 7, characterized in that: The current collection circuit also includes an amplification and conditioning subcircuit; The input end of the amplifying and conditioning subcircuit is connected to the output end of the current sampling subcircuit, the output end of the amplifying and conditioning subcircuit is connected to the input end of the controller, and the amplifying and conditioning subcircuit is used to amplify the output voltage of the current sampling subcircuit.

10. The traffic signal according to claim 9, characterized in that: The amplification and conditioning subcircuit comprises a fourth resistor, a second amplifier, a fifth resistor and a sixth resistor, wherein the resistance of the fourth resistor is equal to the parallel resistance of the fifth resistor and the sixth resistor; One end of the fourth resistor is connected to the output end of the current sampling sub-circuit, and the other end of the fourth resistor is connected to the inverting input end of the second amplifier; One end of the fifth resistor is respectively connected to the non-inverting input terminal of the second amplifier and one end of the sixth resistor, and the other end of the fifth resistor is grounded; The output end of the second amplifier is connected to the other end of the sixth resistor, and the output end of the second amplifier is also connected to the input end of the controller.

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