A lamp leakage protection circuit

Abstract

The utility model discloses a kind of lamp tube electric leakage protection circuit, including power supply circuit, ballast driving circuit, mode detection circuit, LED circuit and ballast switch driving circuit;The output end of power supply circuit is connected with ballast driving circuit and LED circuit respectively, for accessing commercial power or ballast, and provide direct-current power to ballast driving circuit and LED circuit after rectification processing;Ballast driving circuit is connected with ballast switch driving circuit, for the input direct-current power voltage regulation processing is handled, and power supply signal is output to ballast switch driving circuit;Mode detection circuit is connected with the input end of power supply circuit, for detecting the power supply signal of power supply circuit access, and according to power supply signal switch control signal is output to ballast switch driving circuit;Ballast switch driving circuit is connected with LED circuit, for according to power supply signal and switch control signal control the working state of LED circuit. Adopt the utility model, can realize anti-leakage protection.

Description

Technical Field

[0001] This utility model relates to the field of LED technology, and in particular to a lamp leakage protection circuit. Background Technology

[0002] With the widespread use of LED lights, the control requirements for LED tubes are becoming increasingly stringent. Currently, many lighting driver circuits that are compatible with electronic ballasts and mains power have emerged to drive dual-input tubes.

[0003] In the actual installation process of lamp tubes, the operator usually inserts one end of the lamp tube into the lamp holder first, and then inserts the other end. At this time, partial connection may occur. Since the operator's hand needs to hold the end of the lamp tube, if the human body accidentally touches the conductive metal at the end, electric shock may easily occur, affecting operational safety. Therefore, it is particularly important to implement leakage protection for lamp tubes.

[0004] However, current LED lamp circuits primarily rely on a leakage current detection module connected to the power input to detect abnormal current changes and determine the presence of leakage, thus achieving leakage protection. This leakage current detection module typically includes a current detection module (such as a current transformer or sampling resistor), a comparator, and a switching transistor. The comparator compares the current detection signal input from the current detection module with a preset signal and sends the comparison result to the switching transistor to control the lamp circuit's on / off state, or to a processor, which then controls the switching transistor to control the lamp circuit's on / off state. However, this simple current-based method is susceptible to changes in input voltage or external factors affecting current detection accuracy, thus reducing the accuracy of leakage protection control and posing certain safety hazards, resulting in poor safety in use. Furthermore, existing circuits generally only support a single type of ballast to drive the LED lamp, leading to poor compatibility and practicality. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a lamp tube leakage protection circuit that can achieve leakage protection.

[0006] To address the aforementioned technical problems, this utility model provides a lamp leakage protection circuit, comprising a power supply circuit, a ballast drive circuit, a mode detection circuit, an LED circuit, and a ballast switch drive circuit. The output terminal of the power supply circuit is connected to both the ballast drive circuit and the LED circuit, respectively, for connecting to mains power or a ballast, and providing DC power to the ballast drive circuit and the LED circuit after rectification. The ballast drive circuit is connected to the ballast switch drive circuit, for regulating the input DC power supply and outputting a power supply signal to the ballast switch drive circuit. The mode detection circuit is connected to the input terminal of the power supply circuit, for detecting the power supply signal connected to the power supply circuit, and outputting a switch control signal to the ballast switch drive circuit based on the power supply signal. The ballast switch drive circuit is connected to the LED circuit, for controlling the operating state of the LED circuit based on the power supply signal and the switch control signal.

[0007] As an improvement to the above scheme, the ballast switch drive circuit includes a switch module, a conduction control module, and a first switching transistor. The two ends of the switch module are connected to the power supply signal and the first switching transistor, respectively, to control the on / off state of the first switching transistor based on the on / off state of the switch module. The on / off state of the first switching transistor controls the operating state of the LED circuit. The two ends of the conduction control module are connected to the power supply signal and the first switching transistor, respectively, to control the conduction state of the switching transistor based on the conduction state of the conduction control module, thereby controlling the operation of the LED circuit. When the power supply circuit is connected to the ballast, the mode detection circuit is connected to the switch module to send a switch control signal to the switch module based on the voltage difference between the two input terminal groups of the power supply circuit, thereby controlling the on / off state of the switch module. The input terminal group includes two input ports. When there is no voltage difference between the two input terminal groups of the power supply circuit, the power supply signal controls the conduction control module to conduct.

[0008] As an improvement to the above scheme, the pattern detection circuit includes a first detection circuit and a second detection circuit. The switching module includes a second switching transistor connected to the first detection circuit and a third switching transistor connected to the second detection circuit. The first detection circuit is connected to two input ports of the first input terminal group of the power supply circuit, and is used to send a first switching control signal to the second switching transistor according to the voltage difference between the first input terminal groups to control the on / off state of the second switching transistor. The second detection circuit is connected to two input ports of the second input terminal group of the power supply circuit, and is used to send a second switching control signal to the third switching transistor according to the voltage difference between the second input terminal groups to control the on / off state of the third switching transistor. The second switching transistor, the third switching transistor, and the first switching transistor are connected in sequence, and the on / off state of the second switching transistor and the third switching transistor controls the on / off state of the first switching transistor.

[0009] As an improvement to the above solution, the conduction control module includes a Zener diode. The negative terminal of the Zener diode is connected to the power supply signal, and the positive terminal of the Zener diode is connected to the control terminal of the first switching transistor. The two ends of the first switching transistor are connected to the LED circuit and the ground terminal, respectively.

[0010] As an improvement to the above scheme, the two ends of the second switch are connected to the power supply signal and one end of the third switch, respectively, and the other end of the third switch is connected to the control terminal of the first switch. The two ends of the first switch are connected to the LED circuit and the ground terminal, respectively. The control terminal of the second switch is connected to the first detection circuit, and the control terminal of the third switch is connected to the second detection circuit.

[0011] As an improvement to the above scheme, the first detection circuit includes a first optocoupler, the transmitting part of which is connected to two input ports of the first input terminal group, and the receiving part of which is connected to a second switch transistor, for sending a first switch control signal to the second switch transistor according to the voltage difference between the two input ports, so as to control the on / off state of the second switch transistor; the second detection circuit includes a second optocoupler, the transmitting part of which is connected to two input ports of the second input terminal group, and the receiving part of which is connected to a third switch transistor, for sending a second switch control signal to the third switch transistor according to the voltage difference between the two input ports, so as to control the on / off state of the third switch transistor.

[0012] As an improvement to the above solution, the LED circuit includes a constant current drive module and an LED module; when the power supply circuit is connected to the ballast, the constant current drive module does not work; when the power supply circuit is connected to the mains power, the constant current drive module works to drive the LED module to illuminate.

[0013] As an improvement to the above solution, the constant current drive module is equipped with a detection pin, a power supply pin, and an open-drain pin. One end of the LED module and the power supply pin are connected to the output terminal of the power supply circuit; the detection pin is connected to the power supply circuit and is used to detect the current signal of the power supply circuit; the open-drain pin has a built-in switching transistor and is connected to the other end of the LED module. The constant current drive module controls the on / off state of the built-in switching transistor according to the current signal, thereby controlling the on / off state between the constant current drive module and the LED module.

[0014] As an improvement to the above scheme, the ballast drive circuit includes a first resistor module and a second resistor module, each of which includes at least one resistor; the two ends of the first resistor module are respectively connected to the output terminal of the power supply circuit and one end of the second resistor module, and the other end of the second resistor module is connected to the ground terminal; the connection terminal between the first resistor module and the second resistor module is connected to the ballast switch drive circuit, which is used to divide the DC power supply output by the power supply circuit to output a power supply signal to the ballast switch drive circuit.

[0015] As an improvement to the above scheme, the power supply circuit includes a first input terminal group, a second input terminal group, a first rectifier bridge, and a second rectifier bridge. The two input ports of the first input terminal group are respectively connected to the two AC input terminals of the first rectifier bridge, and the two input ports of the second input terminal group are respectively connected to the two AC input terminals of the second rectifier bridge. The first DC output terminal of the first rectifier bridge and the first DC output terminal of the second rectifier bridge are respectively connected to the ballast drive circuit and the LED circuit. The second DC output terminal of the first rectifier bridge and the second DC output terminal of the second rectifier bridge are both connected to the ground terminal. The two input ports of the first input terminal group and the input ports of the second input terminal group are both connected to the mode detection circuit, which is used to control the working state of the mode detection circuit according to the voltage difference between the first input terminal group and the voltage difference between the second input terminal group.

[0016] The beneficial effects of implementing this utility model are as follows:

[0017] This invention, based on a mode detection circuit, a ballast switch drive circuit, and a ballast drive circuit, controls the on / off state of the ballast switch drive circuit according to the power signal input to the power supply circuit, thereby controlling the on / off state of the LED circuit. This provides leakage protection to the circuit connected to the ballast, ensuring excellent safety and protecting the user's personal safety. Furthermore, the ballast switch drive circuit and ballast drive circuit are compatible with other types of ballasts, allowing the circuit to drive the LED circuit normally. This high compatibility and practicality meet diverse user needs.

[0018] Secondly, when connected to mains power, the constant current drive module in the LED circuit works to drive the LED module to illuminate. Moreover, the leakage detection function of the constant current drive module can control the on / off state of the LED module, thus providing leakage protection for the circuit connected to mains power, further improving safety and effectively protecting the personal safety of users. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a lamp leakage protection circuit according to this utility model;

[0020] Figure 2 This is a circuit diagram of a lamp leakage protection circuit according to the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the following will describe this utility model in further detail with reference to the accompanying drawings. It is hereby declared that the terms "up," "down," "left," "right," "front," "back," "inner," and "outer," etc., appearing or about to appear in this document, are based solely on the accompanying drawings and are not intended to specifically limit this utility model.

[0022] like Figures 1 to 2 As shown in the figure, a specific embodiment of this utility model provides a specific structure of a lamp tube leakage protection circuit. The circuit is set in the LED lamp tube and includes a power supply circuit 1, a ballast drive circuit 2, a mode detection circuit 3, an LED circuit 4, and a ballast switch drive circuit 5. The output terminal of the power supply circuit 1 is connected to the ballast drive circuit 2 and the LED circuit 4 respectively, and is used to connect to the mains power or ballast, and provides DC power to the ballast drive circuit 2 and the LED circuit 4 after rectification.

[0023] Ballast drive circuit 2 is connected to ballast switch drive circuit 5, used to regulate the input DC power supply and output a power supply signal to ballast switch drive circuit 5; mode detection circuit 3 is connected to the input terminal of power supply circuit 1, used to detect the power supply signal connected to power supply circuit 1, and output a switch control signal to ballast switch drive circuit 5 according to the power supply signal; ballast switch drive circuit 5 is connected to LED circuit 4, used to control the working state of LED circuit 4 according to the power supply signal and switch control signal. LED circuit 4 includes constant current drive module 41 and LED module 42.

[0024] When power supply circuit 1 is connected to the ballast, based on the electrical characteristics of the ballast, the constant current drive module 41 does not work. The mode detection circuit 3 can output a switch control signal to the ballast switch drive circuit 5 according to the specific power signal detected in power supply circuit 1. At the same time, the input power signal is rectified to provide DC power to LED circuit 4 and ballast drive circuit 2. At this time, ballast drive circuit 2 outputs a power supply signal to ballast switch drive circuit 5 after voltage regulation. Ballast switch drive circuit 5 can control the working state of LED circuit 4 according to the switch control signal and the power supply signal, such as controlling whether LED module 42 in LED circuit 4 works or not. On the one hand, it can drive LED module 42 to work normally. On the other hand, it can disconnect the circuit of LED circuit 4 in time when one end of the LED tube is disconnected from the interface, so as to play a role in preventing leakage current. It has good safety and can protect the personal safety of users.

[0025] When the power supply circuit 1 is connected to the mains power, the constant current drive module 41 works to drive the LED module 42 to illuminate. Moreover, when one end of the LED tube is disconnected from the interface and touched by the user, the leakage detection function of the constant current drive module 41 can control the on / off state of the LED module 42, thereby giving the circuit connected to the mains power a leakage protection function, further improving the safety of use and effectively protecting the personal safety of the user.

[0026] To improve circuit compatibility and accommodate different types of ballasts, the ballast switch drive circuit 5 includes a switch module 51, a conduction control module 52, and a first switching transistor 53. The two ends of the switch module 51 are connected to the power supply signal and the first switching transistor 53, respectively, and are used to control the on / off state of the first switching transistor 53 according to the on / off state of the switch module 51. The on / off state of the first switching transistor 53 controls the working state of the LED circuit 4.

[0027] The two ends of the conduction control module 52 are connected to the power supply signal and the first switching transistor 53, respectively, and are used to control the conduction state of the switching transistor according to the conduction state of the conduction control module 52, thereby controlling the LED circuit 4 to work; wherein, the power supply circuit 1 includes two input terminal groups, and the input terminal groups include two input ports.

[0028] When the power supply circuit 1 is connected to the four-pin ballast, the four pins of the four-pin ballast are connected to the four input ports respectively. The mode detection circuit 3 is connected to the switch module 51 and is used to send a switch control signal to the switch module 51 based on the voltage difference between the two input terminal groups of the power supply circuit 1, so as to control the on / off state of the switch module 51. That is, when a voltage difference is detected in both input terminal groups, the mode detection circuit 3 sends a control switch signal to the switch module 51 to control the switch module 51 to conduct or disconnect, thereby controlling the first switch tube 53 to conduct, and then conducting the circuit of the LED circuit 4, so that the LED module 42 is powered on and illuminates. When one end of the LED tube is disconnected from the interface, there is no voltage difference between any input terminal group. At this time, the mode detection circuit 3 no longer controls the switch module 51 to work, and the switch module 51 is in the off state, thereby disconnecting the circuit of the LED circuit 4. The LED module 42 is de-energized and does not work. Even if the installer touches the electric shock part, it is safe, thus playing a role in preventing leakage current. It has good safety and can protect the personal safety of users.

[0029] When the power supply circuit 1 is connected to the two-pin ballast, the two pins of the two-pin ballast are connected to the two input terminal groups respectively. That is, one pin of the two-pin ballast is connected to the two input ports of one input terminal group, and the two input ports of the input terminal group are equivalent to a short circuit. At this time, there is no voltage difference between the two input terminal groups of the power supply circuit 1, and the mode detection circuit 3 will not detect the relevant voltage difference signal, and the switch module 51 remains in the open state. Since the power supply voltage input to the two-pin ballast is higher than that input to the four-pin ballast, the voltage of the power supply signal output by the two-pin ballast after being stepped down by the ballast drive circuit 2 is also higher than that of the power supply signal when the four-pin ballast is connected. The conduction voltage of the set conduction control module 52 is higher than that of the power supply signal when the four-pin ballast is connected but lower than that of the power supply signal when the two-pin ballast is connected. That is, the conduction control module 52 will only conduct when the two-pin ballast is connected, so the first switch tube 53 conducts. At this time, the loop of the LED circuit 4 is completed, and the LED module 42 can be powered on and illuminated. Therefore, the circuit structure of this utility model is compatible with different types of ballasts and can drive the LED module 42 to power on and work, with high compatibility and practicality.

[0030] It should be noted that the connection method of the live wire and neutral wire of the mains power is the same as that of the two-pin ballast. At this time, there is no voltage difference between the two input terminals, and the switch module 51 is in the open state. However, the power supply voltage of the mains power input is lower than that of the two-pin ballast, that is, the conduction control module 52 is in the open state, and the entire ballast switch drive circuit 5 does not work. Therefore, when connected to mains power, it can only control the LED module 42 for lighting and provide leakage protection by driving the constant current drive module 41.

[0031] Furthermore, the pattern detection circuit 3 includes a first detection circuit 31 and a second detection circuit 32, and the switching module 51 includes a second switching transistor Q2 connected to the first detection circuit 31 and a third switching transistor Q3 connected to the second detection circuit 32.

[0032] The first detection circuit 31 is connected to the two input ports of the first input terminal group 11 of the power supply circuit 1, and is used to send a first switch control signal to the second switch Q2 according to the voltage difference between the first input terminal groups 11, so as to control the on / off state of the second switch Q2; the second detection circuit 32 is connected to the two input ports of the second input terminal group 12 of the power supply circuit 1, and is used to send a second switch control signal to the third switch Q3 according to the voltage difference between the second input terminal groups 12, so as to control the on / off state of the third switch Q3; the second switch Q2, the third switch Q3 and the first switch Q3 are connected in sequence, and the on / off state of the second switch Q2 and the third switch Q3 controls the on / off state of the first switch Q3, thereby controlling the on / off state of the LED circuit 4. When the power supply circuit 1 is connected to the four-pin ballast, the first detection circuit 31 and the second detection circuit 32 control the on / off state of the second switch Q2 and the third switch Q3 respectively, thereby controlling the conduction state of the first switch 53, and then controlling the on / off state of the LED circuit 4. This can control the LED module 42 to work or not work, which can both drive the LED module 42 to illuminate and provide leakage protection.

[0033] Specifically, such as Figure 2 As shown, the power supply circuit 1, ballast drive circuit 2, mode detection circuit 3, LED circuit 4, and ballast switch drive circuit 5 will be described in detail below with reference to specific embodiments:

[0034] I. Power Supply Circuit 1

[0035] The power supply circuit 1 includes a first input terminal group 11, a second input terminal group 12, a first resistor R6, a second resistor RR16, a first capacitor C13, a second capacitor C14, a first rectifier bridge BD1, a second rectifier bridge DB2, a first diode D2, a second diode D3, a third diode D8, and a fourth diode D9.

[0036] The first input port F1 of the first input terminal group 11 is connected to the second input port F2 of the first input terminal group 11 and one end of the first detection circuit 31 via the first resistor R6. The first input port F1 is also connected to the other end of the mode detection circuit 3 via the first capacitor C13. The two AC input terminals of the first rectifier bridge BD1 are connected to the first input port F1 and the second input port F2, respectively. The third input port F3 of the second input terminal group 12 is connected to the fourth input port F4 of the second input terminal group 12 and one end of the second detection circuit 32 via the second resistor R16. The third input port F3 is also connected to the other end of the second detection circuit 32 via the second capacitor C14. The two AC input terminals of the second rectifier bridge DB2 are connected to the third input port F3 and the fourth input port F4, respectively. The first detection circuit 31 and the second detection circuit 32 are used to control the operating state of the mode detection circuit 3 based on the voltage difference between the first input terminal groups 11 and the voltage difference between the second input terminal groups 12.

[0037] The first DC output terminal of the first rectifier bridge BD1 and the first DC output terminal of the second rectifier bridge DB2 are respectively connected to the ballast drive circuit 2 and the LED circuit 4 to provide DC power to the ballast drive circuit 2; the second DC output terminal of the first rectifier bridge BD1 and the second DC output terminal of the second rectifier bridge DB2 are both connected to the ground terminal.

[0038] The first input port F1 is also connected to the negative terminals of the first diode D2, the second diode D3, the third diode D8, and the fourth diode D9 via a forward-biased diode. The second input port F2 is also connected to the negative terminals of the third diode D8 and the fourth diode D9 via a forward-biased diode D3. The third input port F3 is connected to the positive terminal of the third diode D8. The fourth input port F4 is connected to the positive terminal of the fourth diode D9. The connection between the negative terminals of the third diode D8 and the fourth diode D9 is connected to the LED circuit 4.

[0039] It should be noted that the power supply circuit 1 can provide the required power signal to the ballast drive circuit 2, LED circuit 4 and mode detection circuit 3 to ensure that each circuit can work stably when connected to mains power or a ballast.

[0040] II. Ballast drive circuit 2

[0041] The ballast drive circuit 2 includes a first resistor module and a third capacitor of a second resistor module. The first resistor module includes a third resistor R1 and a fourth resistor R2, and the second resistor module includes a fifth resistor R5.

[0042] The two ends of the first resistor module are respectively connected to the output terminal of the power supply circuit 1 and one end of the second resistor module, and the other end of the second resistor module is connected to the ground terminal; the connection terminal between the first resistor module and the second resistor module is connected to the ballast switch drive circuit 5, which is used to divide the DC power output from the power supply circuit 1 to output a power supply signal to the ballast switch drive circuit 5; the connection terminal between the first resistor module and the second resistor module is also connected to the ground terminal through the third capacitor.

[0043] It should be noted that the ballast drive circuit 2 forms a voltage divider circuit structure through the first resistor module and the second resistor module. The voltage divider point in this voltage divider circuit structure is used to send the voltage-divided power supply signal to the ballast switch drive circuit 5 so that the ballast switch drive circuit 5 can realize the corresponding control function based on the power supply signal.

[0044] III. Pattern Detection Circuit 3

[0045] The pattern detection circuit 3 includes a first detection circuit 31 and a second detection circuit 32. The first detection circuit 31 includes a third rectifier bridge BD3, a first optocoupler U1, a fourth capacitor C6, a sixth resistor R12 and a seventh resistor R10.

[0046] The two AC input terminals of the third rectifier bridge BD3 are respectively connected to the two input ports (F1 and F2) of the first input terminal group 11. The first DC output terminal of the third rectifier bridge BD3 is connected to the positive terminal of the transmitter of the first optocoupler U1 via the seventh resistor R10. The first DC output terminal of the third rectifier bridge BD3 is also connected to one end of the fourth capacitor C6 and one end of the sixth resistor R12. The second DC output terminal of the third rectifier bridge BD3 is connected to the other end of the fourth capacitor C6, the other end of the sixth resistor R12, and the negative terminal of the transmitter of the first optocoupler U1. The two terminals of the receiver of the first optocoupler U1 are respectively connected to the control terminal and the ground terminal of the second switch Q2, which are used to send a first switch control signal to the second switch Q2 according to the voltage difference between the two input ports (F1 and F2) to control the on / off state of the second switch Q2.

[0047] The second detection circuit 32 includes a fourth rectifier bridge BD4, a second optocoupler U3, a fifth capacitor C11, an eighth resistor R22, and a ninth resistor R21;

[0048] The two AC input terminals of the fourth rectifier bridge BD4 are respectively connected to the two input ports (F3 and F4) of the second input terminal group 12. The first DC output terminal of the fourth rectifier bridge BD4 is connected to the positive terminal of the transmitter of the second optocoupler U3 via the ninth resistor R21. The first DC output terminal of the fourth rectifier bridge BD4 is also connected to one end of the fifth capacitor C11 and one end of the eighth resistor R22. The second DC output terminal of the third rectifier bridge BD3 is connected to the other end of the fifth capacitor C11, the other end of the eighth resistor R22, and the negative terminal of the transmitter of the second optocoupler U3. The two terminals of the receiver of the second optocoupler U3 are respectively connected to the control terminal and the ground terminal of the third switch Q3, and are used to send a second switch control signal to the second switch Q2 according to the voltage difference between the two input ports (F3 and F4) to control the on / off state of the third switch Q3.

[0049] The second switch Q2, the third switch Q3 and the first switch 53 are connected in sequence, and the on / off state of the second switch Q2 and the third switch Q3 controls the on / off state of the first switch 53.

[0050] It should be noted that when a voltage difference exists in the first input terminal group 11, the transmitter of the first optocoupler U1 is turned on, current flows through the transmitter, and a signal is transmitted to control the receiver to turn on. At this time, the voltage at the control terminal of the second switch Q2 is pulled to ground, which is equivalent to the first optocoupler U1 sending a low-level first switch control signal to control the second switch Q2 to turn on. Similarly, when a voltage difference exists in the second input terminal group 12, the second optocoupler U3 sends a low-level second switch control signal to control the third switch Q3 to turn on, thereby turning on the first switch 53, completing the circuit of the LED circuit 4, and powering on the LED module 42. Correspondingly, when there is no voltage difference in either input terminal group, the first switch 53 is turned off and the circuit of the LED circuit 4 is broken, the LED module 42 is powered off, and leakage protection is provided.

[0051] IV. LED Circuit 4

[0052] LED circuit 4 includes a constant current drive module 41 and an LED module 42. The LED module 42 includes multiple light-emitting diodes connected in series.

[0053] The constant current drive module 41 includes a constant current drive chip U1, a first inductor L1, a first transformer coil T1, a fifth diode D7, a TVS diode TVS1, a first polarized capacitor CE1, a sixth capacitor C3, a seventh capacitor C4, an eighth capacitor C5, a ninth capacitor C7, a tenth capacitor C9, an eleventh capacitor C10, a tenth resistor R7, an eleventh resistor R8, a twelfth resistor R9, a thirteenth resistor R11, a fourteenth resistor R13, a fifteenth resistor R14, a sixteenth resistor R15, a seventeenth resistor R17, an eighteenth resistor R18, and a varistor RV1, wherein:

[0054] The open-drain pin DRA IN of the constant current drive chip U1 is connected to the negative terminal of the LED module 42 through the first transformer coil T1; the open-drain pin DRA IN is also connected to the positive terminal of the fifth diode D7 through the ninth capacitor C9, and the negative terminal of the fifth diode D7 is connected to the positive terminal of the LED module 42; the compile pin I SP is connected to the ground terminal through the seventeenth resistor R17 and the eighteenth resistor R18 respectively; the power supply pin VCC is connected to the ground terminal through the eighth capacitor C5; the ground pin GND is connected to the ground terminal; the detection pin REC is connected to the power supply circuit 1 through the fifteenth resistor R14 and the fourteenth resistor R13 in sequence, and is connected to the ground terminal through the TVS diode TVS1 and the sixteenth resistor R15 respectively; the power supply pin VI N is connected to the positive terminal of the LED module 42 through the eleventh resistor R8;

[0055] One end of the tenth capacitor C10 is connected to the ground terminal, and the other end is connected to the negative terminal of the ballast switch drive circuit 5 and the LED module 42 respectively; one end of the twelfth resistor R9 is connected to the positive terminal of the LED module 42, and the other end is connected to the open-drain pin DRAI N through the seventh capacitor C7; one end of the first polarized capacitor CE1 is connected to the positive terminal of the LED module 42, and the other end is connected to the negative terminal of the LED module 42; the thirteenth resistor R11 is connected in parallel with the first polarized capacitor CE1.

[0056] One end of the varistor RV1 is connected to the positive terminal of the LED module 42, and the other end is connected to the ground terminal; one end of the sixth capacitor C3 is connected to the power supply circuit 1, and the other end is connected to the ground terminal; one end of the seventh capacitor C4 is connected to the positive terminal of the LED module 42, and the other end is connected to the ground terminal; one end of the first inductor L1 is connected to the power supply circuit 1, and the other end is connected to the positive terminal of the LED module 42; the tenth resistor R7 is connected in parallel with the first inductor L1.

[0057] Therefore, when connected to mains power, the first switch 53 is not turned on, and the power supply circuit 1 supplies power to the constant current drive chip U1 and the LED module 42. The constant current drive chip U1 drives the LED module 42 with constant current to ensure that the LED module 42 can be used normally.

[0058] It should be noted that the open-drain pin has a built-in switching transistor. The detection pin REC of the constant current driver chip U1 has an input current detection function; when the input current is greater than 72mA, the constant current driver chip U1 turns on the built-in switching transistor of the open-drain pin DRAIN, which can drive the LED module 42 to illuminate; when the input current is less than 72mA, the constant current driver chip U1 turns off the built-in switching transistor of the open-drain pin DRAIN, the circuit of the LED module 42 is broken, and the LED module 42 does not work. Preferably, the constant current driver chip U1 can be JW1830, JW1831, JW1832 or other similar solutions, but this is not a limitation.

[0059] Therefore, when connected to mains power, the live wire is connected to the first input terminal group 11, and the neutral wire is connected to the second input terminal group 12, or the live wire is connected to the second input terminal group 12, and the neutral wire is connected to the first input terminal group 11. Regardless of the method, there are two power input terminals. When one power input terminal is disconnected and comes into contact with a person, because the person's internal resistance is greater than 500Ω, a resistor is connected to the detection pin REC of the constant current drive chip U1. This reduces the current in the detection pin REC, changing it from a state greater than 72mA to less than 72mA. At this time, the built-in switch of the open-drain pin DRAI N closes, cutting off the LED circuit and providing leakage protection.

[0060] V. Ballast Switch Drive Circuit

[0061] The ballast switch drive circuit 5 includes a twelfth capacitor C12, a nineteenth resistor R24, a twentieth resistor R25, a twenty-first resistor R32, a twenty-second resistor R30, a twenty-third resistor R33, a switch module 51, a conduction control module 52, and a first switching transistor 53. The conduction control module 52 includes a Zener diode ZD1. The switch module 51 includes a second switching transistor Q2 connected to the first detection circuit 31 and a third switching transistor Q3 connected to the second detection circuit 32. The first switching transistor 53 is preferably a bidirectional thyristor, but this is not a limitation.

[0062] One end of the second switch Q2 is connected to the power supply signal and is connected to the control terminal of the second switch Q2 via the nineteenth resistor R24. The control terminal of the second switch Q2 is connected to the output terminal of the first detection circuit 31 to control its own on / off state according to the first switch control signal. The other end of the second switch Q2 is connected to one end of the third switch and is connected to the control terminal of the third switch Q3 via the twentieth resistor R25. The control terminal of the third switch is connected to the output terminal of the second detection circuit 32 to control its own on / off state according to the second switch control signal. The other end of the third switch Q3 is connected to the control terminal of the first switch Q3 and one end of the twenty-third resistor R33 via the twenty-second resistor R30. The other end of the third switch Q3 is also connected to the ground terminal via the twenty-first resistor R32 and the twelfth capacitor C12. The other end of the twenty-third resistor R33 is connected to the ground terminal.

[0063] The negative terminal of Zener diode ZD1 is connected to the power supply signal, and the positive terminal of Zener diode ZD1 is connected to the control terminal of the first switching transistor 53 via the 22nd resistor R30. The two ends of the first switching transistor 53 are respectively connected to the negative terminal and the ground terminal of the LED module 42 in the LED circuit 4.

[0064] It should be noted that when the power supply circuit 1 is connected to the four-pin ballast, the four pins of the four-pin ballast are connected to the four input ports respectively. There is a voltage difference between the first input terminal group 11 and the second input terminal. At this time, the first detection circuit 31 and the second detection circuit 32 work, and send the first switch control signal and the second switch control signal to control the second switch tube Q2 and the third switch tube Q3 to conduct. After the power supply signal is divided by the resistor, a high-level signal is output to the control terminal of the first switch tube 53, so that the first switch tube 53 conducts. The negative terminal of the LED module 42 is connected to the ground terminal, the circuit of the LED module 42 is completed, and it is powered on to illuminate. When one end of the LED tube is disconnected from the interface, there is no voltage difference between any input terminal group. In this case, the second switch Q2 is turned on and the third switch Q3 is turned off, or the second switch Q2 is turned off and the third switch Q3 is turned on. At this time, the first switch 53 is in the off state, thereby disconnecting the loop of LED circuit 4. LED module 42 is de-energized and does not work. Even if the installer touches the electric shock part, it is safe. This provides a leakage protection function, ensuring excellent safety and protecting the user's personal safety.

[0065] When the power supply circuit 1 is connected to the two-pin ballast, the two pins of the two-pin ballast are connected to the two input terminals respectively. That is, one pin of the two-pin ballast is connected to the two input ports of one input terminal group, and the two input ports of the input terminal group are equivalent to a short circuit. At this time, there is no voltage difference between the two input terminals of the power supply circuit 1, the first detection circuit 31 and the second detection circuit 32 are not working, and the second switch Q2 and the third switch Q3 are in the off state. Since the power supply voltage input to the two-pin ballast is higher than the power supply voltage input to the four-pin ballast, the voltage of the power supply signal output by the two-pin ballast after being stepped down by the ballast drive circuit 2 is also higher than the voltage of the power supply signal when the four-pin ballast is connected. The reverse conduction voltage of the Zener diode ZD1 is set to be higher than the voltage of the power supply signal when the four-pin ballast is connected but lower than the voltage of the power supply signal when the two-pin ballast is connected. That is, the Zener diode ZD1 will only conduct in reverse when the two-pin ballast is connected, so the first switch 53 is turned on. At this time, the loop of the LED circuit 4 is turned on, and the LED module 42 can be powered on and illuminated. Therefore, the circuit structure of this utility model is compatible with different types of ballasts and can drive the LED module 42 to power on and work, with high compatibility and practicality.

[0066] In summary, this utility model, based on the configured mode detection circuit, ballast switch drive circuit, and ballast drive circuit, can control the on / off state of the ballast switch drive circuit according to the power signal input to the power supply circuit, thereby controlling the on / off state of the LED circuit. This provides the circuit connected to the ballast with leakage protection, ensuring excellent safety and protecting the user's personal safety. Furthermore, the configured ballast switch drive circuit and ballast drive circuit are compatible with other types of ballasts, allowing the circuit to drive the LED circuit normally. This high compatibility and practicality meet diverse user needs.

[0067] Secondly, when connected to mains power, the constant current drive module in the LED circuit works to drive the LED module to illuminate. Moreover, the leakage detection function of the constant current drive module can control the on / off state of the LED module, thus providing leakage protection for the circuit connected to mains power, further improving safety and effectively protecting the personal safety of users.

[0068] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications are also considered to be within the protection scope of this utility model.

Claims

1. A lamp leakage protection circuit, characterized in that, Includes power supply circuit, ballast drive circuit, mode detection circuit, LED circuit and ballast switch drive circuit; The output terminal of the power supply circuit is connected to the ballast drive circuit and the LED circuit respectively, and is used to connect to the mains power or ballast, and provide DC power to the ballast drive circuit and the LED circuit after rectification. The ballast drive circuit is connected to the ballast switch drive circuit and is used to regulate the input DC power supply and output a power supply signal to the ballast switch drive circuit. The mode detection circuit is connected to the input terminal of the power supply circuit, and is used to detect the power signal connected to the power supply circuit, and output a switch control signal to the ballast switch drive circuit according to the power signal. The ballast switch driving circuit is connected to the LED circuit and is used to control the working state of the LED circuit according to the power supply signal and the switch control signal.

2. The lamp leakage protection circuit as described in claim 1, characterized in that, The ballast switch drive circuit includes a switch module, a conduction control module, and a first switch transistor; The two ends of the switching module are respectively connected to the power supply signal and the first switching transistor, and are used to control the on / off state of the first switching transistor according to the on / off state of the switching module, and the on / off state of the first switching transistor controls the working state of the LED circuit. The two ends of the conduction control module are respectively connected to the power supply signal and the first switching transistor, and are used to control the conduction state of the switching transistor according to the conduction state of the conduction control module, thereby controlling the operation of the LED circuit; When the power supply circuit is connected to the ballast, the mode detection circuit is connected to the switch module and is used to send a switch control signal to the switch module according to the voltage difference between the two input terminal groups of the power supply circuit, so as to control the on / off state of the switch module. The input terminal group includes two input ports. When there is no voltage difference between the two input terminal groups of the power supply circuit, the power supply signal controls the conduction control module to conduct.

3. A lamp leakage protection circuit as described in claim 2, characterized in that, The pattern detection circuit includes a first detection circuit and a second detection circuit, and the switching module includes a second switching transistor connected to the first detection circuit and a third switching transistor connected to the second detection circuit. The first detection circuit is connected to two input ports of the first input terminal group of the power supply circuit, and is used to send a first switching control signal to the second switching transistor according to the voltage difference between the first input terminal groups, so as to control the on and off state of the second switching transistor. The second detection circuit is connected to the two input ports of the second input terminal group of the power supply circuit, and is used to send a second switching control signal to the third switching transistor according to the voltage difference between the second input terminal groups, so as to control the on and off state of the third switching transistor; The second switch, the third switch, and the first switch are connected in sequence, and the on / off state of the second switch and the third switch controls the on / off state of the first switch.

4. A lamp leakage protection circuit as described in claim 2, characterized in that, The conduction control module includes a Zener diode, the negative terminal of which is connected to the power supply signal, and the positive terminal of which is connected to the control terminal of the first switching transistor. The two ends of the first switching transistor are respectively connected to the LED circuit and the ground terminal.

5. A lamp leakage protection circuit as described in claim 3, characterized in that, The two ends of the second switch are respectively connected to the power supply signal and one end of the third switch, the other end of the third switch is connected to the control terminal of the first switch, and the two ends of the first switch are respectively connected to the LED circuit and the ground terminal. The control terminal of the second switching transistor is connected to the first detection circuit, and the control terminal of the third switching transistor is connected to the second detection circuit.

6. A lamp leakage protection circuit as described in claim 3, characterized in that, The first detection circuit includes a first optocoupler. The transmitting part of the first optocoupler is connected to two input ports of the first input terminal group, and the receiving part of the first optocoupler is connected to the second switching transistor. It is used to send a first switching control signal to the second switching transistor according to the voltage difference between the two input ports to control the on / off state of the second switching transistor. The second detection circuit includes a second optocoupler. The transmitting part of the second optocoupler is connected to two input ports of the second input terminal group, and the receiving part of the second optocoupler is connected to the third switch transistor. The second optocoupler is used to send a second switch control signal to the third switch transistor according to the voltage difference between the two input ports, so as to control the on / off state of the third switch transistor.

7. A lamp leakage protection circuit as described in claim 1, characterized in that, The LED circuit includes a constant current drive module and an LED module; When the power supply circuit is connected to the ballast, the constant current drive module does not work; When the power supply circuit is connected to the mains power, the constant current drive module works to drive the LED module to illuminate.

8. A lamp leakage protection circuit as described in claim 7, characterized in that, The constant current drive module is provided with a detection pin, a power supply pin, and an open-drain pin. One end of the LED module and the power supply pin are connected to the output terminal of the power supply circuit. The detection pin is connected to the power supply circuit and is used to detect the current signal of the power supply circuit; the open-drain pin is equipped with a built-in switching transistor, and the open-drain pin is connected to the other end of the LED module. The constant current drive module controls the on / off state of the built-in switching transistor according to the current signal, thereby controlling the on / off state between the constant current drive module and the LED module.

9. A lamp leakage protection circuit as described in claim 1, characterized in that, The ballast drive circuit includes a first resistor module and a second resistor module, and both the first resistor module and the second resistor module include at least one resistor. The two ends of the first resistor module are respectively connected to the output terminal of the power supply circuit and one end of the second resistor module, and the other end of the second resistor module is connected to the ground terminal; The connection terminal between the first resistor module and the second resistor module is connected to the ballast switch drive circuit, which is used to divide the DC power output from the power supply circuit to output a power supply signal to the ballast switch drive circuit.

10. A lamp leakage protection circuit as described in claim 1, characterized in that, The power supply circuit includes a first input terminal group, a second input terminal group, a first rectifier bridge, and a second rectifier bridge; The two input ports of the first input terminal group are respectively connected to the two AC input terminals of the first rectifier bridge, the two input ports of the second input terminal group are respectively connected to the two AC input terminals of the second rectifier bridge, the first DC output terminal of the first rectifier bridge and the first DC output terminal of the second rectifier bridge are respectively connected to the ballast drive circuit and the LED circuit, and the second DC output terminal of the first rectifier bridge and the second DC output terminal of the second rectifier bridge are both connected to the ground terminal; The two input ports of the first input terminal group and the input ports of the second input terminal group are all connected to the pattern detection circuit, and are used to control the working state of the pattern detection circuit according to the voltage difference between the first input terminal group and the voltage difference between the second input terminal group.

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