WO2019085153A1 - Leakage protection circuit for double-ended power led lamp tube - Google Patents

Abstract

A leakage protection circuit for a double-ended power LED lamp tube, comprising a rectification circuit (20) and a main circuit (30), wherein the main circuit (30) comprises a voltage detection circuit (330), a current detection circuit (310) and a logic control module (320); the voltage detection circuit (330) detects a voltage of the main circuit (30); the logic control module (320) compares the magnitude of the voltage of the main circuit (30) and that of a pre-set voltage, and enables an output of the main circuit (30) when the voltage of the main circuit (30) is greater than the pre-set voltage; then, the current detection circuit (310) detects a current of the main circuit (30); and the logic control module (320) compares the magnitude of the current of the main circuit (30) and that of a pre-set current, and disables the output of the main circuit (30) when the current of the main circuit (30) is less than the pre-set current, thereby effectively avoiding the risk of electric shocks, and improving the usage security of a double-ended power LED lamp tube.

Description

Leakage protection circuit for double-ended power LED tube Technical field

The invention relates to the field of LED lamp tubes, in particular to a leakage protection circuit for a double-ended electric LED tube.

Background technique

For the currently-produced (type-A) double-ended incoming LED tube, when one end is connected to the power, the other terminal has a high voltage and a large current, and if it is installed, the human body touches the unwired One end will cause an electric shock to the human body (as shown in Figure 1). Therefore, such lighting fixtures urgently need to design and develop a circuit device for leakage protection.

Therefore, the prior art needs to be improved and improved.

technical problem

The invention mainly provides a leakage protection circuit for a double-ended power LED tube, so as to improve the safety of the double-ended power LED tube.

Technical solution

According to a first aspect, an embodiment provides a leakage protection circuit for a double-ended power LED tube, including a rectifier circuit and a main circuit. The rectifier circuit rectifies the AC power and outputs the same to the main circuit, where the main circuit includes voltage detection. a circuit, a current detecting circuit, and a logic control module;

The voltage detecting circuit detects the voltage of the main circuit; the logic control module compares the voltage of the main circuit with the magnitude of the preset voltage, and when the voltage of the main circuit is greater than the preset voltage, turns on the output of the main circuit; after that, the current detecting circuit The current of the main circuit is detected; the logic control module compares the current of the main circuit with the magnitude of the preset current, and when the current of the main circuit is less than the preset current, the output of the main circuit is turned off.

Beneficial effect

The leakage protection circuit of the double-ended power LED lamp according to the above embodiment comprises a rectifier circuit and a main circuit, wherein the main circuit comprises a voltage detection circuit, a current detection circuit and a logic control module; the voltage detection circuit detects the voltage of the main circuit; The control module compares the voltage of the main circuit with the magnitude of the preset voltage. When the voltage of the main circuit is greater than the preset voltage, it indicates that the main circuit is powered on, and the output of the main circuit is turned on; after that, the current detecting circuit detects the main circuit. The current control module compares the current of the main circuit with the magnitude of the preset current. When the current of the main circuit is less than the preset current, it indicates that an object with a large resistance, such as a person connected to the main circuit, turns off the main The output of the circuit. This effectively protects the human body, avoids the risk of electric shock, and improves the safety of the use of double-ended LED lamps.

DRAWINGS

1 is a schematic view showing a conventional double-ended LED lamp tube connected to a mains at one end and being in contact with a human body at the other end;

2 is a structural block diagram of a leakage protection circuit of a double-ended power LED lamp provided by the present invention;

3 is a circuit diagram of a first embodiment of a leakage protection circuit for a double-ended power LED lamp according to the present invention;

4 is a circuit diagram of a second embodiment of a leakage protection circuit for a double-ended power LED lamp according to the present invention;

5 is a circuit diagram of a third embodiment of a leakage protection circuit for a double-ended power LED lamp according to the present invention;

FIG. 6 is a circuit diagram of a fourth embodiment of a leakage protection circuit for a double-ended power LED tube according to the present invention.

Embodiments of the invention

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings. Similar elements in different embodiments employ associated similar component numbers. In the following embodiments, many of the details are described in order to provide a better understanding of the application. However, those skilled in the art can easily realize that some of the features may be omitted in different situations, or may be replaced by other components, materials, and methods. In some cases, some operations related to the present application have not been shown or described in the specification, in order to avoid that the core portion of the present application is overwhelmed by excessive description, and those skilled in the art will describe these in detail. Related operations are not necessary, they can fully understand the relevant operations according to the description in the manual and the general technical knowledge in the field.

In addition, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be sequentially changed or adjusted in a manner that can be apparent to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of describing a particular embodiment, and are not intended to

The serial numbers themselves for the components herein, such as "first", "second", etc., are only used to distinguish the described objects, and do not have any order or technical meaning. As used herein, "connected" or "coupled", unless otherwise specified, includes both direct and indirect connections (joining).

Referring to FIG. 2 and FIG. 3, the present invention provides a leakage protection circuit for a double-ended power LED tube, comprising a rectifier circuit 20 and a main circuit 30. The AC receiving end 10 is connected to the mains, and the AC power is rectified by the rectifying circuit 20 and output to the main circuit 30.

The main circuit 30 includes a voltage detecting circuit 330, a current detecting circuit 310, a power supply circuit 340, and a logic control module 320. The output end of the rectifying circuit 20 is connected to the logic control module 320 through the current detecting circuit 310 (as shown in FIG. 2), or the current detecting circuit 310 is connected through the logic control module 320. The output end of the rectifying circuit 20 is further connected to the input end of the power supply circuit 340 and the input end of the voltage detecting circuit 330; the output end of the current detecting circuit 310 is connected to the current input end of the logic control module 320; the output end of the power supply circuit 340 is connected to the logic The power input terminal of the control module 320; the output of the voltage detecting circuit 330 is connected to the voltage input terminal of the logic control module 320. The output of the logic control module 320 is coupled to the back end circuit 400.

The power supply circuit 340 is configured to supply power to the logic control module 320 by using the rectified DC power.

The voltage detecting circuit 330 is configured to detect the voltage of the main circuit 30.

The current detecting circuit 310 is configured to detect the current of the main circuit 30.

The logic control module 320 is configured to compare the voltage of the main circuit 30 with a preset voltage, and when the voltage of the main circuit is greater than a preset voltage, turn on the output of the main circuit (ie, the main circuit 30 and the back end) The circuit 400 is turned on; after that, the current detecting circuit 310 is turned on; the current of the main circuit 30 is compared with the magnitude of the preset current, and when the current of the main circuit 30 is less than the preset current, the output of the main circuit 30 is turned off ( That is, the main circuit 30 is disconnected from the back end circuit 400).

It can be seen that the present invention uses the logic control module 320 to determine a specific voltage and current on the main circuit, determine the leakage state of the main circuit according to the specific voltage and current, and then control the switching circuit to form a protection mechanism. This effectively protects the human body, avoids the risk of electric shock, and improves the safety of the use of double-ended LED lamps.

Further, the logic control module 320 includes a logic unit 322 and a switch 321 for controlling the main circuit 30 to be turned on and off. The output end of the logic unit 322 is connected to the control terminal of the switch 321, and the switch 321 is disposed on the main circuit 30. In FIG. 2, the current detecting circuit 310 is connected to the back end circuit 400 through the switch 320.

The logic unit 322 is configured to compare the voltage detected by the voltage detecting circuit 330 with a preset voltage. When the voltage detected by the voltage detecting circuit 330 is less than a preset voltage, the main circuit is turned off by the switch 321 30. When the voltage detected by the voltage detecting circuit 330 is greater than a preset voltage, the main circuit 30 is turned on by the switch 321; the current detected by the current detecting circuit 310 and the magnitude of the preset current are compared at the current. When the current detected by the detecting circuit 310 is less than the preset current, the main circuit 30 is turned off by the switch 321 , and when the current detected by the current detecting circuit 310 is greater than the preset current, the guiding of the main circuit 30 is maintained by the switch 321 through.

Because the double-ended power LED tube is in a normal single-ended power supply, the free terminal voltage is at a high level, and thus a loop cannot be formed in the circuit, and the logic unit 322 first detects whether the voltage in the circuit exceeds a specific value because no loop is formed. The voltage cannot be established, the voltage does not exceed the preset value, the logic unit 322 does not open the switch 321, and the circuit is in a protected state. If there is a connection to the human body, the human body is set to a large resistance. According to the voltage and current set by the detection standard value, the logic unit first determines the integration of the voltage in the circuit, and the circuit works after exceeding the preset value. Then, the logic unit 322 opens the switch 321 in the circuit and detects the current flowing through the main circuit. Below the preset current, it is considered that the human body is connected in the circuit, and the logic unit 322 turns off the protection switch 321 to protect the human body. . The entire circuit control process is as follows:

After the AC mains 10 is rectified by the rectifying circuit 20, a high voltage direct current is formed, and the high voltage direct current supplies power to the power supply circuit 340 in the main circuit 30 to provide sufficient power for the logic unit 322 to be used. After a sufficient power supply voltage is applied to the logic unit 322, the logic unit 322 detects the level of the voltage of the main circuit 30 through the voltage detecting circuit 330 to determine whether to open the high voltage switch 321, and after the voltage detecting circuit 330 meets the ON condition, the logic unit 322 The PWM form turns on the high voltage switch 321 while detecting the total current of the circuit. When the human body touches one end of the LED tube, the current will be too small (less than 5 mA) and will not continue to work. The logic unit 322 considers that it is connected to the human body, judges that the circuit is in error, and directly closes the high voltage switch 321 to complete the protection action. . In the case of normal commercial power supply, the current of the current detecting circuit 310 in the main circuit exceeds 5 mA and continues to work. When the logic unit 322 determines that the system is normal, the high voltage switch 321 is turned on, and the system works normally.

It can be seen that the present invention provides effective protection measures without significantly increasing the cost of the circuit. Type-A lamps often have double-ended wiring in actual operation. After connecting the leakage protection circuit device, the safety of the product can be improved, and the human body can be effectively protected from electric shock during construction and the loss of life and property can be reduced.

The preset voltage and the preset current are set according to actual working conditions or parameters of the LED tube. For example, the preset voltage is set to 60V, and the preset current is 5mA or 10mA.

The logic control module 320 includes a chip, and the chip can be selected from a single chip microcomputer, such as a PIC16F1823 chip. The switch 321 is a high voltage switch.

First embodiment:

As shown in FIG. 3, in the embodiment, the rectifier circuit 20 includes a rectifier bridge; there is no X capacitor between the rectifier bridge and the neutral line N and the live line L to avoid voltage crosstalk. The power supply circuit 340 includes a first diode D1, a first resistor R1 and a second resistor R2; the voltage detecting circuit 330 includes a third resistor R3, a first capacitor C1 and a first Zener diode D2; the logic control module 320 includes a first chip U1; the current detecting circuit 310 includes a sixth resistor R6 and a seventh resistor R7; the leakage protection circuit further includes a first transistor Q1 (this embodiment uses a MOS transistor to function as a switch), and a fourth The resistor R4, the fifth resistor R5, the second diode D4, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the second Zener diode D3 and the second capacitor C2.

The first end a of the rectifier bridge is connected to the anode of the first diode D1, the anode of the first diode D1 is the first output end of the leakage protection circuit; the second output end of the leakage protection circuit is grounded; The anode of the pole D1 is connected to one end of the second resistor R2 through the first resistor R1, and the other end of the second resistor R2 is connected to one end of the third resistor R3 and the VCC end of the first chip U1; the other end of the third resistor R3 is connected a V-terminal of the chip U1, one end of the fourth resistor R4, a cathode of the first Zener diode D2, and one end of the first capacitor C1; the other end of the first capacitor C1 and the anode of the first Zener diode D2 are grounded; The other end of the fourth resistor R4 is connected to the first pole of the first transistor Q1, the second pole of the first transistor Q1 is grounded, and the control electrode of the first transistor Q1 is connected to the OUT terminal of the first chip U1 through the fifth resistor R5; the first chip The V+ end of U1 is connected to one end of the eighth resistor R8, one end of the ninth resistor R9, the cathode of the second Zener diode D3, one end of the second capacitor C2, and one end of the tenth resistor R10; the anode of the second Zener diode D3 The other end of the second capacitor C2 and the other end of the tenth resistor R10 The other end of the ninth resistor R9 is connected to the VCC end of the first chip U1; the other end of the eighth resistor R8 is connected to the cathode of the second diode D4; the anode of the second diode D4 is connected to the first chip U1 The CS terminal is connected to the second end b of the rectifier bridge through a sixth resistor R6 and a seventh resistor R7, respectively.

The power supply circuit 340 further includes two filter capacitors. One end of the two filter capacitors is connected to the VCC end of the first chip U1 and the other end of the second resistor R2. The other ends of the two filter capacitors are grounded.

Second embodiment:

As shown in FIG. 4, in the embodiment, the leakage protection circuit further includes an eleventh resistor R11 and a twelfth resistor R12; the rectifier circuit 20 includes a rectifier bridge; and the current detecting circuit 310 includes a thirteenth resistor R13 and the fourteenth resistor R14; the power supply circuit 340 includes a third capacitor C3; the voltage detecting circuit 330 includes a fifteenth resistor R15, a sixteenth resistor R16 and a seventeenth resistor R17; the switch 321 is a second transistor Q2 (this embodiment uses a MOS transistor); the logic unit 322 includes a second chip U2.

The first end a of the rectifier bridge is connected to one end of the eleventh resistor R11, one end of the eleventh resistor R11 is a first output end of the leakage protection circuit; and the other end of the eleventh resistor R11 is connected by a twelfth resistor R12 The first end of the second chip U2; the fifth end and the sixth end of the second chip U2 are respectively connected to the second end b of the rectifier bridge through the thirteenth resistor R13 and the fourteenth resistor R14; the second chip U2 7 is connected to the control electrode of the second transistor Q2, the second output terminal of the first extremely leakage protection circuit of the second transistor Q2; the second terminal of the second transistor Q2 is connected to the second end b of the rectifier bridge; the second chip U2 The fourth end is connected to the second end b of the rectifier bridge; the second end of the second chip U2 is grounded through the third capacitor C3; one end of the fifteenth resistor R15 is connected to the neutral line, and the other end of the fifteenth resistor R15 is passed the sixteenth The resistor R16 is connected to the third end of the second chip U2 and one end of the seventeenth resistor R17, and the other end of the seventeenth resistor R17 is grounded.

Third embodiment:

As shown in FIG. 5, this embodiment integrates the transistor Q2 of the second embodiment into the chip U2. In other words, the leakage protection circuit further includes an eighteenth resistor R18 and a nineteenth resistor R19; the rectifier circuit 20 includes a rectifier bridge; and the current detection circuit 310 includes a twentieth resistor R20 and a twenty-first a resistor R21; the power supply circuit 340 includes a fourth capacitor C4; the voltage detecting circuit 330 includes a twenty-second resistor R22, a twenty-third resistor R23 and a twenty-fourth resistor R24; the logic control module includes a third chip U3 .

The first end a of the rectifier bridge is connected to one end of the eighteenth resistor R18, one end of the eighteenth resistor R18 is the first output end of the leakage protection circuit; the other end of the eighteenth resistor R18 is connected by the nineteenth resistor R19 The eighth end of the third chip U3; the first end of the third chip U3 is connected to the second end b of the rectifier bridge through the twentieth resistor R20 and the twenty-first resistor R21, respectively; the fourth end of the third chip U3 is leakage a second output end of the protection circuit; a second end of the third chip U3 is grounded through a fourth capacitor C4; one end of the twenty-second resistor R22 is connected to the neutral line, and the other end of the twenty-second resistor R22 is passed through the twenty-third resistor R23 is connected to the sixth end of the third chip U3 and one end of the twenty-fourth resistor R24, and the other end of the twenty-fourth resistor R24 is grounded.

Fourth embodiment:

As shown in FIG. 6, in the embodiment, the power supply circuit 340 includes a twenty-fifth resistor R25, a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, and a twenty-ninth resistor. R29, a third Zener diode D5, a fourth Zener diode D6, a fifth capacitor C5, and a third transistor Q3 (the present embodiment employs a triode); the voltage detecting circuit 310 includes a thirtieth resistor R30; the logic unit 322 includes a fourth chip U4 and a sixth capacitor C6; the current detecting circuit 310 includes a thirty-first resistor R31 and a thirty-second resistor R32; and the switch 321 includes a fourth transistor Q4 (the MOS transistor is used in this embodiment) The leakage protection circuit further includes a thirty-third electron R33, a thirty-fourth electron R34, a sixth capacitor C6, and a seventh capacitor C7.

One end of the twenty-fifth resistor R25 is a first output end of the leakage protection circuit, and is connected to the first end a of the rectifier bridge, and the other end of the twenty-fifth resistor R25 is connected to the third voltage regulator through the second sixteen resistor R26. a cathode of the diode D5, one end of the fifth capacitor C5, one end of the twenty-seventh resistor R27, and a first end of the fourth chip U4; a second end b of the rectifier bridge, a positive pole of the third Zener diode D5, and a fifth capacitor The other end of the C5 is grounded; the other end of the twenty-seventh resistor R27 is connected to the negative terminal of the fourth Zener diode D6, and is connected to the control electrode of the third transistor Q3 through the twenty-eighth resistor R28; the fourth Zener diode D6 The positive pole is grounded; the first pole of the third transistor Q3 is connected to the fourth end of the fourth chip U4, and is grounded through the twenty-ninth resistor R29; the second pole of the third transistor Q3 is connected to one end of the sixth capacitor C6 and the thirtyth One end of the resistor R30; the fifth end of the fourth chip U4 and the other end of the sixth capacitor C6 are grounded; the other end of the thirtieth resistor R30 is connected to one end of the sixth capacitor C6 and the sixth end of the fourth chip U4; The other end of the capacitor C6 is grounded; the eighth end of the fourth chip U4 passes the thirty-third power The sub-R33 is connected to the control electrode of the fourth transistor Q4 and one end of the thirty-fourth electron R34; the second output terminal of the first extremely leakage protection circuit of the fourth transistor Q4, and the second electrode of the fourth transistor Q4 is connected to the fourth chip U4 The second end of the second capacitor and the seventh capacitor C7 are grounded through the thirty-first resistor R31 and the thirty-second resistor R32. The other end of the seventh capacitor C7 and the other end of the thirty-fourth electron R34 are grounded.

The invention has been described above with reference to specific examples, which are merely intended to aid the understanding of the invention and are not intended to limit the invention. Variations to the above-described embodiments may be made in accordance with the teachings of the present invention.

Claims (10)

A leakage protection circuit for a double-ended power LED lamp comprises a rectifier circuit and a main circuit, and the rectifier circuit rectifies the AC power and outputs the same to the main circuit, wherein the main circuit comprises a voltage detection circuit, a current detection circuit and a logic Control module The voltage detecting circuit detects the voltage of the main circuit; the logic control module compares the voltage of the main circuit with the magnitude of the preset voltage, and when the voltage of the main circuit is greater than the preset voltage, turns on the output of the main circuit; after that, the current detecting circuit The current of the main circuit is detected; the logic control module compares the current of the main circuit with the magnitude of the preset current, and when the current of the main circuit is less than the preset current, the output of the main circuit is turned off. A leakage protection circuit for a double-ended power LED lamp according to claim 1, wherein said logic control module comprises a logic unit and a switch for controlling the on/off of the main circuit; and the logic unit compares said voltage detection circuit The detected voltage and the magnitude of the preset voltage, when the voltage detected by the voltage detecting circuit is less than a preset voltage, the main circuit is turned off by the switch, and when the voltage detected by the voltage detecting circuit is greater than a preset voltage, The switch turns on the main circuit; compares the current detected by the current detecting circuit with the magnitude of the preset current, and when the current detected by the current detecting circuit is less than the preset current, turns off the main circuit through the switch, When the current detected by the current detecting circuit is greater than the preset current, the conduction of the main circuit is maintained by the switch. The leakage protection circuit for a double-ended power LED tube according to claim 1, wherein the main circuit further comprises a power supply circuit for supplying power to the logic control module by using the rectified direct current. The leakage protection circuit for a double-ended power LED lamp according to claim 3, wherein the output end of the rectifier circuit is connected to the logic control module through a current detecting circuit, or is connected to the current detecting circuit through a logic control module; The output end of the rectifier circuit is further connected to the input end of the power supply circuit and the input end of the voltage detecting circuit; the output end of the current detecting circuit is connected to the current input end of the logic control module; the output end of the power supply circuit is connected to the power input end of the logic control module; The output of the voltage detection circuit is connected to the voltage input of the logic control module. The leakage protection circuit for a double-ended power LED tube according to claim 1 or 2, wherein the preset current is 5 mA or 10 mA. The leakage protection circuit for a double-ended power LED tube according to claim 1 or 2, wherein the logic control module comprises a chip. A leakage protection circuit for a double-ended power LED lamp according to claim 1, wherein said rectifier circuit comprises a rectifier bridge; said power supply circuit comprises a first diode, a first resistor and a second resistor; The voltage detecting circuit includes a third resistor, a first capacitor and a first Zener diode; the logic control module includes a first chip; the current detecting circuit includes a sixth resistor and a seventh resistor; and the leakage protection circuit further includes a transistor, a fourth resistor, a fifth resistor, a second diode, an eighth resistor, a ninth resistor, a tenth resistor, a second Zener diode, and a second capacitor; The first end of the rectifier bridge is connected to the anode of the first diode, and the anode of the first diode is the output end of the leakage protection circuit; the cathode of the first diode is connected to one end of the second resistor through the first resistor, The other end of the second resistor is connected to one end of the third resistor and the VCC end of the first chip; the other end of the third resistor is connected to the V- terminal of the first chip, one end of the fourth resistor, the cathode of the first Zener diode, and the first One end of a capacitor; the other end of the first capacitor and the anode of the first Zener diode are grounded; the other end of the fourth resistor is connected to the first pole of the first transistor, the second pole of the first transistor is grounded, and the control of the first transistor The pole is connected to the OUT end of the first chip through the fifth resistor; the V+ end of the first chip is connected to one end of the eighth resistor, one end of the ninth resistor, the cathode of the second Zener diode, one end of the second capacitor, and the tenth resistor One end; the positive pole of the second Zener diode, the other end of the second capacitor, and the other end of the tenth resistor are grounded; the other end of the ninth resistor is connected to the VCC end of the first chip; the other end of the eighth resistor is connected to the second second Polar tube The anode of the second diode is connected to the CS terminal of the first chip, and is connected to the second end of the rectifier bridge through a sixth resistor and a seventh resistor, respectively. A leakage protection circuit for a double-ended power LED lamp according to claim 2, wherein said leakage protection circuit further comprises an eleventh resistor and a twelfth resistor; said rectifier circuit comprises a rectifier bridge; The current detecting circuit includes a thirteenth resistor and a fourteenth resistor; the power supply circuit includes a third capacitor; the voltage detecting circuit includes a fifteenth resistor, a sixteenth resistor and a seventeenth resistor; the switch is a second transistor; The logic unit includes a second chip; The first end of the rectifier bridge is connected to one end of the eleventh resistor, one end of the eleventh resistor is a first output end of the leakage protection circuit; and the other end of the eleventh resistor is connected to the second chip by a twelfth resistor 1st end; the 5th end and the 6th end of the second chip are respectively connected to the second end of the rectifier bridge through the thirteenth resistor and the fourteenth resistor; the seventh end of the second chip is connected to the control pole of the second transistor, a second output terminal of the first extremely leakage protection circuit of the second transistor; a second electrode of the second transistor is connected to the second end of the rectifier bridge; a fourth end of the second chip is connected to the second end of the rectifier bridge; The second end is grounded through the third capacitor; one end of the fifteenth resistor is connected to the neutral line, and the other end of the fifteenth resistor is connected to the third end of the second chip and one end of the seventeenth resistor through the sixteenth resistor, the seventeenth resistor The other end is grounded. A leakage protection circuit for a double-ended power LED lamp according to claim 1, wherein said leakage protection circuit further comprises an eighteenth resistor and a nineteenth resistor; said rectifier circuit comprises a rectifier bridge; The current detecting circuit includes a twentieth resistor and a twenty-first resistor; the power supply circuit includes a fourth capacitor; the voltage detecting circuit includes a twenty-second resistor, a twenty-third resistor, and a twenty-fourth resistor; the logic control The module includes a third chip; The first end of the rectifier bridge is connected to one end of the eighteenth resistor, one end of the eighteenth resistor is a first output end of the leakage protection circuit; and the other end of the eighteenth resistor is connected to the third chip by a nineteenth resistor 8th end; the first end of the third chip is connected to the second end of the rectifier bridge through the twentieth resistor and the twenty-first resistor respectively; the fourth end of the third chip is the second output end of the leakage protection circuit; the third chip The second end is grounded through the fourth capacitor; one end of the twenty-second resistor is connected to the neutral line, and the other end of the twenty-second resistor is connected to the sixth end of the third chip and the twenty-fourth resistor through the twenty-third resistor At one end, the other end of the twenty-fourth resistor is grounded. The leakage protection circuit for a double-ended power LED tube according to claim 2, wherein the power supply circuit comprises a twenty-fifth resistor, a twenty-sixth resistor, a twenty-seventh resistor, and a twenty-eighth a resistor, a twenty-ninth resistor, a third Zener diode, a fourth Zener diode, a fifth capacitor, and a third transistor; the voltage detecting circuit includes a thirtieth resistor; the logic unit includes a fourth chip and a sixth a capacitor; the current detecting circuit includes a thirty-first resistor and a thirty-second resistor; the switch includes a fourth transistor; One end of the twenty-fifth resistor is a first output end of the leakage protection circuit, and is connected to the first end of the rectifier bridge, and the other end of the twenty-fifth resistor is connected to the cathode of the third Zener diode through a second sixteen resistor, One end of the fifth capacitor, one end of the twenty-seventh resistor, and the first end of the fourth chip; the second end of the rectifier bridge, the anode of the third Zener diode, and the other end of the fifth capacitor are grounded; The other end of the resistor is connected to the negative pole of the fourth Zener diode, and is connected to the control pole of the third transistor through the twenty-eighth resistor; the anode of the fourth Zener diode is grounded; the first pole of the third transistor is connected to the fourth chip 4 end, and grounded through the 29th resistor; the second pole of the third transistor is connected to one end of the sixth capacitor and one end of the thirtieth resistor; the fifth end of the fourth chip and the other end of the sixth capacitor are grounded; The other end of the thirty-resistance is connected to the sixth end of the fourth chip; the eighth end of the fourth chip is connected to the control electrode of the fourth transistor, the second output end of the first extremely leakage protection circuit of the fourth transistor, and the fourth transistor Second pole connection The second end of the chip resistor and to ground through the thirty-first and thirty-second resistor.