Built-in drive LED lamp tube with current input end

Abstract

The invention discloses a built-in driving LED lamp tube with a current input end, the built-in driving LED lamp tube comprises a tube body, a constant current driving circuit and an LED light emitting circuit, the constant current driving circuit and the LED light emitting circuit are both arranged in the tube body, two ends of the tube body are both provided with two lamp feet, the two lamp feet at one end of the tube body are used as two voltage lamp feet for being connected with a mains supply, and the two voltage lamp feet are used for being connected with the mains supply. When the two voltage lamp pins are connected to alternating current voltage of the mains supply, the constant current driving circuit converts the alternating current voltage of the mains supply into direct current to drive the LED light-emitting circuit to emit light, and the two lamp pins at the other end of the tube body serve as two current lamp pins and are used for being connected to direct current for driving the LED light-emitting circuit to emit light. The LED driving circuit has the advantages that the LED driving circuit can be matched with an external power supply with constant power / constant current output, direct current output by the external power supply can be used for driving the LED light emitting circuit to emit light without converting direct current signals output by the external power supply through a constant current driving circuit, and therefore the output characteristic of the external power supply does not need to be compatible with the constant current driving circuit; and the application range is wide.

Description

Technical Field

[0001] The invention relates to an LED lamp tube, and in particular to a built-in driving LED lamp tube with a current input end. Background Art

[0002] The current built-in drive LED lamp tube is a tubular structure, usually including a tube body, a constant current drive circuit and an LED light-emitting circuit. The constant current drive circuit and the LED light-emitting circuit are arranged inside the tube body, and both ends of the tube body have two lamp pins. The current built-in drive LED lamp tube has two voltage access forms: double-end access voltage and single-end access voltage. According to its voltage access form, it is divided into two categories: double-end access lamp tube and single-end access lamp tube. In the double-end access lamp tube, at least one lamp pin at one end of the tube body is used to connect the live wire of the mains, and at least one lamp pin at the other end is used to connect the neutral wire of the mains, while in the single-end access lamp tube, the two lamp pins at one end of the tube body are used to connect the live wire and the neutral wire of the mains respectively, and the two lamp pins at the other end are suspended and not connected to the internal circuit. When the two lamp pins used to connect to the mains in the current built-in drive LED lamp tube are connected to the AC voltage of the mains, the constant current drive circuit converts the AC voltage of the mains connected to the two lamp pins connected to the mains into a DC current to drive the LED light-emitting circuit to emit light.

[0003] Currently, built-in driver LED lamps are usually used in conjunction with other types of external power supplies with constant current or constant power output, such as an external emergency power supply, to form an LED lamp with emergency lighting function.

[0004] When the built-in LED lamp and the external emergency power supply are combined to form an LED lamp with emergency lighting function, the external emergency power supply is arranged outside the built-in LED lamp, and its positive output terminal and negative output terminal are connected to the two lamp pins of the built-in LED lamp for connecting to the mains in a one-to-one correspondence. When the mains is normal, the two lamp pins of the built-in LED lamp for connecting to the mains are connected to the AC voltage of the mains. At this time, the constant current driving circuit converts the AC voltage of the mains connected to the two lamp pins into a DC current to drive the LED light-emitting circuit to emit light, and the built-in LED lamp achieves normal lighting; when the mains is abnormally cut off, the two lamp pins of the built-in LED lamp for connecting to the mains are connected to the DC current provided by the external emergency power supply, and the DC current is converted by the constant current driving circuit to drive the LED light-emitting circuit to emit light, and the built-in LED lamp achieves emergency lighting. The DC current provided by the external emergency power supply is the DC current obtained by converting the electric energy of its internal battery, and the maximum voltage output by the external emergency power supply is equivalent to the AC voltage of the mains.

[0005] Compared with the built-in emergency power supply, the external emergency power supply has the characteristics of large battery capacity, so it has the advantages of large output power and long maintenance time when used for emergency lighting. However, the power output of the external emergency power supply is usually less than the power of the built-in driver LED lamp when it is connected to the AC voltage of the mains. When the built-in driver LED lamp is used for emergency lighting, it is required that the built-in driver LED lamp can automatically reduce its power to be consistent with the power output of the external emergency power supply, so that the built-in driver LED lamp can maintain stable light emission when a lower power is connected.

[0006] Therefore, in practical applications, if there is an external power supply to cooperate with the built-in driver LED lamp tube, in order to utilize the LED light-emitting circuit in the built-in driver LED lamp tube to emit light for emergency lighting, it is necessary to consider whether its output characteristics are compatible with the constant current drive circuit in the built-in driver LED lamp tube. Only when its output characteristics are compatible with the constant current drive circuit in the built-in driver LED lamp tube, can the constant current drive circuit convert its output DC current to power the LED light-emitting circuit and drive the LED light-emitting circuit to emit light stably, which results in a significant limitation on the scope of use of the built-in driver LED lamp tube. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide an external power supply that can cooperate with a constant power / constant current output, and can use the DC current output by the external power supply to drive the LED light-emitting circuit to emit light without converting the DC signal output by the external power supply through a constant current driving circuit. Therefore, the output characteristics of the external power supply do not need to be compatible with the constant current driving circuit, and the LED lamp tube with a built-in drive with a current input terminal has a wide range of use.

[0008] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a built-in drive LED lamp tube with a current input end, including a tube body, a constant current drive circuit and an LED light-emitting circuit, the constant current drive circuit and the LED light-emitting circuit are both arranged inside the tube body, and both ends of the tube body have two lamp pins. The two lamp pins at one end of the tube body are used to connect to the mains, and the two lamp pins are called two voltage lamp pins. When the two voltage lamp pins are connected to the mains AC voltage, the constant current drive circuit converts the mains AC voltage connected to the two voltage lamp pins into a DC current to drive the LED light-emitting circuit to emit light, and the two lamp pins at the other end of the tube body are called two current lamp pins, and the two current lamp pins are used to connect to the DC current that drives the LED light-emitting circuit to emit light.

[0009] A protection circuit is also provided inside the tube body. The constant current drive circuit, the LED light-emitting circuit and the protection circuit are arranged in sequence. The constant current drive circuit is close to two voltage lamp pins, and the protection circuit is close to two current lamp pins. The constant current drive circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal. When the AC voltage of the mains is connected between the first input terminal and the second input terminal, a DC current is output between the positive output terminal and the negative output terminal. The LED light-emitting circuit has a positive pole and a negative pole. When a DC current is connected between the positive pole and the negative pole of the LED light-emitting circuit, the LED light-emitting circuit emits light. The protection circuit is a constant current input terminal protection circuit, which has a first input terminal, a second output terminal, a positive output terminal and a negative output terminal. The protection circuit has multiple protection kinetic energy to avoid the LED lamp tube of the present invention from being electrocuted or damaged during installation. The positive output end of the constant current drive circuit and the positive output end of the protection circuit are both connected to the positive electrode of the LED light-emitting circuit, the negative output end of the constant current drive power supply and the negative output end of the protection circuit are both connected to the negative electrode of the LED light-emitting circuit, the first input end and the second input end of the constant current drive circuit are connected to the two voltage lamp pins one-to-one, and the first input end and the second input end of the protection circuit are connected to the two current lamp pins one-to-one.

[0010] The protection circuit comprises a rectifier bridge stack, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a first diode, a second diode, a first MOS tube and a second MOS tube. The first diode is a voltage-stabilizing diode, the second diode is a rectifier diode, the rectifier bridge stack has two AC input pins, a positive output end and a negative output end, one of the AC input pins of the rectifier bridge stack is the first input end of the protection circuit, the other AC input pin of the rectifier bridge stack is the second input end of the protection circuit, the positive output end of the rectifier bridge stack, one end of the first resistor, one end of the third resistor and the positive electrode of the second diode are connected, and the cathode of the second diode is the protection circuit The positive output end of the protection circuit is connected to the positive output end of the protection circuit, the other end of the first resistor, one end of the second resistor, one end of the first capacitor and the gate of the first MOS tube are connected, the other end of the third resistor, the drain of the first MOS tube, the negative electrode of the first diode, one end of the fourth resistor and the gate of the second MOS tube are connected, the drain of the second MOS tube is the negative output end of the protection circuit, the source of the second MOS tube is connected to one end of the fifth resistor, the other end of the second resistor, the other end of the fourth resistor, the other end of the fifth resistor, the positive electrode of the first diode, the other end of the first capacitor, the source of the first MOS tube and the negative output end of the rectifier bridge stack are connected.

[0011] The constant current drive circuit includes a step-down constant current circuit and an anti-backflow diode that adopts a step-down mode to drive the LED light-emitting circuit to emit light. The anti-backflow diode is a rectifier diode. The step-down constant current circuit has a live wire input end, a neutral wire input end, a positive output end and a negative output end. The live wire input end and the neutral wire input end of the step-down constant current circuit are respectively the first input end and the second input end of the constant current drive circuit. The positive output end of the step-down constant current circuit is connected to the positive electrode of the anti-backflow diode. The cathode of the anti-backflow diode is the positive output end of the constant current drive circuit. The negative output end of the step-down constant current circuit is the negative output end of the constant current drive circuit.

[0012] Compared with the prior art, the advantage of the present invention lies in that the two current lamp pins connected to the other end of the tube body of the lamp tube at a single end are used as current input ends for connecting the DC current that drives the LED light-emitting circuit to emit light. When the two voltage lamp pins are connected to the AC voltage of the mains, the constant current driving circuit converts the AC voltage of the mains into a DC current to drive the LED light-emitting circuit to emit light. When the two current lamp pins are connected to the DC current provided by an external power supply, the DC current drives the LED light-emitting circuit to emit light. Therefore, the built-in driving LED lamp tube with a current input end of the present invention can cooperate with an external power supply with constant power / constant current output. The DC signal output by the external power supply is not converted through the constant current driving circuit, and the DC current output by the external power supply can be used to drive the LED light-emitting circuit to emit light, thereby eliminating the need for the output characteristics of the external power supply to be compatible with the constant current driving circuit, and has a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural diagram of a built-in driver LED lamp tube with a current input terminal of the present invention;

[0014] Figure 2 A circuit diagram of a protection circuit for a built-in LED lamp driver with a current input terminal according to the present invention;

[0015] Figure 3 It is a structural diagram of a constant current driving circuit with a current input terminal and a built-in driving LED lamp tube of the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below with reference to the accompanying drawings.

[0017] Embodiment 1: Figure 1 As shown, a built-in drive LED lamp tube with a current input end includes a tube body, a constant current drive circuit and an LED light-emitting circuit. The constant current drive circuit and the LED light-emitting circuit are both arranged inside the tube body. Both ends of the tube body have two lamp pins. The two lamp pins at one end of the tube body are used to connect to the mains. The two lamp pins are called two voltage lamp pins. When the two voltage lamp pins are connected to the mains AC voltage, the constant current drive circuit converts the mains AC voltage connected to the two voltage lamp pins into a DC current to drive the LED light-emitting circuit to emit light. The two lamp pins at the other end of the tube body are called two current lamp pins. The two current lamp pins are used to connect to the DC current that drives the LED light-emitting circuit to emit light.

[0018] In the present embodiment, the two current lamp pins connected to the other end of the tube body of the lamp tube at a single end are used as current input ends for connecting the DC current that drives the LED light-emitting circuit to emit light. When the two voltage lamp pins are connected to the AC voltage of the mains, the constant current driving circuit converts the AC voltage of the mains into a DC current to drive the LED light-emitting circuit to emit light. When the two current lamp pins are connected to the DC current provided by an external power supply, the DC current drives the LED light-emitting circuit to emit light. Therefore, the built-in driving LED lamp tube with a current input end of the present invention can cooperate with an external power supply with constant power / constant current output. The DC signal output by the external power supply is not converted through the constant current driving circuit, and the DC current output by the external power supply can be used to drive the LED light-emitting circuit to emit light. Therefore, the output characteristics of the external power supply do not need to be compatible with the constant current driving circuit, and it has a wider range of use.

[0019] Embodiment 2: This embodiment is basically the same as Embodiment 1, with the difference that: in this embodiment, a protection circuit is also provided inside the tube body, and a constant current drive circuit, an LED light-emitting circuit and a protection circuit are arranged in sequence, the constant current drive circuit is close to two voltage lamp pins, and the protection circuit is close to two current lamp pins. The constant current drive circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal. When the AC voltage of the mains is connected between the first input terminal and the second input terminal, a DC current is output between the positive output terminal and the negative output terminal. The LED light-emitting circuit has a positive electrode and a negative electrode. When a DC current is connected between the positive electrode and the negative electrode of the LED light-emitting circuit, the LED light-emitting circuit emits light. The protection circuit is a constant current input terminal protection circuit, having a first input terminal, a second output terminal, a positive output terminal and a negative output terminal. The protection circuit has a plurality of protection kinetic energy to avoid the LED lamp tube of the present invention from being electrocuted or damaged during installation. The positive output end of the constant current drive circuit and the positive output end of the protection circuit are both connected to the positive pole of the LED light-emitting circuit, the negative output end of the constant current drive power supply and the negative output end of the protection circuit are both connected to the negative pole of the LED light-emitting circuit, the first input end and the second input end of the constant current drive circuit are connected to the two voltage lamp pins one-to-one, and the first input end and the second input end of the protection circuit are connected to the two current lamp pins one-to-one.

[0020] In the present embodiment, when the two voltage lamp pins of the built-in driving LED lamp tube with current input end of the present invention are connected to the AC voltage of the mains, the constant current driving circuit converts the AC voltage of the mains into a DC current, driving the LED light-emitting circuit to emit light; when the two current lamp pins of the built-in driving LED lamp tube with current input end of the present invention are connected to the DC current provided by an external power supply, the positive output end of the protection circuit outputs a positive current, and its negative output end outputs a negative current, driving the LED light-emitting circuit to emit light; one end of the connecting line of the positive pole of the LED light-emitting circuit is connected to the positive output end of the constant current driving circuit, and the other end is connected to the positive output end of the protection circuit; one end of the connecting line of the negative pole of the LED light-emitting circuit is connected to the negative output end of the constant current driving circuit, and the other end is connected to the negative output end of the protection circuit. Therefore, in actual use, the LED light-emitting circuit can be connected to the constant current driving circuit and the protection circuit by routing on the PCB board where the constant current driving circuit, the LED light-emitting circuit and the protection circuit are located, so that no additional routing is required, and the size of the PCB board used can be reduced.

[0021] Embodiment 3: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 2 As shown, the protection circuit includes a rectifier bridge DB1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a first diode D1, a second diode D2, a first MOS tube Q1 and a second MOS tube Q2. The first diode D1 is a voltage-stabilizing diode, and the second diode D2 is a rectifier diode. The rectifier bridge DB1 has two AC input pins, a positive output terminal and a negative output terminal. One of the AC input pins of the rectifier bridge DB1 is the first input terminal of the protection circuit, and the other AC input pin of the rectifier bridge DB1 is the second input terminal of the protection circuit. The positive output terminal of the rectifier bridge DB1, one end of the first resistor R1, one end of the third resistor R3 and the positive electrode of the second diode D2 are connected. The cathode of the second diode D2 is the positive output end of the protection circuit, the other end of the first resistor R1, one end of the second resistor R2, one end of the first capacitor C1 and the gate of the first MOS tube Q1 are connected, the other end of the third resistor R3, the drain of the first MOS tube Q1, the cathode of the first diode D1, one end of the fourth resistor R4 and the gate of the second MOS tube Q2 are connected, the source of the second MOS tube Q2 is the negative output end of the protection circuit, the source of the second MOS tube Q2 is connected to one end of the fifth resistor R5, the other end of the second resistor R2, the other end of the fourth resistor R4, the other end of the fifth resistor R5, the anode of the first diode D1, the other end of the first capacitor C1, the source of the first MOS tube Q1 and the negative output end of the rectifier bridge DB1 are connected.

[0022] In the present embodiment, in addition to being able to automatically convert the polarity of the current connected to its first input terminal and the second input terminal, the protection circuit also has overvoltage protection and current limiting functions. When the voltage connected between the first input terminal and the second input terminal of the protection circuit is zero, a current path cannot be formed from its positive output terminal and negative output terminal to its first input terminal and the second input terminal, that is, the current cannot flow from its positive output terminal and the negative output terminal to its first input terminal and the second input terminal. When installing the built-in driver LED lamp tube with a current input terminal of the present invention, even if its two voltage lamp pins are connected to the AC voltage, the installer will not be electrocuted if he accidentally touches its two current lamp pins.

[0023] In this embodiment, when the built-in driving LED lamp tube with current input terminal of the present invention is used together with the lamp holder for installing the LED lamp tube to form an LED lamp with replaceable LED lamp tube, one end of the lamp holder used in conjunction provides the mains voltage, and the other end can provide a constant current similar to the output of an external emergency power supply. When the built-in driving LED lamp tube with current input terminal of the present invention is accurately installed on the matching lamp holder, its two voltage lamp pins are connected to one end of the lamp holder that provides the mains voltage, and its two current lamp pins are connected to one end of the lamp holder that is used for the external power supply to provide current. When installing the built-in driving LED lamp tube with current input terminal of the present invention, if its two current lamp pins are mistakenly connected to the end of the lamp holder that provides the mains voltage, the protection circuit of the built-in driving LED lamp tube with current input terminal of the present invention will either enter the overvoltage protection state or the current limiting state, and in both states, the built-in driving LED lamp tube with current input terminal of the present invention will not be damaged.

[0024] Embodiment 4: This embodiment is basically the same as Embodiment 2, except that: in this embodiment, Figure 3 As shown, the constant current drive circuit includes a step-down constant current circuit and an anti-backflow diode D3 that adopts a step-down mode to drive the LED light-emitting circuit to emit light. The anti-backflow diode D3 is a rectifier diode. The step-down constant current circuit has a live input terminal, a neutral input terminal, a positive output terminal and a negative output terminal. The live input terminal and the neutral input terminal of the step-down constant current circuit are respectively the first input terminal and the second input terminal of the constant current drive circuit. The positive output terminal of the step-down constant current circuit is connected to the positive electrode of the anti-backflow diode D3. The cathode of the anti-backflow diode D3 is the positive output terminal of the constant current drive circuit. The negative output terminal of the step-down constant current circuit is the negative output terminal of the constant current drive circuit.

[0025] In the present embodiment, in the constant current driving circuit, when the voltage connected between the first input terminal and the second input terminal of the step-down constant current circuit is zero, the current cannot be conducted from the positive output terminal and the negative output terminal of the step-down constant current circuit to its first input terminal and the second input terminal. At this time, a current path cannot be formed from its positive output terminal and the negative output terminal to its first input terminal and the second input terminal, that is, the current cannot flow from its positive output terminal and the negative output terminal to its first input terminal and the second input terminal. When installing the built-in driving LED lamp tube with current input terminal of the present invention, even if the two current lamp pins are connected to the AC voltage, the installer will not be electrocuted if he accidentally touches the two voltage lamp pins.

[0026] If the built-in driven LED lamp tube with current input terminal of the present invention is mistakenly installed on a lamp holder of an unmatched double-end access lamp tube, then the AC voltage is connected between the two voltage lamp pins and the two current lamp pins of the built-in driven LED lamp tube with current input terminal of the present invention, because the two voltage lamp pins of the built-in driven LED lamp tube with current input terminal of the present invention are only connected to one of the live wire and the neutral wire of the AC power, there is no voltage between the two voltage lamp pins, and the two current lamp pins are also only connected to one of the live wire and the neutral wire of the AC power, and there is no voltage between the two current lamp pins. In this way, the two voltage lamp pins and the two current lamp pins of the built-in driven LED lamp tube with current input terminal of the present invention maintain an AC cut-off state, so the built-in driven LED lamp tube with current input terminal of the present invention does not emit light and will not be damaged.

Claims

1. A built-in drive LED lamp tube with a current input end, comprising a tube body, a constant current drive circuit and an LED light-emitting circuit, wherein the constant current drive circuit and the LED light-emitting circuit are both arranged inside the tube body, and both ends of the tube body have two lamp pins, and the two lamp pins at one end of the tube body are used to connect to the mains, and the two lamp pins are called two voltage lamp pins. When the two voltage lamp pins are connected to the mains AC voltage, the constant current drive circuit converts the mains AC voltage connected to the two voltage lamp pins into a DC current to drive the LED light-emitting circuit to emit light, characterized in that The two lamp pins at the other end of the tube body are called two current lamp pins, and the two current lamp pins are used to connect the direct current that drives the LED lighting circuit to emit light.

2. The LED lamp tube with a built-in driver and a current input terminal according to claim 1, characterized in that A protection circuit is also provided inside the tube body. The constant current drive circuit, the LED light-emitting circuit and the protection circuit are arranged in sequence. The constant current drive circuit is close to two voltage lamp pins, and the protection circuit is close to two current lamp pins. The constant current drive circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal. When the AC voltage of the mains is connected between the first input terminal and the second input terminal, a DC current is output between the positive output terminal and the negative output terminal. The LED light-emitting circuit has a positive pole and a negative pole. When a DC current is connected between the positive pole and the negative pole of the LED light-emitting circuit, the LED light-emitting circuit emits light. The protection circuit is a constant current input terminal protection circuit, which has a first input terminal, a second output terminal, a positive output terminal and a negative output terminal. The protection circuit has multiple protection kinetic energy to avoid the LED lamp tube of the present invention from being electrocuted or damaged during installation. The positive output end of the constant current drive circuit and the positive output end of the protection circuit are both connected to the positive electrode of the LED light-emitting circuit, the negative output end of the constant current drive power supply and the negative output end of the protection circuit are both connected to the negative electrode of the LED light-emitting circuit, the first input end and the second input end of the constant current drive circuit are connected to the two voltage lamp pins one-to-one, and the first input end and the second input end of the protection circuit are connected to the two current lamp pins one-to-one.

3. The LED lamp tube with a built-in driver and a current input terminal according to claim 2, characterized in that The protection circuit comprises a rectifier bridge stack, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first capacitor, a first diode, a second diode, a first MOS tube and a second MOS tube. The first diode is a voltage-stabilizing diode, the second diode is a rectifier diode, the rectifier bridge stack has two AC input pins, a positive output end and a negative output end, one of the AC input pins of the rectifier bridge stack is the first input end of the protection circuit, the other AC input pin of the rectifier bridge stack is the second input end of the protection circuit, the positive output end of the rectifier bridge stack, one end of the first resistor, one end of the third resistor and the positive electrode of the second diode are connected, and the cathode of the second diode is the protection circuit The positive output end of the protection circuit is connected to the positive output end of the protection circuit, the other end of the first resistor, one end of the second resistor, one end of the first capacitor and the gate of the first MOS tube are connected, the other end of the third resistor, the drain of the first MOS tube, the negative electrode of the first diode, one end of the fourth resistor and the gate of the second MOS tube are connected, the drain of the second MOS tube is the negative output end of the protection circuit, the source of the second MOS tube is connected to one end of the fifth resistor, the other end of the second resistor, the other end of the fourth resistor, the other end of the fifth resistor, the positive electrode of the first diode, the other end of the first capacitor, the source of the first MOS tube and the negative output end of the rectifier bridge stack are connected.

4. The LED lamp tube with a built-in driver and a current input terminal according to claim 2, characterized in that The constant current drive circuit includes a step-down constant current circuit and an anti-backflow diode that adopts a step-down mode to drive the LED light-emitting circuit to emit light. The anti-backflow diode is a rectifier diode. The step-down constant current circuit has a live wire input end, a neutral wire input end, a positive output end and a negative output end. The live wire input end and the neutral wire input end of the step-down constant current circuit are respectively the first input end and the second input end of the constant current drive circuit. The positive output end of the step-down constant current circuit is connected to the positive electrode of the anti-backflow diode. The cathode of the anti-backflow diode is the positive output end of the constant current drive circuit. The negative output end of the step-down constant current circuit is the negative output end of the constant current drive circuit.

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