CN214101853U

CN214101853U - Constant current LED lamp circuit with function of turning off light in time delay

Info

Publication number: CN214101853U
Application number: CN202022918697.4U
Authority: CN
Inventors: 赵肖玲
Original assignee: Shaoxing Jiuxin Electronic Sci Tech Co ltd
Current assignee: Shaoxing Jiuxin Electronic Sci Tech Co ltd
Priority date: 2020-12-08
Filing date: 2020-12-08
Publication date: 2021-08-31
Anticipated expiration: 2030-12-08

Abstract

The utility model discloses a constant current LED lamp circuit with function of putting off light in time delay, including rectifier circuit, LED lighting circuit, two sections constant current circuit and time delay control circuit, rectifier circuit's positive output end is connected with two sections constant current circuit's positive pole and time delay control circuit's positive pole respectively, two sections constant current circuit's voltage detection end and rectifier circuit's voltage signal end are connected, two sections constant current circuit's positive output end and LED lighting circuit's positive pole are connected, two sections constant current circuit's negative output end and LED lighting circuit's negative pole are connected, two sections constant current circuit's current signal end and time delay control circuit's signal input part are connected, two sections constant current circuit's control end and time delay control circuit's output are connected; the time-delay light-off circuit has the advantages that the time-delay light-off is realized through the matching of the rectifying circuit, the two sections of constant current circuits and the time-delay control circuit, compared with the prior art that a trigger switching circuit is omitted, the circuit structure is simpler, and the overall cost is lower.

Description

Constant current LED lamp circuit with function of turning off light in time delay

Technical Field

The utility model relates to a constant current LED lamp circuit especially relates to a constant current LED lamp circuit with function of turning off the light in time delay.

Background

With the rapid development of intelligent LED lighting technology, LED lamps with various functions appear on the market. The LED lamp with the function of delayed turn-off can turn off the lamp after a delay time is set after being disconnected from a power supply, so that a user can conveniently move, and the LED lamp is widely applied.

Chinese patent No. CN201910197201.8 discloses an LED lamp circuit with a function of time-delay light-off, which has two working states: normal working state and delayed light-off working state. The LED lamp circuit is characterized in that the normal working state is consistent with the traditional lighting function, when the power supply control switch is switched on, the LED lamp circuit always keeps normal luminous brightness, and when the power supply control switch is switched off in the delayed light-off working state, the LED lamp circuit firstly adopts low-brightness light emission and keeps the low-brightness light emission for a certain time, and then turns to no light emission, so that the LED lamp circuit has the characteristic of not being instantly extinguished after the light-off operation, and has the advantage of being convenient for a user to act.

The two working states of the LED lamp circuit can be switched by switching the off state and the on state of the power control switch. However, in this LED lamp circuit, the trigger switching circuit is disposed between the rectifying circuit and the filtering circuit, and the delay trigger signal is generated by obtaining the instantaneous power-off signal of the power control switch, so that the LED lamp circuit is switched from the normal operating state to the delay light-off operating state under the control of the delay trigger signal. The LED lamp circuit adopts a mode of realizing time delay control by a trigger signal, a trigger conversion circuit and a time delay control circuit are required to be arranged at the same time, the circuit structure is complex, and the overall cost is increased.

Disclosure of Invention

The utility model aims to solve the technical problem that a circuit structure is simple, the lower constant current LED lamp circuit that has the function of turn off the light in a delayed manner of whole cost is provided.

The utility model provides a technical scheme that above-mentioned technical problem adopted does: a constant current LED lamp circuit with a function of time delay light-off comprises a rectifying circuit, an LED light-emitting circuit, two sections of constant current circuits and a time delay control circuit, wherein the rectifying circuit is provided with a first input end, a second input end, an output end, a grounding end and a voltage signal end, the LED light-emitting circuit is provided with a positive electrode and a negative electrode, the two sections of constant current circuits are provided with a positive electrode, a negative electrode, a voltage detection end, a positive output end, a negative output end, a current signal end and a control end, the time delay control circuit is provided with a positive electrode, a negative electrode, a signal input end and an output end, the first input end and the second input end of the rectifying circuit are connected to an external power supply through a power supply control switch, when the power supply control switch is switched on, voltage is switched in a power-on state between the first input end and the second input end of the rectifying circuit, the rectifying circuit, when the power supply control switch is switched off, no voltage is connected between the first input end and the second input end of the rectifying circuit and is in a power-off state, no direct-current voltage is output from the positive output end of the rectifying circuit, zero voltage is output from the voltage signal end of the rectifying circuit, and the positive output end of the rectifying circuit is respectively connected with the positive electrodes of the two sections of constant-current circuits and the positive electrode of the delay control circuit; the voltage detection ends of the two sections of constant current circuits are connected with the voltage signal end of the rectifying circuit; the positive output ends of the two sections of constant current circuits are connected with the positive electrode of the LED light-emitting circuit, and the negative output ends of the two sections of constant current circuits are connected with the negative electrode of the LED light-emitting circuit; the current signal ends of the two sections of constant current circuits are connected with the signal input end of the delay control circuit, and the control ends of the two sections of constant current circuits are connected with the output end of the delay control circuit; the negative pole of the delay control circuit, the negative poles of the two constant current circuits are connected with the grounding end of the rectifying circuit, the two constant current circuits can judge the power-off time of the rectifying circuit through the voltage signal output by the voltage signal end of the rectifying circuit, the two constant current circuits are internally provided with power-off time thresholds, the delay control circuit has a dormant state and a working state, the delay control circuit is internally provided with delay time, the power control switch is realized by adopting a normally closed key switch, the constant current LED lamp circuit and the two constant current circuits both have two working states of a normal working state and a delay working state, when the two constant current circuits enter the normal working state, the constant current LED lamp circuit also enters the normal working state, and at the moment, the two constant current circuits output larger preset direct current at the positive output ends thereof to drive the LED light-emitting circuit When the two sections of constant current circuits enter a time-delay working state, the constant current LED lamp circuit also enters the time-delay working state, at the moment, the two sections of constant current circuits output smaller direct current preset in the two sections of constant current circuits at the positive output ends of the two sections of constant current circuits to drive the LED light-emitting circuit to enter a low-brightness light-emitting state, and output current control signals matched with the time-delay working state at the current signal ends of the two sections of constant current circuits;

in an initial state, the two sections of constant current circuits and the constant current LED lamp circuit are in a normal working state, the time delay control circuit is in a dormant state, one operation of firstly disconnecting and then connecting the normally closed key switch is taken as a control instruction, if the disconnection time is less than a power-off time threshold value, the control instruction is a switching instruction, the two sections of constant current circuits detect the switching instruction through a voltage detection end thereof and switch from the current working state to another working state, a current signal end thereof outputs a current control signal matched with the switched working state, if the current control signal is matched with the normal working state, the time delay control circuit cannot be awakened, the dormant state is continuously kept, a control signal is not output at an output end thereof to control the two sections of constant current circuits, and if the current control signal is matched with the time delay working state, the delay control circuit is awakened to enter a working state from a dormant state, the delay control circuit starts timing, if the current control signal is not changed before the timing reaches the delay time, when the delay time is reached, the output end of the delay control circuit outputs a control signal to control the output current of the positive output ends of the two sections of constant current circuits to be zero, the LED light-emitting circuit is enabled not to emit light, the constant current LED lamp circuit is turned off, and if the current control signal is changed into the current control signal matched with the working state before the timing reaches the delay time, the delay control circuit enters the dormant state again.

The two sections of constant current circuits comprise a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a first MOS (metal oxide semiconductor) tube and a first integrated circuit, the first capacitor is an electrolytic capacitor, the model of the first integrated circuit is SM2212EA, one end of the first resistor is a voltage detection end of the two sections of constant current circuits, the positive electrode of the first capacitor is connected with one end of the second capacitor, the connecting end of the first capacitor is the positive electrode of the two sections of constant current circuits, the positive output end of the two sections of constant current circuits is also the positive output end of the two sections of constant current circuits, the other end of the second resistor, the 5 th pin and the 6 th pin of the first integrated circuit are connected, the connecting end of the first resistor is the negative output end of the two sections of constant current circuits, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit, the 1 st pin of the first integrated circuit is connected with one end of the second capacitor, the 2 nd pin of the first integrated circuit is connected with one end of the third capacitor, the 3 rd pin of the first integrated circuit is connected with one end of the fourth resistor, the connecting end of the fourth integrated circuit is a current signal end of the two constant current circuits, the 4 th pin of the first integrated circuit is connected with the drain electrode of the first MOS tube, the source electrode of the first MOS tube is connected with one end of the third resistor, the grid electrode of the first MOS tube is a control end of the two constant current circuits, the bottom electrode of the first integrated circuit, the cathode of the first capacitor, the other end of the second capacitor, the other end of the third resistor and the other end of the fourth resistor are connected, and the connecting end of the bottom electrode of the first integrated circuit is the cathode of the two constant current circuits. In the two sections of constant current circuits, when the two sections of constant current circuits output larger direct current, the current signal ends output non-zero positive voltage, and when the two sections of constant current circuits output smaller direct current, the current signal ends output zero voltage.

The delay control circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, a fourth capacitor, a first diode and a triode, wherein the fourth capacitor is an electrolytic capacitor, the first diode is a voltage stabilizing diode, one end of the fifth resistor is a signal input end of the delay control circuit, the other end of the fifth resistor is connected with a base electrode of the triode, a collector electrode of the triode and one end of the sixth resistor are connected with an anode of the fourth capacitor, the other end of the sixth resistor is an anode of the delay control circuit, a cathode of the fourth capacitor, a cathode of the first diode and one end of the seventh resistor are connected, and a connecting end of the sixth resistor is an output end of the delay control circuit; and the emitter of the triode, the anode of the first diode and the other end of the seventh resistor are connected, and the connecting end of the triode and the anode of the first diode are the cathodes of the time delay control circuit. In the time delay control circuit, when the voltage connected to the fifth resistor is greater than or equal to the conduction voltage between the base electrode and the emitter electrode of the triode, the collector electrode and the emitter electrode of the triode are conducted, the fourth capacitor is discharged until the two ends of the fourth capacitor are in a zero voltage state, when the voltage connected to the fifth resistor is smaller than the conduction voltage between the base electrode and the emitter electrode of the triode, the collector electrode and the emitter electrode of the triode are cut off, the fourth capacitor is charged through the sixth resistor, the output end of the time delay control circuit keeps output voltage in the charging process until the voltage at the two ends of the fourth capacitor is not increased, the voltage at the output end of the time delay control circuit is converted into zero, the time delay control circuit quickly discharges the fourth capacitor when the two constant current circuits are in a normal working state, and charges the fourth capacitor when the two constant current circuits are in a time delay light-off working state, the time for charging the fourth capacitor is used as the set delay time, and the whole circuit structure can be realized by using discrete components, so that the cost is low.

Rectifier circuit include full-bridge rectifier circuit and second diode, the second diode be the rectifier diode, two alternating current input ends of full-bridge rectifier circuit do respectively rectifier circuit's first input and second input, full-bridge rectifier circuit's positive output with the positive of second diode connect and its link do rectifier circuit's voltage signal end, the negative pole of second diode do rectifier circuit's positive output, full-bridge rectifier circuit's negative output do rectifier circuit's earthing terminal.

Compared with the prior art, the utility model has the advantages that the constant current LED lamp circuit with the function of time delay light-off is constructed by the rectifying circuit, the LED luminous circuit, two sections of constant current circuits and the time delay control circuit, the rectifying circuit is provided with a first input end, a second input end, an output end, a grounding end and a voltage signal end, the LED luminous circuit is provided with a positive pole and a negative pole, the two sections of constant current circuits are provided with a positive pole, a negative pole, a voltage detection end, a positive output end, a negative output end, a current signal end and a control end, the time delay control circuit is provided with a positive pole, a negative pole, a signal input end and an output end, the first input end and the second input end of the rectifying circuit are connected to an external power supply through the power supply control switch, when the power supply control switch is switched on, the voltage is switched in a power-on state between the first input end and the second input end of the rectifying circuit, the rectifying circuit converts the switched-on voltage into the direct current voltage to be output at the positive output end of the rectifying circuit, when the power supply control switch is switched off, no voltage is connected between the first input end and the second input end of the rectifying circuit and is in a power-off state, no direct-current voltage is output at the positive output end of the rectifying circuit, zero voltage is output at the voltage signal end of the rectifying circuit, and the positive output end of the rectifying circuit is respectively connected with the positive electrodes of the two sections of constant-current circuits and the positive electrode of the delay control circuit; the voltage detection ends of the two sections of constant current circuits are connected with the voltage signal end of the rectifying circuit; the positive output ends of the two sections of constant current circuits are connected with the positive electrode of the LED light-emitting circuit, and the negative output ends of the two sections of constant current circuits are connected with the negative electrode of the LED light-emitting circuit; the current signal ends of the two sections of constant current circuits are connected with the signal input end of the delay control circuit, and the control ends of the two sections of constant current circuits are connected with the output end of the delay control circuit; the negative pole of the time delay control circuit, the negative poles of the two sections of constant current circuits are connected with the grounding end of the rectifying circuit, the two sections of constant current circuits can judge the power-off time of the rectifying circuit through the voltage signal output by the voltage signal end of the rectifying circuit, the two sections of constant current circuits are internally provided with power-off time thresholds, the time delay control circuit has a dormant state and a working state, the time delay control circuit is internally provided with time delay time, a power supply control switch is realized by adopting a normally closed key switch, the constant current LED lamp circuit and the two sections of constant current circuits both have two working states of a normal working state and a time delay working state, when the two sections of constant current circuits enter the normal working state, the constant current LED lamp circuit also enters the normal working state, at the moment, the two sections of constant current circuits output larger direct current preset in the two sections of constant current circuits at the positive output ends of the two sections of constant current circuits to drive the LED light-emitting circuit to enter the high-brightness light-emitting state, and output current control signals matched with the normal working state at the current signal ends of the two sections of constant current circuits, when the two sections of constant current circuits enter a time-delay working state, the constant current LED lamp circuit also enters the time-delay working state, at the moment, the two sections of constant current circuits output smaller direct current preset in the two sections of constant current circuits at the positive output end of the two sections of constant current circuits to drive the LED light-emitting circuit to enter a low-brightness light-emitting state, and output current control signals matched with the time-delay working state at the current signal end of the two sections of constant current circuits; in an initial state, the two sections of constant current circuits and the constant current LED lamp circuit are in a normal working state, the time delay control circuit is in a dormant state, one operation of firstly disconnecting and then connecting the normally closed key switch is taken as a control instruction, if the disconnection time is less than a disconnection time threshold value, the control instruction is a switching instruction, the two sections of constant current circuits detect the switching instruction through a voltage detection end and switch from the current working state to another working state, a current signal end outputs a current control signal matched with the switched working state, if the current control signal is matched with the normal working state, the time delay control circuit cannot be awakened, the dormant state is continuously kept, a control signal is not output at an output end of the time delay control circuit to control the two sections of constant current circuits, and if the current control signal is matched with the time delay working state, the time delay control circuit is awakened, get into operating condition from the dormancy state, delay control circuit begins the timing, this current control signal does not change before the timing reaches the delay time, when reaching the delay time, the positive output end output current of two sections constant current circuit of delay control circuit's output control signal control is zero, makes LED lighting circuit not luminous, constant current LED lamp circuit lights out, if this current control signal takes place to change into the current control signal that operating condition matches before the timing reaches the delay time, delay control circuit gets into the dormancy state once more, from this the utility model discloses a rectifier circuit, two sections constant current circuit and delay control circuit's cooperation realizes delaying to turn off the light, has left out trigger converting circuit for prior art, and circuit structure is fairly simple, and overall cost is lower.

Drawings

Fig. 1 is a block diagram of the constant current LED lamp circuit with a function of time-delay light-off according to the present invention;

fig. 2 is a circuit diagram of the constant current LED lamp circuit with the function of time delay light-off.

Detailed Description

The present invention will be described in further detail with reference to the following embodiments.

Example (b): as shown in FIG. 1, a constant current LED lamp circuit LED1 with a function of time-delay light-off comprises a rectifying circuit, an LED light-emitting circuit, two sections of constant current circuits and a time-delay control circuit, wherein the rectifying circuit has a first input end, a second input end, an output end, a grounding end and a voltage signal end, the LED light-emitting circuit has a positive electrode and a negative electrode, the two sections of constant current circuits have a positive electrode, a negative electrode, a voltage detection end, a positive output end, a negative output end, a current signal end and a control end, the time-delay control circuit has a positive electrode, a negative electrode, a signal input end and an output end, the first input end and the second input end of the rectifying circuit are connected to an external power supply through a power control switch, when the power control switch is switched on, a voltage is switched in a power-on state between the first input end and the second input end of the rectifying circuit, the rectifying circuit converts the switched-on voltage into a direct current voltage to be output at the positive output end, when the power supply control switch is switched off, no voltage is connected between the first input end and the second input end of the rectifying circuit and is in a power-off state, no direct-current voltage is output at the positive output end of the rectifying circuit, zero voltage is output at the voltage signal end of the rectifying circuit, and the positive output end of the rectifying circuit is respectively connected with the positive electrodes of the two sections of constant-current circuits and the positive electrode of the delay control circuit; the voltage detection ends of the two sections of constant current circuits are connected with the voltage signal end of the rectifying circuit; the positive output ends of the two sections of constant current circuits are connected with the positive electrode of the LED light-emitting circuit, and the negative output ends of the two sections of constant current circuits are connected with the negative electrode of the LED light-emitting circuit; the current signal ends of the two sections of constant current circuits are connected with the signal input end of the delay control circuit, and the control ends of the two sections of constant current circuits are connected with the output end of the delay control circuit; the negative pole of the time delay control circuit, the negative poles of the two sections of constant current circuits are connected with the grounding end of the rectifying circuit, the two sections of constant current circuits can judge the power-off time of the rectifying circuit through the voltage signal output by the voltage signal end of the rectifying circuit, the two sections of constant current circuits are internally provided with power-off time thresholds, the time delay control circuit has a dormant state and a working state, the time delay control circuit is internally provided with time delay time, a power supply control switch is realized by a normally closed key switch S1, the constant current LED lamp circuit and the two sections of constant current circuits both have two working states of a normal working state and a time delay working state, when the two sections of constant current circuits enter the normal working state, the constant current LED lamp circuit also enters the normal working state, the two sections of constant current circuits output larger direct current preset in the two sections of constant current circuits at the positive output ends of the two sections of constant current circuits to drive the LED light-emitting circuit to enter a high-brightness light-emitting state, and output current control signals matched with the normal working state at the current signal ends of the two sections of constant current circuits, when the two sections of constant current circuits enter a time-delay working state, the constant current LED lamp circuit also enters the time-delay working state, at the moment, the two sections of constant current circuits output smaller direct current preset in the two sections of constant current circuits at the positive output end of the two sections of constant current circuits to drive the LED light-emitting circuit to enter a low-brightness light-emitting state, and output current control signals matched with the time-delay working state at the current signal end of the two sections of constant current circuits; in an initial state, the two sections of constant current circuits and the constant current LED lamp circuit are in a normal working state, the time delay control circuit is in a dormant state, one operation of firstly disconnecting and then connecting the normally closed key switch is taken as a control instruction, if the disconnection time is less than a disconnection time threshold value, the control instruction is a switching instruction, the two sections of constant current circuits detect the switching instruction through a voltage detection end and switch from the current working state to another working state, a current signal end outputs a current control signal matched with the switched working state, if the current control signal is matched with the normal working state, the time delay control circuit cannot be awakened, the dormant state is continuously kept, a control signal is not output at an output end of the time delay control circuit to control the two sections of constant current circuits, and if the current control signal is matched with the time delay working state, the time delay control circuit is awakened, and if the current control signal is changed into the current control signal matched with the working state before the timing reaches the delay time, the delay control circuit enters the dormant state again.

As shown in fig. 2, in this embodiment, the two segments of constant current circuits include a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first MOS transistor M1 and a first integrated circuit U1, the first capacitor C1 is an electrolytic capacitor, the first integrated circuit U1 is of the type SM2212EA, one end of the first resistor R1 is a voltage detection end of the two segments of constant current circuits, a positive electrode of the first capacitor C1 is connected to one end of the second resistor R2, a connection end of the first capacitor C1 is a positive electrode of the two segments of constant current circuits and is a positive output end of the two segments of constant current circuits, the other end of the second resistor R2 is connected to a 5 th pin and a 6 th pin of the first integrated circuit U1, a connection end of the second resistor R1 is a negative output end of the two segments of the constant current circuits, the other end of the first resistor R1 is connected to a first pin 1 of the first integrated circuit U1, and the first terminal of the first integrated circuit U461 is connected to a second terminal of the first integrated circuit U2, the 2 nd pin of the first integrated circuit U1 is connected with one end of a third capacitor C3, the 3 rd pin of the first integrated circuit U1 is connected with one end of a fourth resistor R4, the connecting end of the first integrated circuit U1 is a current signal end of two sections of constant current circuits, the 4 th pin of the first integrated circuit U1 is connected with the drain electrode of a first MOS tube M1, the source electrode of the first MOS tube M1 is connected with one end of a third resistor R3, the grid electrode of the first MOS tube M1 is a control end of two sections of constant current circuits, the bottom electrode of the first integrated circuit U1, the negative electrode of the first capacitor C1, the other end of the second capacitor C2, the other end of the third capacitor C3, the other end of the third resistor R3 is connected with the other end of the fourth resistor R4, and the connecting end of the two sections of constant current circuits is the negative electrode of the constant current circuits.

As shown in fig. 2, in this embodiment, the delay control circuit includes a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a fourth capacitor C4, a first diode D1 and a transistor Q1, the fourth capacitor C4 is an electrolytic capacitor, the first diode D1 is a zener diode, one end of the fifth resistor R5 is a signal input end of the delay control circuit, the other end of the fifth resistor R5 is connected to a base of the transistor Q1, a collector of the transistor Q1, one end of the sixth resistor R6 and an anode of the fourth capacitor C4 are connected, the other end of the sixth resistor R6 is an anode of the delay control circuit, a cathode of the fourth capacitor C4, a cathode of the first diode D1 and one end of the seventh resistor R7 are connected, and a connection end of the sixth resistor R6 is an output end of the delay control circuit; the emitter of the triode Q1, the anode of the first diode D1 and the other end of the seventh resistor R7 are connected, and the connection end is the cathode of the delay control circuit.

As shown in fig. 2, in this embodiment, the rectifying circuit includes a full-bridge rectifying circuit Db and a second diode D2, the second diode D2 is a rectifying diode, two ac input terminals of the full-bridge rectifying circuit Db are respectively a first input terminal and a second input terminal of the rectifying circuit, a positive output terminal of the full-bridge rectifying circuit Db is connected to a positive terminal of the second diode D2, and a connection terminal thereof is a voltage signal terminal of the rectifying circuit, a negative terminal of the second diode D2 is a positive output terminal of the rectifying circuit, and a negative output terminal of the full-bridge rectifying circuit Db is a ground terminal of the rectifying circuit.

Claims

1. A constant current LED lamp circuit with a function of time-delay light-out is characterized by comprising a rectifying circuit, an LED light-emitting circuit, two sections of constant current circuits and a time-delay control circuit, wherein the rectifying circuit is provided with a first input end, a second input end, an output end, a grounding end and a voltage signal end, the LED light-emitting circuit is provided with a positive electrode and a negative electrode, the two sections of constant current circuits are provided with a positive electrode, a negative electrode, a voltage detection end, a positive output end, a negative output end, a current signal end and a control end, the time-delay control circuit is provided with a positive electrode, a negative electrode, a signal input end and an output end, the first input end and the second input end of the rectifying circuit are connected to an external power supply through a power supply control switch, when the power supply control switch is switched on, voltage is switched in a power-on state between the first input end and the second input end of the rectifying circuit, the rectifying circuit converts the switched-on voltage into direct current voltage to be output at the positive output end of the rectifying circuit, when the power supply control switch is switched off, no voltage is connected between the first input end and the second input end of the rectifying circuit and is in a power-off state, no direct-current voltage is output from the positive output end of the rectifying circuit, zero voltage is output from the voltage signal end of the rectifying circuit, and the positive output end of the rectifying circuit is respectively connected with the positive electrodes of the two sections of constant-current circuits and the positive electrode of the delay control circuit; the voltage detection ends of the two sections of constant current circuits are connected with the voltage signal end of the rectifying circuit; the positive output ends of the two sections of constant current circuits are connected with the positive electrode of the LED light-emitting circuit, and the negative output ends of the two sections of constant current circuits are connected with the negative electrode of the LED light-emitting circuit; the current signal ends of the two sections of constant current circuits are connected with the signal input end of the delay control circuit, and the control ends of the two sections of constant current circuits are connected with the output end of the delay control circuit; the negative pole of the delay control circuit, the negative poles of the two constant current circuits are connected with the grounding end of the rectifying circuit, the two constant current circuits can judge the power-off time of the rectifying circuit through the voltage signal output by the voltage signal end of the rectifying circuit, the two constant current circuits are internally provided with power-off time thresholds, the delay control circuit has a dormant state and a working state, the delay control circuit is internally provided with delay time, the power control switch is realized by adopting a normally closed key switch, the constant current LED lamp circuit and the two constant current circuits both have two working states of a normal working state and a delay working state, when the two constant current circuits enter the normal working state, the constant current LED lamp circuit also enters the normal working state, and at the moment, the two constant current circuits output larger preset direct current at the positive output ends thereof to drive the LED light-emitting circuit When the two sections of constant current circuits enter a time-delay working state, the constant current LED lamp circuit also enters the time-delay working state, at the moment, the two sections of constant current circuits output smaller direct current preset in the two sections of constant current circuits at the positive output ends of the two sections of constant current circuits to drive the LED light-emitting circuit to enter a low-brightness light-emitting state, and output current control signals matched with the time-delay working state at the current signal ends of the two sections of constant current circuits;

2. The constant current LED lamp circuit with the function of time delay light-off according to claim 1, characterized in that the two segments of constant current circuits comprise a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third capacitor, a first MOS tube and a first integrated circuit, the first capacitor is an electrolytic capacitor, the first integrated circuit is SM2212EA in model, one end of the first resistor is a voltage detection end of the two segments of constant current circuits, the anode of the first capacitor is connected with one end of the second resistor, the connection end of the first capacitor is the anode of the two segments of constant current circuits and is also a positive output end of the two segments of constant current circuits, the other end of the second resistor, the 5 th pin and the 6 th pin of the first integrated circuit are connected, and the connection end of the second resistor is a negative output end of the two segments of constant current circuits, the other end of the first resistor is connected with the 8 th pin of the first integrated circuit, the 1 st pin of the first integrated circuit is connected with one end of the second capacitor, the 2 nd pin of the first integrated circuit is connected with one end of the third capacitor, the 3 rd pin of the first integrated circuit is connected with one end of the fourth resistor, the connecting end of the first integrated circuit is the current signal end of the two constant current circuits, the 4 th pin of the first integrated circuit is connected with the drain electrode of the first MOS tube, the source electrode of the first MOS tube is connected with one end of the third resistor, the grid electrode of the first MOS tube is the control end of the two constant current circuits, the bottom electrode of the first integrated circuit, the negative electrode of the first capacitor, the other end of the second capacitor, the other end of the third resistor and the other end of the fourth resistor are connected, and the connecting end of the third resistor is the connecting end of the second capacitor The cathodes of the two sections of constant current circuits.

3. The constant-current LED lamp circuit with the function of delayed light-off as claimed in claim 1, it is characterized in that the delay control circuit comprises a fifth resistor, a sixth resistor, a seventh resistor, a fourth capacitor, a first diode and a triode, the fourth capacitor is an electrolytic capacitor, the first diode is a voltage stabilizing diode, one end of the fifth resistor is a signal input end of the delay control circuit, the other end of the fifth resistor is connected with the base electrode of the triode, the collector electrode of the triode and one end of the sixth resistor are connected with the anode of the fourth capacitor, the other end of the sixth resistor is the anode of the delay control circuit, the cathode of the fourth capacitor, the cathode of the first diode and one end of the seventh resistor are connected, and the connecting end of the sixth resistor is the output end of the delay control circuit; and the emitter of the triode, the anode of the first diode and the other end of the seventh resistor are connected, and the connecting end of the triode and the anode of the first diode are the cathodes of the time delay control circuit.

4. The constant current LED lamp circuit according to claim 1, wherein the rectifying circuit comprises a full bridge rectifying circuit and a second diode, the second diode is a rectifying diode, the two ac input terminals of the full bridge rectifying circuit are respectively the first input terminal and the second input terminal of the rectifying circuit, the positive output terminal of the full bridge rectifying circuit is connected to the positive electrode of the second diode, the connection terminal of the full bridge rectifying circuit is the voltage signal terminal of the rectifying circuit, the negative electrode of the second diode is the positive output terminal of the rectifying circuit, and the negative output terminal of the full bridge rectifying circuit is the ground terminal of the rectifying circuit.