CN221467948U - Wide-voltage linear constant-current LED lamp circuit - Google Patents

Abstract

The utility model discloses a wide-voltage linear constant-current LED lamp circuit, which comprises a full-bridge rectifying circuit, a linear conversion circuit, a storage circuit and an LED light-emitting circuit, wherein the LED light-emitting circuit comprises a first LED lamp string, a second LED lamp string, a third LED lamp string, a first integrated circuit, a second integrated circuit, a first resistor, a second resistor and a first diode, the first resistor sets the maximum current flowing through the output end of the first integrated circuit, the second resistor sets the maximum current flowing through the output end of the second integrated circuit, the maximum current of the output end of the first integrated circuit is 2 times of the maximum current of the output end of the second integrated circuit, and the maximum current of the output end of the first integrated circuit is smaller than the maximum output current of the constant-current output end of the linear conversion circuit; the LED lamp has the advantages that the LED lamp has higher luminous efficiency when being connected with the rated voltage of the mains supply, can still keep higher luminous brightness within a certain voltage range with reduced fluctuation of the mains supply, and has less application area limitation.

Description

A wide voltage linear constant current LED lamp circuit

Technical Field

The utility model relates to a linear constant current LED lamp circuit, in particular to a wide voltage linear constant current LED lamp circuit.

Background technique

As shown in FIG1 , the existing linear constant current LED lamp circuit generally includes a full-bridge rectifier circuit, a linear conversion circuit, an energy storage circuit and an LED light-emitting circuit. The full-bridge rectifier circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal, the linear conversion circuit has a positive electrode, a negative electrode, a constant current output terminal and an energy storage connection terminal, the constant current output terminal of the linear conversion circuit is provided with a maximum output current, the energy storage circuit has a positive electrode and a negative electrode, the LED light-emitting circuit has a positive electrode and a negative electrode, the LED light-emitting circuit is an LED light string formed by connecting a number of LED light-emitting bodies in series and in parallel, and its operating voltage is determined by the number and connection mode of the LED light-emitting bodies, so that the operating voltage of the LED light-emitting circuit cannot be changed automatically; the positive electrode of the linear conversion circuit is connected to the positive output terminal of the full-bridge rectifier circuit, the energy storage connection terminal of the linear conversion circuit is connected to the positive electrode of the energy storage circuit, the constant current output terminal of the linear conversion circuit is connected to the positive electrode of the LED light-emitting circuit, and the negative electrode of the LED light-emitting circuit, the negative electrode of the energy storage circuit and the negative output terminal of the full-bridge rectifier circuit are connected. When the first input terminal and the second output terminal of the full-bridge rectifier circuit are connected to the AC voltage of the mains, a DC voltage with a positive half-cycle sine wave waveform that changes periodically is output between the positive output terminal and the negative output terminal of the full-bridge rectifier circuit. The linear conversion circuit charges the energy storage circuit in a specific time period when the DC voltage output by the full-bridge rectifier circuit is close to its voltage peak, and when the DC voltage output by the full-bridge rectifier circuit is less than or equal to the working voltage of the LED light-emitting circuit, the energy storage circuit is controlled to discharge, and the current is output at its constant current output terminal to drive the LED light-emitting circuit to emit light, so that the LED light-emitting circuit can maintain continuous light emission during the change cycle of the AC voltage of the mains.

The above linear constant current LED lamp circuit has been widely used because it has the advantage of low cost compared to the switching constant current LED lamp circuit and can meet the harmonic and flicker indicators required by the latest industry standards.

In the above linear constant current LED lamp circuit, the maximum voltage outputted by the constant current output terminal of the linear conversion circuit corresponds to the magnitude of the mains voltage. The lower the mains voltage, the lower the maximum voltage outputted by the constant current output terminal of the linear conversion circuit. Therefore, the working voltage of the LED light-emitting circuit will be reasonably set according to the magnitude of the mains voltage. The higher the working voltage of the LED light-emitting circuit, the higher the luminous efficiency of the LED light-emitting circuit. However, it is easy for the LED light-emitting circuit to not emit light when the mains voltage fluctuates and decreases to below its working voltage. On the contrary, the lower the working voltage of the LED light-emitting circuit, the higher the working voltage can be when the mains voltage fluctuates and decreases. The LED light-emitting circuit can still keep emitting light, but the luminous efficiency of the LED light-emitting circuit is lower.

At present, in order to maintain a high luminous efficiency, the existing linear constant current LED lamp circuit sets the working voltage of the LED lighting circuit to be relatively high. Therefore, it can usually only be used in areas where the mains voltage is relatively stable, and the use area is greatly restricted.

Summary of the invention

The technical problem to be solved by the utility model is to provide a wide-voltage linear constant-current LED lamp circuit which has high luminous efficiency when connected to the rated voltage of the mains, can still maintain high luminous brightness within a certain voltage range where the mains voltage fluctuation is reduced, and has fewer application area restrictions.

The technical solution adopted by the utility model to solve the above technical problems is: a wide voltage linear constant current LED lamp circuit, including a full-bridge rectifier circuit, a linear conversion circuit, an energy storage circuit and an LED light-emitting circuit, the full-bridge rectifier circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal, the linear conversion circuit has a positive electrode, a negative electrode, a current output terminal and a power storage connection terminal, the constant current output terminal of the linear conversion circuit is provided with a maximum output current, the energy storage circuit has a positive electrode and a negative electrode, the LED light-emitting circuit has a positive electrode and a negative electrode, the positive electrode of the linear conversion circuit is connected to the full-bridge rectifier circuit The positive output end of the linear conversion circuit is connected to the positive electrode of the energy storage circuit, the constant current output end of the linear conversion circuit is connected to the positive electrode of the LED light-emitting circuit, the negative electrode of the energy storage circuit, the negative electrode of the LED light-emitting circuit and the negative output end of the full-bridge rectifier circuit are connected, and the LED light-emitting circuit includes a first LED light string, a second LED light string, a third LED light string, a first integrated circuit, a second integrated circuit, a first resistor, a second resistor and a first diode, wherein the first diode is a rectifier diode, and the first LED light string and the second LED light string are connected. The strings have the same characteristics, the resistance of the first resistor is half of the resistance of the second resistor, the first integrated circuit and the second integrated circuit are respectively implemented by a three-terminal linear constant current circuit, the first integrated circuit and the second integrated circuit each have an output terminal, an adjustment terminal and a negative electrode, the first LED light string, the second LED light string and the third LED light string each have a positive electrode and a negative electrode, the positive electrode of the third LED light string is the positive electrode of the LED light-emitting circuit, the negative electrode of the third LED light string, the positive electrode of the first LED light string and the output terminal of the second integrated circuit are connected, the adjustment terminal of the second integrated circuit, one end of the second resistor and the negative electrode of the first diode are connected, the other end of the second resistor, the negative electrode of the second integrated circuit and the positive electrode of the second LED light string are connected, the positive electrode of the first diode, the negative electrode of the first LED light string and the output terminal of the first integrated circuit are connected, the adjustment terminal of the first integrated circuit, one end of the first resistor and the negative electrode of the second LED light string are connected, the other end of the first resistor and the negative electrode of the first integrated circuit are connected, and the connection end is the negative electrode of the LED light-emitting circuit.

The linear conversion circuit includes a third integrated circuit of model BP5218EC and a third resistor, the BUS pin of the third integrated circuit is the positive electrode of the linear conversion circuit, the CS pin of the third integrated circuit is connected to one end of the third resistor, the other end of the third resistor is connected to the GND pin of the third integrated circuit, and the connection end is the constant current output end of the linear conversion circuit, and the HV pin of the third integrated circuit is the power storage connection end of the linear conversion circuit.

The energy storage circuit includes a fourth resistor and a first capacitor, the first capacitor is an electrolytic capacitor, one end of the fourth resistor is connected to the positive electrode of the first capacitor, and its connection end is the positive electrode of the energy storage circuit, and the other end of the fourth resistor is connected to the negative electrode of the first capacitor, and its connection end is the negative electrode of the energy storage circuit.

The full-bridge rectifier circuit is a full-bridge rectifier bridge stack, which has two AC input pins, a positive voltage output pin and a negative voltage output pin. The two AC input pins of the full-bridge rectifier bridge stack are the first input end and the second input end of the full-bridge rectifier circuit, the positive voltage output pin of the full-bridge rectifier bridge stack is the positive output end of the full-bridge rectifier circuit, and the negative voltage output pin of the full-bridge rectifier bridge stack is the negative output end of the full-bridge rectifier circuit.

The three-terminal linear constant current circuit adopts an integrated circuit of model SM2082.

Compared with the prior art, the utility model has the advantage that an LED light-emitting circuit is formed by a first LED light string, a second LED light string, a third LED light string, a first integrated circuit, a second integrated circuit, a first resistor, a second resistor and a first diode, the first resistor is used to set the maximum current flowing through the output end of the first integrated circuit, the second resistor is used to set the maximum current flowing through the output end of the second integrated circuit, the maximum current of the output end of the first integrated circuit is twice the maximum current of the output end of the second integrated circuit, the maximum current of the output end of the first integrated circuit is less than the maximum output current of the constant current output end of the linear conversion circuit, and when the first input end and the second input end of the full-bridge rectifier current are connected to the rated voltage of the mains, the maximum output current of the constant current output end of the linear conversion circuit is The maximum voltage is greater than or equal to the sum of the operating voltages of the first LED light string, the second LED light string and the third LED light string, and the current output by the constant current output end of the linear conversion circuit is its maximum output current. At this time, the current output by the constant current output end of the linear conversion circuit passes through the third LED light string, the first LED light string, the first diode, the second resistor, the second LED light string, the first resistor to the negative electrode of the LED light-emitting circuit. When this current passes through the first resistor and the second resistor, the current at the output end of the first integrated circuit and the output end of the second integrated circuit are both 0, and the currents flowing through the first LED light string, the second LED light string and the third LED light string are all the maximum output currents of the constant current output end of the linear conversion circuit, that is, under the rated voltage of the mains, the wide voltage linear The constant current LED lamp circuit has a high luminous efficiency; when the mains voltage fluctuates, the first input end and the second input end of the full-bridge rectifier current are connected to a lower mains voltage, and the maximum voltage output at the constant current output end of the linear conversion circuit is less than the sum of the operating voltages of the first LED light string, the second LED light string and the third LED light string, but greater than or equal to the sum of the operating voltages of the first LED light string and the third LED light, the current output from the constant current output end of the linear conversion circuit is split after passing through the third LED light string, half of the current passes through the first LED light string, the first integrated circuit and the first resistor and then reaches the negative pole of the LED light-emitting circuit, and the other half of the current passes through the second integrated circuit, the second resistor, the second LED light string and the first resistor and then reaches the negative pole of the LED light-emitting circuit. , the current flowing through the first diode is 0. Although in this case the current flowing through the first LED light string and the second LED light string are both half of the current flowing through the third LED light string, and the current flowing through the third LED light string is also slightly smaller than the maximum output current of the constant current output end of the linear conversion circuit, the first LED light string, the second LED light string and the third LED light string can all emit light and maintain a relatively high luminous brightness, that is, the wide voltage linear constant current LED lamp circuit of the present invention can still maintain a relatively high luminous brightness within a certain voltage range when the mains voltage is reduced; therefore, the present invention has a relatively high luminous efficiency when connected to the rated voltage of the mains, and can still maintain a relatively high luminous brightness within a certain voltage range when the mains voltage fluctuation is reduced, and has fewer restrictions on application areas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a structural diagram of an existing linear constant current LED lamp circuit and a wide voltage linear constant current LED lamp circuit of the present utility model;

FIG2 is a structural diagram of an LED light-emitting circuit of a wide-voltage linear constant-current LED lamp circuit of the present invention;

FIG3 is a partial circuit diagram of an LED light-emitting circuit of a wide-voltage linear constant-current LED lamp circuit of the present invention.

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings.

Embodiment 1: As shown in FIG. 1 and FIG. 2, a wide voltage linear constant current LED lamp circuit includes a full-bridge rectifier circuit, a linear conversion circuit, an energy storage circuit and an LED light-emitting circuit. The full-bridge rectifier circuit has a first input terminal, a second input terminal, a positive output terminal and a negative output terminal. The linear conversion circuit has a positive electrode, a negative electrode, a current output terminal and a power storage connection terminal. The constant current output terminal of the linear conversion circuit is provided with a maximum output current. The energy storage circuit has a positive electrode and a negative electrode. The LED light-emitting circuit has a positive electrode and a negative electrode. The positive electrode of the linear conversion circuit is connected to the positive output terminal of the full-bridge rectifier circuit. The linear conversion circuit The power storage connection end of the circuit is connected to the positive electrode of the energy storage circuit, the constant current output end of the linear conversion circuit is connected to the positive electrode of the LED light-emitting circuit, the negative electrode of the energy storage circuit, the negative electrode of the LED light-emitting circuit and the negative output end of the full-bridge rectifier circuit are connected, and the LED light-emitting circuit includes a first LED light string, a second LED light string, a third LED light string, a first integrated circuit U1, a second integrated circuit U2, a first resistor R1, a second resistor R2 and a first diode D1, wherein the first diode D1 is a rectifier diode, the first LED light string and the second LED light string have the same characteristics, and the first resistor R1 The resistance value is half of the resistance value of the second resistor R2. The first integrated circuit U1 and the second integrated circuit U2 are respectively implemented by a three-terminal linear constant current circuit. The three-terminal linear constant current circuit adopts an integrated circuit of model SM2082. The first integrated circuit U1 and the second integrated circuit U2 both have an output terminal, an adjustment terminal and a cathode. The first LED light string, the second LED light string and the third LED light string all have a positive electrode and a negative electrode. The positive electrode of the third LED light string is the positive electrode of the LED light-emitting circuit. The cathode of the third LED light string, the positive electrode of the first LED light string and the input terminal of the second integrated circuit U2 The output end is connected, the adjustment end of the second integrated circuit U2, one end of the second resistor R2 and the cathode of the first diode D1 are connected, the other end of the second resistor R2, the cathode of the second integrated circuit U2 and the anode of the second LED light string are connected, the anode of the first diode D1, the cathode of the first LED light string and the output end of the first integrated circuit U1 are connected, the adjustment end of the first integrated circuit U1, one end of the first resistor R1 and the cathode of the second LED light string are connected, the other end of the first resistor R1 is connected to the cathode of the first integrated circuit U1, and its connection end is the cathode of the LED light-emitting circuit.

In the wide voltage linear constant current LED lamp circuit of the present embodiment, the first resistor R1 of the LED light emitting circuit is used to set the maximum current flowing through the output end of the first integrated circuit U1, and the second resistor R2 is used to set the maximum current flowing through the output end of the second integrated circuit U2. The maximum current of the output end of the first integrated circuit U1 is less than the maximum output current of the constant current output end of the linear conversion circuit, and since the resistance value of the first resistor R1 is half of the resistance value of the second resistor R2, the maximum current of the output end of the first integrated circuit U1 is twice the maximum current of the output end of the second integrated circuit U2. When the first input end and the second input end of the full-bridge rectifier current are connected to the rated voltage of the mains, the maximum output current of the constant current output end of the linear conversion circuit is The maximum voltage is greater than or equal to the sum of the operating voltages of the first LED light string, the second LED light string and the third LED light string, and the current output by the constant current output end of the linear conversion circuit is its maximum output current. At this time, the current output by the constant current output end of the linear conversion circuit passes through the third LED light string, the first LED light string, the first diode D1, the second resistor R2, the second LED light string, the first resistor R1 to the negative electrode of the LED light-emitting circuit. When the first resistor R1 and the second resistor R2 pass through this current, the current at the output end of the first integrated circuit U1 and the output end of the second integrated circuit U2 are both 0, and the current flowing through the first LED light string, the second LED light string and the third LED light string are all the current of the constant current output end of the linear conversion circuit. The maximum output current, that is, under the rated voltage of the mains, the wide voltage linear constant current LED lamp circuit of the utility model has a higher luminous efficiency; when the mains voltage fluctuates, the first input terminal and the second input terminal of the full-bridge rectifier current are connected to a lower mains voltage, and the maximum voltage output at the constant current output terminal of the linear conversion circuit is less than the sum of the operating voltages of the first LED light string, the second LED light string and the third LED light string, but greater than or equal to the sum of the operating voltages of the first LED light string and the third LED light, the current output from the constant current output terminal of the linear conversion circuit passes through the third LED light string and is shunted, and half of the current passes through the first LED light string, the first integrated circuit U1 and the first resistor R1 and then to the negative pole of the LED light-emitting circuit. The other half of the current passes through the second integrated circuit U2, the second resistor R2, the second LED light string and the first resistor R1 and then reaches the negative electrode of the LED light-emitting circuit. The current flowing through the first diode D1 is 0. Although in this case the currents flowing through the first LED light string and the second LED light string are both half of the current flowing through the third LED light string, and the current flowing through the third LED light string is also slightly smaller than the maximum output current of the constant current output end of the linear conversion circuit, the first LED light string, the second LED light string and the third LED light string can all emit light and maintain a relatively high light brightness, that is, the wide voltage linear constant current LED lamp circuit of the present invention can still maintain a relatively high light brightness within a certain voltage range where the mains voltage is reduced.

It can be seen from this that the wide voltage linear constant current LED lamp circuit of the utility model can not only meet the current requirements on harmonics and flicker, maintain a high luminous efficiency when the rated voltage of the mains is input, but also maintain a high luminous brightness and luminous efficiency within a certain voltage range when the mains voltage is reduced, and can make all the LED light-emitting bodies used (the first LED light string, the second LED light string and the third LED light string) emit light. It can be suitable for the high luminous efficiency requirements in areas with stable mains voltage, and can also be used in areas with unstable mains voltage and where the mains voltage fluctuates within a certain voltage range, while achieving high luminous efficiency and maintaining the luminous function, and the application area has been expanded.

Embodiment 2: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, as shown in FIG. 3 , the linear conversion circuit includes a third integrated circuit U3 of model BP5218EC and a third resistor R3, the BUS pin of the third integrated circuit U3 is the positive electrode of the linear conversion circuit, the CS pin of the third integrated circuit U3 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to the GND pin of the third integrated circuit U3, and the connection end thereof is the constant current output end of the linear conversion circuit, and the HV pin of the third integrated circuit U3 is the power storage connection end of the linear conversion circuit.

In the linear conversion circuit of this embodiment, the maximum output current of the constant current output end of the linear conversion circuit can be set by changing the resistance value of the third resistor R3, which is convenient to set.

Embodiment 3: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, as shown in FIG. 3 , the energy storage circuit includes a fourth resistor R4 and a first capacitor C1, the first capacitor C1 is an electrolytic capacitor, one end of the fourth resistor R4 is connected to the positive electrode of the first capacitor C1, and its connection end is the positive electrode of the energy storage circuit, and the other end of the fourth resistor R4 is connected to the negative electrode of the first capacitor C1, and its connection end is the negative electrode of the energy storage circuit.

Embodiment 4: This embodiment is basically the same as Embodiment 1, except that: in this embodiment, as shown in Figure 3, the full-bridge rectifier circuit is a full-bridge rectifier bridge stack Db, and the full-bridge rectifier bridge stack Db has two AC input pins, a positive voltage output pin and a negative voltage output pin. The two AC input pins of the full-bridge rectifier bridge stack Db are the first input terminal and the second input terminal of the full-bridge rectifier circuit, the positive voltage output pin of the full-bridge rectifier bridge stack Db is the positive output terminal of the full-bridge rectifier circuit, and the negative voltage output pin of the full-bridge rectifier bridge stack Db is the negative output terminal of the full-bridge rectifier circuit.

Claims (5)

1. The wide-voltage linear constant-current LED lamp circuit comprises a full-bridge rectifying circuit, a linear conversion circuit, an energy storage circuit and an LED luminous circuit, wherein the full-bridge rectifying circuit is provided with a first input end, a second input end, a positive output end and a negative output end, the linear conversion circuit is provided with a positive electrode, a negative electrode, a current output end and an electricity storage connection end, the constant-current output end of the linear conversion circuit is provided with a maximum output current, the energy storage circuit is provided with a positive electrode and a negative electrode, the LED luminous circuit is provided with a positive electrode and a negative electrode, the positive electrode of the full-bridge rectifying circuit is connected with the positive electrode of the energy storage circuit, the electricity storage connection end of the linear conversion circuit is connected with the positive electrode of the LED luminous circuit, the negative pole of the energy storage circuit, the negative pole of the LED light-emitting circuit and the negative output end of the full-bridge rectifying circuit are connected, and the LED light-emitting circuit is characterized by comprising a first LED lamp string, a second LED lamp string, a third LED lamp string, a first integrated circuit, a second integrated circuit, a first resistor, a second resistor and a first diode, wherein the first diode is a rectifying diode, the first LED lamp string and the second LED lamp string have the same characteristics, the resistance value of the first resistor is half of the resistance value of the second resistor, the first integrated circuit and the second integrated circuit are respectively realized by three-terminal linear constant current circuits, the first integrated circuit and the second integrated circuit are respectively provided with an output end, an adjusting end and a negative pole, the first LED lamp string, the second LED lamp string and the third LED lamp string are respectively provided with a positive pole and a negative pole, the LED lamp comprises a first LED lamp string, a second LED lamp string, a third LED lamp string, a first integrated circuit, a second integrated circuit, a first resistor, a second resistor, a first diode, a second diode, a first resistor, a second resistor, a first LED lamp string, a second diode, a first LED lamp string and a second LED lamp string.

2. The wide-voltage linear constant-current LED lamp circuit according to claim 1, wherein the linear conversion circuit comprises a third integrated circuit with the model BP5218EC and a third resistor, wherein a BUS pin of the third integrated circuit is a positive electrode of the linear conversion circuit, a CS pin of the third integrated circuit is connected with one end of the third resistor, the other end of the third resistor is connected with a GND pin of the third integrated circuit, and the connection end of the third resistor is a constant-current output end of the linear conversion circuit, and a HV pin of the third integrated circuit is a power storage connection end of the linear conversion circuit.

3. The wide-voltage linear constant-current LED lamp circuit according to claim 1, wherein the energy storage circuit comprises a fourth resistor and a first capacitor, the first capacitor is an electrolytic capacitor, one end of the fourth resistor is connected with the positive electrode of the first capacitor, the connecting end of the fourth resistor is the positive electrode of the energy storage circuit, the other end of the fourth resistor is connected with the negative electrode of the first capacitor, and the connecting end of the fourth resistor is the negative electrode of the energy storage circuit.

4. The wide-voltage linear constant-current LED lamp circuit according to claim 1, wherein the full-bridge rectifier circuit is a full-bridge rectifier bridge stack, the full-bridge rectifier bridge stack is provided with two alternating-current input pins, a positive voltage output pin and a negative voltage output pin, the two alternating-current input pins of the full-bridge rectifier bridge stack are a first input end and a second input end of the full-bridge rectifier circuit, the positive voltage output pin of the full-bridge rectifier bridge stack is a positive output end of the full-bridge rectifier circuit, and the negative voltage output pin of the full-bridge rectifier bridge stack is a negative output end of the full-bridge rectifier circuit.

5. The wide-voltage linear constant-current LED lamp circuit according to claim 1, wherein the three-terminal linear constant-current circuit is an integrated circuit with a model number of SM 2082.