A dual voltage adaptive LED load topology regulation circuit

Abstract

This invention relates to the field of LED lighting driver technology, and discloses a dual-voltage adaptive LED load topology adjustment circuit, comprising: an input rectification module, a load branch module, a topology control module, and a linear constant current adjustment module; the topology control module uses a voltage regulator detection branch to monitor the rectified voltage amplitude, generates a control level based on the internal semiconductor breakdown characteristics, and drives a transistor switching array to reconstruct the connection path between load branches; when the rectified voltage is in the first range, the parallel circuit is connected, and when the voltage reaches a threshold, it switches to the series circuit, and the linear constant current adjustment module regulates the current of the light-emitting device; this invention achieves spontaneous reconstruction of the load topology through hardware physical response, reduces redundant voltage drop and power loss in the driver circuit, and maintains the consistency of luminous brightness under different input voltages.

Description

Technical Field

[0001] This invention relates to a dual-voltage adaptive LED load topology adjustment circuit, belonging to the field of LED lighting driver technology. Background Technology

[0002] In the field of low-voltage DC lighting circuits, 12V and 24V power supply systems constitute the common electrical standards for automotive and industrial lighting. To maintain luminous efficiency and stabilize circuit operation, conventional driver circuits pre-set a fixed series-parallel topology of LED beads based on the rated input voltage, so that the total forward voltage drop of the LED load is close to the power supply voltage, reducing the redundant voltage shared by the driver components. As lighting equipment has increasingly higher requirements for adaptability to multi-voltage environments, a single topology is difficult to be compatible with different power supply levels. Existing dual-voltage adaptation solutions usually use switching converters or multi-stage linear buck circuits. Although they can broaden the input range, the switching frequency switching generates electromagnetic interference, and the increased number of circuit components leads to a larger driver module size, which restricts the compact design of luminaires.

[0003] To simplify control logic, some solutions attempt to use manual DIP switches or electromagnetic relays. However, manual adjustment faces the physical risk of overcurrent damage to LED chips due to operational errors, and relay contacts suffer from mechanical fatigue and contact resistance fluctuations under vibration. Simply increasing the heat dissipation area of ​​the driver components to dissipate the excessive voltage drop at a 24V input will lead to severe temperature rise and shorten the lifespan of semiconductor devices. Analysis of existing technologies reveals the following main shortcomings: 1. Balancing wide voltage compatibility requirements with electromagnetic compatibility indicators is difficult; 2. It is difficult to simultaneously achieve automatic voltage recognition mechanisms and simplified circuit design; 3. The reliability of maintaining consistent luminous flux of the LED load under different input voltages is low.

[0004] Therefore, how to construct an adaptive reconfiguration topology with physical energy level sensing capability using discrete components, achieve automatic adaptation between 12V and 24V power supply systems without generating high-frequency interference, and ensure constant current of LED load across the entire voltage range has become a technical issue that needs to be addressed by those skilled in the art. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A dual-voltage adaptive LED load topology adjustment circuit, comprising: The input rectifier module is connected to the power input terminal and is used to convert the input voltage into the system rectified voltage. The load branch module includes a first lighting branch unit and a second lighting branch unit, each of which is composed of LED light-emitting devices connected in series; The topology control module consists of a voltage regulator detection branch and a transistor switching array. The voltage regulator detection branch detects the amplitude of the system rectified voltage and generates a control level based on the reverse breakdown characteristics of the Zener diode. The transistor switching array responds to the control level to reconstruct the physical connection path between the first lighting branch unit and the second lighting branch unit. When the system rectified voltage is in the first voltage range, the voltage regulator detection branch is in the off state, driving the transistor switching array to connect the parallel circuit of the load branch module. When the system rectified voltage is in the second voltage range and reaches the reverse breakdown threshold of the Zener diode in the voltage regulator detection branch, the voltage regulator detection branch conducts and generates a bias current, driving the transistor switching array to turn off the parallel circuit and couple the cathode of the first lighting branch unit with the anode of the second lighting branch unit to form a series circuit. The linear constant current regulation module includes a feedback sampling unit. The linear constant current regulation module is connected in series in the common circuit of the load branch module and is used to regulate the operating current of the LED light-emitting device.

[0006] Preferably, the transistor switching array consists of three interconnected electronic switch modules; one end of the voltage regulation detection branch is connected to the positive output of the input rectifier module, and the other end is connected to the control reference terminal of transistors Q1 and Q4, which serve as the first electronic switch module, through a bias impedance component; the conduction path of the first electronic switch module is connected in series between the cathode of the first lighting branch unit and the linear constant current regulation module, for providing a load current branch in the first voltage range; the isolation diode D2, which serves as the second electronic switch module, is connected between the cathode of the first lighting branch unit and the anode of the second lighting branch unit, for establishing a series relay point in the second voltage range; transistors Q2 and Q3, which serve as the third electronic switch module, are connected to the control reference terminal of the second electronic switch module, for limiting the conduction state of the second electronic switch module in the first voltage range through potential clamping.

[0007] Preferably, the linear constant current regulation module further includes a constant current control module. The input terminal of the constant current control module is connected to the cathode of the second lighting branch unit, and its feedback terminal is connected to the feedback sampling unit. The linear constant current regulation module regulates the current according to the following quantization rules: ,in, This refers to the single-channel operating current of the LED light-emitting device. This is the internal reference voltage of the linear constant current regulation module. The value of the sampling resistor in the feedback sampling unit is given; the current sampling resistor corresponds to resistor R4 in the circuit diagram; the feedback sampling unit carries the sum of the currents of two lighting branches in a parallel circuit, and carries the current of a single lighting branch in a series circuit.

[0008] Preferably, the input circuit of the input rectifier module is also connected in series with a surge suppression capacitor for suppressing transient voltage surges and a protection diode for preventing reverse connection.

[0009] Preferably, the rated value of the first voltage range is 12V, and the rated value of the second voltage range is 24V; the physical breakdown threshold of the voltage regulation detection branch is between 15V and 18V.

[0010] Preferably, both the first lighting branch unit and the second lighting branch unit are composed of three LED light-emitting devices connected in series with a forward voltage drop of 3V. When the system rectified voltage rises to 24V, the physical connection path is reconstructed using a transistor switching array, and the load is reconstructed into a total of six LED light-emitting devices connected in series, so that the total voltage drop of the load branch module changes from 9V to 18V, thereby reducing the power loss of the linear constant current regulation module.

[0011] Preferably, the first electronic switch module, the second electronic switch module, and the third electronic switch module are all in a saturated conduction state or a cutoff state; the physical switching characteristics of each electronic switch module in the transistor switching array are used to complete the contactless topology reconstruction.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. By leveraging the threshold breakdown characteristics of the Zener diode and the state interlocking logic of the transistor array, the circuit achieves physical sensing and spontaneous topology reconstruction of the input voltage energy level. When the input voltage rises from 12V to 24V, the circuit utilizes the forward conduction characteristics of the diode to switch the originally parallel LED units to a series structure. This topology adjustment mechanism, which relies on the inherent physical response of the hardware, eliminates the dependence on external control logic or complex sampling algorithms, thereby improving the circuit's response speed under millisecond-level voltage fluctuations.

[0013] 2. Because the transistor array and the LED load topology form a deeply coupled closed-loop path, the circuit can maintain the total forward voltage drop of the LED load close to the input power supply voltage under different input voltage modes. This dynamic mapping of the physical structure of the load side keeps the redundant voltage shared by the linear constant current circuit in both working modes at a low range, reduces the heat loss of the driving components, and maintains the consistency of the luminous brightness of the LED beads under 12V and 24V conditions.

[0014] 3. By coordinating the layout of the current sampling resistor and the transistor base bias circuit, the circuit integrates the topology switching logic and constant current control function using only discrete components. Each LED in the circuit is in an effective working path under different voltage modes, maximizing the utilization of LED resources. Furthermore, due to the simplified number of components and compact layout, the physical size of the drive module is effectively reduced, the system's dependence on complex heat dissipation structures is reduced, and its integration and engineering feasibility in miniaturized lighting fixtures are improved. Attached Figure Description

[0015] Figure 1 This is a block diagram of the circuit module structure of the present invention; Figure 2 This is a flowchart illustrating the working principle of the present invention in the second voltage range.

[0016] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0018] A dual-voltage adaptive LED load topology regulation circuit, comprising: The input rectifier module is connected to the power input terminal and is used to convert the input voltage into the system rectified voltage. The load branch module includes a first lighting branch unit and a second lighting branch unit, each of which is composed of LED light-emitting devices connected in series; The topology control module consists of a voltage regulator detection branch and a transistor switching array. The voltage regulator detection branch detects the amplitude of the system rectified voltage and generates a control level based on the reverse breakdown characteristics of the Zener diode. The transistor switching array responds to the control level to reconstruct the physical connection path between the first lighting branch unit and the second lighting branch unit. When the system rectified voltage is in the first voltage range, the voltage regulator detection branch is in the off state, driving the transistor switching array to connect the parallel circuit of the load branch module. When the system rectified voltage is in the second voltage range and reaches the reverse breakdown threshold of the Zener diode in the voltage regulator detection branch, the voltage regulator detection branch conducts and generates a bias current, driving the transistor switching array to turn off the parallel circuit and couple the cathode of the first lighting branch unit with the anode of the second lighting branch unit to form a series circuit. The linear constant current regulation module includes a feedback sampling unit. The linear constant current regulation module is connected in series in the common circuit of the load branch module and is used to regulate the operating current of the LED light-emitting device.

[0019] Preferably, the transistor switching array consists of three interconnected electronic switch modules; one end of the voltage regulation detection branch is connected to the positive output of the input rectifier module, and the other end is connected to the control reference terminal of the first electronic switch module and the third electronic switch module through a bias impedance component; the conduction path of the first electronic switch module is connected in series between the cathode of the first lighting branch unit and the linear constant current regulation module, for providing a load current branch in the first voltage range; the second electronic switch module is connected between the cathode of the first lighting branch unit and the anode of the second lighting branch unit, for establishing a series relay point in the second voltage range; the third electronic switch module is connected to the control reference terminal of the second electronic switch module, for limiting the conduction state of the second electronic switch module in the first voltage range through potential clamping.

[0020] Preferably, the linear constant current regulation module further includes a constant current control module. The input terminal of the constant current control module is connected to the cathode of the second lighting branch unit, and its feedback terminal is connected to the feedback sampling unit. The linear constant current regulation module regulates the current according to the following quantization rules: ,in, This refers to the single-channel operating current of the LED light-emitting device. This is the internal reference voltage of the linear constant current regulation module. The value of the sampling resistor in the feedback sampling unit is given; the current sampling resistor corresponds to resistor R4 in the circuit diagram; the feedback sampling unit carries the sum of the currents of two lighting branches in a parallel circuit, and carries the current of a single lighting branch in a series circuit.

[0021] Preferably, the input circuit of the input rectifier module is also connected in series with a surge suppression capacitor for suppressing transient voltage surges and a protection diode for preventing reverse connection.

[0022] Preferably, the rated value of the first voltage range is 12V, and the rated value of the second voltage range is 24V; the physical breakdown threshold of the voltage regulation detection branch is between 15V and 18V.

[0023] Preferably, both the first lighting branch unit and the second lighting branch unit are composed of three LED light-emitting devices connected in series with a forward voltage drop of 3V. When the system rectified voltage rises to 24V, the physical connection path is reconstructed using a transistor switching array, and the load is reconstructed into a total of six LED light-emitting devices connected in series, so that the total voltage drop of the load branch module changes from 9V to 18V, thereby reducing the power loss of the linear constant current regulation module.

[0024] Preferably, the first electronic switch module, the second electronic switch module, and the third electronic switch module are all in a saturated conduction state or a cutoff state; the physical switching characteristics of each electronic switch module in the transistor switching array are used to complete the contactless topology reconstruction.

[0025] Example 1: This example combines Figures 1 to 2 The description of the dual-voltage adaptive LED load topology adjustment circuit shows that the voltage regulation detection branch specifically includes Zener diodes D1 and D3, the transistor switching array specifically includes transistors Q1, Q2, Q3, and Q4, and an isolation diode D2 connects the first lighting branch unit and the second lighting branch unit. Its automatic identification and switching process is as follows: Figure 1 As shown, in the 12VDC input operating mode: after inputting a 12V DC voltage, because the 12V voltage is lower than the reverse breakdown voltage of the Zener diodes D1 and D3, D1 and D3 remain in the off state, causing transistors Q1 and Q4 to be cut off due to the lack of base current injection; at this time, transistors Q2 and Q3 are turned on due to forward bias, and the isolation diode D2 is turned off due to reverse bias; in this state, the first lighting branch unit and the second lighting branch unit form a parallel path.

[0026] like Figure 2 As shown, in the 24VDC input operating mode: when a 24V DC voltage is input, because the voltage is higher than the breakdown threshold of Zener diodes D1 and D3, D1 and D3 undergo reverse breakdown and conduction; the breakdown current drives transistors Q1 and Q4 to turn on; the conduction of Q1 and Q4 pulls down the base potential of transistors Q2 and Q3, forcing Q2 and Q3 to turn off from on; at this time, the original parallel path is cut off, and the isolation diode D2 becomes forward biased and conducts, thereby physically connecting the cathode of the first lighting branch unit and the anode of the second lighting branch unit in series, so that the circuit spontaneously reconstructs into a total series topology.

[0027] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dual-voltage adaptive LED load topology regulation circuit, characterized in that, include: The input rectifier module is connected to the power input terminal and is used to convert the input voltage into the system rectified voltage. The load branch module includes a first lighting branch unit and a second lighting branch unit, each of which is composed of LED light-emitting devices connected in series; The topology control module consists of a voltage regulator detection branch and a transistor switching array. The voltage regulator detection branch detects the amplitude of the system rectified voltage and generates a control level based on the reverse breakdown characteristics of the Zener diode. The transistor switching array responds to the control level to reconstruct the physical connection path between the first lighting branch unit and the second lighting branch unit. When the system rectified voltage is in the first voltage range, the voltage regulator detection branch is in the off state, driving the transistor switching array to connect the parallel circuit of the load branch module. When the system rectified voltage is in the second voltage range and reaches the reverse breakdown threshold of the Zener diode in the voltage regulator detection branch, the voltage regulator detection branch is turned on and generates a bias current, driving the transistor switching array to turn off the parallel circuit and couple the cathode of the first lighting branch unit with the anode of the second lighting branch unit to form a series circuit. The linear constant current regulation module includes a feedback sampling unit. The linear constant current regulation module is connected in series in the common circuit of the load branch module and is used to regulate the operating current of the LED light-emitting device.

2. The dual-voltage adaptive LED load topology adjustment circuit according to claim 1, characterized in that, The transistor switching array consists of three interconnected electronic switch modules; one end of the voltage regulation detection branch is connected to the positive output of the input rectifier module, and the other end is connected to the control reference terminal of transistors Q1 and Q4 of the first electronic switch module through the bias impedance component; the conduction path of the first electronic switch module is connected in series between the cathode of the first lighting branch unit and the linear constant current regulation module, and is used to provide the load current branch in the first voltage range. The isolation diode D2 of the second electronic switch module is connected between the cathode of the first lighting branch unit and the anode of the second lighting branch unit to establish a series relay point in the second voltage range; the transistors Q2 and Q3 of the third electronic switch module are connected to the control reference terminal of the second electronic switch module to limit the conduction state of the second electronic switch module in the first voltage range through potential clamping.

3. The dual-voltage adaptive LED load topology adjustment circuit according to claim 2, characterized in that, The linear constant current regulation module also includes a constant current control module. The input terminal of the constant current control module is connected to the cathode of the second lighting branch unit, and its feedback terminal is connected to the feedback sampling unit. The linear constant current regulating module controls the current according to the following quantization rules: ,in, This refers to the single-channel operating current of the LED light-emitting device. This is the internal reference voltage of the linear constant current regulation module. The value of the sampling resistor in the feedback sampling unit is given; the current sampling resistor corresponds to resistor R4 in the circuit diagram; the feedback sampling unit carries the sum of the currents of two lighting branches in a parallel circuit, and carries the current of a single lighting branch in a series circuit.

4. The dual-voltage adaptive LED load topology adjustment circuit according to claim 2, characterized in that, The input circuit of the input rectifier module is also connected in series with a surge suppression capacitor to suppress transient voltage surges and a protection diode to prevent reverse connection.

5. The dual-voltage adaptive LED load topology adjustment circuit according to claim 1, characterized in that, The rated value for the first voltage range is 12V, and the rated value for the second voltage range is 24V; the physical breakdown threshold of the voltage regulation detection branch is between 15V and 18V.

6. The dual-voltage adaptive LED load topology adjustment circuit according to claim 1, characterized in that, Both the first and second lighting branch units consist of three LED light-emitting devices connected in series with a forward voltage drop of 3V. When the system rectified voltage rises to 24V, the physical connection path is reconfigured by using a transistor switching array pair to reconfigure the load into a total of six LED light-emitting devices connected in series, so that the total voltage drop of the load branch module changes from 9V to 18V, thereby reducing the power loss of the linear constant current regulation module.

7. The dual-voltage adaptive LED load topology adjustment circuit according to claim 2, characterized in that, The first, second, and third electronic switch modules are all in a saturated conduction state or a cutoff state; the physical switching characteristics of each electronic switch module in the transistor switching array are used to complete the contactless topology reconstruction.

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