Silicon controlled rectifier dimming linear LED drive circuit

Abstract

The utility model provides a silicon controlled rectifier dimming linear LED (light-emitting diode) driving circuit, which comprises a rectifying circuit, a power factor and total harmonic distortion control circuit and a silicon controlled rectifier dimming linear LED constant-current control circuit, and is characterized in that a first terminal and a second terminal of the rectifying circuit are used for connecting two ends of an alternating-current power supply; the third terminal is connected to the first terminal of the power factor and total harmonic distortion control circuit, and the fourth terminal is grounded; a first terminal, a second terminal, a third terminal and a fourth terminal of the power factor and total harmonic distortion control circuit are respectively connected to a first terminal, a second terminal, a third terminal and a fourth terminal of the silicon controlled dimming linear LED constant current control circuit, and a fifth terminal is grounded; and a fifth terminal and a sixth terminal of the silicon controlled dimming linear LED constant current control circuit are used for connecting two ends of an LED lamp string, and a seventh terminal is grounded.

Description

TECHNICAL FIELD

[0001] The utility model relates to a circuit field especially relates to a silicon controlled rectifier light regulating linear LED drive circuit. BACKGROUND

[0002] Although the traditional light emitting diode (LED) linear silicon controlled rectifier light regulating scheme can realize that power factor (PF) is greater than 0.9 and total harmonic distortion (THD) is less than 25%, but compared with the switching power supply scheme of electrolytic capacitor and inductance magnetic device, the system efficiency is low (the system efficiency is all less than 70%). The switching power supply scheme of electrolytic capacitor and inductance magnetic device cannot adapt to small volume applications such as bulb, filament lamp and the like due to the oversized driving circuit volume, and due to the multiple circuit devices, the system cost is too high, cannot satisfy the low cost requirement of customers. SUMMARY

[0003] According to the silicon controlled rectifier light regulating linear LED drive circuit of the utility model embodiment, including rectifier circuit, power factor (PF) and total harmonic distortion (THD) control circuit and silicon controlled rectifier light regulating linear LED constant current control circuit, wherein: the first terminal and the second terminal of rectifier circuit are used to connect the two ends of alternating current power supply, the third terminal is connected to the first terminal of PF and THD control circuit, the fourth terminal is grounded;The first terminal, the second terminal, the third terminal and the fourth terminal of PF and THD control circuit are connected to the first terminal, the second terminal, the third terminal and the fourth terminal of silicon controlled rectifier light regulating linear LED constant current control circuit respectively, and the fifth terminal is grounded;The fifth terminal and the sixth terminal of silicon controlled rectifier light regulating linear LED constant current control circuit are used to connect the two ends of LED lamp string, and the seventh terminal is grounded.

[0004] In some embodiments, the PF and THD control circuit includes a first control chip including a high voltage power supply pin, a first capacitor charging control switch tube drain pin, a second capacitor charging control switch tube drain pin, an internal switch tube drain pin, a first charging current sampling pin, a second charging current sampling pin, a communication pin, and a ground pin. The high voltage power supply pin of the first control chip is connected to the third terminal of the silicon controlled rectifier dimming linear LED constant current control circuit as the third terminal of the PF and THD control circuit. The communication pin of the first control chip is connected to the fourth terminal of the silicon controlled rectifier dimming linear LED constant current control circuit as the fourth terminal of the PF and THD control circuit. The first control chip includes a first power switch tube, a second power switch tube, and a third power switch tube, wherein: the drain and source of the first power switch tube are connected to the first capacitor charging control switch tube drain pin and the first charging current sampling pin, respectively, the drain and source of the second power switch tube are connected to the second capacitor charging control switch tube drain pin and the second charging current sampling pin, respectively, and the drain and source of the third power switch tube are connected to the internal switch tube drain pin and the first capacitor charging control switch tube drain pin, respectively. The first capacitor charging control switch tube drain pin is connected to the second terminal of the PF and THD control circuit via a first electrolytic capacitor and is connected to the first terminal of the PF and THD control circuit via the first electrolytic capacitor and a first diode, the second capacitor charging control switch tube drain pin is connected to the first terminal of the PF and THD control circuit via a second electrolytic capacitor and a second diode and is connected to the fifth terminal of the PF and THD control circuit via a third diode, the first charging current sampling pin is connected to the fifth terminal of the PF and THD control circuit via a first resistor, the second charging current sampling pin is connected to the fifth terminal of the PF and THD control circuit via a second resistor, and the internal switch tube drain pin is connected to the first terminal of the PF and THD control circuit via the second diode and is connected to the fifth terminal of the PF and THD control circuit via the second electrolytic capacitor and the third diode.

[0005] In some embodiments, the silicon controlled rectifier dimming linear LED constant current control circuit includes a second control chip including a high voltage power supply pin, an internal switch tube drain pin, a communication and PF control multiplexing pin, a current sensing pin, a high voltage maintaining current detection pin, and a ground pin. The high voltage power supply pin of the second control chip is connected to the third terminal of the silicon controlled rectifier dimming linear LED constant current control circuit. Alternatively, the high voltage power supply pin of the second control chip is connected to the sixth terminal of the PF and THD control circuit as the eighth terminal of the silicon controlled rectifier dimming linear LED constant current control circuit.

[0006] In some embodiments, the thyristor dimming linear LED drive circuit further comprises a power supply circuit, wherein the first terminal of the power supply circuit is connected to the second terminal of the rectifier circuit, the second terminal is connected to the high-voltage power supply pin of the second control chip, and the third terminal is grounded, and the high-voltage power supply pin of the second control chip serves as the eighth terminal of the thyristor dimming linear LED constant current control circuit.

[0007] In some embodiments, the thyristor dimming linear LED drive circuit further comprises a power supply circuit, wherein the first terminal of the power supply circuit is connected to the third terminal of the rectifier circuit, the second terminal is connected to the high-voltage power supply pin of the second control chip, and the third terminal is grounded, and the high-voltage power supply pin of the second control chip serves as the eighth terminal of the thyristor dimming linear LED constant current control circuit.

[0008] In some embodiments, the thyristor dimming linear LED drive circuit further comprises a power supply circuit, wherein the first terminal and the second terminal of the power supply circuit are respectively connected to the first terminal and the second terminal of the rectifier circuit, the third terminal is connected to the high-voltage power supply pin of the second control chip, and the fourth terminal is grounded, and the high-voltage power supply pin of the second control chip serves as the eighth terminal of the thyristor dimming linear LED constant current control circuit.

[0009] In some embodiments, the thyristor dimming linear LED drive circuit further comprises a power supply circuit, wherein the first terminal of the power supply circuit is connected to the first terminal of the rectifier circuit, the second terminal is connected to the high-voltage power supply pin of the second control chip, and the third terminal is grounded, and the high-voltage power supply pin of the second control chip serves as the eighth terminal of the thyristor dimming linear LED constant current control circuit. BRIEF DESCRIPTION OF DRAWINGS

[0010] The utility model can be better understood from the following description of the specific implementation of the utility model in combination with the drawings, in which:

[0011] FIG. 1A It is the circuit structure schematic diagram of the thyristor dimming linear LED drive circuit according to the utility model embodiment.

[0012] FIG. 1B It is the circuit structure schematic diagram of the thyristor dimming linear LED drive circuit according to another embodiment of the utility model.

[0013] FIG. 1C It is the circuit structure schematic diagram of the thyristor dimming linear LED drive circuit according to another embodiment of the utility model.

[0014] FIG. 1D It is the circuit structure schematic diagram of the thyristor dimming linear LED drive circuit according to another embodiment of the utility model.

[0015] FIG. 1Eis a circuit structure schematic diagram of the silicon controlled rectifier dimming linear LED driving circuit according to another embodiment of the utility model.

[0016] FIG. 1F is a circuit structure schematic diagram of the silicon controlled rectifier dimming linear LED driving circuit according to another embodiment of the utility model.

[0017] FIG. 2 is a circuit structure schematic diagram of FIGS. 1A-1F The waveform diagram of rectified sine wave voltage and rectified input current generated by the rectifier circuit shown in the figure to the alternating input voltage.

[0018] FIG. 3 is a circuit structure schematic diagram of FIGS. 1A-1F The internal circuit structure and pin layout schematic diagram of the control circuit U1 shown in the figure.

[0019] FIG. 4 is a circuit structure schematic diagram of FIGS. 1A-1F The internal circuit structure and pin layout schematic diagram of the control circuit U2 shown in the figure. DETAILED DESCRIPTION

[0020] The features and exemplary embodiments of each aspect of the utility model will be described in detail below. In the following detailed description, many specific details are proposed in order to provide a comprehensive understanding of the utility model. However, it is obvious to those skilled in the art that the utility model can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the utility model by showing examples of the utility model. The utility model is never limited to any specific configuration proposed below, but covers any modification, replacement and improvement of elements and components without departing from the spirit of the utility model. In the drawings and the following description, the known structures and technologies are not shown in order to avoid unnecessary obscuring of the utility model. In addition, it should be noted that the phrase "A is connected with B" used herein can mean "A is directly connected with B" or "A is indirectly connected with B via one or more other elements".

[0021] In view of one or more problems existing in the traditional LED linear silicon controlled rectifier dimming scheme and the switching power supply scheme using electrolytic capacitor and inductive magnetic device, the silicon controlled rectifier dimming linear LED driving circuit according to the embodiment of the utility model is proposed, which can realize efficient regulation of PF and THD through lower system cost and smaller circuit volume.

[0022] FIG. 1A is a circuit structure schematic diagram of the silicon controlled rectifier dimming linear LED driving circuit according to the embodiment of the utility model. As FIG. 1AAs shown, in some embodiments, the SCR-modulated optical LED driver circuit 100A includes a rectifier circuit 102, a power factor (PF) and power density (THD) control circuit 104, and a SCR-modulated optical LED constant current control circuit 106. Specifically: the first and second terminals of the rectifier circuit 102 are connected to the two ends of an AC power supply; the third terminal is connected to the first terminal of the PF and THD control circuit 104; and the fourth terminal is grounded. The first, second, third, and fourth terminals of the PF and THD control circuit 104 are respectively connected to the first, second, third, and fourth terminals of the SCR-modulated optical LED constant current control circuit 106; and the fifth terminal is grounded. The fifth and sixth terminals of the SCR-modulated optical LED constant current control circuit 106 are connected to the two ends of an LED string; and the seventh terminal is grounded.

[0023] like FIG. 1A As shown, in some embodiments, the rectifier circuit 102 includes a fuse resistor F1 and a rectifier bridge BD1.

[0024] like FIG. 1A As shown, in some embodiments, the PF and THD control circuit 104 includes a control chip U1, diodes D1, D2, and D5, electrolytic capacitors C1 and C2, and resistors R1 and R2. Specifically: diode D1 prevents electrolytic capacitor C1 from discharging through resistor R3 in the thyristor-controlled optical LED constant current control circuit 106; diode D2 prevents electrolytic capacitor C2 from discharging through diode D1 and resistor R3 in the thyristor-controlled optical LED constant current control circuit 106; diode D5 provides a discharge path for electrolytic capacitor C2; electrolytic capacitor C1 stores energy in the second stage after rectified sinusoidal voltage (generated by rectifier circuit 102 rectifying the AC input voltage); electrolytic capacitor C2 stores energy in the third stage after rectified sinusoidal voltage; resistor R1 sets the charging current of electrolytic capacitor C1; and resistor R2 sets the charging current of electrolytic capacitor C2. Here, the high-voltage power supply pin (i.e., HV pin) of the control chip U1 is connected as the third terminal of the PF and THD control circuit 104 to the third terminal of the thyristor-controlled optical LED constant current control circuit 106.

[0025] like FIG. 1AAs shown, in some embodiments, the thyristor dimming linear LED constant current control circuit 106 includes a control chip U2, a diode D4, an electrolytic capacitor C4, resistors R3, R4, R5, and R6, and a voltage-dependent resistor MOV1, wherein: the diode D4 functions to prevent the electrolytic capacitor C4 from reverse charging the electrolytic capacitor C1 in the PF and THD control circuit 104; the electrolytic capacitor C4 functions to provide a filtering function for the system output current (i.e., the current flowing through the LED lamp string); the resistor R3 functions to limit the current flowing into the HVB pin; the resistor R4 functions to discharge the electrolytic capacitor C4 after the system is powered off; the resistor R5 functions to set the size of the system output current; the resistor R6 functions to set the size of the PF control current in the first stage of the rectified sinusoidal wave voltage; and the voltage-dependent resistor MOV1 functions to absorb ringing wave energy and ensure safe operation of the system. Here, the high-voltage supply pin (i.e., the HV pin) of the control chip U2 is connected to the third terminal of the thyristor dimming linear LED constant current control circuit 106.

[0026] FIG. 1A The thyristor dimming linear LED drive circuit 100A as shown can be applied to scenarios in which the PF is greater than 0.9 and the dimming angle is greater than 27 degrees.

[0027] FIG. 1B is a circuit structure schematic diagram illustrating a thyristor dimming linear LED drive circuit according to another embodiment of the present application. As shown in FIG. 1A and FIG. 1B As shown, the thyristor dimming linear LED drive circuit 100B differs from the thyristor dimming linear LED drive circuit 100A in that the HV pin of the control chip U2 in the thyristor dimming linear LED constant current control circuit 106 is used as the eighth terminal of the thyristor dimming linear LED constant current control circuit 106 and is connected to the sixth terminal of the PF and THD control circuit 104.

[0028] Compared with FIG. 1A the thyristor dimming linear LED drive circuit 100A as shown, FIG. 1B the system efficiency and system dimming travel of the thyristor dimming linear LED drive circuit 100B as shown are optimized, while the system cost remains unchanged, and the circuit can be applied to scenarios in which the PF is greater than 0.9 and the dimming angle is greater than 25 degrees.

[0029] FIG. 1C is a circuit structure schematic diagram illustrating a thyristor dimming linear LED drive circuit according to another embodiment of the present application. As shown in FIG. 1A and FIG. 1CAs shown, the difference between the thyristor dimming linear LED drive circuit 100C and the thyristor dimming linear LED drive circuit 100A is that, in addition to including the rectifier circuit 102, the PF and THD control circuit 104, and the thyristor dimming linear LED constant current control circuit 106, it further includes a power supply circuit 108-1, wherein: the first terminal of the power supply circuit 108-1 is connected to the second terminal of the rectifier circuit 102, the second terminal is connected to the HV pin of the control chip U2 in the thyristor dimming linear LED constant current control circuit 106, and the third terminal is grounded; the HV pin of the control chip U2 in the thyristor dimming linear LED constant current control circuit 106 is used as the eighth terminal of the thyristor dimming linear LED constant current control circuit 106. In some examples, the power supply circuit 108-1 includes a rectifier diode D3 and a filter capacitor C3.

[0030] Compared with FIG. 1A the thyristor dimming linear LED drive circuit 100A / B shown in FIG. 1A / B, FIG. 1C the system dimming stroke of the thyristor dimming linear LED drive circuit 100C shown in FIG. 1C is optimized, but the system cost is increased, and it can be applied to scenes where the dimming stroke is preferred.

[0031] FIG. 1D is a circuit structure schematic diagram illustrating a thyristor dimming linear LED drive circuit according to another embodiment of the present application. As shown in FIG. 1D, FIG. 1A and FIG. 1D The difference between the thyristor dimming linear LED drive circuit 100D and the thyristor dimming linear LED drive circuit 100A is that, in addition to including the rectifier circuit 102, the PF and THD control circuit 104, and the thyristor dimming linear LED constant current control circuit 106, it further includes a power supply circuit 108-2, wherein: the first terminal of the power supply circuit 108-2 is connected to the third terminal of the rectifier circuit 102, the second terminal is connected to the HV pin of the control chip U2 in the thyristor dimming linear LED constant current control circuit 106, and the third terminal is grounded; the HV pin of the control chip U2 in the thyristor dimming linear LED constant current control circuit 106 is used as the eighth terminal of the thyristor dimming linear LED constant current control circuit 106. In some examples, the power supply circuit 108-2 includes a rectifier diode D6 and a filter capacitor C3.

[0032] Compared with FIG. 1C the thyristor dimming linear LED drive circuit 100C shown in FIG. 1C, FIG. 1D the system dimming stroke of the thyristor dimming linear LED drive circuit 100D shown in FIG. 1D is further optimized, and it can be applied to scenes where the dimming stroke is preferred.

[0033] FIG. 1Eis a circuit structure schematic diagram of the silicon-controlled dimming linear LED drive circuit according to another embodiment of the utility model. FIG. 1A and FIG. 1E As shown in the silicon-controlled dimming linear LED drive circuit 100E and the silicon-controlled dimming linear LED drive circuit 100A, in addition to including the rectifier circuit 102, the PF and THD control circuit 104 and the silicon-controlled dimming linear LED constant current control circuit 106, it further includes the power supply circuit 108-3, wherein: the first terminal and the second terminal of the power supply circuit 108-3 are connected to the first terminal and the second terminal of the rectifier circuit 102 respectively, the third terminal is connected to the HV pin of the control chip U2 in the silicon-controlled dimming linear LED constant current control circuit 106, and the fourth terminal is grounded; the HV pin of the control chip U2 in the silicon-controlled dimming linear LED constant current control circuit 106 is used as the eighth terminal of the silicon-controlled dimming linear LED constant current control circuit 106. In some examples, the power supply circuit 108-3 includes rectifier diodes D3 and D6 and a filter capacitor C3.

[0034] Compared with the silicon-controlled dimming linear LED drive circuit 100D shown in FIG. 1D , FIG. 1E The system dimming stroke of the silicon-controlled dimming linear LED drive circuit 100E shown in is further optimized, but the system cost is higher, and it can be applied to scenes where the dimming stroke is preferred.

[0035] FIG. 1F is a circuit structure schematic diagram of the silicon-controlled dimming linear LED drive circuit according to another embodiment of the utility model. As shown in FIG. 1A and FIG. 1F As shown in the silicon-controlled dimming linear LED drive circuit 100F and the silicon-controlled dimming linear LED drive circuit 100A, in addition to including the rectifier circuit 102, the PF and THD control circuit 104 and the silicon-controlled dimming linear LED constant current control circuit 106, it further includes the power supply circuit 108-4, wherein: the first terminal of the power supply circuit 108-4 is connected to the first terminal of the rectifier circuit 102, the second terminal is connected to the HV pin of the control chip U2 in the silicon-controlled dimming linear LED constant current control circuit 106, and the third terminal is grounded; the HV pin of the control chip U2 in the silicon-controlled dimming linear LED constant current control circuit 106 is used as the eighth terminal of the silicon-controlled dimming linear LED constant current control circuit 106. In some examples, the power supply circuit 108-4 includes rectifier diodes D6 and a filter capacitor C3.

[0036] Compared with the silicon-controlled dimming linear LED drive circuit 100E shown in FIG. 1E , FIG. 1FThe system cost of the illustrated silicon-controlled dimming linear LED driving circuit 100F is optimized, and the advantages of high system efficiency and optimal system dimming stroke are retained, which can be applied to scenarios that require both system dimming stroke and system efficiency.

[0037] FIG. 2 is a waveform diagram illustrating the rectified sine wave voltage and the rectified input current generated by the rectifier circuit FIGS. 1A-1F The illustrated rectified sine wave voltage is the rectified sine wave voltage mentioned in the description of FIG. 1A and the following is for FIG. 3 and FIG. 4 The rectified sine wave voltage mentioned in the description of FIG. 2 is the rectified sine wave voltage illustrated in

[0038] FIG. 3 is a waveform diagram illustrating the rectified sine wave voltage and the rectified input current generated by the rectifier circuit FIGS. 1A-1F The internal circuit structure and pin layout diagram of the control circuit U1 illustrated in FIG. 3 As illustrated in

[0039] The internal power supply module 302 is configured to provide internal power AVDD and reference voltage VREF[0:3] for the control chip U1 based on the voltage at the HV pin;

[0040] The PF and THD control module 304 is configured to generate switch control signals S1, S2, and S3 for controlling the turn-on and turn-off of the power switch tubes S1, S2, and S3 based on the signal at the CTRL pin;

[0041] The S3 driver module 306 is configured to drive the turn-on and turn-off of the power switch tube S3 based on the switch control signal S3;

[0042] The S2 driver module 308 is configured to drive the turn-on and turn-off of the power switch tube S2 based on the switch control signal S2; and

[0043] The S1 driver module 310 is configured to drive the turn-on and turn-off of the power switch tube S1 based on the switch control signal S1.

[0044] As illustrated in FIG. 3 In some embodiments, the control chip U1 has the following pins:

[0045] The high-voltage power supply pin (i.e., the HV pin), wherein the internal power supply module 302 provides power to each circuit module inside the control chip U1 and provides four reference voltages after voltage reduction and voltage stabilization at the HV pin;

[0046] C1 charging control switch N1 drain pin (i.e., D1 pin), wherein PF and THD control module 304 control power switch N1 to be in the conducting state in the second stage after rectification of sine wave voltage, so as to provide a charging path for electrolytic capacitor C1.

[0047] C2 charging control switch N2 drain pin (i.e., D2 pin), wherein PF and THD control module 304 control power switch N2 to be in the conducting state in the third stage after rectification of sine wave voltage, so as to provide a charging path for electrolytic capacitor C2;

[0048] The drain pin (i.e., D3 pin) of the internal switching transistor N3, where PF and THD control module 304 control the power switching transistor N3 to be in the conducting state in the first stage of the rectified sine wave voltage, and connect electrolytic capacitor C1 and electrolytic capacitor C2 in series to provide energy for the thyristor-controlled optical LED constant current control circuit 106.

[0049] The C1 charging current sampling pin (i.e., pin S1) has a resistor R1 connected between pin S1 and ground to set the charging current of electrolytic capacitor C1, thereby adjusting the PF value and THD value.

[0050] The C2 charging current sampling pin (i.e., pin S2) has a resistor R2 connected between pin S2 and ground to set the charging current of electrolytic capacitor C2, thereby adjusting the PF value and THD value.

[0051] The communication pin (i.e., the CTRL pin) is used to receive PF and THD control signals from the control chip U2 and to send status indication signals to the control chip U2 indicating whether one or more of the power switches S1, S2, and S3 are in the on or off state; and

[0052] Grounding pin (i.e., GND pin).

[0053] It should be noted that the power switches S1, S2, S3, N1, N2, and N3 can be implemented as, for example, metal-oxide-semiconductor field-effect transistors (MOSFETs).

[0054] like FIG. 3 As shown, in some embodiments, the control chip U1 includes power switch N1, power switch N2, and power switch N3. The drain and source of power switch N1 are connected to pin D1 and pin S1 of control chip U1, respectively. The drain and source of power switch N2 are connected to pin D2 and pin S2 of control chip U2, respectively. The drain and source of power switch N3 are connected to pin D3 and pin D1 of control chip U1, respectively.

[0055] like FIGS. 1A-1FAs shown, in some embodiments, the D1 pin of the control chip U1 is connected to the second terminal of the PF and THD control circuit 104 via the electrolytic capacitor C1 and is connected to the first terminal of the PF and THD control circuit 104 via the electrolytic capacitor C1 and the diode D1; the D2 pin of the control chip U1 is connected to the first terminal of the PF and THD control circuit 104 via the electrolytic capacitor C2 and the diode D2 and is connected to the fifth terminal of the PF and THD control circuit 104 via the diode D5; the S1 pin of the control chip U1 is connected to the fifth terminal of the PF and THD control circuit 104 via the resistor R1; the S2 pin of the control chip U1 is connected to the fifth terminal of the PF and THD control circuit 104 via the resistor R2; the D3 pin of the control chip U1 is connected to the first terminal of the PF and THD control circuit 104 via the diode D2 and is connected to the fifth terminal of the PF and THD control circuit via the electrolytic capacitor C2 and the diode D5.

[0056] FIG. 4 is a schematic diagram illustrating the internal circuit structure and pin layout of the control circuit U2 shown in FIGS. 1A-1F As shown, in some embodiments, the control chip U2 includes the following circuit modules: FIG. 4

[0057] the internal power supply module 402 is configured to provide the internal power supply AVDD and the reference voltage VREF[0:3] for the control chip U2 based on the voltage at the HV pin;

[0058] the communication control module 404 is configured to receive the state indication signal from the control chip U1 via the CTRL pin and transmit the received signal to the logic control module 408, and receive the PF and THD control signal from the logic control module 408 and transmit the received signal to the control chip U1, the state indication signal indicating whether one or more of the power switch tubes S1, S2, and S3 is in the on state or the off state;

[0059] the dimming control module 406 is configured to divide the voltage at the HVB pin and transmit the divided voltage to the logic control module 408;

[0060] the logic control module 408 is configured to generate the dimming mode control signal mode, the dimming angle control signal dim, and the maintenance current control signal Bleed ctr based on the signals from the communication control module 404 and the dimming control module 406;

[0061] the maintenance current control module 410 is configured to control the silicon-controlled dimming maintenance current based on the maintenance current control signal Bleed ctr;

[0062] ​LED current regulation module 412 is used to regulate the system output current based on dimming mode control signal mode and dimming angle control signal dim.

[0063] like FIG. 4 As shown, in some embodiments, the control chip U2 has the following pins:

[0064] The high-voltage power supply pin (i.e., the HV pin) is provided by the internal power supply module 402, which steps down and regulates the voltage at the HV pin to supply power to the various circuit modules inside the control chip U2 and provides a reference voltage.

[0065] The internal switching transistor drain pin (i.e., the drain pin) is used to connect the cathode of the LED lamp to the LED current regulation module 412 via the drain pin.

[0066] The communication and PF control multiplexed pin (i.e., CTRL pin) is used to send PF and THD control signals to the control chip U1 and receive a status indication signal from the control chip U1 indicating whether one or more of the power switches S1, S2 and S3 are in the on or off state. In the PF control state, it is used to set the PF control current of the first stage of the rectified sine wave voltage through resistor R6.

[0067] The current sensing pin (i.e., the CS pin) is used by the LED current regulation module 412 to generate a gate voltage value for controlling the power switch M1 based on the average voltage at the CS pin, thereby adjusting the system output current so that the average value of the system output current is the design value.

[0068] The high-voltage sustaining current detection pin (i.e., the HVB pin) is used by the dimming control module 406 to detect the voltage at the HVB pin and send the detection result to the logic control module 410. This allows the logic control module 410 to determine the operating state (non-dimming, leading-edge dimming, trailing-edge dimming, etc.) and generate corresponding sustaining current control signals, which are then sent to the sustaining current control module 410. Additionally, it generates corresponding dimming mode control signals (mode and dimming angle control signals (dim) which are sent to the LED current adjustment module 412.

[0069] Grounding pin (i.e., GND pin).

[0070] like FIGS. 1A-1F As shown, in some embodiments, the CTRL pin of the control chip U1 is connected as the fourth terminal of the PF and THD control circuit 104 to the fourth terminal of the thyristor-controlled optical LED constant current control circuit 106 (i.e., the CTRL pin of the control chip U2).

[0071] The features, structures, or characteristics described above can be combined in any suitable manner in one or more embodiments. In the above description, numerous specific details are recited to provide a full understanding of embodiments of the present application. One skilled in the relevant art will recognize, however, that the application can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring the main aspects of the application.

Claims

1. A silicon controlled rectifier (SCR) modulated linear LED driving circuit, characterized in that, This includes a rectifier circuit, a power factor and total harmonic distortion control circuit, and a thyristor-controlled optical LED constant current control circuit, wherein: The first and second terminals of the rectifier circuit are used to connect to the two ends of the AC power supply, the third terminal is connected to the first terminal of the power factor and total harmonic distortion control circuit, and the fourth terminal is grounded. The first, second, third, and fourth terminals of the power factor and total harmonic distortion control circuit are respectively connected to the first, second, third, and fourth terminals of the thyristor-controlled optical LED constant current control circuit, and the fifth terminal is grounded. The fifth and sixth terminals of the thyristor-controlled optical LED constant current control circuit are used to connect the two ends of the LED string, and the seventh terminal is grounded.

2. The thyristor-controlled dimmable linear LED driving circuit according to claim 1, characterized in that, The power factor and total harmonic distortion control circuit includes a first control chip, which includes a high-voltage power supply pin, a drain pin of a first capacitor charging control switch, a drain pin of a second capacitor charging control switch, a drain pin of an internal switch, a first charging current sampling pin, a second charging current sampling pin, a communication pin, and a ground pin.

3. The thyristor-controlled dimmable linear LED driving circuit according to claim 2, characterized in that, The high-voltage power supply pin of the first control chip is connected to the third terminal of the thyristor-controlled optical LED constant current control circuit as the third terminal of the power factor and total harmonic distortion control circuit.

4. The thyristor-controlled optical LED driving circuit according to claim 2, characterized in that, The communication pin of the first control chip is connected to the fourth terminal of the thyristor-controlled optical LED constant current control circuit as the fourth terminal of the power factor and total harmonic distortion control circuit.

5. The thyristor-controlled dimmable linear LED driving circuit according to claim 2, characterized in that, The first control chip includes a first power switch, a second power switch, and a third power switch. The drain and source of the first power switch are respectively connected to the drain pin of the first capacitor charging control switch and the first charging current sampling pin. The drain and source of the second power switch are respectively connected to the drain pin of the second capacitor charging control switch and the second charging current sampling pin. The drain and source of the third power switch are respectively connected to the drain pin of the internal switch and the drain pin of the first capacitor charging control switch.

6. The thyristor-controlled dimmable linear LED driving circuit according to claim 2, characterized in that, The drain pin of the first capacitor charging control switch is connected to the second terminal of the power factor and total harmonic distortion (THD) control circuit via a first electrolytic capacitor and to the first terminal of the power factor and THD control circuit via the first electrolytic capacitor and a first diode. The drain pin of the second capacitor charging control switch is connected to the first terminal of the power factor and THD control circuit via a second electrolytic capacitor and a second diode and to the fifth terminal of the power factor and THD control circuit via a third diode. The first charging current sampling pin is connected to the fifth terminal of the power factor and THD control circuit via a first resistor. The second charging current sampling pin is connected to the fifth terminal of the power factor and THD control circuit via a second resistor. The drain pin of the internal switch is connected to the first terminal of the power factor and THD control circuit via the second diode and to the fifth terminal of the power factor and THD control circuit via the second electrolytic capacitor and the third diode.

7. The thyristor-controlled dimmable linear LED driving circuit according to claim 2, characterized in that, The thyristor-controlled optical LED constant current control circuit includes a second control chip, which includes a high-voltage power supply pin, an internal switching transistor drain pin, a communication and power factor control multiplexing pin, a current sensing pin, a high-voltage sustaining current detection pin, and a grounding pin.

8. The thyristor-controlled dimmable linear LED driving circuit according to claim 7, characterized in that, The high-voltage power supply pin of the second control chip is connected to the third terminal of the thyristor-controlled optical LED constant current control circuit.

9. The thyristor-controlled dimmable linear LED driving circuit according to claim 7, characterized in that, The high-voltage power supply pin of the second control chip is used as the eighth terminal of the thyristor-controlled dimmable linear LED constant current control circuit and connected to the sixth terminal of the power factor and total harmonic distortion control circuit.

10. The thyristor-controlled optical LED driving circuit according to claim 7, characterized in that, It also includes a power supply circuit, wherein the first terminal of the power supply circuit is connected to the second terminal of the rectifier circuit, the second terminal is connected to the high voltage power supply pin of the second control chip, and the third terminal is grounded. The high voltage power supply pin of the second control chip is used as the eighth terminal of the thyristor-controlled dimmable linear LED constant current control circuit.

11. The thyristor-controlled dimmable linear LED driving circuit according to claim 7, characterized in that, It also includes a power supply circuit, wherein the first terminal of the power supply circuit is connected to the third terminal of the rectifier circuit, the second terminal is connected to the high voltage power supply pin of the second control chip, and the third terminal is grounded. The high voltage power supply pin of the second control chip is used as the eighth terminal of the thyristor-controlled dimmable linear LED constant current control circuit.

12. The thyristor-controlled dimmable linear LED driving circuit according to claim 7, characterized in that, It also includes a power supply circuit, wherein the first and second terminals of the power supply circuit are respectively connected to the first and second terminals of the rectifier circuit, the third terminal is connected to the high voltage power supply pin of the second control chip, and the fourth terminal is grounded. The high voltage power supply pin of the second control chip is used as the eighth terminal of the thyristor-controlled dimmable linear LED constant current control circuit.

13. The thyristor-controlled dimmable linear LED driving circuit according to claim 7, characterized in that, It also includes a power supply circuit, wherein the first terminal of the power supply circuit is connected to the first terminal of the rectifier circuit, the second terminal is connected to the high voltage power supply pin of the second control chip, and the third terminal is grounded. The high voltage power supply pin of the second control chip is used as the eighth terminal of the thyristor-controlled dimmable linear LED constant current control circuit.

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