Control device and control method for constant-current driving power line carrier LED light source

Abstract

The invention discloses a control device and a control method of a constant current driving power line carrier LED light source, the control device of the constant current driving power line carrier LED light source comprises a constant current source circuit connected with an alternating current source, the constant current source circuit is connected with the input end of a carrier modulation circuit, the output end of the carrier modulation circuit is connected with an LED light source circuit, and the LED light source circuit is connected with the constant current source circuit. The constant current source circuit is electrically connected with the carrier modulation circuit through the power supply step-down circuit and the carrier modulation control circuit; the constant current source circuit comprises a switch type constant current source with a buck topological structure; the LED light source is a power line carrier LED light source. According to the control device and the control method for the constant-current driving power line carrier LED light source, the output voltage can be dynamically adjusted according to the number of the load series power line carrier LED lamp beads, different numbers of lamp beads can be adapted, and series connection of resistors is not needed; a buck type constant current source with a buck topological structure is adopted, so that the problem of heating of a linear constant current source device is reduced; the system energy efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power line carrier LED light source driving, and in particular to a control device and a control method for a constant current driven power line carrier LED light source. Background Art

[0002] Constant current drive is widely used in the field of LED lighting, but in the field of LED decorative lights, constant voltage is basically used to provide power to the load because of the need to control the color and flashing mode of the lamp beads, and the constant voltage source is relatively common. In the application of LED decorative lamp beads in series, the number of series lamp beads varies due to the needs of different decorative lamp shapes, and it is difficult to design a constant voltage source with different output voltages for different numbers of series lamp beads. To meet the requirements of different numbers of lamp beads in series, it is usually used to adapt the constant voltage source by connecting different numbers of resistors in series in the lamp string. Connecting resistors of different numbers and resistance values ​​in series will cause complexity in the production process and difficulty in management. Summary of the invention

[0003] The present invention overcomes the shortcomings of the prior art and provides a control device and a control method for a constant current driven power line carrier LED light source, which can dynamically adjust the output voltage according to the number of power line carrier LED lamp beads connected in series with the load to adapt to different numbers of lamp beads, thereby eliminating the need for series resistors; a buck topology step-down constant current source is used to reduce the problem of heating of the linear constant current source device itself; and the energy efficiency of the entire system is improved.

[0004] To achieve the above object, the technical solution adopted by the present invention is: a control device for a constant current driven power line carrier LED light source, comprising: a constant current source circuit connected to an AC source, the constant current source circuit is connected to an input end of a carrier modulation circuit, the output end of the carrier modulation circuit is connected to an LED light source circuit, and the constant current source circuit is electrically connected to the carrier modulation circuit through a power supply step-down circuit and a carrier modulation control circuit; The constant current source circuit comprises a switch type constant current source of buck topology structure; The LED light source is a power line carrier LED light source.

[0005] In a preferred embodiment of the present invention, the AC source is connected to the constant current source circuit via a filter circuit, and / or the constant current source circuit is connected to the carrier modulation circuit via a filter circuit; And / or, the constant current source circuit is a step-down constant current source circuit, which is used to step down and rectify the introduced AC source; and / or, the carrier modulation control circuit provides a control signal to the carrier modulation circuit; And / or, after receiving the control signal from the carrier modulation control circuit, the carrier modulation circuit controls the power on and off between the constant current source circuit and the LED light source circuit; And / or, the power line carrier LED light source adopts a power line carrier LED light source that multiplexes the power line and the signal line; And / or, the switch output of the controlled carrier modulation control circuit of the power line carrier LED light source can modulate the carrier signal to the power line of the power line carrier LED light source by turning off the switch of the carrier modulation circuit.

[0006] In a preferred embodiment of the present invention, the AC source is connected to the input end of the step-down constant current source chip of the constant current source circuit. The rectifier output pin of the step-down constant current source chip is connected to the input end of the filter circuit, the output end of the filter circuit is connected in parallel with a resistor R12, and the output end of the filter circuit is connected to the input end of the carrier modulation circuit through a diode D1; Furthermore, the duty cycle adjustment end of the step-down constant current source chip is connected to the capacitor EC1 through the inductor L2, the other end of the capacitor EC1 is connected to the output end of the filter circuit and the connection node of the diode D1, and then connected to the power supply VCC provided by the power supply step-down circuit, and the two ends of the capacitor EC1 are connected in parallel with a resistor R11; The overvoltage protection threshold adjustment terminal of the step-down constant current source chip is grounded at a common point through a resistor R2 and a resistor R1 connected in parallel; The filter circuit adopts a π-type filter circuit.

[0007] More specifically, the π-type filter circuit adopts an LC type π-type filter.

[0008] In a preferred embodiment of the present invention, the carrier modulation circuit includes a transistor Q1 and a transistor Q2, the emitter of the transistor Q1 is connected to the reverse end of the diode D1, the emitter and collector of the transistor Q1 are connected in parallel with a capacitor C4, a resistor R4 is connected in parallel between the base and emitter of the transistor Q1, the base of the transistor Q1 is connected to the collector of the transistor Q2 through a resistor R3, the emitter of the transistor Q2 and the connection node of the resistor R2 and the resistor R1 are grounded at a common point, and the base of the transistor Q2 is connected to the control end of the carrier modulation control circuit through a resistor R5.

[0009] In a preferred embodiment of the present invention, the collector of the transistor Q1 is connected to the input end of the LED light source circuit, and the output end of the LED light source circuit is connected to the connection node of the inductor L2 and the capacitor EC1.

[0010] In a preferred embodiment of the present invention, the π-type filter circuit adopts an LC-type π-type filter, one end of the inductor L1 of the π-type filter is connected to the rectifier output terminal HV pin of the step-down constant current source chip, the other end of the inductor L1 is connected to the forward end of the diode D1, and the two ends of the inductor L1 are grounded at a common point through capacitors EC3 and EC4 respectively, and a resistor 12 is connected in parallel to the two ends of capacitor EC4.

[0011] In a preferred embodiment of the present invention, the power supply step-down circuit includes a step-down chip, a capacitor C1 is connected in parallel to the VCC input terminal and the ground terminal of the step-down chip, the VCC input terminal is connected to the reverse end of the diode D2, the reverse end of the diode D2 is connected to the ground terminal of the step-down chip through the inductor L3, the ground terminal of the step-down chip is connected to the reverse end of the diode D3, the forward end of the diode D3 is connected to the connection node of the inductor L3 and the diode D2 through the resistor R8, the two ends of the resistor R8 are connected in parallel with the capacitor EC2, and the two ends of the capacitor EC2 are connected in parallel with the capacitor C2.

[0012] In a preferred embodiment of the present invention, the carrier modulation control circuit includes a logic control chip, the PA3 input terminal of the logic control chip is connected to the input terminal of the step-down constant current source chip through a resistor R6, the PA3 input terminal is also grounded at a common point through a resistor R7 and a capacitor C3 arranged in parallel, the PA2 input terminal of the logic control chip is grounded through a switch SW1, the PA2 input terminal is connected to the VDD input terminal of the logic control chip through a resistor R9 and is connected to the output voltage of the power supply step-down circuit, and the VDD input terminal is connected to the VSS input terminal of the logic control chip through a capacitor C5 and is grounded at a common point, and the control terminal of the logic control chip is connected to the base of the transistor Q2 of the carrier modulation circuit through the resistor R5.

[0013] In a preferred embodiment of the present invention, the constant current source circuit adopts a buck topology step-down LED constant current driver chip; And / or, the carrier modulation circuit adopts one of a MOS tube (field effect transistor), a triode tube, and an IGBT tube (insulated gate bipolar transistor); And / or, the logic control chip adopts one of an MCU logic control chip, a Bluetooth SOC logic control chip, and a WifiSOC logic control chip.

[0014] In a preferred embodiment of the present invention, a control method of a control device for a constant current driving power line carrier LED light source is implemented using a control device for a constant current driving power line carrier LED light source, comprising the following steps: The alternating current of the alternating current source is output through a step-down constant current source circuit and a π-type filter circuit to output a rectified and filtered direct current as a constant current source output, the constant current source is connected to the LED light source circuit through a carrier modulation circuit, and the carrier modulation circuit is used as a switch circuit to control the output of the constant current source to supply power to the LED light source circuit, thereby controlling the LED light source of the LED light source circuit; Furthermore, the carrier modulation circuit provides a control signal to the carrier modulation circuit through the power supply step-down circuit and the carrier modulation control circuit.

[0015] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are: The present invention discloses a control method and device for a constant current driven power line carrier LED light source. Because it is a constant current output, the device can dynamically adjust the output voltage to adapt to different numbers of lamp beads according to the number of power line carrier LED lamp beads connected in series with the load, thereby eliminating the need for a series resistor. At the same time, the present invention adopts a buck topology step-down constant current source, which will not cause the problem of heating of the linear constant current source device itself. Since the light string does not require a series resistor, there is no power dissipation of the resistor, thereby improving the energy efficiency of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0017] Figure 1 This is a principle block diagram of a control device and a control method for a constant current driven power line carrier LED light source of the present invention; Figure 2 A circuit structure diagram of a control device and a control method for a constant current driving power line carrier LED light source of the present invention; Figure 3 A circuit board layout diagram of an LED light source with a demodulated carrier signal used in a control device for a constant current driven power line carrier LED light source of the present invention; Figure 4 A product structure layout diagram of an LED light source used in a control method and device for a constant current driven power line carrier LED light source of the present invention; Figure 5 This is a test result diagram of the EMI conduction test exceeding the standard when the control method and device for constant current driving power line carrier LED light source is not provided with a π-type filtering circuit (wherein part 15B (QP) and part 15B (AV) are both corresponding upper limit values); Figure 6 This is a test result diagram of a control method and device for a constant current driven power line carrier LED light source of the present invention after adding π-type filtering for improvement (wherein part15B (QP) and part15B (AV) are both corresponding upper limit values). DETAILED DESCRIPTION

[0018] The present invention will now be further described in detail with reference to the accompanying drawings and embodiments. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0019] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) involved in the embodiments of the present invention, the directional indication is only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Embodiment 1

[0020] A control device for a constant current driven power line carrier LED light source, comprising: an interface circuit connected to an AC source, the interface circuit is connected to the input end of a carrier modulation circuit through a constant current source circuit, the output end of the carrier modulation circuit is connected to an LED light source circuit, and the constant current source circuit is electrically connected to the carrier modulation circuit through a power supply step-down circuit and a carrier modulation control circuit; and the interface circuit is connected to the constant current source circuit through a filter circuit, and / or the constant current source circuit is connected to the carrier modulation circuit through a filter circuit. The constant current source circuit in this embodiment comprises a switch-type constant current source of a buck topology structure; the LED light source adopts a power line carrier LED light source, and the control device for a constant current driven power line carrier LED light source in this embodiment is formulated for the control of a power line carrier LED light source.

[0021] Specifically, Figure 1 The constant current source circuit shown can directly receive the alternating current input from the alternating current source when using a step-down constant current chip with an integrated rectifier bridge, or receive the rectified direct current after being rectified by a rectifier bridge. The DC output end of the step-down constant current chip with an integrated rectifier bridge or the DC input end of the rectifier bridge is filtered by a filter circuit to filter the pulsating direct current into a smooth direct current. The filter circuit can use a filter circuit composed of ordinary electrolytic capacitors, or a π-type filter, that is, the π-type filter is added to the rear-stage DC output to improve the EMC capability of the method and device of the present invention.

[0022] The π-type filter can not only filter the pulsating DC into smooth DC, but also improve the EMC (Electromagnetic Compatibility) capability of the circuit. The post-filter is the carrier modulation circuit, which is a switch circuit controlled by the logic circuit. The carrier signal of a specific timing combination of a specific time length or a specific timing combination composed of different numbers of pulses can be modulated by the switch circuit through the logic device. The carrier signal is transmitted through the power line to the LED light source circuit capable of decoding the carrier signal. The LED light source circuit works in different colors and flashing modes according to the decoded information. The logic circuit is attached Figure 1 The carrier modulation control circuit outputs signals representing different colors and flashing modes to the carrier modulation circuit according to the received "button / infrared / RF input" signal. The carrier modulation control circuit (logic circuit) requires a low-voltage DC power supply, and takes power from the DC output end of the step-down constant current source circuit or the DC input end of the rectifier bridge, and outputs a lower voltage adapted to the operation of the logic circuit through the power supply step-down circuit.

[0023] Interface P1 in the interface circuit is used to introduce an AC source; the buck constant current source circuit is used to step down and rectify the introduced AC source; the carrier modulation control circuit provides a control signal to the carrier modulation circuit; after receiving the control signal from the carrier modulation control circuit, the carrier modulation circuit controls the power on and off between the buck constant current source circuit and the LED light source circuit. The buck constant current source circuit uses a buck topology buck constant current source.

[0024] In this embodiment, the π-type filter circuit adopts an LC type π-type filter. The buck-type constant current source circuit adopts a buck-type LED constant current driver chip with a buck topology structure. The carrier modulation circuit adopts one of a MOS tube (field effect transistor), a triode, and an IGBT tube (insulated gate bipolar transistor). The logic control chip U2 adopts one of an MCU logic control chip, a Bluetooth SOC logic control chip, and a WifiSOC logic control chip.

[0025] Furthermore, the step-down constant current source circuit adopts a step-down constant current source output circuit of a buck topology structure, and the output of the constant current source is controlled by a switch circuit in a carrier modulation control circuit. The step-down constant current source output circuit of the buck topology structure adopted by the step-down constant current source circuit is a switch-type constant current source of a Buck topology structure. Compared with a linear constant current source, a switch-type constant current source of a Buck topology structure is prone to heat generation, while a switch-type constant current source of a Buck topology structure is not prone to heat generation, which solves the heat generation problem of products in the prior art during use.

[0026] The load end of the buck topology step-down constant current source output circuit controlled by the switch circuit in the carrier modulation control circuit is an LED light source circuit capable of demodulating the power line carrier signal. The carrier modulation control circuit in the carrier modulation control circuit can modulate the carrier signal to the power line by controlling the on and off of the switch device of the switch circuit in the carrier modulation control circuit.

[0027] In this embodiment, the controlled switch controls the output of a constant current source of a buck topology structure; the power line carrier LED light source multiplexes the power line and the signal line; the LED light source can demodulate the power line carrier signal; the controlled switch output can modulate the carrier signal to the power line by turning off the switch. First of all, the application scope of this case is the power line carrier LED light source, and secondly, the constant current source of this case adopts a constant current source of a buck topology structure, which is a switch type constant current source, which is mainly different from a linear constant current source and has the advantage of not generating heat. Embodiment 2

[0028] Based on the first embodiment, the LED light source circuit capable of demodulating power line carrier signal adopts the method of multiplexing power line and signal line to realize power supply and signal transmission. The carrier signal is a timing combination composed of different numbers of pulses output by the switch device of the switch circuit in the carrier modulation control circuit. Embodiment 3

[0029] On the basis of Example 1, the input end of the interface circuit is connected to the AC source, the output end of the interface P1 of the interface circuit is connected to the input end of the buck constant current source chip U1 of the buck constant current source circuit, the rectifier output end HV pin of the buck constant current source chip U1 is connected to the input end of the π-type filter circuit, the output end of the π-type filter circuit is connected in parallel with a resistor R12, and the output end of the π-type filter circuit is connected to the input end of the carrier modulation circuit through a diode D1.

[0030] The duty cycle adjustment end of the buck constant current source chip U1 is connected to the capacitor EC1 through the inductor L2, and the other end of the capacitor EC1 is connected to the output end of the π-type filter circuit and the connection node of the diode D1, and then connected to the power supply VCC provided by the power supply buck circuit, and the two ends of the capacitor EC1 are connected in parallel with a resistor R11; the overvoltage protection threshold adjustment end of the buck constant current source chip U1 is grounded through the parallel resistor R2 and the resistor R1. However, it is not limited to the type of buck constant current source chip U1 shown in the drawings of the specification. In other embodiments, other types of buck constant current source chips in the prior art can be selected according to actual use requirements, as long as they can be used as constant current of the buck topology structure.

[0031] The carrier modulation circuit includes transistors Q1 and Q2, the emitter of transistor Q1 is connected to the reverse end of diode D1, the emitter and collector of transistor Q1 are connected in parallel with capacitor C4, the base and emitter of transistor Q1 are connected in parallel with resistor R4, the base of transistor Q1 is connected to the collector of transistor Q2 through resistor R3, the emitter of transistor Q2 is grounded at a common point with the connection node of resistor R2 and resistor R1, and the base of transistor Q2 is connected to the control end of the carrier modulation control circuit through resistor R5. The collector of transistor Q1 is connected to the input end of the LED light source circuit, and the output end of the LED light source circuit is connected to the connection node of inductor L2 and capacitor EC1. However, it is not limited to this. In other embodiments, transistors Q1 and Q2 in the carrier modulation circuit can select other types of MOS tubes as devices in the control circuit of the carrier modulation circuit according to actual use requirements.

[0032] One end of the inductor L1 of the LC type π-type filter is connected to the rectifier output terminal HV pin of the buck constant current source chip U1, and the other end of the inductor L1 is connected to the forward end of the diode D1. The two ends of the inductor L1 are grounded at a common point through capacitors EC3 and EC4 respectively, and resistor 12 is connected in parallel to the two ends of capacitor EC4.

[0033] The power supply step-down circuit includes a step-down chip U3, a capacitor C1 is connected in parallel to the VCC input terminal and the ground terminal of the step-down chip U3, the VCC input terminal is connected to the reverse end of the diode D2, the reverse end of the diode D2 is connected to the ground terminal of the step-down chip U3 through the inductor L3, the ground terminal of the step-down chip U3 is connected to the reverse end of the diode D3, the forward end of the diode D3 is connected to the connection node between the inductor L3 and the diode D2 through the resistor R8, a capacitor EC2 is connected in parallel to both ends of the resistor R8, and a capacitor C2 is connected in parallel to both ends of the capacitor EC2.

[0034] The carrier modulation control circuit includes a logic control chip U2, the PA3 input terminal of the logic control chip U2 is connected to the input terminal of the step-down constant current source chip U1 through a resistor R6, the PA3 input terminal is also grounded at a common point through a resistor R7 and a capacitor C3 arranged in parallel, the PA2 input terminal of the logic control chip U2 is grounded through a switch SW1, the PA2 input terminal is connected to the VDD input terminal of the logic control chip U2 through a resistor R9 and is connected to the output voltage of the power supply step-down circuit, and the VDD input terminal is connected to the VSS input terminal of the logic control chip U2 through a capacitor C5 and is grounded at a common point, and the control terminal of the logic control chip U2 is connected to the base of the transistor Q2 of the carrier modulation circuit through a resistor R5.

[0035] Working principle: As attached Figure 2As shown, interface P1 is an AC input interface. This embodiment adopts a method of connecting a π-type filter to the DC output terminal, so there is no π-type filter for AC input. The AC input is given to the two ACIN AC input pins of the buck constant current source chip U1. The buck constant current source chip U1 is a buck topology buck constant current source chip with an integrated rectifier bridge. After the buck constant current source chip U1 completes the rectification, it outputs pulsating DC power through the HV pin, and the π-type filter composed of capacitor EC3, capacitor EC4, and inductor L1 converts the pulsating DC power into a stable DC power. The resistor R12 connected in parallel to the capacitor EC4 is used to quickly discharge the electric energy stored in the π-type filter when the power is off. The resistor R2 connected to the CS pin of the buck constant current source chip U1 is used to adjust the output circuit of the constant current source chip, and the resistor R3 connected to the Rovp pin of the buck constant current source chip U1 is used to adjust the overvoltage protection threshold of the constant current source chip. The DRAIN pin of the buck constant current source chip U1 outputs a square wave with a variable duty cycle and a variable frequency to the energy storage inductor L2, and after filtering by the capacitor EC1, a constant current output is generated. The resistor R11 connected in parallel to the capacitor EC1 is used to quickly discharge the electric energy stored in the capacitor EC1 and the inductor L2 when the power is off. The diode D1 is a fast recovery diode, which is used to prevent the switching signal of the transistor Q1 from being filtered by the capacitor EC1. The switching circuit composed of the transistor Q1 and the transistor Q2 and the resistors R3, R4 and R5 is used to control the output of the constant current source and can be used to modulate the carrier signal to the LED light source. The logic control chip U2 is an MCU logic control chip, which outputs the carrier control signal to the resistor R5 as a logic control to control the switching circuit to modulate the carrier signal to the LED light source. The capacitor C5 is the decoupling capacitor of the logic control chip U2. The second pin of the logic control chip U2 is connected to a button. The logic control chip U2 outputs a carrier control signal representing the color and flashing mode by collecting the input signal of the button. Resistor R9 is an external pull-up resistor for the key acquisition input port to enhance the anti-interference ability of the key input signal. The power frequency signal acquisition circuit composed of resistor R6, resistor R7, and capacitor C3 collects the power frequency signal to the fourth pin of the logic control chip U2. The logic control chip U2 can realize the synchronous control of the two MCUs according to the power frequency signal. The buck chip U3 is an auxiliary power supply DC to DC buck chip, which can convert high voltage DC into 5V DC for the logic control chip U2 to work. Diode D2, diode D3, inductor L3, resistor R8, capacitor EC2, capacitor C1, and capacitor C2 are peripheral devices of the buck chip U3 as an auxiliary power supply DC to DC buck chip.

[0036] The switch circuit controlled by the MCU of the logic control chip U2 modulates a specific timing combination of a specific time length or outputs a carrier control signal of a specific timing combination composed of different numbers of pulses, and controls the switch circuit to modulate the power line carrier signal to the LED light source. The LED light source has the ability to demodulate the carrier signal, and can drive 3 or 4 red, green, blue or warm white LED chips to work in different colors and flashing modes according to the carrier signal. Embodiment 4

[0037] Based on the first or third embodiment, the LED light source circuit adopts a lamp bead light source in which a driver IC and an LED chip that can demodulate the carrier signal and drive the LED to flash are sealed into one device. The carrier signal is a specific timing combination that controls the duration of the switch circuit's switch device being turned off and on.

[0038] like Figure 3 As shown in FIG. 1 , it is a kind of LED light source capable of demodulating carrier signals. Figure 3 The LED light source shown mounts the buck constant current source chip U1 and LED1 lamp beads on the same PCB substrate through the SMT process. This light source has only two input terminals, L+ and L-, which are used to transmit the power required by this light source and the carrier signal modulated to the power line. The U1 driver chip demodulates the carrier signal to drive the LED1 lamp beads to work in different colors and flashing modes. Embodiment 5

[0039] Based on the first or third embodiment, the LED light source circuit adopts an LED light source in which the driver IC and the lamp beads that can demodulate the carrier signal and drive the LED to flash are separated and assembled on a light board. The carrier signal is a specific timing combination that controls the duration of the switch circuit's switch off and on.

[0040] like Figure 4 The LED light source in the LED light source circuit shown is a LED light source that seals a driver IC and three or four red, green, blue or warm white LED chips into a single lamp bead using a bonding process. Figure 4 401 is a driver IC, and 404, 405, 403, and 402 are red, green, blue, and warm white LED chips, respectively. The bonding interconnection process is used to connect the above devices inside the same lamp bead. The output pins of this light source are VDD and GND, which are used to transmit the power required by this light source and the carrier signal modulated to the power line. Embodiment 6

[0041] On the basis of the first or third embodiment, a control method of a control device for driving a power line carrier LED light source with a constant current includes the following steps: The AC source is introduced through the interface circuit, and the AC power is output as the constant current source output after rectification and filtering through the step-down constant current source circuit and the π-type filter circuit. The constant current source is connected to the LED light source circuit through the carrier modulation circuit, and the carrier modulation circuit is used as a switch circuit to control the output of the constant current source to power the LED light source circuit, thereby controlling the LED light source of the LED light source circuit. Furthermore, the carrier modulation circuit provides a control signal to the carrier modulation circuit through the power supply step-down circuit and the carrier modulation control circuit.

[0042] Further, on the basis of the third embodiment, the interface P1 is an AC input interface. This embodiment adopts the method of connecting a π-type filter to the DC output terminal, so there is no π-type filter for the AC input. The AC input is given to the two AC IN AC input pins of the buck constant current source chip U1. The buck constant current source chip U1 is a buck topology buck constant current source chip with an integrated rectifier bridge. After the buck constant current source chip U1 completes the rectification, it outputs pulsating DC power through the HV pin, and the π-type filter composed of capacitor EC3, capacitor EC4, and inductor L1 converts the pulsating DC power into a stable DC power. The resistor R12 connected in parallel to the capacitor EC4 is used to quickly discharge the electric energy stored in the π-type filter when the power is off. The resistor R2 connected to the CS pin of the buck constant current source chip U1 is used to adjust the output circuit of the constant current source chip, and the resistor R3 connected to the Rovp pin of the buck constant current source chip U1 is used to adjust the overvoltage protection threshold of the constant current source chip. The DRAIN pin of the buck constant current source chip U1 outputs a square wave with a variable duty cycle and a variable frequency to the energy storage inductor L2, and after filtering by the capacitor EC1, a constant current output is generated. The resistor R11 connected in parallel to the capacitor EC1 is used to quickly discharge the electric energy stored in the capacitor EC1 and the inductor L2 when the power is off. The diode D1 is a fast recovery diode, which is used to prevent the switching signal of the transistor Q1 from being filtered by the capacitor EC1. The switching circuit composed of the transistor Q1 and the transistor Q2 and the resistors R3, R4 and R5 is used to control the output of the constant current source and can be used to modulate the carrier signal to the LED light source. The logic control chip U2 is an MCU logic control chip, which outputs the carrier control signal to the resistor R5 as a logic control to control the switching circuit to modulate the carrier signal to the LED light source. The capacitor C5 is the decoupling capacitor of the logic control chip U2. The second pin of the logic control chip U2 is connected to a button. The logic control chip U2 outputs a carrier control signal representing the color and flashing mode by collecting the input signal of the button. Resistor R9 is an external pull-up resistor for the key acquisition input port to enhance the anti-interference ability of the key input signal. The power frequency signal acquisition circuit composed of resistor R6, resistor R7, and capacitor C3 collects the power frequency signal to the fourth pin of the logic control chip U2. The logic control chip U2 can realize the synchronous control of the two MCUs according to the power frequency signal. The buck chip U3 is an auxiliary power supply DC to DC buck chip, which can convert high voltage DC into 5V DC for the logic control chip U2 to work. Diode D2, diode D3, inductor L3, resistor R8, capacitor EC2, capacitor C1, and capacitor C2 are peripheral devices of the buck chip U3 as an auxiliary power supply DC to DC buck chip.

[0043] Working principle: The present invention discloses a device and method for driving a power line carrier LED light source with constant current, which can dynamically adjust the output voltage according to the number of power line carrier LED lamp beads connected in series with the load to adapt to the LED light source composed of different numbers of power line carrier lamp beads connected in series. The same device can be adapted to power line carrier LED light sources of various specifications without the need for series resistors, thereby simplifying the production process and improving production efficiency. At the same time, the present invention adopts a step-down constant current source with a buck topology structure, which will not cause the problem of heating of the linear constant current source device itself, and does not require series resistors. Since there are no linear constant current source devices and resistors to dissipate power, the energy efficiency of the entire system is improved.

[0044] The above specific implementation methods are specific support for the scheme ideas proposed in the present invention, and cannot be used to limit the protection scope of the present invention. Any equivalent changes or equivalent modifications made on the basis of this technical scheme in accordance with the technical ideas proposed in the present invention still fall within the scope of protection of the technical scheme of the present invention.

Claims

1. A control device for a constant current driving power line carrier LED light source, characterized in that: include: A constant current source circuit connected to an AC source, wherein the constant current source circuit is connected to an input end of a carrier modulation circuit, an output end of the carrier modulation circuit is connected to an LED light source circuit, and the constant current source circuit is electrically connected to the carrier modulation circuit via a power supply step-down circuit and a carrier modulation control circuit; The constant current source circuit comprises a switch type constant current source of buck topology structure; The LED light source is a power line carrier LED light source.

2. The control device for constant current driving power line carrier LED light source according to claim 1, characterized in that: The AC source is connected to the constant current source circuit via a filter circuit, and / or the constant current source circuit is connected to the carrier modulation circuit via a filter circuit; And / or, the constant current source circuit is a step-down constant current source circuit, which is used to step down and rectify the introduced AC source; and / or, the carrier modulation control circuit provides a control signal to the carrier modulation circuit; And / or, after receiving the control signal from the carrier modulation control circuit, the carrier modulation circuit controls the power on and off between the constant current source circuit and the LED light source circuit; And / or, the power line carrier LED light source adopts a power line carrier LED light source that multiplexes the power line and the signal line; And / or, the switch output of the controlled carrier modulation control circuit of the power line carrier LED light source can modulate the carrier signal to the power line of the power line carrier LED light source by turning off the switch of the carrier modulation circuit.

3. The control device for constant current driving power line carrier LED light source according to claim 1, characterized in that: The AC source is connected to the input end of the step-down constant current source chip of the constant current source circuit. The rectifier output pin of the step-down constant current source chip is connected to the input end of the filter circuit, the output end of the filter circuit is connected in parallel with a resistor R12, and the output end of the filter circuit is connected to the input end of the carrier modulation circuit through a diode D1; Furthermore, the duty cycle adjustment end of the step-down constant current source chip is connected to the capacitor EC1 through the inductor L2, the other end of the capacitor EC1 is connected to the output end of the filter circuit and the connection node of the diode D1, and then connected to the power supply VCC provided by the power supply step-down circuit, and the two ends of the capacitor EC1 are connected in parallel with a resistor R11; The overvoltage protection threshold adjustment terminal of the step-down constant current source chip is grounded at a common point through a resistor R2 and a resistor R1 connected in parallel; The filter circuit adopts a π-type filter circuit.

4. The control device for constant current driving power line carrier LED light source according to claim 3, characterized in that: The carrier modulation circuit includes a transistor Q1 and a transistor Q2, the emitter of the transistor Q1 is connected to the reverse end of the diode D1, the emitter and collector of the transistor Q1 are connected in parallel with a capacitor C4, a resistor R4 is connected in parallel between the base and the emitter of the transistor Q1, the base of the transistor Q1 is connected to the collector of the transistor Q2 through a resistor R3, the emitter of the transistor Q2 and the connection node of the resistor R2 and the resistor R1 are grounded at a common point, and the base of the transistor Q2 is connected to the control end of the carrier modulation control circuit through a resistor R5.

5. The control device for constant current driving power line carrier LED light source according to claim 4, characterized in that: The collector of the transistor Q1 is connected to the input end of the LED light source circuit, and the output end of the LED light source circuit is connected to the connection node between the inductor L2 and the capacitor EC1.

6. The control device for constant current driving power line carrier LED light source according to claim 5, characterized in that: The π-type filter circuit adopts an LC type π-type filter, one end of the inductor L1 of the π-type filter is connected to the rectifier output terminal HV pin of the step-down constant current source chip, the other end of the inductor L1 is connected to the forward end of the diode D1, the two ends of the inductor L1 are respectively grounded through capacitors EC3 and EC4, and resistor 12 is connected in parallel at both ends of capacitor EC4.

7. The control device for constant current driving power line carrier LED light source according to claim 6, characterized in that: The power supply step-down circuit includes a step-down chip, a capacitor C1 is connected in parallel to a VCC input terminal and a ground terminal of the step-down chip, the VCC input terminal is connected to a reverse end of a diode D2, the reverse end of the diode D2 is connected to a ground terminal of the step-down chip through an inductor L3, the ground terminal of the step-down chip is connected to a reverse end of the diode D3, a forward end of the diode D3 is connected to a connection node between the inductor L3 and the diode D2 through a resistor R8, a capacitor EC2 is connected in parallel to both ends of the resistor R8, and a capacitor C2 is connected in parallel to both ends of the capacitor EC2.

8. The control device for constant current driving power line carrier LED light source according to claim 7, characterized in that: The carrier modulation control circuit includes a logic control chip, the PA3 input terminal of the logic control chip is connected to the input terminal of the step-down constant current source chip through a resistor R6, the PA3 input terminal is also grounded at a common point through a resistor R7 and a capacitor C3 arranged in parallel, the PA2 input terminal of the logic control chip is grounded through a switch SW1, the PA2 input terminal is connected to the VDD input terminal of the logic control chip through a resistor R9 and is connected to the output voltage of the power supply step-down circuit, and the VDD input terminal is connected to the VSS input terminal of the logic control chip through a capacitor C5 and is grounded at a common point, and the control terminal of the logic control chip is connected to the base of the transistor Q2 of the carrier modulation circuit through the resistor R5.

9. The control device for constant current driving power line carrier LED light source according to claim 1, characterized in that: The constant current source circuit adopts a buck topology step-down LED constant current driver chip; And / or, the carrier modulation circuit adopts one of a MOS tube (field effect transistor), a triode tube, and an IGBT tube (insulated gate bipolar transistor); And / or, the logic control chip adopts one of an MCU logic control chip, a Bluetooth SOC logic control chip, and a Wifi SOC logic control chip.

10. A control method for a control device of a constant current driving power line carrier LED light source, characterized in that: The control device for driving a power line carrier LED light source with a constant current as claimed in any one of claims 1 to 9 is implemented, comprising the following steps: The alternating current of the alternating current source is output through a step-down constant current source circuit and a π-type filter circuit to output a rectified and filtered direct current as a constant current source output, the constant current source is connected to the LED light source circuit through a carrier modulation circuit, and the carrier modulation circuit is used as a switch circuit to control the output of the constant current source to supply power to the LED light source circuit, thereby controlling the LED light source of the LED light source circuit; Furthermore, the carrier modulation circuit provides a control signal to the carrier modulation circuit through the power supply step-down circuit and the carrier modulation control circuit.

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