CN112738947B - Lighting circuit and its synchronization method - Google Patents

Abstract

The application relates to a lighting circuit comprising: an alternating current power supply; the first LED light-emitting component and the second LED light-emitting component; the first driving circuit is connected between the alternating current power supply and the first LED luminous component; the second driving circuit is connected between the alternating current power supply and the second LED luminous component; the LED driving circuit comprises a first LED light-emitting component, a second LED light-emitting component, a control signal generating device and a control signal generating device, wherein the control signal generating device can detect the time difference of the starting current of the first LED light-emitting component and the starting current of the second LED light-emitting component, which are respectively obtained by the first driving circuit and the second driving circuit, and supply power for the first driving circuit/the second driving circuit which obtain the starting current at a delay so as to realize synchronous lighting of the first LED light-emitting component and the second LED light-emitting component.

Description

Lighting circuit and its synchronization method

technical field

The invention relates to the technical field of lighting, in particular to a lighting circuit and a synchronization method thereof.

Background technique

In the prior art, synchronous control of multiple light-emitting components is usually achieved through multiple driving circuits. Taking the synchronous control of two LED light-emitting components as an example, the schematic diagram is shown in Figure 1. The AC power supply 1 passes through the first driving circuit 3 and the second driving circuit 4 are respectively connected to the first LED lighting assembly 5 and the second LED lighting assembly 6, due to the difference in start-up time between the first driving circuit 3 and the second driving circuit 4 and the start-up of the first LED lighting assembly 5 There is also a difference between the voltage and the start-up voltage of the second LED light-emitting assembly 6; the existence of the above two differences makes the lighting of the first LED light-emitting assembly 5 and the second LED light-emitting assembly 6 asynchronous, which affects the lighting effect. To avoid the occurrence of the above situation, the designer often needs to modify the hardware parameters or software programs of the first driving circuit 3 or the second driving circuit 4, so that the start-up time of the first LED lighting assembly 5 and the second LED lighting assembly 6 are synchronized, such that Modification requires a lot of design effort, and the product number of the driving circuit will increase due to changes in hardware parameters or software programs, which is not conducive to the normalization of products.

Therefore, it is necessary to improve the lighting circuit of the existing lighting assembly.

Contents of the invention

The present invention is proposed to solve the above-mentioned technical problems, and the purpose is to provide a lighting circuit capable of realizing synchronous lighting of multiple light-emitting components under the premise of ensuring the consistency of the driving circuit structure.

Specifically, the present invention provides a lighting circuit, including: an AC power supply; a first LED lighting assembly and a second LED lighting assembly; a first drive circuit connected between the AC power supply and the first LED lighting assembly; The driving circuit is connected between the AC power supply and the second LED lighting assembly; it also includes a control signal generating device, which can detect the first driving circuit and the second driving circuit to obtain the first LED lighting assembly and the second LED respectively. The time difference of the start-up current of the light-emitting component, and hysteresis power supply to the first drive circuit/second drive circuit that obtains the start-up current first, so as to realize the synchronous lighting of the first LED light-emitting component and the second LED light-emitting component.

Compared with the prior art, the present invention obtains the start-up current time difference between the first LED lighting component and the second LED lighting component respectively by setting and controlling the signal generating device to detect the first driving circuit and the second driving circuit respectively, and sends The first drive circuit/the second drive circuit that first obtains the start-up current supplies power hysteresis to realize synchronous lighting of the first LED light-emitting assembly and the second LED light-emitting assembly.

In a preferred technical solution of the present invention, the control signal generating device includes: a first switch circuit connected between the AC power supply and the first drive circuit; a second switch circuit connected between the AC power supply and the second drive circuit; The control unit is configured to send control signals to the first switch circuit and the second switch circuit respectively to control the on-off of the first switch circuit and the second switch circuit.

In a preferred technical solution of the present invention, the control unit includes: an A/D converter, wherein one port of the A/D converter is connected to the first resistor and/or the second resistor, and the other port is connected to the electronic switch; One terminal of the switch is connected to the A/D converter, and the other terminal can alternatively be connected to the first input terminal of the comparator, or connected to the second input terminal of the comparator via a register; the timer is connected to the comparator's output connection.

In a preferred technical solution of the present invention, the first switch circuit includes: a first relay, the first relay has a third inductance, a first relay contact and a first contactor; and a first triode, the first triode The base of the tube is connected to the control signal transmitter of the control unit on the one hand, and connected to one end of the third inductor on the other hand. The emitter of the first triode is connected to the ground terminal of the AC power supply on the one hand, and the other On the one hand, it is connected to the ground terminal of the first drive circuit, and the collector of the first triode is connected to the other end of the third inductance through the ninth resistor; the second switch circuit includes: a second relay, and the second relay has a first Four inductors, the second relay contact and the second contactor; and the second triode, the base of the second triode is connected with the control signal transmitting end of the control unit on the one hand, and connected with the fourth inductance on the other hand One of the ends is connected, the emitter of the second triode is connected to the ground terminal of the AC power supply on the one hand, and connected to the ground terminal of the second drive circuit on the other hand, and the collector of the second triode is passed through the tenth resistor It is connected with the other end of the fourth inductance; wherein, the first triode and the second triode can be turned on or off under the drive of the control unit, and the first contactor and the second contactor can be connected in the first triode When the tube and the second triode are turned on or off, they engage or disengage with the first relay contact and the second relay contact accordingly, so as to realize the connection or disconnection between the AC power supply and the drive circuit and the second drive circuit .

In the preferred technical solution of the present invention, the first drive circuit at least includes a first constant current circuit, the load terminal of the first constant current circuit is connected to the first light-emitting component; the second drive circuit includes at least a second constant current circuit, and the The load end of the second constant current circuit is connected with the second light emitting component.

In the preferred technical solution of the present invention, it also includes: a first detection circuit and a second detection circuit, the first detection circuit includes: a first secondary inductance coupled with the first main inductance of the first constant current circuit; A first resistor connected in series with the secondary inductor; a first diode connected in series with the first secondary inductor; a first capacitor connected in parallel with the first resistor; a first voltage dividing resistor connected in series with the first secondary inductor; a second detection circuit Comprising: a second secondary inductance coupled with the second main inductance of the second constant current circuit; a second resistor connected in series with the second secondary inductor; a second diode connected in series with the second secondary inductor; The second capacitance; and the second voltage dividing resistor connected in series with the second secondary inductance; wherein, the control signal generation circuit is connected with the first detection circuit and the second detection circuit respectively, so as to detect the first resistance at both ends of the first resistance and the second resistance. voltage and the second voltage, the control signal generation circuit can determine the time difference between the voltages of the first main inductor and the second main inductor reaching a steady state according to the detection results of the first voltage and the second voltage.

In this technical solution, the purpose of setting the first detection circuit and the second detection circuit is to detect the time when the current flowing through the first main inductance and the second main inductance enters a steady state. In this embodiment, the first auxiliary inductance is set The second auxiliary inductance is coupled with the first main inductance and the second main inductance respectively, specifically, the first auxiliary inductance and the first main inductance, the second main inductance and the second auxiliary inductance are respectively wound on the same iron core or A transformer is formed on the magnetic core, and the first secondary inductance and the second secondary inductance can respectively generate induced currents when the first main inductance and the second main inductance have current flowing through them, so the first resistance connected in series with the first secondary inductance can be measured And the time when the voltage values V1 and V2 at both ends of the second resistor connected in series with the second secondary inductance enter a steady state Confirm the time for the current of the first main inductance and the second main inductance to enter a steady state, only when the first main inductance L1 and the second main inductance The first LED light-emitting component and the second LED light-emitting component can obtain the start-up current when the two main inductors enter a steady state.

In this technical solution, taking the first detection circuit as an example, the size of V1 can be adjusted by the coil turns ratio of the first secondary inductance and the first main inductance and the resistance value of the first voltage dividing resistor, so as to be compatible with the control signal generating device In some technical solutions, the first voltage dividing resistor may not be provided, and V1 is regulated only by the coil turns ratio of the first secondary inductance and the first main inductance.

In order to achieve the purpose of the above invention, the present invention provides a synchronization method for synchronizing the start-up times of different constant current circuits in the above-mentioned lighting circuit including a plurality of constant current circuits. The synchronization method includes the following steps: a steady-state voltage supply step , providing the first constant current circuit and the second constant current circuit in a steady state, the voltage values X1 and X2 at both ends of the first resistor and the second resistor; the time difference determination step, during the startup process, determine the voltage value V1 of the first resistor The time difference between the moment when X1 is reached and the moment when the voltage value V2 of the second resistor reaches X2; in the control signal output step, according to the time difference determined in the time difference determination step, for the first main inductance or the second main inductance that first reaches the steady state , output the control signal to the corresponding first switch circuit or the second switch circuit with hysteresis.

In a preferred technical solution of the present invention, the lag time between the control signals output to the first switch circuit and the second switch circuit is equal to the time difference.

In the preferred technical solution of the present invention, the following steps are also included: the step of saving the lag time, saving the lag time.

In the preferred technical solution of the present invention, before the time difference determining step, it also includes: a synchronous mode switching step, switching the lighting circuit to a synchronous mode; after the time difference determining step, before the control signal output step, it also includes: working mode The switching step is to switch the lighting circuit to the working mode.

Description of drawings

Fig. 1 is a schematic diagram of an existing lighting circuit;

Fig. 2 is the schematic diagram of the lighting circuit of the preferred technical solution of the present invention;

Fig. 3 is a circuit diagram of the first constant current circuit and the first detection circuit of the lighting circuit of the preferred technical solution of the present invention;

Fig. 4 is a circuit diagram of the second constant current circuit and the second detection circuit of the lighting circuit of the preferred technical solution of the present invention;

Fig. 5 is a circuit diagram of the control unit of the lighting circuit of the preferred technical solution of the present invention;

Fig. 6 is a schematic diagram of the first switch circuit of the lighting circuit of the preferred technical solution of the present invention;

Fig. 7 is a schematic diagram of the second switch circuit of the lighting circuit of the preferred technical solution of the present invention;

Fig. 8 is a waveform diagram of the voltage value at both ends of the first resistor R1 and the current value flowing through the first LED light-emitting component in the lighting circuit of the preferred technical solution of the present invention;

Fig. 9 is a flow chart of the synchronization method of the preferred technical solution of the present invention.

Explanation of reference signs:

1-AC power supply; 2-control signal generator, 21-first switch circuit, 211-first relay, 212-third inductor, 213-first relay contact, 214-first contactor, 215-first Transistor; 22-second switch circuit, 221-second relay, 222-fourth inductance, 223-second relay contact, 224-second contactor, 225-second triode, control unit 23; 3-the first drive circuit, 31-the first constant current circuit, 41-the first input rectification circuit; 4-the second drive circuit, 41-the second constant current circuit, 42-the second input rectification circuit; 5-the first LED light-emitting component; 6-second LED light-emitting component; 7-first detection circuit; 8-second detection circuit; R1-first resistor, R2-second resistor, R3-third resistor, R4-fourth resistor, R5-first voltage divider resistor, R6-sixth resistor, R7-seventh resistor, R8-second voltage divider resistor, R9-ninth resistor, R10-tenth resistor; D1-first diode, D2- The second diode, D3-the third diode, D5-the fourth diode; C1-the first capacitor, C2-the second capacitor, C3-the third capacitor, C4-the fourth capacitor, C5-the fifth Capacitance, C6-the sixth capacitor; L1-the first main inductance, L2-the first auxiliary inductance, L3-the second main inductance, L4-the second auxiliary inductance; IC1-the first driver, IC2-the second driver; Q1- The first N-channel MOS transistor, Q2-the second N-channel MOS transistor; A/D1-the first A/D converter, A/D2-the second A/D converter; S1-the first electronic switch, S2 - second electronic switch; U1 - first comparator, U2 - second comparator; 100 - first register, 200 - second register; 101 - first timer, 201 - second timer, 102 - first INT signal circuit, 202-second INT signal circuit; 103-processor.

Detailed ways

Hereinafter, the present invention will be further described in detail through the embodiments in combination with the accompanying drawings. It should be noted here that the description of the embodiments is used to help understand the present invention, but does not constitute a limitation to the present invention.

Fig. 2 shows the schematic diagram of the lighting circuit of this embodiment, the lighting circuit includes: an AC power supply 1, a control signal generating device 2, a first drive circuit 3, a second drive circuit 4, a first LED lighting assembly 5 and a second LED The light-emitting assembly 6, the first detection circuit 7 and the second detection circuit 8; wherein, the AC power supply 1 is connected to the control signal generator 2, and the control signal generator 2 passes through the first drive circuit 3 and the second drive circuit 4 respectively on the one hand. Correspondingly connected with the first LED lighting assembly 5 and the second LED lighting assembly 6, on the other hand, the first detection circuit 7 and the second driving circuit 4 are respectively connected between the control signal generating device 2 and the first driving circuit 3 and the second driving circuit 4. The second detection circuit 8, specifically, the control signal generator 2 can detect the first drive circuit 3 and the second drive circuit 4 through the first detection circuit 7 and the second detection circuit 8 to obtain the first LED light-emitting assembly 5 and the second drive circuit respectively. The time difference between the start-up currents of the two LED light-emitting components 6, and hysteretic power supply to the first drive circuit 3/second drive circuit 4 that first obtains the start-up current to realize the synchronization point of the first LED light-emitting component 5 and the second LED light-emitting component 6 Bright.

Specifically, as shown in FIG. 2, FIG. 6 and FIG. 7, the control signal generating device 2 includes a first switch circuit 21, which is connected between the AC power supply 1 and the first drive circuit 3; a second switch circuit 22, which is connected to the AC Between the power supply 1 and the second drive circuit 4; the control unit 23, including a voltage signal receiving terminal and a control signal transmitting terminal, is used to send control signals to the first switch circuit 21 and the second switch circuit 22 respectively to control the first switch circuit 21 and the second switch circuit 22, and then control the on-off between the AC power supply 1 and the first drive circuit 3 and the second drive circuit 4; the first drive circuit 3 includes at least the first constant current circuit 31 and the first The input rectification circuit 32, the second drive circuit 4 at least includes a second constant current circuit 41 and a second input rectification circuit 42, the first detection circuit 7 and the second detection circuit 8 correspond to the first constant current circuit 31 and the second constant current circuit 31 and the second constant current circuit 42 respectively. The current circuit 41 is connected with the voltage signal receiving end of the control signal generating device 2 at the same time, so as to detect the time difference between the current starting time in the first driving circuit 3 and the second driving circuit 4 .

Fig. 3 is a specific circuit diagram of the first constant current circuit 31 and the first detection circuit 7 in the lighting circuit. According to Fig. 3, the first detection circuit 7 is inside the dashed line frame, and the first constant current circuit 31 is outside the dashed line frame , the first constant current circuit 31 includes a first N-channel MOS transistor Q1, the source of the first N-channel MOS transistor Q1 is connected to the grounded third capacitor C3 through a third resistor R3 connected in series on the one hand, and on the other hand through The fourth resistor R4 connected in series with the input terminal CS1 of the first driver IC1 of the first constant current circuit 31, the first driver IC1 has an input terminal CS1 capable of detecting current signals, a ground terminal GND1, a driving power supply Vcc1 and an output terminal Gate1; The drain of the N-channel MOS transistor Q1 is connected in series with the first main inductor L1 on the one hand, and connected to the third capacitor C3 through the third diode D3 on the other hand, and the cathode of the third diode D3 is connected to the third capacitor C3 , the anode is connected to the drain of the first N-channel MOS transistor Q1, the first main inductor L1 is connected to the third capacitor C3 through the first LED light-emitting component 5 in series on the one hand, and connected to the third capacitor C3 through the fourth capacitor C4 in series on the other hand The gate of the first N-channel MOS transistor Q1 is connected to the output terminal Gate1 of the drive IC1; GND1 is connected to the ground terminal; the first detection circuit 7 includes a first auxiliary inductance L2 coupled with the first main inductance L1, the first One end of the auxiliary inductor L2 is connected in series with the first diode D1 and connected to the ground terminal of the third capacitor C3, and the other end is connected in series with the first voltage dividing resistor R5 and the first resistor R1 in series, and the two ends of the first resistor R1 are connected in parallel There is a first capacitor C1, one end of the first resistor R1 is connected to the first voltage dividing resistor R5 on the one hand, and is used to connect to the voltage signal receiving end of the control unit 23 on the other hand, and the other end is connected to the first diode D1 is connected to form a loop, wherein the cathode of the first diode D1 is connected to the first auxiliary inductor L2, and the anode is connected to the first resistor R1; it should be noted that Vcc1 is connected to the first switch circuit 21, And it can obtain a high level to drive the first constant current circuit 31 to supply power to the output terminal when the first switch circuit 21 is connected.

As shown in FIG. 4, the circuit structure of the second constant current circuit 41 is the same as that of the first constant current circuit 31, specifically, the second detection circuit 8 is inside the dashed line frame, and the second constant current circuit 41 is outside the dashed line frame. The second constant current circuit 41 includes a second N-channel MOS transistor Q2, the source of the second N-channel MOS transistor Q2 is connected to the grounded fifth capacitor C5 through a series resistor R6 on the one hand, and connected to the fifth capacitor C5 through a series resistor R7 on the other hand. The input terminal CS2 of the second driver IC2 of the second constant current circuit 41, the second driver IC2 has the input terminal CS2 capable of detecting current, the ground terminal GND2, the driving power supply Vcc2 and the output terminal Gate2; the second N-channel MOS transistor Q2 On the one hand, the drain is connected in series with the second main inductor L3, on the other hand, it is connected to the fifth capacitor C5 through the fourth diode D4, the cathode of the fourth diode D4 is connected to the fifth capacitor C5, and the anode is connected to the second N The drain of the channel MOS transistor Q2, the second main inductor L3 is connected to the fifth capacitor C5 through the second LED light-emitting component 6 in series on the one hand, and connected to the fifth capacitor C5 through the sixth capacitor C6 in series on the other hand; the second N-channel The gate of the MOS transistor Q1 is connected to the output terminal Gate2 of the second drive IC2; GND2 is connected to the ground terminal; Vcc2 is connected to the second switch circuit 22; the second detection circuit 8 includes a second secondary inductance coupled with the second main inductance L3 L4, one end of the second secondary inductance L4 is connected in series with the second diode D2 and connected to the ground end of the fifth capacitor C5, and the other end is connected in series with the second voltage dividing resistor R8 and the second resistor R2, the second resistor The two ends of R2 are connected in parallel with a second capacitor C2, one end of the second resistor R2 is connected to the second voltage dividing resistor R8 on the one hand, and is used to connect to the voltage signal receiving end of the control signal generating device 2 on the other hand, and the other end It is connected with the second diode D2 to form a loop, wherein the cathode of the second diode D2 is connected with the second auxiliary inductor L4, and the anode is connected with the second resistor R2.

It should be noted that, in the preferred implementation manner of this embodiment, as shown in Figure 3 and Figure 4, both the first constant current circuit 31 and the second constant current circuit 32 are designed as BUCK circuits, in some alternative implementation manners Among them, the first constant current circuit 31 and the second constant current circuit 32 can also be designed as other types of constant current circuits, as long as the output terminal of the constant current circuit is connected in series with an inductance to prevent sudden changes in current, both can be designed and the first detection circuit 7 or the same or equivalent detection circuit as the second detection circuit 8 samples the time when the inductance enters a steady state to obtain the time difference between the start-up times of the current in the first drive circuit 3 and the second drive circuit 4 .

Referring to Fig. 5 below, the control unit 23 is described, the voltage signal receiving end of the control unit 23 is provided with a first A/D converter A/D1 and a second A/D converter A/D2, the first A/D conversion The converter A/D1 and the second A/D converter A/D2 each have a corresponding port connected to the first resistor R1 and the second resistor R2, because the first constant current circuit 31 and the second constant current circuit 41 and The connection relationship of the control unit 23 is the same. First, the structure corresponding to the first constant current circuit 31 in the control unit 23 will be described below. The control unit 23 also has a first electronic switch S1, and one terminal of the first electronic switch S1 is connected to the first electronic switch S1 An A/D converter A/D1 is connected, and the other terminal is a switchable terminal, which can alternatively be connected to the first input terminal of the first comparator U1, or, via the first register 100, to the first comparator U1 The second input terminal of the first comparator U1 is connected with the first timer 101, an input port of the first timer 101 is connected with the first INT signal circuit 102, and an output port of the first timer 101 connected to the processor 103; similarly, the control unit 23 also has a second electronic switch S2, one terminal of the second electronic switch S2 is connected to the second A/D converter A/D2, and the other terminal is a switchable terminal, It can alternatively be connected to the first input terminal of the second comparator U2, or connected to the second input terminal of the second comparator U2 via the second register 200, the output terminal of the second comparator U2 is connected to the second clock One input port of the second timer 201 is connected with the second INT signal circuit 202, the output port of the second timer 201 is connected with the processor 10, and the processor 103 is connected with the first switch circuit 21 and the second The switch circuits 22 are respectively connected to send control signals to the first switch circuit 21 and the second switch circuit 22 respectively. The control signals include the first control signal and the second control signal. It should be noted that in this embodiment, because The first constant current circuit 31 and the second constant current circuit 41 share the same AC power supply 1 and are powered on synchronously. The first INT signal circuit 102 and the second INT signal circuit 202 do not need to be set separately, and only one INT signal circuit can be set to detect Voltage signal of AC power source 1.

Referring to Fig. 6 below, the first switch circuit 21 is described, the first switch circuit 21 includes: a first relay 211, the first relay 211 has a third inductance 212, a first relay contact 213, a first contactor 214 and a first contactor 214. A triode 215, the base of the first triode 215 is connected with the control signal transmitting end of the control unit 23 on the one hand, and connected with one end of the third inductor 212 on the other hand, the first triode 215 The emitter is connected to the ground terminal of the AC power supply 1 on the one hand, and is connected to the ground terminal of the first constant current circuit 31 on the other hand. The other end is connected, one end of the first relay contact 213 is connected to the positive pole of the AC power source 1 , and the other end is connected to Vcc1 .

As shown in Figure 7, the second switch circuit 22 includes: a second relay 221, the second relay 221 has a fourth inductance 222, a second relay contact 223 and a second contactor 224; and a second triode 225, the second The base of the second triode 225 is connected with the control signal transmitting end of the control unit 23 on the one hand, and is connected with one end of the fourth inductance 222 on the other hand, and the emitter of the second triode 225 is connected with the AC power supply on the one hand. 1 is connected to the ground terminal, and on the other hand is connected to the ground terminal of the second constant current circuit 41, the collector of the second triode 225 is connected to the other end of the fourth inductance 222 through the tenth resistor R10, and the second One end of the relay contact 223 is connected to the positive pole of the AC power supply 1 , and the other end is connected to Vcc2 .

Wherein, the first triode 215 and the second triode 225 can be turned on or off under the driving of the control signal transmitting terminal, and the first contactor 214 and the second contactor 224 can be connected between the first triode 215 and the second When the triode 225 is turned on or off, it engages or disengages with the first relay contact 213 and the second relay contact 223 accordingly, so as to realize the connection between the AC power supply 1 and the first constant current circuit 31 and the second constant current circuit 41. Specifically, the control signal includes a first control signal and a second control signal. Taking the first switch circuit 21 as an example, the first transistor 215 is an NPN transistor, and the first control signal is a voltage signal , when the first control signal is received, that is, the base is applied with a forward voltage, the first triode 215 is turned on, the third inductor 212 generates an induced current, and the first contactor 214 is pulled in to contact with the first relay. The head 213 contacts, the AC power source 1 and the first constant current circuit 31 are connected and supply power to the first constant current circuit 31, and then light the first LED light-emitting assembly 5. It should be noted that in some technical solutions, the first three The transistor 215 can be a PNP transistor, and correspondingly adjusted to output the first control signal as a low-level signal to realize the conduction of the first transistor 215. In other technical solutions, the first transistor 215 can also be Replace it with other semiconductor switching tubes, such as MOS tubes.

The working principle of the above-mentioned lighting circuit will be described below in conjunction with FIG. 2 to FIG. 7:

The purpose of setting the first detection circuit 7 and the second detection circuit 8 is to detect the time when the current flowing through the first main inductance L1 and the second main inductance L3 enters a steady state. In this embodiment, the first auxiliary inductance L2 and the second main inductance L3 are set The second secondary inductance L4 is respectively coupled with the first main inductance L1 and the second main inductance L3, specifically, the first secondary inductance L2 and the first main inductance L1, the second main inductance L3 and the second secondary inductance L4 are respectively wound Set on the same iron core or magnetic core to form a transformer, the first secondary inductance L2 and the second secondary inductance L4 can respectively generate induced currents when the first main inductance L1 and the second main inductance L3 have current flowing through them, so they can be measured by The time when the voltage values V1 and V2 at both ends of the first resistor R1 connected in series with the first auxiliary inductor L2 and the second resistor R2 connected in series with the second auxiliary inductor L4 enters a steady state is confirmed by the first main inductor L1 and the second main inductor L3 When the current enters a steady state, only when the first main inductor L1 and the second main inductor L3 enter a steady state can the first LED light-emitting assembly 5 and the second LED light-emitting assembly 6 obtain the start-up current.

Taking the first detection circuit 7 as an example, when a current flows through the first main inductor L1, the induced current generated in the first secondary inductor L2 charges the first capacitor C1, and the electric energy is stored in the first secondary inductor L2 at the same time. It also provides energy for the first resistor R1 and the first voltage dividing resistor R5. When the current in the first main inductor L1 gradually decreases to zero, the first secondary inductor L2 forms a conduction loop through the first diode D1, Thereby providing energy to the first resistor R1 and the first voltage dividing resistor R5 of the output load, and at the same time, the first capacitor C1 also discharges the first resistor R1 and the first voltage dividing resistor R5 to provide energy. In this embodiment, The size of V1 can be regulated by the coil turns ratio of the first secondary inductance L2 and the first main inductance L1 and the resistance value of the first voltage dividing resistor R5 respectively, so as to match the voltage signal receiving end of the control signal generating device 2. In some embodiments, the first voltage dividing resistor R5 may not be provided, and V1 is regulated only by the coil turns ratio of the first secondary inductance L2 and the first main inductance L1. The structure of the second detection circuit 8 and the first detection circuit 7 The structure and working principle are the same and will not be repeated here.

The control signal generator 2 has a synchronous mode that can be used to modify the control parameters to synchronize the start-up time of the first LED lighting assembly 5 and the second LED lighting assembly 6, and utilize the modified control parameters in the synchronous mode to regulate the first LED lighting. Component 5 and the working mode of the light-emitting state of the second LED light-emitting component 6, the control signal generator 2 can switch between the synchronous mode and the working mode under the trigger of an external signal. Specifically, in this embodiment, through the infrared remote control (not shown) is provided with a synchronization mode button for the user to switch between the synchronization mode and the working mode. In some alternative implementations, the switching between the synchronization mode and the working mode can also be triggered by other means, for example, a power switch Switch on and off three times in a row, and no further description will be given here.

After the lighting circuit enters the synchronous mode, when the AC power supply 1 is turned on for the first time, the first switch circuit 21 and the second switch circuit 22 are turned on, and the first constant current circuit 31 and the second constant current circuit 41 are connected from the AC power supply 1 respectively. The voltages Vcc1 and Vcc2 for driving the first driver IC1 and the second driver IC2 are obtained, and the first constant current circuit 31 and the second constant current circuit 41 respectively output currents to the first LED lighting assembly 5 and the second LED lighting assembly 6 to point Turn on the first LED lighting assembly 5 and the second LED lighting assembly 6 until the first LED lighting assembly 5 and the second LED lighting assembly 6 emit light stably. During this process, the first control signal and the second control signal are sent from the processor 103 Synchronous output, the switchable terminals of the first electronic switch S1 and the second electronic switch S2 connected to the first A/D converter A/D1 and the second A/D converter A/D2 are respectively connected to the first register 100 and the second register 200 side, when the first LED lighting assembly 5 and the second LED lighting assembly 6 are stably emitting light, the voltage signal detected from the first constant current circuit 31 and the second constant current circuit 41, that is, the first resistor The voltage across R1 and the second resistor R2 is converted into a digital signal by the first A/D converter A/D1 and the second A/D converter A/D2, and then the voltage value X1 and the voltage value X2 are stored in the first register 100 and the second register 200.

The voltage value X1 and the voltage value X2 are respectively the corresponding voltage values across the first resistor R1 and the second resistor R2 when the first constant current circuit 31 and the second constant current circuit 41 are in a stable state. In subsequent steps, the time for the first constant current circuit 31 and the second constant current circuit 41 to reach a steady state will be reflected by the time when both ends of the first resistor R1 and the second resistor R2 respectively reach the voltage value.

Next, turn off the AC power supply 1, and correspond to the switchable terminals of the first electronic switch S1 and the second electronic switch S2 connected to the first A/D converter A/D1 and the second A/D converter A/D2 respectively Connect to the first comparator U1 and second comparator U2 sides.

When the AC power supply 1 is turned on again, the first INT signal circuit 102 and the second INT signal circuit 202 are triggered, wherein the first INT signal circuit 102 and the second INT signal circuit 202 can respectively detect the first constant current circuit 31 and The input voltage signal of the second constant current circuit 41 triggers the first timer 101 and the second timer 201 to start counting when the voltage signal is detected. Specifically, in this embodiment, when the AC power supply 1 is turned on again , the first timer 101 and the second timer 201 start counting, and the first comparator U1 and the second comparator U2 can obtain the real-time obtained voltage value V1 across the first resistor R1 and the voltage value across the second resistor R2 V2 is compared with X1 and X2 respectively, and timing is stopped when V1=X1 and V2=X2 respectively.

Referring to FIG. 8 , the inventor found through theoretical analysis and waveform detection that, taking the first LED light-emitting component 5 as an example, the starting point of the waveform of the current I _out flowing through the first LED light-emitting component 5 is related to the voltage value at both ends of the first resistor R1 The stable point of the V1 waveform is almost the same, therefore, the start-up time of the current output can be judged by detecting the time when the voltage value V1 and the voltage value V2 reach the stable point at start-up. Therefore, when V1 and V2 reach X1 and X2 respectively and stop counting, the counting time T1 and T2 are also the current starting time of the first constant current circuit 31 and the second constant current circuit 41 .

Afterwards, the processor 103 delays the output of the first control signal/second control signal according to the time difference ΔT between T1 and T2, specifically, when T1>T2, delays the output time of the second control signal by |ΔT|; when T1 When <T2, the output time of the first control signal is delayed by |ΔT|.

After calculating |ΔT| after obtaining the output time, the synchronization setting of the lighting circuit is completed, and the hysteresis output information of the first control signal/second control signal is saved for calling in the working mode, so as to realize the first control signal in the working mode Synchronous lighting of the LED lighting assembly 5 and the second LED lighting assembly 6 .

In this embodiment, in the synchronous mode, the control signal generating device 2 can respond accordingly according to the on/off of the AC power supply 1, and its specific implementation method can be to combine the power switch (not shown) of the AC power supply 1 with the control signal The processor 103 of the generating device 2 is connected in communication. In some alternative implementations, the response of the control signal generating device 2 may also be triggered by other signals.

Referring to FIG. 9 , this embodiment provides a synchronization method based on the above-mentioned lighting circuit for synchronizing the start-up times of different constant-current circuits in a lighting circuit containing multiple constant-current circuits, including the following steps:

S01: a synchronous mode switching step, switching the lighting circuit to a synchronous mode;

S02: a steady-state voltage providing step, providing the first constant current circuit 31 and the second constant current circuit 41 in a steady state, the voltage values X1 and X2 at both ends of the first resistor R1 and the second resistor R2;

S03: Time difference determination step, during the start-up process, determine the time difference between the moment when the voltage value V1 of the first voltage reaches X1 and the moment when the voltage value V2 of the second voltage reaches X2.

S04: working mode switching step, switching the lighting circuit to the working mode.

S05: the control signal output step, according to the time difference determined in the time difference determination step, for the first main inductance L1 or the second main inductance L3 that first reaches the steady state, lagging behind the corresponding first switch circuit 21 or the second switch circuit 22 to output the control signal.

S06: lag time saving step, save the lag time.

In some alternative implementations, the working mode switching step can also be set after the lag time saving step, that is, the synchronous setting of the first LED lighting assembly 5 and the second LED lighting assembly 6 is completed in the synchronous mode.

Those of ordinary skill in the art can understand that in the foregoing implementation manners, many technical details are provided for readers to better understand the present application. However, even without these technical details and various changes and modifications based on the above-mentioned embodiments, the technical solution claimed in each claim of the present application can be basically realized. Therefore, in practice, various changes may be made to the above-described embodiments in form and detail without departing from the spirit and scope of the present invention.

Claims (8)

1. A lighting circuit, comprising:

an alternating current power supply;

the first LED light-emitting component and the second LED light-emitting component;

the first driving circuit is connected between the alternating current power supply and the first LED luminous component;

the first driving circuit at least comprises a first constant current circuit, the load end of the first constant current circuit is connected with the first LED light-emitting component, and the load end of the first constant current circuit is connected with a first main inductor;

the second driving circuit is connected between the alternating current power supply and the second LED luminous component;

the second driving circuit at least comprises a second constant current circuit, the load end of the second constant current circuit is connected with the second LED light-emitting component, and the load end of the second constant current circuit is connected with a second main inductor;

characterized in that it also comprises

The first detection circuit is connected corresponding to the first constant current circuit and can detect the time when the current flowing through the first main inductor reaches a steady state;

the second detection circuit is connected corresponding to the second constant current circuit and can detect the time when the current flowing through the second main inductor reaches a steady state;

the control signal generating device includes:

the first switch circuit is connected between the alternating current power supply and the first driving circuit;

the second switch circuit is connected between the alternating current power supply and the second driving circuit;

the control unit is used for respectively sending control signals to the first switch circuit and the second switch circuit so as to control the on-off of the first switch circuit and the second switch circuit;

the control signal generating device can determine the time difference that the voltage of the first main inductor and the second main inductor reaches a steady state, and for the first main inductor or the second main inductor which reaches the steady state first, the control signal generating device outputs a control signal to a corresponding first switch circuit or second switch circuit in a lagging way so as to realize synchronous lighting of the first LED light emitting component and the second LED light emitting component.

2. The lighting circuit of claim 1, wherein the first switching circuit comprises:

a first relay having a third inductance, a first relay contact, and a first contactor; and

the base electrode of the first triode is connected with the control signal emission end of the control unit on one hand, the base electrode of the first triode is connected with one end of the third inductor on the other hand, the emitter electrode of the first triode is connected with the grounding end of the alternating current power supply on the other hand, the base electrode of the first triode is connected with the grounding end of the first driving circuit, and the collector electrode of the first triode is connected with the other end of the third inductor through a ninth resistor;

the second switching circuit includes:

a second relay having a fourth inductance, a second relay contact, and a second contactor; and

the base electrode of the second triode is connected with the control signal emission end of the control unit on one hand, the base electrode of the second triode is connected with one end of the fourth inductor on the other hand, the emitter electrode of the second triode is connected with the grounding end of the alternating current power supply on the other hand, the base electrode of the second triode is connected with the grounding end of the second driving circuit, and the collector electrode of the second triode is connected with the other end of the fourth inductor through a tenth resistor;

the first triode and the second triode can be switched on or off under the drive of the control unit, and the first contactor and the second contactor can be correspondingly connected with or disconnected from the first relay contact and the second relay contact when the first triode and the second triode are switched on or off so as to realize the connection or disconnection between the alternating current power supply and the driving circuit and the second driving circuit.

3. The illumination circuit according to claim 2, wherein,

the first detection circuit includes:

a first secondary inductor coupled to the first primary inductor of the first constant current circuit;

a first resistor connected in series with the first secondary inductor;

a first diode in series with the first secondary inductor;

a first capacitor connected in parallel with the first resistor; and

a first voltage dividing resistor connected in series with the first auxiliary inductor;

the second detection circuit includes:

a second secondary inductor coupled to the second primary inductor of the second constant current circuit;

a second resistor in series with the second secondary inductance;

a second diode in series with the second secondary inductance;

a second capacitor connected in parallel with the second resistor; and

a second shunt resistor connected in series with the second secondary inductor;

the control signal generating device is respectively connected with the first detection circuit and the second detection circuit to detect first voltage and second voltage at two ends of the first resistor and the second resistor, and the control signal generating device can determine the time difference that the voltages of the first main inductor and the second main inductor reach a steady state according to the detection results of the first voltage and the second voltage.

4. A lighting circuit as recited in claim 3, wherein said control unit comprises:

one port of the A/D converter is connected with the first resistor and/or the second resistor, and the other port of the A/D converter is connected with an electronic switch;

one terminal of the electronic switch is connected with the A/D converter, and the other terminal of the electronic switch can be alternatively connected with the first input end of the comparator or connected with the second input end of the comparator through a register;

and the timer is connected with the output end of the comparator.

5. A synchronization method for synchronizing start-up times of different constant current circuits in a lighting circuit including a plurality of constant current circuits, characterized in that the lighting circuit is the lighting circuit as claimed in claim 4, the synchronization method comprising the steps of:

a steady-state voltage providing step of providing voltage values X1 and X2 of two ends of the first resistor and the second resistor under a steady state of the first constant-current circuit and the second constant-current circuit;

a time difference determining step of determining, in a starting process, a time difference between a time when the voltage value V1 of the first resistor reaches X1 and a time when the voltage value V2 of the second resistor reaches X2;

and a control signal output step of outputting a control signal to the corresponding first switching circuit or second switching circuit with hysteresis for the first main inductance or second main inductance that first reaches a steady state, based on the time difference determined in the time difference determination step.

6. The synchronization method according to claim 5, wherein a lag time between control signals output to the first switching circuit and the second switching circuit is equal to the time difference.

7. The synchronization method according to claim 5 or 6, further comprising the step of:

and a lag time preservation step of preserving the lag time.

8. The synchronization method of claim 7, further comprising, prior to the time difference determining step:

a synchronous mode switching step of switching the lighting circuit to a synchronous mode;

after the time difference determining step, before the control signal outputting step, further comprising:

and a working mode switching step of switching the lighting circuit to a working mode.