CN112738946A - Lighting circuit and synchronization method thereof - Google Patents
Lighting circuit and synchronization method thereof Download PDFInfo
- Publication number
- CN112738946A CN112738946A CN201910979612.2A CN201910979612A CN112738946A CN 112738946 A CN112738946 A CN 112738946A CN 201910979612 A CN201910979612 A CN 201910979612A CN 112738946 A CN112738946 A CN 112738946A
- Authority
- CN
- China
- Prior art keywords
- circuit
- constant current
- resistor
- current circuit
- control signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Landscapes
- Circuit Arrangement For Electric Light Sources In General (AREA)
Abstract
The invention relates to a lighting circuit and a synchronization method thereof, wherein the lighting circuit comprises: an input rectification loop; the first constant current circuit is connected between the input rectifying circuit and the first LED light-emitting component; the second constant current circuit is connected between the input rectifying circuit and the second LED light-emitting component; the lighting circuit also comprises a first detection circuit and a second detection circuit, detects the time when the first main inductor and the second main inductor enter a steady state and sends detection signals to the control signal generation circuit of the lighting circuit, and realizes synchronous lighting of the first LED light-emitting component and the second LED light-emitting component by outputting PWM control signals after the first main inductor or the second main inductor reaches the steady state first.
Description
Technical Field
The invention relates to the technical field of illumination, in particular to an illumination circuit and a synchronization method thereof.
Background
In the prior art, the synchronous control of a plurality of light emitting components is usually realized by a constant current circuit, taking the synchronous control of two LED light emitting components as an example, the schematic diagram is shown in fig. 1, after the power supply of the first LED light emitting component 8 and the second LED light emitting component 9 is powered on, the first constant current circuit 3 and the second constant current circuit 4 respectively obtain the voltages Vcc1 and Vcc2 of the driving IC (not shown) from the input rectifying circuit 2, and detect the PWM control signal lighting indication from the control signal generating circuit 5, after receiving the PWM control signal, the first constant current circuit 3 and the second constant current circuit 4 respectively output current to the first LED light emitting component 8 and the second LED light emitting component 9 to light the first LED light emitting component 8 and the second LED light emitting component 9, in this process, the PWM control signal is synchronously output, but because of the time difference between Vcc1 of the first constant current circuit 3 and Vcc2 charging time of the second constant current circuit 4, causing a difference in voltage across the first LED lighting assembly 8 and the second LED lighting assembly 9, and therefore a time difference in current start-up time of the two circuits; in addition, the starting voltage Vf1 of the first LED light-emitting component 8 and the starting voltage Vf2 of the second LED light-emitting component 9 are different; the two problems are that the first LED light emitting assembly 8 and the second LED light emitting assembly 9 are not lighted synchronously, which affects the lighting effect.
Therefore, there is a need for an improved lighting circuit for an existing light emitting assembly.
Disclosure of Invention
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an illumination circuit capable of obtaining data for more accurately determining current start time.
Specifically, the present invention provides a lighting circuit comprising: an input rectification loop; the first constant current circuit is connected between the input rectifying circuit and the first LED light-emitting component; the second constant current circuit is connected between the input rectifying circuit and the second LED light-emitting component; the control signal generating circuit is connected with the first constant current circuit and the second constant current circuit, outputs a PWM control signal to control the first constant current circuit and the second constant current circuit to output current to the first LED light-emitting component and the second LED light-emitting component, the lighting circuit further comprises a first detection circuit and a second detection circuit, and the first detection circuit comprises: a first secondary inductor coupled to a first primary inductor of the first constant current circuit; a first resistor in series with the first secondary inductor; a first diode connected in series with the first secondary inductor; a first capacitor connected in parallel with the first resistor; and a first divider resistor in series with the first secondary inductor; the second detection circuit includes: a second secondary inductor coupled to a second primary inductor of the second constant current circuit; a second resistor connected in series with the second secondary inductor; a second diode in series with the second secondary inductor; a second capacitor connected in parallel with the second resistor; and a second voltage divider resistor connected in series with the second secondary inductor; the control signal generating circuit is respectively connected with the first detecting circuit and the second detecting circuit so as to detect a first voltage and a second voltage at two ends of the first resistor and the second resistor, and the control signal generating circuit can determine the time difference of the voltage of the first main inductor and the voltage of the second main inductor reaching a steady state according to the detection result of the first voltage and the second voltage.
Compared with the prior art, the invention is provided with the first detection circuit and the second detection circuit which are respectively coupled with the first main inductor of the first constant current circuit and the second main inductor of the second constant current circuit, the first detection circuit and the second detection circuit can respectively detect the time when the first main inductor and the second main inductor enter the steady state and send the detection signals to the control signal generation circuit of the lighting circuit, the time difference of the current starting time in the first constant current circuit and the second constant current circuit is calculated by the control signal generating circuit, and the PWM control signal is output according to the time difference and lagging to the first main inductor or the second main inductor which reaches a steady state first, so that the current starting time in the first constant current circuit and the second constant current circuit is kept consistent, and further, synchronous lighting of the first LED light-emitting component and the second LED light-emitting component which are respectively connected with the first constant current circuit and the second constant current circuit is realized.
The first detection circuit and the second detection circuit are arranged to detect the time when the current flowing through the first main inductor and the second main inductor enters the steady state, in this embodiment, a first secondary inductor and a second secondary inductor are arranged to be respectively coupled with the first main inductor and the second main inductor correspondingly, specifically, the first secondary inductor and the first main inductor, the second main inductor and the second secondary inductor are respectively wound on the same iron core or magnetic core to form a transformer, the first secondary inductor and the second secondary inductor can respectively generate induction current when the current flows through the first main inductor and the second main inductor, therefore, the time when the current of the first main inductor and the second main inductor enters the steady state can be confirmed by measuring the time when the voltage values V1 and V2 at two ends of a first resistor connected in series with the first secondary inductor and a second resistor connected in series with the second secondary inductor enter the steady state, only when the first main inductor L1 and the second main inductor enter the steady state, the first LED lighting assembly and the second LED lighting assembly can obtain the starting current.
Taking the first detection circuit as an example, the magnitude of V1 can be respectively regulated and controlled by the coil turn ratio of the first secondary inductor and the first primary inductor and the resistance value of the first voltage dividing resistor to be matched with the voltage signal receiving end of the control signal generation circuit, in some technical solutions, the first voltage dividing resistor may not be provided, and V1 can be regulated and controlled only by the coil turn ratio of the first secondary inductor and the first primary inductor.
In a preferred embodiment of the present invention, the control signal generating circuit may output the PWM control signal to the first constant current circuit or the second constant current circuit corresponding to the first main inductor or the second main inductor which reaches the steady state first, with a delay, according to a time difference between the voltages of the first main inductor and the second main inductor which are determined to reach the steady state.
In a preferred technical scheme of the invention, the first constant current circuit and the second constant current circuit are both BUCK circuits.
In some alternative technical schemes, the first constant current circuit and the second constant current circuit can be designed as BUCK circuits, and as long as the output end of the constant current circuit is connected in series with an inductor for preventing current mutation, the time for the inductor to enter a steady state can be sampled by a detection circuit which is designed to be the same as or equal to the first detection circuit or the second detection circuit, so as to obtain the time difference of the current starting time in the first constant current circuit and the second constant current circuit.
In a preferred embodiment of the present invention, the control signal generating circuit includes: 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 the electronic switch; one terminal of the electronic switch is connected to the a/D converter, and the other terminal is alternatively connectable to the first input terminal of the comparator, or to the second input terminal of the comparator via the register; and the timer is connected with the output end of the comparator.
In order to achieve the object of the present invention, the present invention further provides a synchronization method for synchronizing start times of different constant current circuits in a lighting circuit including a plurality of constant current circuits, to which the above lighting circuit is applied, the synchronization method including the steps of:
a steady-state voltage providing step of providing voltage values X1 and X2 of the first constant current circuit and the second constant current circuit at two ends of the first resistor and the second resistor in a steady state;
a time difference determining step of determining a time difference between a time at which the voltage value V1 of the first resistor reaches X1 and a time at which the voltage value V2 of the second resistor reaches X2 during the starting process;
and a PWM control signal output step of outputting a PWM control signal to the corresponding first constant current circuit or second constant current circuit with a delay with respect to the first main inductor or second main inductor which reaches the steady state first, based on the time difference determined in the time difference determination step.
In a preferred embodiment of the present invention, a delay time between the PWN control signals output to the first constant current circuit and the second constant current circuit is equal to a time difference.
In the preferred technical scheme of the invention, the method also comprises the following steps: and a lag time storage step of storing the lag time.
In a preferred embodiment of the present invention, before the step of determining the time difference, the method further includes: a synchronous mode switching step of switching the lighting circuit to a synchronous mode; after the time difference determining step, before the PWM control signal outputting step, further comprising: and a working mode switching step, namely switching the lighting circuit to a working mode.
Drawings
FIG. 1 is a schematic diagram of a prior art lighting circuit;
FIG. 2 is a schematic diagram of a lighting circuit of a preferred embodiment of the present invention;
FIG. 3 is a circuit diagram of a lighting circuit of a preferred embodiment of the present invention;
fig. 4 is a waveform diagram of the voltage value across the first resistor R1 and the current value flowing through the first LED lighting assembly in the lighting circuit according to the preferred embodiment of the present invention;
fig. 5 is a flow chart of the synchronization method of the preferred embodiment of the present invention.
Description of reference numerals:
1-an alternating current power supply; 2-input rectifying circuit; 3-a first constant current circuit; 4-a second constant current circuit; 5-a control signal generating circuit; 6-a first detection circuit; 7-a second detection circuit; 8-a first LED lighting assembly; 9-a second LED lighting assembly; r1-a first resistor, R2-a second resistor, R3-a third resistor, R4-a fourth resistor, R5-a first divider resistor, R6-a sixth resistor, R7-a seventh resistor, and R8-a second divider resistor; d1-first diode, D2-second diode, D3-third diode, D4-fourth diode, D5-fifth diode, D6-sixth diode; c1-first capacitor, C2-second capacitor, C3-third capacitor, C4-fourth capacitor, C5-fifth capacitor, C6-sixth capacitor; l1-first main inductor, L2-first auxiliary inductor, L3-second main inductor, L4-second auxiliary inductor; IC 1-first drive, IC 2-second drive; q1-first N channel MOS tube, Q2-second N channel MOS tube; A/D1-first A/D converter, A/D2-second A/D converter; s1-first electronic switch, S2-second electronic switch; u1-first comparator, U2-second comparator; 100-a first register, 200-a second register; 101-a first timer, 201-a second timer, 102-a first INT signal circuit, 202-a second INT signal circuit; 10-a processor.
Detailed Description
The present invention will be described in further detail below with reference to the accompanying drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto.
Fig. 2 shows a schematic diagram of a lighting circuit of the present embodiment, the lighting circuit including: the LED driving circuit comprises an alternating current power supply 1, an input rectifying circuit 2, a first constant current circuit 3, a second constant current circuit 4, a control signal generating circuit 5, a first detection circuit 6, a second detection circuit 7, a first LED light-emitting component 8 and a second LED light-emitting component 9; the alternating current power supply 1 is connected with the input rectifying circuit 2, the input rectifying circuit 2 is connected with the first constant current circuit 3 and the second constant current circuit 4, when the alternating current power supply 1 is powered on, electric energy can be provided for the first constant current circuit 3 and the second constant current circuit 4 after being rectified by the input rectifying circuit 2, the output ends of the first constant current circuit 3 and the second constant current circuit 4 are respectively and correspondingly connected with the first LED light-emitting component 8 and the second LED light-emitting component 9, and the control signal generating circuit 5 is connected with the first constant current circuit 3 and the second constant current circuit 4 and can send signals to the first constant current circuit 3 and the second constant current circuit 4 so that the first constant current circuit 3 and the second constant current circuit 4 can provide current for the output ends of the first constant current circuit 3 and the second constant current circuit 4 to light the first LED light-emitting component 8 and the second LED; the first detection circuit 6 and the second detection circuit 7 are respectively connected with the first constant current circuit 3 and the second constant current circuit 4 correspondingly, and are connected with a voltage signal receiving end of the control signal generating circuit 5 to detect the time difference of the current starting time in the first constant current circuit 3 and the second constant current circuit 4.
Fig. 3 is a specific circuit diagram of the lighting circuit, according to fig. 3, the first constant current circuit 3 includes a first N-channel MOS transistor Q1, a source of the first N-channel MOS transistor Q1 is connected to a third capacitor C3 connected to ground through a third resistor R3 in series, and is connected to an input terminal CS1 of a first driving IC1 of the first constant current circuit 3 through a fourth resistor R4 in series, the first driving IC1 has an input terminal CS1 capable of detecting a current signal, a ground terminal GND1, a driving power supply Vcc1, and an output terminal Gate 1; the drain of the first N-channel MOS transistor Q1 is connected in series to the first main inductor L1, on the other hand, to a third capacitor C3 through a third diode D3, the cathode of the third diode D3 is connected to a 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 series first LED lighting element 8, on the other hand, to the third capacitor C3 through the series fourth capacitor C4; the Gate of the first N-channel MOS transistor Q1 is connected to the output Gate1 of the driver IC 1; GND1 is grounded; vcc1 is connected to ac power supply 1 via input rectifying circuit 2; the first detection circuit 6 comprises a first secondary inductor L2 coupled with a first main inductor L1, one end of the first secondary inductor L2 is connected in series with a first diode D1 and connected with the ground terminal of a third capacitor C3, the other end is connected in series with a first voltage dividing resistor R5 and a first resistor R1 in sequence, two ends of the first resistor R1 are connected in parallel with the first capacitor C1, one end of the first resistor R1 is connected with the first voltage dividing resistor R5 on the one hand and the voltage signal receiving end of the control signal generation circuit 5 on the other hand, and the other end is connected with a first diode D1 to form a loop, wherein the cathode of the first diode D1 is connected with the first secondary inductor L2, and the anode is connected with the first resistor R1; the circuit structure of the second constant current circuit 4 is the same as that of the first constant current circuit 3, the second constant current circuit 4 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, and is connected to the input terminal CS2 of the second drive IC2 of the second constant current circuit 4 through a series resistor R7, and the second drive IC2 has an input terminal CS2 capable of detecting current, a ground terminal GND2, a drive power supply Vcc2, and an output terminal Gate 2; the drain of the second N-channel MOS transistor Q2 is connected in series to the second main inductor L3, on the other hand, to a fifth capacitor C5 through a fifth diode D5, the cathode of the fifth diode D5 is connected to a fifth capacitor C5, the anode is connected to the drain of the second N-channel MOS transistor Q2, the second main inductor L3 is connected to the fifth capacitor C5 through the series second LED lighting assembly 9, on the other hand, to the fifth capacitor C5 through the series sixth capacitor C6; the Gate of the second N-channel MOS transistor Q1 is connected to the output Gate2 of the second driver IC 2; GND2 is grounded; vcc2 is connected to ac power supply 1 via input rectifying circuit 2; the second detection circuit 7 includes a second secondary inductor L4 coupled to the second main inductor L3, one end of the second secondary inductor L4 is connected in series to a second diode D2 and connected to the ground terminal of the fifth capacitor C5, the other end of the second secondary inductor L4 is connected in series to a second voltage dividing resistor R8 and a second resistor R2, the two ends of the second resistor R2 are connected in parallel to the second capacitor C2, one end of the second resistor R2 is connected to the second voltage dividing resistor R8, the other end of the second resistor R2 is connected to the voltage signal receiving terminal of the control signal generating circuit 5, and the other end of the second resistor R2 is connected to form a loop, wherein the cathode of the second diode D2 is connected to the second secondary inductor L4, and the anode is connected to the second resistor R2.
It should be noted that in this embodiment, N-channel MOS transistors are used for Q1 and Q2, and in some alternative embodiments, other types of switching transistors, such as a transistor, may be used for Q1 and Q2 instead, and the above embodiments are within the scope of the present invention.
In addition, in the present embodiment, the first constant current circuit 3 and the second constant current circuit 4 are both designed as BUCK circuits, and in some alternative embodiments, the first constant current circuit 3 and the second constant current circuit 4 may also be designed as other types of constant current circuits, as long as an inductor for preventing current mutation is connected in series to an output end of the constant current circuit, the time when the inductor enters a steady state may be sampled by a detection circuit designed to be the same as or equivalent to the first detection circuit 6 or the second detection circuit 7, so as to obtain the time difference of the current start time in the first constant current circuit 3 and the second constant current circuit 4.
Continuing with fig. 3, the control signal generating circuit 5 will be described, the voltage signal receiving end of the control signal generating circuit 5 is provided with a first a/D converter a/D1 and a second a/D converter a/D2, the first a/D converter a/D1 and the second a/D converter a/D2 each have a port respectively corresponding to the connection with the first resistor R1 and the second resistor R2, because the connection relationship between the first constant current circuit 3 and the second constant current circuit 4 and the control signal generating circuit 5 is the same, the structure corresponding to the first constant current circuit 3 in the control signal generating circuit 5 will be described first, the control signal generating circuit 5 further has a first electronic switch S1, one terminal of the first electronic switch S1 is connected to the first a/D converter a/D1, and the other terminal is a switchable terminal, it can be alternatively connected to a first input of a first comparator U1 or, via a first register 100, to a second input of a first comparator U1, the output of the first comparator U1 being connected to a first timer 101, one input port of the first timer 101 being connected to a first INT signal circuit 102, the output port of the first timer 101 being connected to the processor 10; similarly, the control signal generating circuit 5 further has a second electronic switch S2, one terminal of the second electronic switch S2 is connected to the second a/D converter a/D2, the other terminal is a switchable terminal, which can be alternatively 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 300, the output terminal of the second comparator U2 is connected to the second timer 201, one input port of the second timer 201 is connected to the second INT signal circuit 202, the output port of the second timer 201 is connected to the processor 10, the processor 10 is connected to the CS1 of the first driving IC1 and the CS2 of the second driving IC2 via the fourth diode D4 and the sixth diode D6, respectively, to transmit PWM control signals to the first driving IC1 and the second driving IC2, respectively, the PWM control signals include a first PWM control signal for driving the first driving IC1 and a second PWM control signal for driving the second driving IC2, and the PWM control signal for driving the first driving IC 3683 and the second driving IC2 In this embodiment, since the first constant current circuit 3 and the second constant current circuit 4 share one ac power supply 1 and are synchronously powered on, the first INT signal circuit 102 and the second INT signal circuit 202 do not need to be separately configured, and only one INT signal circuit is configured to detect the voltage signal of the ac power supply 1.
The operation principle of the lighting circuit is explained as follows:
the first detection circuit 6 and the second detection circuit 7 are provided for detecting the time when the current flowing through the first main inductor L1 and the second main inductor L3 enters the steady state, in the present embodiment, the first sub-inductor L2 and the second sub-inductor L4 are provided to be coupled to the first main inductor L1 and the second main inductor L3, respectively, specifically, the first sub-inductor L2 and the first main inductor L1, the second main inductor L3 and the second sub-inductor L4 are wound around the same iron core or magnetic core to form a transformer, respectively, the first sub-inductor L2 and the second sub-inductor L4 can generate an induced current when the current flows through the first main inductor L1 and the second main inductor L3, respectively, and therefore, the time when the voltage values V1 and V5 across the first resistor R4642 connected in series with the first sub-inductor L2 and the second resistor R2 connected in series enter the steady state can be measured to confirm the time when the current entering the first main inductor L1 and the second main inductor L3 enter the steady state, the first LED lighting assembly 8 and the second LED lighting assembly 9 can obtain the starting current only when the first main inductor L1 and the second main inductor L3 enter the steady state.
Taking the first detection circuit 6 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, the electric energy is stored in the first secondary inductor L2 and also powers 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 conducting loop through the first diode D1, so as to power the output load, the first resistor R1 and the first voltage dividing resistor R5, and at the same time, the first capacitor C1 also discharges to power the first resistor R1 and the first voltage dividing resistor R5, in this embodiment, the magnitude of V1 can be regulated by the coil turn ratio of the first secondary inductor L2 and the first main inductor L1 and the resistance value of the first voltage dividing resistor R5, respectively, so as to be adapted to the voltage signal receiving end of the control signal generation circuit 5, in some embodiments, the first voltage dividing resistor R5 may not be provided, the V1 is regulated and controlled only by the winding turns ratio of the first secondary inductor L2 and the first primary inductor L1, and the structure of the second detection circuit 7 is the same as the structure and the operation principle of the first detection circuit 6, and will not be described again.
The control signal generating circuit 5 has a synchronization mode capable of modifying a control parameter to synchronize the start time of the first LED lighting assembly 8 and the second LED lighting assembly 9 and an operation mode for controlling the lighting states of the first LED lighting assembly 8 and the second LED lighting assembly 9 by using the modified control parameter in the synchronization mode, and the control signal generating circuit 5 can switch between the synchronization mode and the operation mode under the triggering of an external signal.
When the ac power supply 1 is turned on for the first time after the lighting circuit enters the synchronous mode, the first constant current circuit 3 and the second constant current circuit 4 obtain voltages Vcc1 and Vcc2 for driving the first driver IC1 and the second driver IC2, respectively, from the input rectifying circuit 2, and detect the first PWM control signal and the second PWM control signal from the processor 10 to receive a lighting instruction, and after receiving the first PWM control signal and the second PWM control signal from the processor 10, the first constant current circuit 3 and the second constant current circuit 4 output currents to the first LED lighting assembly 8 and the second LED lighting assembly 9, respectively, to light the first LED lighting assembly 8 and the second LED lighting assembly 9 until the first LED lighting assembly 8 and the second LED lighting assembly 9 stably emit light, and during this process, the first PWM control signal and the second PWM control signal are synchronously output from the processor 10, and are connected to the first electronic switch connected to the first a/D converter a/D1 and the second a/D converter a/D2 The switchable terminals of the switch S1 and the second electronic switch S2 are respectively and correspondingly connected to the first register 100 and the second register 200, and when the first LED lighting assembly 8 and the second LED lighting assembly 9 stably emit light, the voltage signals detected by the first constant current circuit 3 and the second constant current circuit 4, that is, the voltages at the two ends of the first resistor R1 and the second resistor R2 are converted into digital signals 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 voltage values corresponding to two ends of the first resistor R1 and the second resistor R2 when the first constant current circuit 3 and the second constant current circuit 4 are in a stable state, respectively. In the subsequent steps, the time when the two ends of the first resistor R1 and the second resistor R2 reach the voltage values respectively reflects the time when the first constant current circuit 3 and the second constant current circuit 4 reach the steady state.
Next, the ac power supply 1 is turned off, and 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 connected to the first comparator U1 and the second comparator U2 side, respectively.
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 detect the input voltage signals of the first constant current circuit 3 and the second constant current circuit 4, respectively, and trigger the first timer 101 and the second timer 201 to start timing when the voltage signals are detected, specifically, in the present embodiment, when the ac power supply 1 is turned on again, the first timer 101 and the second timer 201 start timing, and the first comparator U1 and the second comparator U2 can compare the voltage value V1 at both ends of the first resistor R1 and the voltage value V2 at both ends of the second resistor R2, which are obtained in real time, with the X1 and the X2, respectively, and stop timing when V1 is equal to X1 and V2 is equal to X2, respectively.
Referring to fig. 4, the inventor finds, through theoretical analysis and waveform detection, that, taking the first LED lighting assembly 8 as an example, the current I flowing through the first LED lighting assembly 8outThe start point of the waveform of (2) is almost identical to the stable point of the voltage value V1 waveform across the first resistor R1, and therefore, the start time of the current output can be determined by detecting the time when the start-time voltage value V1 and the voltage value V2 reach the stable point. Therefore, when V1 and V2 reach X1 and X2, respectively, and the timing is stopped, the timing times T1 and T2 are current start times of the first constant current circuit 3 and the second constant current circuit 4.
Thereafter, the processor 10 delays the output of the first/second PWM control signals by | Δ T | according to the time difference Δ T of T1 and T2, and particularly, when T1 > T2, delays the output of the second PWM control signal by | Δ T |; when T1 < T2, the output of the first PWM control signal is time delayed by | Δ T |.
After | Δ T | after the output time is obtained through calculation, the synchronous setting of the lighting circuit is completed, and the hysteresis output information of the first PWM control signal/the second PWM control signal is saved for the operation mode to call, so as to realize the synchronous lighting of the first LED lighting assembly 8 and the second LED lighting assembly 9 in the operation mode.
In the present embodiment, in the synchronous mode, the control signal generating circuit 5 can respond according to the on/off of the ac power supply 1, and a specific implementation may be to communicatively connect a power switch (not shown) of the ac power supply 1 with the processor 10 of the control signal generating circuit 5, and in some alternative implementations, the response made by the control signal generating circuit 5 may also be triggered by other signals.
Referring to fig. 5, the present embodiment provides a synchronization method based on the lighting circuit described above for synchronizing the start times of different constant current circuits in the lighting circuit including a plurality of constant current circuits, including the steps of:
a synchronous mode switching step of switching the lighting circuit to a synchronous mode;
a steady-state voltage providing step of providing voltage values X1 and X2 across the first resistor R1 and the second resistor R2 in a steady state of the first constant current circuit 3 and the second constant current circuit 4;
a time difference determining step of determining a time difference between a time at which the voltage value V1 of the first voltage reaches X1 and a time at which the voltage value V2 of the second voltage reaches X2 during the starting process.
And a working mode switching step, namely switching the lighting circuit to a working mode.
And a PWM control signal output step of outputting a PWM control signal to the corresponding first constant current circuit 3 or second constant current circuit 4 with a delay with respect to the first main inductor L1 or second main inductor L3 which has first reached the steady state, based on the time difference determined in the time difference determination step.
And a lag time storage step of storing the lag time.
In some alternative embodiments, the operation mode switching step may also be arranged after the lag time saving step, i.e. the synchronous setting of the first LED lighting assembly 8 and the second LED lighting assembly 9 is completed in the synchronous mode.
It will be appreciated by those of ordinary skill in the art that in the embodiments described above, numerous technical details are set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the claims of the present application can be basically implemented without these technical details and various changes and modifications based on the above-described embodiments. Accordingly, in actual practice, various changes in form and detail may be made to the above-described embodiments without departing from the spirit and scope of the invention.
Claims (8)
1. A lighting circuit, comprising:
an input rectification loop;
the first constant current circuit is connected between the input rectifying circuit and the first LED light-emitting component;
the second constant current circuit is connected between the input rectifying circuit and the second LED light-emitting component;
a control signal generating circuit connected to the first constant current circuit and the second constant current circuit, for outputting a PWM control signal to control the first constant current circuit and the second constant current circuit to output current to the first LED light emitting assembly and the second LED light emitting assembly,
it is characterized in that the preparation method is characterized in that,
the lighting circuit further comprises a first detection circuit and a second detection circuit,
the first detection circuit includes:
a first secondary inductor coupled to a first primary inductor of the first constant current circuit;
a first resistor 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 secondary inductor;
the second detection circuit includes:
a second secondary inductor coupled to a second primary inductor of the second constant current circuit;
a second resistor in series with the second secondary inductor;
a second diode in series with the second secondary inductor;
a second capacitor connected in parallel with the second resistor; and
a second voltage divider resistor connected in series with the second secondary inductor;
the control signal generating circuit is respectively connected with the first detecting circuit and the second detecting circuit to detect a first voltage and a second voltage at two ends of the first resistor and the second resistor, and the control signal generating circuit can determine a time difference of 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.
2. The lighting circuit according to claim 1, wherein the control signal generation circuit is capable of outputting the PWM control signal to the corresponding first constant current circuit or second constant current circuit with hysteresis with respect to the first main inductance or second main inductance which reaches the steady state first, in accordance with the determined time difference between the voltages of the first main inductance and the second main inductance reaching the steady state.
3. The lighting circuit of claim 1, wherein the control signal generation circuit 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 to the a/D converter, the other terminal being alternatively connectable to a first input of a comparator or, via a register, to a second input of the comparator;
and the timer is connected with the output end of the comparator.
4. A lighting circuit according to any one of claims 1 to 3, wherein the first constant current circuit and the second constant current circuit are both BUCK circuits.
5. A synchronization method for synchronizing the start times of different constant current circuits in an illumination circuit including a plurality of constant current circuits, wherein the illumination circuit is an illumination circuit according to any one of claims 1 to 4, the synchronization method comprising the steps of:
a steady-state voltage providing step of providing voltage values X1 and X2 of the first resistor and the second resistor at two ends of the first constant current circuit and the second constant current circuit in a steady state;
a time difference determining step of determining 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 during the starting process;
and a PWM control signal output step of outputting a PWM control signal to the corresponding first constant current circuit or second constant current circuit with a delay with respect to the first main inductor or second main inductor which reaches the steady state first, based on the time difference determined in the time difference determination step.
6. The synchronization method according to claim 1, wherein a lag time between PWM control signals output to the first constant current circuit and the second constant current circuit is equal to the time difference.
7. The synchronization method according to claim 5 or 6, further comprising the steps of:
and a lag time storage step of storing the lag time.
8. The synchronization method of claim 1, prior to the time difference determining step, further comprising:
a synchronous mode switching step of switching the lighting circuit to a synchronous mode;
after the time difference determining step, before the PWM control signal outputting step, further comprising:
and a working mode switching step of switching the lighting circuit to a working mode.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910979612.2A CN112738946B (en) | 2019-10-15 | 2019-10-15 | Lighting circuit and synchronization method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910979612.2A CN112738946B (en) | 2019-10-15 | 2019-10-15 | Lighting circuit and synchronization method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112738946A true CN112738946A (en) | 2021-04-30 |
| CN112738946B CN112738946B (en) | 2023-04-07 |
Family
ID=75589301
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910979612.2A Active CN112738946B (en) | 2019-10-15 | 2019-10-15 | Lighting circuit and synchronization method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112738946B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005210820A (en) * | 2004-01-22 | 2005-08-04 | Fuji Electric Device Technology Co Ltd | Synchronous rectification dc/dc converter |
| TW200629328A (en) * | 2005-02-03 | 2006-08-16 | Univ Nat Taiwan Science Tech | Dead-time-modulated synchronous PWM controller for dimmable CCFL Royer inverter |
| CN101471577A (en) * | 2007-12-29 | 2009-07-01 | 比亚迪股份有限公司 | Voltage balance circuit for double-burl chargeable battery |
| CN101494418A (en) * | 2008-01-23 | 2009-07-29 | 尼克森微电子股份有限公司 | Synchronous commutation control device and forward type synchronous commutation circuit |
| CN102197707A (en) * | 2008-10-30 | 2011-09-21 | 三菱电机株式会社 | LED operation power source and LED operation system |
| CN103648219A (en) * | 2013-12-19 | 2014-03-19 | 上海莱托思电子科技有限公司 | Light-emitting diode (LED) switch constant-current driving circuit |
| CN103731127A (en) * | 2012-10-16 | 2014-04-16 | 通用电气公司 | Circuit for synchronous control of electronic switches connected in series |
| TWM496317U (en) * | 2014-10-14 | 2015-02-21 | Wen-xing Zhao | Adjustable light driver for LED lamp |
| CN205283403U (en) * | 2015-04-30 | 2016-06-01 | 意法半导体股份有限公司 | A controller and system for multiphase converter |
| RU2631012C1 (en) * | 2016-04-19 | 2017-09-15 | Акционерное общество "Арзамасский приборостроительный завод имени П.И. Пландина" - АО "АПЗ" | Method of control of fixed electromagnetic flowmeter and electromagnetic flowmeter with self-control function |
-
2019
- 2019-10-15 CN CN201910979612.2A patent/CN112738946B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005210820A (en) * | 2004-01-22 | 2005-08-04 | Fuji Electric Device Technology Co Ltd | Synchronous rectification dc/dc converter |
| TW200629328A (en) * | 2005-02-03 | 2006-08-16 | Univ Nat Taiwan Science Tech | Dead-time-modulated synchronous PWM controller for dimmable CCFL Royer inverter |
| CN101471577A (en) * | 2007-12-29 | 2009-07-01 | 比亚迪股份有限公司 | Voltage balance circuit for double-burl chargeable battery |
| CN101494418A (en) * | 2008-01-23 | 2009-07-29 | 尼克森微电子股份有限公司 | Synchronous commutation control device and forward type synchronous commutation circuit |
| CN102197707A (en) * | 2008-10-30 | 2011-09-21 | 三菱电机株式会社 | LED operation power source and LED operation system |
| CN103731127A (en) * | 2012-10-16 | 2014-04-16 | 通用电气公司 | Circuit for synchronous control of electronic switches connected in series |
| CN103648219A (en) * | 2013-12-19 | 2014-03-19 | 上海莱托思电子科技有限公司 | Light-emitting diode (LED) switch constant-current driving circuit |
| TWM496317U (en) * | 2014-10-14 | 2015-02-21 | Wen-xing Zhao | Adjustable light driver for LED lamp |
| CN205283403U (en) * | 2015-04-30 | 2016-06-01 | 意法半导体股份有限公司 | A controller and system for multiphase converter |
| RU2631012C1 (en) * | 2016-04-19 | 2017-09-15 | Акционерное общество "Арзамасский приборостроительный завод имени П.И. Пландина" - АО "АПЗ" | Method of control of fixed electromagnetic flowmeter and electromagnetic flowmeter with self-control function |
Non-Patent Citations (1)
| Title |
|---|
| 欧阳斌林等: "基于开关式测量的电感式位移传感器设计", 《自动化技术与应用》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112738946B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10361633B2 (en) | Control method and device for switching power supplies having more than one control mode | |
| US10651753B1 (en) | Accurate valley detection for secondary controlled flyback converter | |
| US7636249B2 (en) | Rectifier circuit | |
| EP1215808B1 (en) | A power supply circuit and method thereof to detect demagnitization of the power supply | |
| KR101468719B1 (en) | Power converter and driving method thereof | |
| CN100566071C (en) | The circuit and the method that are used for capacitator charging circuit | |
| KR101727290B1 (en) | Converter and the driving method thereof | |
| US20070201253A1 (en) | Switching power supply apparatus | |
| CN103887986A (en) | Control Circuit Of Flyback Type Power Converter Time Predictive Control | |
| CN102356538B (en) | Semiconductor apparatus and method of controlling operation thereof | |
| JP3839737B2 (en) | DC voltage conversion circuit | |
| CN102104338A (en) | Power supply device and image forming apparatus | |
| JP2021153390A (en) | Switching power supply device | |
| KR102143254B1 (en) | Pwm controlling apparatus for flyback converter | |
| CN111641340A (en) | Switching power supply device | |
| US9642199B2 (en) | LED driver circuit and electronic device | |
| TWI729807B (en) | Flyback power converter and active clamp snubber and overcharging protection circuit thereof | |
| KR100685104B1 (en) | Switching Mode Power Supply | |
| JP4414446B2 (en) | Switching power supply circuit | |
| CN112738946B (en) | Lighting circuit and synchronization method thereof | |
| US20220321019A1 (en) | Power conversion apparatus and power conversion system | |
| KR101837469B1 (en) | Rectifier capable of overload prevention by sequential switching control | |
| CN112713778B (en) | Switching control circuit and method for controlling flyback power supply circuit | |
| CN113574785B (en) | Flyback converter circuit, operating device and control method | |
| CN115211015A (en) | Power supply control device, DC-DC converter, and AC-DC converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |