CN115942545B - Phase-cut dimmer holding current circuit and compatible EMC control circuit - Google Patents
Phase-cut dimmer holding current circuit and compatible EMC control circuit Download PDFInfo
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Abstract
The invention provides a phase-cut dimmer maintaining current circuit and a compatible EMC control circuit, comprising: the device comprises a bridge rectifier circuit, an LC filter circuit, a full-wave rectifier circuit, a reference voltage circuit, a current limiting circuit, a conduction selection circuit, a maintenance current turn-off circuit, an EMC control circuit, a chopper detection control circuit, a first switching tube and a first resistor; the circuit provided by the invention is easy to debug, high in precision, small in temperature drift influence, high in reliability, low in standby power consumption, high in efficiency, not easy to cause noise of the phase-cut dimmer, relatively simple and efficient, compatible with EMC and the front phase-cut (front edge) and rear phase-cut (rear edge) phase-cut dimmers.
Description
Technical Field
The invention relates to the technical field of phase-cut dimming, in particular to a phase-cut dimmer maintaining current circuit and a compatible EMC control circuit.
Background
In the use of a phase-cut dimming power supply, in order to achieve a good dimming effect, the phase-cut dimming power supply needs to supply a current for maintaining a conducting state to a transistor in the phase-cut dimmer. This current is not only stable, but also cannot be excessive because it requires the power supply to add more losses, reducing the overall conversion efficiency of the power supply. If EMC is to be compatible, the capacity of the filter capacitor after the bridge is relatively large, but the capacity is large, and the compatibility of the power supply and the dimmer and the dimming effect are not good.
At present, a plurality of methods are applied, wherein an X capacitor (or a thin film capacitor) and a bleeder resistor are connected through a power input end, or an X capacitor (or a thin film capacitor) is connected, and a differential mode inductor is connected in series in front of the X capacitor to provide a maintenance current for a dimmer. The method also has the advantages that the maintenance current is difficult to control and debug, and the dimmer is easy to generate oscillation to generate noise.
Or a constant current circuit formed by a field effect transistor and a triode, the method has the advantages of poor precision of maintaining current, larger influence of temperature, various types of phase-cut dimmers on the market, poor integral consistency and unsatisfactory compatibility effect.
The filter structure composed of C or LC is used more after the bridge, and the capacity is smaller. The filter structure has poor EMC performance.
In summary, the phase-cut dimmer in the prior art has the defects of high energy consumption, high temperature rise, difficult debugging, easy generation of noise, poor precision, larger temperature influence, EMC sacrifice for realizing the compatibility and dimming effect of the dimmer, and the like.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention aims to provide a phase-cut dimmer maintaining current circuit and a compatible EMC control circuit.
In order to achieve the above object, the present invention provides the following solutions:
a phase cut dimmer holding current circuit and compatible EMC control circuit, comprising: the device comprises a bridge rectifier circuit, an LC filter circuit, a full-wave rectifier circuit, a reference voltage circuit, a current limiting circuit, a conduction selection circuit, a maintenance current turn-off circuit, an EMC control circuit, a chopper detection control circuit, a first switching tube and a first resistor;
the input end of the bridge rectifier circuit and the input end of the full-wave rectifier circuit are connected with the mains supply; the LC filter circuit comprises a first inductor and a third capacitor which are sequentially connected; the output end of the bridge rectifier circuit is respectively connected with one end of the EMC control circuit and one end of the first inductor; the other end of the EMC control circuit is connected with the other end of the first inductor; the third capacitor is respectively connected with the grounding end of the EMC control circuit and the bridge rectifier circuit; the output end of the full-wave rectifying circuit is respectively connected with the conduction selection circuit, the chopping detection control circuit and the first end of the first switching tube; the chopping detection control circuit is respectively connected with the EMC control circuit and the maintenance current turn-off circuit; the second end of the first switching tube is connected with the first resistor and the current limiting circuit respectively; the third end of the first switching tube is respectively connected with the current limiting circuit, the on-selection circuit and the maintenance current turn-off circuit; the reference voltage circuit is respectively connected with the current limiting circuit and the conduction selection circuit.
Preferably, the bridge rectifier circuit includes: a first diode, a second diode, a third diode, and a fourth diode;
the first end of the first diode is connected with one end of the first inductor and the first end of the second diode respectively; the second end of the third diode is connected with the second ends of the EMC control circuit, the third capacitor and the fourth diode respectively; the second end of the first diode is connected with the live wire of the mains supply and the first end of the third diode respectively; and the second end of the second diode is respectively connected with the zero line of the mains supply and the first end of the fourth diode.
Preferably, the EMC control circuit includes: the first control capacitor, the second control capacitor, the fifth switching tube, the sixth switching tube and the eleventh resistor;
one end of the first control capacitor is connected with one end of the first inductor and the output end of the bridge rectifier circuit respectively; the other end of the first control capacitor is connected with the first end of the fifth switch tube; one end of the second control capacitor is connected with the other end of the first inductor; the other end of the second control capacitor is connected with one end of the eleventh resistor and the first end of the sixth switching tube respectively; the second end of the fifth switching tube is respectively connected with the second end of the sixth switching tube and the chopping detection control circuit; and the third end of the fifth switching tube is respectively connected with the bridge rectifier circuit, the other end of the eleventh resistor, the third end of the sixth switching tube and the ground.
Preferably, the full-wave rectifying circuit includes: a fifth diode and a sixth diode;
the first end of the fifth diode is respectively connected with the conduction selection circuit, the chopping detection control circuit, the first end of the first switching tube and the first end of the sixth diode; the second end of the fifth diode is connected with a zero line of the mains supply; and the second end of the sixth diode is connected with the live wire of the mains supply.
Preferably, the reference voltage circuit includes: a reference voltage stabilizing chip and a fifth resistor;
the first end of the reference voltage stabilizing chip is respectively connected with the first end of the fifth resistor, the conduction selection circuit, the second end of the reference voltage stabilizing chip and the current limiting circuit; the third end of the reference voltage stabilizing chip is connected with the ground; the second end of the fifth resistor is connected with the power supply end.
Preferably, the on selection circuit includes: a first comparator, a second resistor, a third resistor, and a fourth resistor;
the first end of the second resistor is respectively connected with the first switching tube, the current limiting circuit and the maintenance current turn-off circuit; the second end of the second resistor is connected with the output end of the first comparator; the first input end of the first comparator is connected with the reference voltage circuit; the second input end of the first comparator is respectively connected with the first end of the fourth resistor and the first end of the third resistor; the first comparator is also respectively connected with a power supply end, a second end of the fourth resistor and ground; and the second end of the third resistor is respectively connected with the chopping detection control circuit, the full-wave rectifying circuit and the first switching tube.
Preferably, the current limiting circuit includes: the second switch tube, the first capacitor, the sixth resistor, the seventh resistor and the second comparator;
the first end of the second switching tube is respectively connected with the maintaining current shutoff circuit and the third end of the first switching tube; the second end of the second switch tube is respectively connected with the first end of the first capacitor, the first end of the seventh resistor and the ground; the third end of the second switching tube is connected with the output end of the second comparator; the first input end of the second comparator is respectively connected with the second end of the first capacitor, the second end of the seventh resistor and the first end of the sixth resistor; the second input end of the second comparator is connected with the second end of the fourth switching tube; the second end of the sixth resistor is connected with the reference voltage circuit.
Preferably, the sustain current shutoff circuit includes: a third switching tube;
the first end of the third switching tube is respectively connected with the third end of the first switching tube and the current limiting circuit; the second end of the third switch tube is connected with the ground; and a third end of the third switching tube is connected with the chopping detection control circuit.
Preferably, the chopper detection control circuit includes: an eighth resistor, a ninth resistor, a tenth resistor, a fourth transistor and a microprocessor;
the first pin of the microprocessor is connected with the EMC control circuit, and the seventh pin of the microprocessor is connected with the maintenance current turn-off circuit; the second pin of the microprocessor is respectively connected with the first end of the tenth resistor and the first end of the fourth transistor; the second end of the tenth resistor is connected with the power supply end; the second end of the fourth transistor is respectively connected with the first end of the ninth resistor and the ground; the third end of the fourth transistor is respectively connected with the second end of the ninth resistor and the first end of the eighth resistor; the second end of the eighth resistor is connected with the first end of the first switching tube.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a phase-cut dimmer maintaining current circuit and a compatible EMC control circuit, comprising: the device comprises a bridge rectifier circuit, an LC filter circuit, a full-wave rectifier circuit, a reference voltage circuit, a current limiting circuit, a conduction selection circuit, a maintenance current turn-off circuit, an EMC control circuit, a chopper detection control circuit, a first switching tube and a first resistor; the input end of the bridge rectifier circuit and the input end of the full-wave rectifier circuit are connected with the mains supply; the LC filter circuit comprises a first inductor and a third capacitor which are sequentially connected; the output end of the bridge rectifier circuit is respectively connected with one end of the EMC control circuit and one end of the first inductor; the other end of the EMC control circuit is connected with the other end of the first inductor; the third capacitor is respectively connected with the grounding end of the EMC control circuit and the bridge rectifier circuit; the output end of the full-wave rectifying circuit is respectively connected with the conduction selection circuit, the chopping detection control circuit and the first end of the first switching tube; the chopping detection control circuit is respectively connected with the EMC control circuit and the maintenance current turn-off circuit; the second end of the first switching tube is connected with the first resistor and the current limiting circuit respectively; the third end of the first switching tube is respectively connected with the current limiting circuit, the on-selection circuit and the maintenance current turn-off circuit; the reference voltage circuit is respectively connected with the current limiting circuit and the conduction selection circuit. The circuit provided by the invention is easy to debug, high in precision, small in temperature drift influence, high in reliability, low in standby power consumption, high in efficiency, not easy to cause noise of the phase-cut dimmer, relatively simple and efficient, compatible with EMC and the front phase-cut (front edge) and rear phase-cut (rear edge) phase-cut dimmers.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings that are needed in the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a phase-cut dimmer holding current circuit and a compatible EMC control circuit for a phase-cut dimming power supply according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a circuit according to an embodiment of the present invention;
reference numerals illustrate:
the power supply comprises a reference voltage circuit, a 102-current limiting circuit, a 103-conduction selection circuit, a 104-maintenance current turn-off circuit, a 105-EMC control circuit, a 106-chopper detection control circuit, a D1-first diode, a D2-second diode, a D3-third diode, a D4-fourth diode, a D5-fifth diode, a D6-sixth diode, a U2-reference voltage stabilizing chip, a CD 1-first control capacitor, a CD 2-second control capacitor, a CD 3-third capacitor, a C1-first capacitor, a Q1-first switching tube, a Q2-second switching tube, a Q3-third switching tube, a Q4-fourth transistor, a Q5-fifth switching tube, a Q6-sixth switching tube, a R1-first resistor, a R2-second resistor, a R3-third resistor, a R4-fourth resistor, a R5-fifth resistor, a R6-sixth resistor, a R7-seventh resistor, a R8-eighth resistor, a R9-ninth resistor, a R10-U, a U1-ninth resistor, a U1-third resistor, a wire, a VDD, a L1-fourth resistor, a wire and a power supply.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The terms "first," "second," "third," and "fourth" and the like in the description and in the claims of this application and in the drawings, are used for distinguishing between different objects and not for describing a particular sequential order. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, inclusion of a list of steps, processes, methods, etc. is not limited to the listed steps but may alternatively include steps not listed or may alternatively include other steps inherent to such processes, methods, products, or apparatus.
The invention aims to provide a phase cut dimmer maintaining current circuit and a compatible EMC control circuit, which are easy to debug, high in precision, small in temperature drift influence, high in reliability, low in standby power consumption, high in efficiency, and relatively simple and efficient in circuit, and compatible with EMC and front phase cut (front edge) and rear phase cut (rear edge) phase cut dimmers, and noise is not easily generated by the phase cut dimmers.
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Fig. 1 is a schematic diagram of a phase-cut dimmer holding current circuit and a compatible EMC control circuit for a phase-cut dimming power supply according to an embodiment of the present invention, and as shown in fig. 1, the present invention provides a phase-cut dimmer holding current circuit and a compatible EMC control circuit, including: a bridge rectifier circuit, an LC filter circuit, a full-wave rectifier circuit, a reference voltage circuit 101, a current limiting circuit 102, a turn-on selection circuit 103, a holding current turn-off circuit 104, an EMC control circuit 105, a chopper detection control circuit 106, a first switching tube Q1, and a first resistor R1; the input end of the bridge rectifier circuit and the input end of the full-wave rectifier circuit are connected with the mains supply; the LC filter circuit comprises a first inductor and a third capacitor CD3 which are sequentially connected; the output end of the bridge rectifier circuit is respectively connected with one end of the EMC control circuit 105 and one end of the first inductor; the other end of the EMC control circuit 105 is connected with the other end of the first inductor; the third capacitor CD3 is connected to the ground terminal of the EMC control circuit 105 and the bridge rectifier circuit, respectively; the output end of the full-wave rectifying circuit is respectively connected with the conduction selection circuit 103, the chopping detection control circuit 106 and the first end of the first switching tube Q1; the chopper detection control circuit 106 is connected to the EMC control circuit 105 and the holding current shut-off circuit 104, respectively; the second end of the first switching tube Q1 is respectively connected with the first resistor R1 and the current limiting circuit 102; a third end of the first switching tube Q1 is connected to the current limiting circuit 102, the on-selection circuit 103 and the holding current off circuit 104, respectively; the reference voltage circuit 101 is connected to the current limiting circuit 102 and the conduction selection circuit 103, respectively.
Fig. 2 is a schematic circuit diagram according to an embodiment of the present invention, as shown in fig. 2, where the bridge rectifier circuit includes: a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4; the first end of the first diode D1 is connected with one end of a first inductor and the first end of the second diode D2 respectively; a second end of the third diode D3 is connected to the EMC control circuit 105, the third capacitor CD3, and a second end of the fourth diode D4, respectively; the second end of the first diode D1 is connected with the live wire L of the mains supply and the first end of the third diode D3 respectively; the second end of the second diode D2 is connected to the neutral line N of the mains supply and the first end of the fourth diode D4, respectively. The EMC control circuit 105 includes: the first control capacitor CD1, the second control capacitor CD2, the fifth switching tube Q5, the sixth switching tube Q6 and the eleventh resistor R11; one end of the first control capacitor CD1 is respectively connected with one end of the first inductor and the output end of the bridge rectifier circuit; the other end of the first control capacitor CD1 is connected with the first end of the fifth switch tube Q5; one end of the second control capacitor CD2 is connected with the other end of the first inductor; the other end of the second control capacitor CD2 is connected to one end of the eleventh resistor R11 and the first end of the sixth switching tube Q6 respectively; the second end of the fifth switching tube Q5 is connected to the second end of the sixth switching tube Q6 and the chopper detection control circuit 106, respectively; a third end of the fifth switching tube Q5 is connected with the bridge rectifier circuit, the other end of the eleventh resistor R11, a third section of the sixth switching tube Q6 and ground respectively; the full-wave rectification circuit includes: a fifth diode D5 and a sixth diode D6; a first end of the fifth diode D5 is connected to the conduction selection circuit 103, the chopper detection control circuit 106, a first end of the first switching tube Q1, and a first end of the sixth diode D6, respectively; the second end of the fifth diode D5 is connected with a zero line N of the mains supply; the second end of the sixth diode D6 is connected with the live wire L of the mains supply. The reference voltage circuit 101 includes: a reference voltage stabilizing chip U2 and a fifth resistor R5; the first end of the reference voltage stabilizing chip U2 is connected with the first end of the fifth resistor R5, the conduction selection circuit 103, the second end of the reference voltage stabilizing chip U2 and the current limiting circuit 102, respectively; the third end of the reference voltage stabilizing chip U2 is connected with the ground; the second terminal of the fifth resistor R5 is connected to the power supply terminal VDD. The on selection circuit 103 includes: a first comparator U1A, a second resistor R2, a third resistor R3, and a fourth resistor R4; the first end of the second resistor R2 is connected to the first switching tube Q1, the current-limiting short circuit and the holding current turn-off circuit 104, respectively; the second end of the second resistor R2 is connected with the output end of the first comparator U1A; a first input end of the first comparator U1A is connected to the reference voltage circuit 101; the second input end of the first comparator U1A is respectively connected with the first end of the fourth resistor R4 and the first end of the third resistor R3; the first comparator U1A is also respectively connected with a power supply end VDD, a second end of the fourth resistor R4 and ground; the second end of the third resistor R3 is connected to the chopper detection control circuit 106, the full-wave rectification circuit, and the first switching tube Q1, respectively. The current limiting circuit 102 includes: the second switch tube Q2, the first capacitor C1, the sixth resistor R6, the seventh resistor R7 and the second comparator U1B; a first end of the second switching tube Q2 is connected to the maintaining current shutoff circuit 104 and a third end of the first switching tube Q1, respectively; the second end of the second switching tube Q2 is respectively connected with the first end of the first capacitor C1, the first end of the seventh resistor R7 and the ground; the third end of the second switching tube Q2 is connected with the output end of the second comparator U1B; the first input end of the second comparator U1B is respectively connected with the second end of the first capacitor C1, the second end of the seventh resistor R7 and the first end of the sixth resistor R6; the second input end of the second comparator U1B is connected with the second end of the first switch tube Q1; a second end of the sixth resistor R6 is connected to the reference voltage circuit 101. The sustain current shutoff circuit 104 includes: a third switching tube Q3; the first end of the third switching tube Q3 is connected with the third end of the first switching tube Q1 and the current limiting circuit 102 respectively; the second end of the third switching tube Q3 is connected with the ground; a third end of the third switching tube Q3 is connected to the chopper detection control circuit 106. The chopper detection control circuit 106 includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a fourth transistor Q4, and a microprocessor U3; a first pin of the microprocessor U3 is connected to the EMC control circuit 105, and a seventh pin of the microprocessor U3 is connected to the holding current turn-off circuit 104; the second pin of the microprocessor U3 is respectively connected with the first end of the tenth resistor R10 and the first end of the fourth transistor Q4; the second end of the tenth resistor R10 is connected with the power supply end VDD; the second end of the fourth transistor Q4 is respectively connected with the first end of the ninth resistor R9 and the ground; a third end of the fourth transistor Q4 is connected to the second section of the ninth resistor R9 and the first end of the eighth resistor R8, respectively; the second end of the eighth resistor R8 is connected to the first end of the first switching tube Q1.
The working principle of the circuit provided by the embodiment is as follows:
when the system is powered on, L, N is connected to two ends of a bridge-type rectifying AC input consisting of D1, D2, D3 and D4, and after bridge rectification, the system is subjected to LC (liquid crystal) filtering after passing through a bridge consisting of L1 and CD3, and then the power supply main circuit is powered.
LN also obtains a full-wave rectified voltage by full-wave rectification consisting of D5 and D6. VDD is output by the main circuit transformer auxiliary winding or auxiliary power supply.
Reference voltage circuit 101 is a reference voltage source formed by VDD, which is limited by R5, connected to pins 1 and 2 of U2, and pin 3 of U2 connected to ground.
The current limiting circuit 102 obtains voltage references from pins 1 and 2 of U2 through resistors R6 and R7 to divide the voltage, the voltage is filtered by C1 and then supplied to pin 6 of U1, pin 5 of U1 is connected to R1, when Q1 is conducted, current flows through R1 to generate a voltage value, the voltage value is added to voltage comparison between the pin 5 and pin 6 of U1, so that pin 7 of U1 outputs high level to gate of Q2 to enable Q2 to be conducted, high level of gate of Q1 is pulled down to enable Q1 to be cut off, and the magnitude of maintaining current provided for the phase-cut dimmer is accurately controlled by the current limiting circuit.
The turn-on selection circuit 103 is powered by VDD connected to pin 8 of U1, pin 4 of U1 being grounded. The 3 pin of U1 is connected to the 1 pin and the 2 pin of U2 to obtain a voltage reference, the cathodes of D5 and D6 are divided into the 2 pin of U1 through the resistors of R3 and R4, and the 1 pin of U1 is connected with the grid electrode of R2 driving Q1. The voltage value of the 2 pins of the U1 can be set by adjusting the resistance values of R3 and R4, and compared with the voltage reference value of the 3 pins of the U1, when the full-wave rectification voltage is lower, the 1 pin of the U1 outputs a high level, and the grid electrode of the Q1 is driven by R2 to lead the Q1 to be conducted. When the full-wave rectification voltage is relatively high, the 1 pin output low level of the U1 drives the grid electrode of the Q1 through the R2 to cut off the Q1. The full-wave rectification and the grounding from R1 to bridge rectification return to the power grid to form a loop when Q1 is conducted, so as to provide maintenance current for phase-cut dimming, the resistance values of R3 and R4 can be flexibly and accurately set to cut off at any point of full-wave rectification voltage, and the phase-cut dimmer can stably work by avoiding the current consumed by the power supply while the high loss of the full-wave rectification voltage is relatively large.
The holding current turn-off circuit 104 is composed of a drain electrode of Q3 connected to a gate electrode of Q1, a gate electrode of Q3 connected to a 1 pin of the microprocessor U3, and a source electrode of Q3 connected to ground.
The EMC control circuit is connected to the output cathode of the bridge rectifier by one end of the CD1, the other end of the CD1 is connected to the drain electrode of the Q5, the source electrode of the Q5 is connected to the ground, and the grid electrode of the Q5 is connected to the 1 pin of the U3. One point of CD2 is connected to the drain of Q6 and one end of R11, the source of Q6 is connected to ground, the gate of Q6 is connected to pin 1 of U3, and the other end of R11 is connected to ground.
The chopper detection control circuit 106 is configured to sample the full-wave rectified voltage by R8 and R9 voltage dividing resistors to turn on and off Q4 following the full-wave rectified voltage waveform, and to form a duty cycle signal from the voltage sampled by R10 from VDD following the full-wave rectified voltage waveform to be sent to the 2 pin of U3 for detection. The power supply has a phase cut when connected to the phase cut dimmer and does not pass through the phase cut when not connected to the dimmer. The chopper detection control circuit 106 determines whether the detected power source has a phase cut, and whether the detected power source has a phase cut dimmer, so that the compatibility and the dimming effect are not affected when the power source does not have the phase cut dimmer. When the light modulator is detected to be not connected or the light modulator is dimmed to the lowest, the power supply enters standby, the 7 pin of U3 outputs high level, the high level is supplied to the grid electrode of Q3 of the maintaining current cut-off circuit, the grid electrode potential of Q1 is pulled down, Q1 is in a cut-off state, the efficiency of the power supply when the light modulator is not connected in standby, no-load or full-load is effectively improved, and the power consumption and the heating are reduced. Meanwhile, the fact that the 1 pin which is not connected with the dimmer U3 outputs high level is detected, the high level is supplied to the grid electrodes of Q5 and Q6 of the EMC control circuit, one ends of CD1 and CD2 are connected to the ground, pi-type filtering is formed, the filtering capacity is increased, and the EMC filtering effect is better.
Further, the chopper detection control circuit may also be controlled by converting the full-wave rectified voltage into a direct-current voltage through a comparator. An optical coupler can be added to carry out isolated transmission on signals.
The beneficial effects of the invention are as follows:
the phase-cut dimmer maintenance current circuit and the compatible EMC control circuit of the invention have the advantages of easy debugging, high precision, small temperature drift influence, high reliability, high efficiency, low standby power consumption and compatibility with EMC.
In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.
The principles and embodiments of the present invention have been described herein with reference to specific examples, the description of which is intended only to assist in understanding the methods of the present invention and the core ideas thereof; also, it is within the scope of the present invention to be modified by those of ordinary skill in the art in light of the present teachings. In view of the foregoing, this description should not be construed as limiting the invention.
Claims (9)
1. A phase cut dimmer holding current circuit and a compatible EMC control circuit, comprising: the device comprises a bridge rectifier circuit, an LC filter circuit, a full-wave rectifier circuit, a reference voltage circuit, a current limiting circuit, a conduction selection circuit, a maintenance current turn-off circuit, an EMC control circuit, a chopper detection control circuit, a first switching tube and a first resistor;
the input end of the bridge rectifier circuit and the input end of the full-wave rectifier circuit are connected with the mains supply; the LC filter circuit comprises a first inductor and a third capacitor which are sequentially connected; the output end of the bridge rectifier circuit is respectively connected with one end of the EMC control circuit and one end of the first inductor; the other end of the EMC control circuit is connected with the other end of the first inductor; the third capacitor is respectively connected with the grounding end of the EMC control circuit and the bridge rectifier circuit; the output end of the full-wave rectifying circuit is respectively connected with the conduction selection circuit, the chopping detection control circuit and the first end of the first switching tube; the chopping detection control circuit is respectively connected with the EMC control circuit and the maintenance current turn-off circuit; the second end of the first switching tube is connected with the first resistor and the current limiting circuit respectively; the third end of the first switching tube is respectively connected with the current limiting circuit, the on-selection circuit and the maintenance current turn-off circuit; the reference voltage circuit is respectively connected with the current limiting circuit and the conduction selection circuit.
2. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the bridge rectifier circuit comprises: a first diode, a second diode, a third diode, and a fourth diode;
the first end of the first diode is connected with one end of the first inductor and the first end of the second diode respectively; the second end of the third diode is connected with the second ends of the EMC control circuit, the third capacitor and the fourth diode respectively; the second end of the first diode is connected with the live wire of the mains supply and the first end of the third diode respectively; and the second end of the second diode is respectively connected with the zero line of the mains supply and the first end of the fourth diode.
3. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the EMC control circuit comprises: the first control capacitor, the second control capacitor, the fifth switching tube, the sixth switching tube and the eleventh resistor;
one end of the first control capacitor is connected with one end of the first inductor and the output end of the bridge rectifier circuit respectively; the other end of the first control capacitor is connected with the first end of the fifth switch tube; one end of the second control capacitor is connected with the other end of the first inductor; the other end of the second control capacitor is connected with one end of the eleventh resistor and the first end of the sixth switching tube respectively; the second end of the fifth switching tube is respectively connected with the second end of the sixth switching tube and the chopping detection control circuit; and the third end of the fifth switching tube is respectively connected with the bridge rectifier circuit, the other end of the eleventh resistor, the third end of the sixth switching tube and the ground.
4. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the full wave rectifying circuit comprises: a fifth diode and a sixth diode;
the first end of the fifth diode is respectively connected with the conduction selection circuit, the chopping detection control circuit, the first end of the first switching tube and the first end of the sixth diode; the second end of the fifth diode is connected with a zero line of the mains supply; and the second end of the sixth diode is connected with the live wire of the mains supply.
5. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the reference voltage circuit comprises: a reference voltage stabilizing chip and a fifth resistor;
the first end of the reference voltage stabilizing chip is respectively connected with the first end of the fifth resistor, the conduction selection circuit, the second end of the reference voltage stabilizing chip and the current limiting circuit; the third end of the reference voltage stabilizing chip is connected with the ground; the second end of the fifth resistor is connected with the power supply end.
6. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the on-select circuit comprises: a first comparator, a second resistor, a third resistor, and a fourth resistor;
the first end of the second resistor is respectively connected with the first switching tube, the current limiting circuit and the maintenance current turn-off circuit; the second end of the second resistor is connected with the output end of the first comparator; the first input end of the first comparator is connected with the reference voltage circuit; the second input end of the first comparator is respectively connected with the first end of the fourth resistor and the first end of the third resistor; the first comparator is also respectively connected with a power supply end, a second end of the fourth resistor and ground; and the second end of the third resistor is respectively connected with the chopping detection control circuit, the full-wave rectifying circuit and the first switching tube.
7. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the current limiting circuit comprises: the second switch tube, the first capacitor, the sixth resistor, the seventh resistor and the second comparator;
the first end of the second switching tube is respectively connected with the maintaining current shutoff circuit and the third end of the first switching tube; the second end of the second switch tube is respectively connected with the first end of the first capacitor, the first end of the seventh resistor and the ground; the third end of the second switching tube is connected with the output end of the second comparator; the first input end of the second comparator is respectively connected with the second end of the first capacitor, the second end of the seventh resistor and the first end of the sixth resistor; the second input end of the second comparator is connected with the second end of the first switching tube; the second end of the sixth resistor is connected with the reference voltage circuit.
8. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the maintenance current shutdown circuit comprises: a third switching tube;
the first end of the third switching tube is respectively connected with the third end of the first switching tube and the current limiting circuit; the second end of the third switch tube is connected with the ground; and a third end of the third switching tube is connected with the chopping detection control circuit.
9. The phase cut dimmer maintenance current circuit and compatible EMC control circuit of claim 1, wherein the chopping detection control circuit comprises: an eighth resistor, a ninth resistor, a tenth resistor, a fourth transistor and a microprocessor;
the first pin of the microprocessor is connected with the EMC control circuit, and the seventh pin of the microprocessor is connected with the maintenance current turn-off circuit; the second pin of the microprocessor is respectively connected with the first end of the tenth resistor and the first end of the fourth transistor; the second end of the tenth resistor is connected with the power supply end; the second end of the fourth transistor is respectively connected with the first end of the ninth resistor and the ground; the third end of the fourth transistor is respectively connected with the second end of the ninth resistor and the first end of the eighth resistor; the second end of the eighth resistor is connected with the first end of the first switching tube.
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| CN202211627231.6A CN115942545B (en) | 2022-12-16 | 2022-12-16 | Phase-cut dimmer holding current circuit and compatible EMC control circuit |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202211627231.6A CN115942545B (en) | 2022-12-16 | 2022-12-16 | Phase-cut dimmer holding current circuit and compatible EMC control circuit |
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| CN115942545B true CN115942545B (en) | 2023-07-21 |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205249536U (en) * | 2015-12-23 | 2016-05-18 | 珠海市圣昌电子有限公司 | A cut looks light modulator and maintain current control circuit for cutting power of adjusting luminance mutually |
| CN208386961U (en) * | 2018-07-19 | 2019-01-15 | 上海晶丰明源半导体股份有限公司 | Rising edge trigger circuit, driving chip and lighting driving system |
| CN112437521A (en) * | 2020-11-30 | 2021-03-02 | 广州河东科技有限公司 | Intelligent back-edge dimming device based on MOSFET |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11452189B2 (en) * | 2020-08-14 | 2022-09-20 | ERP Power, LLC | External zero-crossing detection circuit for LED drivers |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205249536U (en) * | 2015-12-23 | 2016-05-18 | 珠海市圣昌电子有限公司 | A cut looks light modulator and maintain current control circuit for cutting power of adjusting luminance mutually |
| CN208386961U (en) * | 2018-07-19 | 2019-01-15 | 上海晶丰明源半导体股份有限公司 | Rising edge trigger circuit, driving chip and lighting driving system |
| CN112437521A (en) * | 2020-11-30 | 2021-03-02 | 广州河东科技有限公司 | Intelligent back-edge dimming device based on MOSFET |
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