CN218997925U - Silicon controlled rectifier control system and switching power supply - Google Patents
Silicon controlled rectifier control system and switching power supply Download PDFInfo
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- CN218997925U CN218997925U CN202223128312.XU CN202223128312U CN218997925U CN 218997925 U CN218997925 U CN 218997925U CN 202223128312 U CN202223128312 U CN 202223128312U CN 218997925 U CN218997925 U CN 218997925U
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Abstract
The embodiment of the utility model discloses a silicon controlled rectifier control system and a switching power supply, wherein the system comprises: the power supply circuit, the zero crossing detection circuit for detecting the zero crossing signal of alternating current, the silicon controlled rectifier control circuit for controlling the load and the MCU control circuit; the power supply circuit is electrically connected with the zero-crossing detection circuit, the silicon controlled rectifier control circuit and the MCU control circuit and used for converting alternating current into 12V direct current and 5V direct current; the MCU control circuit is electrically connected with the zero-crossing detection circuit and the silicon controlled rectifier control circuit and is used for controlling the on-off of the silicon controlled rectifier control circuit according to the zero-crossing signal; a freewheel diode corresponding to the 12V direct current is provided in the zero-crossing detection circuit, and the freewheel diode corresponding to the 5V direct current is not provided in the zero-crossing detection circuit. Therefore, voltage backflow is avoided, damage to components is avoided, and stability of the system is improved.
Description
Technical Field
The utility model relates to the technical field of switching power supplies, in particular to a silicon controlled rectifier control system and a switching power supply.
Background
In the current silicon controlled rectifier control system, a zero crossing detection circuit is adopted to detect a zero crossing signal of alternating current, and an MCU (micro control unit) chip controls the on-off of the silicon controlled rectifier control circuit through the zero crossing signal. Under normal conditions, current flows from high level to low level, but when the existing silicon controlled rectifier control system is in a positive half wave, negative current exists, and voltage backflow can be formed, so that components are damaged, and the stability of the system is affected.
Disclosure of Invention
Based on the above, it is necessary to provide a thyristor control system and a switching power supply, which are necessary to solve the problems that the existing thyristor control system has negative current during positive half wave and can form voltage backflow, thereby damaging components and affecting the stability of the system.
The application provides a silicon controlled rectifier control system, the system includes: the power supply circuit, the zero crossing detection circuit for detecting the zero crossing signal of alternating current, the silicon controlled rectifier control circuit for controlling the load and the MCU control circuit;
the power supply circuit is electrically connected with the zero-crossing detection circuit, the silicon controlled rectifier control circuit and the MCU control circuit and used for converting alternating current into 12V direct current and 5V direct current;
the MCU control circuit is electrically connected with the zero-crossing detection circuit and the silicon controlled rectifier control circuit and is used for controlling the on-off of the silicon controlled rectifier control circuit according to the zero-crossing signal;
a freewheel diode corresponding to the 12V direct current is provided in the zero-crossing detection circuit, and the freewheel diode corresponding to the 5V direct current is not provided in the zero-crossing detection circuit.
Further, the zero-crossing detection circuit includes: the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor, the freewheel diode, the first capacitor and the PNP triode;
the first end of the first resistor is electrically connected with the power circuit, the second end of the first resistor is electrically connected with the first end of the second resistor, the anode of the freewheel diode is electrically connected with the second end of the second resistor, the first end of the third resistor and the B pole of the PNP triode, the cathode of the freewheel diode is electrically connected with the 12V direct current output end of the power circuit, and the second end of the third resistor and the E pole of the PNP triode are electrically connected with the 5V direct current output end of the power circuit;
the C pole of the PNP triode is electrically connected with the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fifth resistor and the first end of the first capacitor are electrically connected with the MCU control circuit, and the second end of the fourth resistor and the second end of the first capacitor are grounded.
Further, the power supply circuit includes: a piezoresistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode, a second diode, a third diode, a fourth diode, a first inductor, a second inductor, a common mode inductor, a first electrolytic capacitor, a second electrolytic capacitor, a third electrolytic capacitor, a fourth electrolytic capacitor, a fifth electrolytic capacitor, a ground terminal, a switching power supply chip and a buck chip;
the first end of the piezoresistor, the first end of the second capacitor, the first end of the eighth resistor, the first end of the third capacitor, the first end of the first inductor and the negative electrode of the first electrolytic capacitor are all electrically connected with a zero line of an alternating current power supply, the first end of the sixth resistor is electrically connected with a live wire of the alternating current power supply, the second end of the sixth resistor is electrically connected with the second end of the piezoresistor, the second end of the second capacitor, the first end of the seventh resistor, the first end of the fourth capacitor, the first end of the first resistor and the positive electrode of the first diode, the second end of the seventh resistor is electrically connected with the second end of the eighth resistor, and the ground end is connected between the second end of the fourth capacitor and the second end of the third capacitor;
the cathode of the first diode is electrically connected with the anode of the second diode, and the cathode of the second diode is electrically connected with the anode of the first electrolytic capacitor and the first end of the second inductor;
the second end of the first inductor is electrically connected with the negative electrode of the second electrolytic capacitor, the first end of the common mode inductor, the positive electrode of the fourth electrolytic capacitor, the positive electrode of the third diode, the output end of the 12V direct current, the first end of the eleventh resistor, the first end of the seventh capacitor, the first end of the eighth capacitor and the VIN pin of the buck chip;
the second end of the second inductor is electrically connected with the positive electrode of the second electrolytic capacitor, the switch power supply chip and the first end of the fifth capacitor, the first end of the ninth resistor is electrically connected with the second end of the fifth capacitor, the second end of the ninth resistor is electrically connected with two GND pins of the switch power supply chip, the negative electrode of the third electrolytic capacitor, the second end of the common mode inductor, the first end of the sixth capacitor and the negative electrode of the fourth diode, the VCC pin of the switch power supply chip is electrically connected with the positive electrode of the third electrolytic capacitor and the negative electrode of the third diode, and the second end of the sixth capacitor is electrically connected with the first end of the tenth resistor;
the VOUT pin of the buck chip is electrically connected with the first end of the ninth capacitor, the positive electrode of the fifth electrolytic capacitor, the first end of the twelfth resistor, the first end of the tenth capacitor and the output end of the 5V direct current;
the second end of the tenth resistor, the anode of the fourth diode, the cathode of the fourth electrolytic capacitor, the second end of the eleventh resistor, the second end of the seventh capacitor, the second end of the eighth capacitor, the GND pin of the buck chip, the second end of the ninth capacitor, the cathode of the fifth electrolytic capacitor, the second end of the twelfth resistor and the second end of the tenth capacitor are all grounded.
Further, the system further comprises: the middle heating wire and the side heating wire are connected in series with the silicon controlled rectifier control circuit and then connected in parallel with the side heating wire, and the side heating wire is connected between the zero line and the live line;
the thyristor control circuit includes: thirteenth resistor, fourteenth resistor, fifteenth resistor, sixteenth resistor, seventeenth resistor, eleventh capacitor, twelfth capacitor, optocoupler and silicon controlled rectifier;
the first end of the intermediate heating wire is electrically connected with the live wire, the second end of the intermediate heating wire is electrically connected with the first end of the eleventh capacitor, the first end of the silicon controlled rectifier and the fourth pin of the optocoupler, and the second end of the eleventh capacitor is electrically connected with the first end of the thirteenth resistor;
the second end of the silicon controlled rectifier is electrically connected with the first end of the fourteenth resistor and the first end of the sixteenth resistor, the second end of the fourteenth resistor is electrically connected with the first end of the twelfth capacitor and the first end of the fifteenth resistor, and the second end of the sixteenth resistor is electrically connected with the 6 th pin of the optocoupler;
the 2 nd pin of the optical coupler is grounded, the 1 st pin of the optical coupler is electrically connected with the first end of the seventeenth resistor, and the second end of the seventeenth resistor is electrically connected with the MCU control circuit;
the second end of the thirteenth resistor, the third end of the controllable silicon, the second end of the twelfth capacitor and the second end of the fifteenth resistor are all electrically connected with the zero line.
Further, the silicon controlled rectifier control circuit further comprises a connector, wherein the first end of the connector is electrically connected with the first end of the eleventh capacitor, the first end of the silicon controlled rectifier and the fourth pin of the optocoupler, and the second end of the connector is electrically connected with the second end of the intermediate heating wire, and the connector is a copper insert.
Further, the thyristor control circuit further includes: and the test end is electrically connected with the third end of the controllable silicon.
Further, the system further comprises: and the double-pole switch is connected between the power supply circuit and the silicon controlled rectifier control circuit.
Further, the system further comprises: the zero line relay is arranged between the zero line output end of the double-pole switch and the silicon controlled rectifier control circuit, and the zero line relay is electrically connected with the 12V direct current output end and the MCU control circuit.
Further, the system further comprises: the first end of the live wire relay is electrically connected with the live wire output end of the double-pole switch, and the second end of the live wire relay is electrically connected with the middle heating wire and the side heating wire.
The application also proposes a switching power supply, the switching power supply includes: a thyristor control system according to any preceding claim.
According to the thyristor control system, alternating current is converted into 12V direct current and 5V direct current through the power supply circuit, the freewheeling diode corresponding to the 12V direct current is arranged in the zero-crossing detection circuit, and the freewheeling diode corresponding to the 5V direct current is not arranged in the zero-crossing detection circuit, so that voltage backflow is avoided, damage to components is avoided, and stability of the system is improved.
Drawings
In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Wherein:
FIG. 1 is a block diagram of a thyristor control system according to one embodiment;
FIG. 2 is a schematic diagram of MCU control circuitry in one embodiment;
FIG. 3 is a schematic diagram of a power supply circuit and zero crossing detection circuit in one embodiment;
FIG. 4 is a schematic diagram of a thyristor control circuit, a neutral relay, and a hot relay in one embodiment;
FIG. 5 is a schematic diagram of current direction with voltage back-off;
fig. 6 is a schematic diagram of the current direction of the positive half-wave of the alternating current of the present application.
Detailed Description
The following description of the embodiments of the present utility model 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 utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.
As shown in fig. 1, the present application proposes a thyristor Q11 control system, which includes: a power supply circuit 100, a zero-crossing detection circuit 200 for detecting a zero-crossing signal of alternating current, a silicon controlled rectifier Q11 control circuit 400 for controlling a load, and an MCU control circuit;
the power supply circuit 100 is electrically connected with the zero crossing detection circuit 200, the silicon controlled rectifier Q11 control circuit 400 and the MCU control circuit and is used for converting alternating current into 12V direct current and 5V direct current;
the MCU control circuit is electrically connected with the zero-crossing detection circuit 200 and the silicon controlled rectifier Q11 control circuit 400 and is used for controlling the on-off of the silicon controlled rectifier Q11 control circuit 400 according to the zero-crossing signal;
a freewheel diode corresponding to the 12V direct current is provided in the zero-cross detection circuit 200, and the freewheel diode corresponding to the 5V direct current is not provided in the zero-cross detection circuit 200.
The system of the embodiment converts the alternating current into 12V direct current and 5V direct current through the power circuit 100, the freewheeling diode corresponding to the 12V direct current is arranged in the zero-crossing detection circuit 200, and the freewheeling diode corresponding to the 5V direct current is not arranged in the zero-crossing detection circuit 200, so that voltage backflow is avoided, damage to components is avoided, and stability of the system is improved.
Loads include, but are not limited to, incandescent lamps.
The power circuit 100 receives ac power from an ac power source through an ac interface and then converts the ac power into 12V dc power and 5V dc power. The 12V direct current is 12V direct current. 5V direct current is 5V direct current.
As shown in fig. 2, the MCU control circuit includes an MCU chip U3 and a supporting circuit. The MCU chip controls the on and off of the optocoupler U4 of the scr Q11 control circuit 400 by outputting high and low levels, and controls the scr Q11 in the scr Q11 control circuit 400 by the on and off of the optocoupler U4. The MCU control circuit is electrically connected with the output end of the 5V direct current of the power supply circuit 100.
The freewheeling diode adopts a diode.
As shown in fig. 3, in one embodiment, the zero-crossing detection circuit 200 includes: the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R75, the fifth resistor R79, the freewheel diode, the first capacitor C1 and the PNP triode Q1;
the first end of the first resistor R1 is electrically connected with the power circuit 100, the second end of the first resistor R1 is electrically connected with the first end of the second resistor R2, the anode of the freewheeling diode is electrically connected with the second end of the second resistor R2, the first end of the third resistor R3 and the B pole of the PNP type triode Q1, the cathode of the freewheeling diode is electrically connected with the 12V dc output end of the power circuit 100, and the second end of the third resistor R3 and the E pole of the PNP type triode Q1 are electrically connected with the 5V dc output end of the power circuit 100;
the C pole of the PNP transistor Q1 is electrically connected to the first end of the fourth resistor R75 and the first end of the fifth resistor R79, the second end of the fifth resistor R79 and the first end of the first capacitor C1 are electrically connected to the MCU control circuit, and the second end of the fourth resistor R75 and the second end of the first capacitor C1 are grounded. By arranging the freewheeling diode corresponding to the 12V direct current and not arranging the freewheeling diode corresponding to the 5V direct current in the zero-crossing detection circuit 200, voltage backflow is avoided, damage to components is avoided, and system stability is improved.
The first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R75, and the fifth resistor R79 all adopt resistors.
The first capacitor C1 is a capacitor.
As shown in fig. 3, in one embodiment, the power supply circuit 100 includes: a varistor MOV1, a sixth resistor R10, a seventh resistor R8, an eighth resistor R5, a ninth resistor R9, a tenth resistor R11, an eleventh resistor R6, a twelfth resistor R7, a second capacitor CX1, a third capacitor CY1, a fourth capacitor CY2, a fifth capacitor C6, a sixth capacitor C7, a seventh capacitor C5, an eighth capacitor C3, a ninth capacitor C2, a tenth capacitor C4, a first diode D3, a second diode D4, a third diode D1, a fourth diode D5, a first inductance L1, a second inductance L3, a common-mode inductance L2, a first electrolytic capacitor EC1, a second electrolytic capacitor EC4, a third electrolytic capacitor EC5, a fourth electrolytic capacitor EC2, a fifth electrolytic capacitor EC3, a ground terminal, a switching power supply chip U2, and a buck chip U1;
the first end of the varistor MOV1, the first end of the second capacitor CX1, the first end of the eighth resistor R5, the first end of the third capacitor CY1, the first end of the first inductor L1, and the negative electrode of the first electrolytic capacitor EC1 are all electrically connected to the zero line of the ac power supply, the first end of the sixth resistor R10 is electrically connected to the live line of the ac power supply, the second end of the sixth resistor R10 is electrically connected to the second end of the varistor MOV1, the second end of the second capacitor CX1, the first end of the seventh resistor R8, the first end of the fourth capacitor CY2, the first end of the first resistor R1, and the positive electrode of the first diode D3, the second end of the seventh resistor R8 is electrically connected to the second end of the eighth resistor R5, and the ground is electrically connected between the second end of the fourth capacitor CY2 and the second end of the third capacitor CY 1;
the cathode of the first diode D3 is electrically connected with the anode of the second diode D4, and the cathode of the second diode D4 is electrically connected with the anode of the first electrolytic capacitor EC1 and the first end of the second inductor L3;
the second end of the first inductor L1 is electrically connected to the negative electrode of the second electrolytic capacitor EC4, the first end of the common-mode inductor L2, the positive electrode of the fourth electrolytic capacitor EC2, the positive electrode of the third diode D1, the output end of the 12V dc, the first end of the eleventh resistor R6, the first end of the seventh capacitor C5, the first end of the eighth capacitor C3, and the VIN pin of the buck chip U1;
the second end of the second inductor L3 is electrically connected to the positive electrode of the second electrolytic capacitor EC4, the switching power supply chip U2 and the first end of the fifth capacitor C6, the first end of the ninth resistor R9 is electrically connected to the second end of the fifth capacitor C6, the second end of the ninth resistor R9 is electrically connected to the two GND pins of the switching power supply chip U2, the negative electrode of the third electrolytic capacitor EC5, the second end of the common mode inductor L2, the first end of the sixth capacitor C7 and the negative electrode of the fourth diode D5, the VCC pin of the switching power supply chip U2 is electrically connected to the positive electrode of the third electrolytic capacitor EC5 and the negative electrode of the third diode D1, and the second end of the sixth capacitor C7 is electrically connected to the first end of the tenth resistor R11;
the VOUT pin of the buck chip U1 is electrically connected to the first end of the ninth capacitor C2, the positive electrode of the fifth electrolytic capacitor EC3, the first end of the twelfth resistor R7, the first end of the tenth capacitor C4, and the output end of the 5V dc;
the second end of the tenth resistor R11, the anode of the fourth diode D5, the cathode of the fourth electrolytic capacitor EC2, the second end of the eleventh resistor R6, the second end of the seventh capacitor C5, the second end of the eighth capacitor C3, the GND pin of the buck chip U1, the second end of the ninth capacitor C2, the cathode of the fifth electrolytic capacitor EC3, the second end of the twelfth resistor R7, and the second end of the tenth capacitor C4 are all grounded.
The sixth resistor R10, the seventh resistor R8, the eighth resistor R5, the ninth resistor R9, the tenth resistor R11, the eleventh resistor R6, and the twelfth resistor R7 are resistors.
The second capacitor CX1, the third capacitor CY1, the fourth capacitor CY2, the fifth capacitor C6, the sixth capacitor C7, the seventh capacitor C5, the eighth capacitor C3, the ninth capacitor C2, and the tenth capacitor C4 all adopt capacitors.
The first diode D3, the second diode D4, the third diode D1, and the fourth diode D5 all adopt diodes.
The first inductor L1 and the second inductor L3 adopt inductors.
The common mode inductance L2 is an inductance using a tape core or iron core.
The first electrolytic capacitor EC1, the second electrolytic capacitor EC4, the third electrolytic capacitor EC5, the fourth electrolytic capacitor EC2 and the fifth electrolytic capacitor EC3 are all electrolytic capacitors.
Copper inserts are used as interfaces for the ground terminals.
The switching power supply chip U2, also called a switching power supply management chip, is used for converting ac power into dc power.
The step-down chip U1 is a chip capable of reducing the voltage.
The second end of the second inductor L3 is electrically connected with the 5 th, 6 th, 7 th and 8 th pins of the switching power supply chip U2, the 5 th and 6 th pins of the switching power supply chip U2 are NC, and the 7 th and 8 th pins of the switching power supply chip U2 are SW.
As shown in fig. 4, in one embodiment, the system further includes: the middle heating wire HOT2 and the side heating wire HOT1 are connected in parallel with the side heating wire HOT1 after being connected in series with the silicon controlled rectifier Q11 control circuit 400, and the side heating wire HOT1 is connected between the zero line and the fire wire;
the thyristor Q11 control circuit 400 includes: thirteenth resistor R4, fourteenth resistor R76, fifteenth resistor R84, sixteenth resistor R13, seventeenth resistor R77, eleventh capacitor C16, twelfth capacitor C17, optocoupler U4, and thyristor Q11;
the first end of the intermediate heating wire HOT2 is electrically connected with the live wire, the second end of the intermediate heating wire HOT2 is electrically connected with the first end of the eleventh capacitor C16, the first end of the thyristor Q11 and the fourth pin of the optocoupler U4, and the second end of the eleventh capacitor C16 is electrically connected with the first end of the thirteenth resistor R4;
the second end of the thyristor Q11 is electrically connected to the first end of the fourteenth resistor R76 and the first end of the sixteenth resistor R13, the second end of the fourteenth resistor R76 is electrically connected to the first end of the twelfth capacitor C17 and the first end of the fifteenth resistor R84, and the second end of the sixteenth resistor R13 is electrically connected to the 6 th pin of the optocoupler U4;
the 2 nd pin of the optical coupler U4 is grounded, the 1 st pin of the optical coupler U4 is electrically connected with the first end of the seventeenth resistor R77, and the second end of the seventeenth resistor R77 is electrically connected with the MCU control circuit;
the second end of the thirteenth resistor R4, the third end of the thyristor Q11, the second end of the twelfth capacitor C17, and the second end of the fifteenth resistor R84 are all electrically connected to the zero line.
The middle heating wire HOT2 and the side heating wire HOT1 are both heating wires.
The thirteenth resistor R4, the fourteenth resistor R76, the fifteenth resistor R84, the sixteenth resistor R13, and the seventeenth resistor R77 are resistors.
The eleventh capacitor C16 and the twelfth capacitor C17 each use a capacitor.
The second end of the seventeenth resistor R77 is connected with the 19 pin of the MCU chip U3 of the MCU control circuit.
In one embodiment, the control circuit 400 of the thyristor Q11 further includes a connector, where a first end of the connector is electrically connected to the first end of the eleventh capacitor C16, the first end of the thyristor Q11, and the fourth pin of the optocoupler U4, and a second end of the connector is electrically connected to the second end of the intermediate heating wire HOT2, and the connector is a copper insert. The copper insert is beneficial to quickly and accurately connecting the middle heating wire HOT2.
In one embodiment, the scr Q11 control circuit 400 further includes: and the test end is electrically connected with the third end of the controllable silicon Q11. The test end is used for testing the silicon controlled rectifier Q11 control system.
In one embodiment, the system further comprises: a double pole switch connected between the power supply circuit 100 and the thyristor Q11 control circuit 400. It is to be understood that, in this embodiment, the first end of the varistor MOV1, the first end of the second capacitor CX1, the first end of the eighth resistor R5, the first end of the third capacitor CY1, the first end of the first inductor L1, and the negative electrode of the first electrolytic capacitor EC1 are all electrically connected to the neutral line of the ac power supply, and the first end of the sixth resistor R10 is electrically connected to the live line of the ac power supply.
The double-pole switch comprises a first switch and a second switch. The first end of the first switch is electrically connected with the zero line of the alternating current power supply, and the second end of the first switch is electrically connected with the silicon controlled rectifier Q11 control circuit 400. The first end of the second switch is electrically connected with the live wire of the alternating current power supply, and the second end of the first switch is electrically connected with the silicon controlled rectifier Q11 control circuit 400.
As shown in fig. 4, in one embodiment, the system further includes: the zero line relay is arranged between the zero line output end of the double-pole switch and the silicon controlled rectifier Q11 control circuit 400, and the zero line relay is electrically connected with the 12V direct current output end and the MCU control circuit.
As shown in fig. 4, in one embodiment, the system further includes: the first end of the fire wire relay is electrically connected with the fire wire output end of the double-pole switch, and the second end of the fire wire relay is electrically connected with the middle heating wire HOT2 and the side heating wire HOT 1.
Fig. 4 illustrates a neutral relay and a hot relay; in the live wire relay, R17, R19 and RJ25 are resistors, Q4 is an NPN triode, GND is a grounding end, VDD_12V is connected with the output end of the 12V direct current, one end of R17 far away from Q4 is connected with a pin 23 of an MCU chip U3 of the MCU control circuit, D7 is a diode, and RY1 is a three-phase switch; in the zero line relay, R18, R20 and RJ1 are resistors, Q5 is an NPN triode, GND is a grounding end, VDD_12V is connected with the output end of the 12V direct current, one end of R18 far away from Q5 is connected with 24 pins of an MCU chip U3 of the MCU control circuit, D6 is a diode, and RY2 is a three-phase switch.
Fig. 5 schematically shows a current direction in which a freewheel diode corresponding to the 5V direct current is provided in the zero-cross detection circuit 200 and the freewheel diode corresponding to the 12V direct current is not provided in the zero-cross detection circuit 200; (a) is the current direction at the negative half-wave of the alternating current; (b) The current direction is the current direction when the alternating current is positive half wave, and at the moment, the current returns to the output end of the 5V direct current through the diode D2 after passing through the current limiting resistors R1 and R2 from the live wire, and then returns to the zero line after passing through the U1, so that a complete loop is formed. Under normal conditions, current should flow from high level 12V to low level 5V, but in (b), the circuit can form a loop, but negative current exists, voltage backflow can be formed, and the negative current also passes through U1, so that damage is caused to U1, and the stability of the whole circuit is affected; in (b), the zero-crossing detection circuit 200 has serious distortion, and when the control circuit 400 is matched with the thyristor Q11, the time of actually switching the thyristor Q11 and the ac power supply have large errors due to the distortion of the zero-crossing signal.
When the load is controlled by the thyristor Q11, in theory, the closer the timing of the on/off of the thyristor Q11 is to the zero point of the ac power supply, the smaller the influence on EMI (i.e., the circuit formed by the HOT wire, the intermediate heating wire HOT2, the 2 pin of Q11, the 1 pin of Q11, and the zero line) is.
Fig. 6 illustrates that a freewheeling diode corresponding to the 12V dc is disposed in the zero-crossing detection circuit 200, and the current direction of the freewheeling diode corresponding to the 5V dc is not disposed in the zero-crossing detection circuit 200, in which, when the ac is positive half-wave, the current directly returns to the zero line from the output end of the 12V dc, without the step-down of U1, thus avoiding the reverse voltage, retaining all 5V components, and improving the accuracy of the zero-crossing signal, so that the zero-crossing signal substantially coincides with the zero of the ac power supply, and the switching time of the thyristor Q11 is infinitely close to the zero of the ac power supply, thereby reducing the electromagnetic interference of the whole circuit.
As shown in fig. 4, in one embodiment, the scr Q11 control system further includes: resistor R82, resistor R85, and capacitor CX2.
The application also proposes a switching power supply, the switching power supply includes: a silicon controlled rectifier Q11 control system as in any one of the above;
the system comprises: a power supply circuit 100, a zero-crossing detection circuit 200 for detecting a zero-crossing signal of alternating current, a silicon controlled rectifier Q11 control circuit 400 for controlling a load, and an MCU control circuit;
the power supply circuit 100 is electrically connected with the zero crossing detection circuit 200, the silicon controlled rectifier Q11 control circuit 400 and the MCU control circuit and is used for converting alternating current into 12V direct current and 5V direct current;
the MCU control circuit is electrically connected with the zero-crossing detection circuit 200 and the silicon controlled rectifier Q11 control circuit 400 and is used for controlling the on-off of the silicon controlled rectifier Q11 control circuit 400 according to the zero-crossing signal;
a freewheel diode corresponding to the 12V direct current is provided in the zero-cross detection circuit 200, and the freewheel diode corresponding to the 5V direct current is not provided in the zero-cross detection circuit 200.
The system of the embodiment converts the alternating current into 12V direct current and 5V direct current through the power circuit 100, the freewheeling diode corresponding to the 12V direct current is arranged in the zero-crossing detection circuit 200, and the freewheeling diode corresponding to the 5V direct current is not arranged in the zero-crossing detection circuit 200, so that voltage backflow is avoided, damage to components is avoided, and stability of the system is improved.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.
Claims (10)
1. A thyristor control system, the system comprising: the power supply circuit, the zero crossing detection circuit for detecting the zero crossing signal of alternating current, the silicon controlled rectifier control circuit for controlling the load and the MCU control circuit;
the power supply circuit is electrically connected with the zero-crossing detection circuit, the silicon controlled rectifier control circuit and the MCU control circuit and used for converting alternating current into 12V direct current and 5V direct current;
the MCU control circuit is electrically connected with the zero-crossing detection circuit and the silicon controlled rectifier control circuit and is used for controlling the on-off of the silicon controlled rectifier control circuit according to the zero-crossing signal;
a freewheel diode corresponding to the 12V direct current is provided in the zero-crossing detection circuit, and the freewheel diode corresponding to the 5V direct current is not provided in the zero-crossing detection circuit.
2. The thyristor control system according to claim 1, wherein the zero crossing detection circuit comprises: the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor, the freewheel diode, the first capacitor and the PNP triode;
the first end of the first resistor is electrically connected with the power circuit, the second end of the first resistor is electrically connected with the first end of the second resistor, the anode of the freewheel diode is electrically connected with the second end of the second resistor, the first end of the third resistor and the B pole of the PNP triode, the cathode of the freewheel diode is electrically connected with the 12V direct current output end of the power circuit, and the second end of the third resistor and the E pole of the PNP triode are electrically connected with the 5V direct current output end of the power circuit;
the C pole of the PNP triode is electrically connected with the first end of the fourth resistor and the first end of the fifth resistor, the second end of the fifth resistor and the first end of the first capacitor are electrically connected with the MCU control circuit, and the second end of the fourth resistor and the second end of the first capacitor are grounded.
3. The thyristor control system according to claim 2, wherein the power circuit comprises: a piezoresistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode, a second diode, a third diode, a fourth diode, a first inductor, a second inductor, a common mode inductor, a first electrolytic capacitor, a second electrolytic capacitor, a third electrolytic capacitor, a fourth electrolytic capacitor, a fifth electrolytic capacitor, a ground terminal, a switching power supply chip and a buck chip;
the first end of the piezoresistor, the first end of the second capacitor, the first end of the eighth resistor, the first end of the third capacitor, the first end of the first inductor and the negative electrode of the first electrolytic capacitor are all electrically connected with a zero line of an alternating current power supply, the first end of the sixth resistor is electrically connected with a live wire of the alternating current power supply, the second end of the sixth resistor is electrically connected with the second end of the piezoresistor, the second end of the second capacitor, the first end of the seventh resistor, the first end of the fourth capacitor, the first end of the first resistor and the positive electrode of the first diode, the second end of the seventh resistor is electrically connected with the second end of the eighth resistor, and the ground end is connected between the second end of the fourth capacitor and the second end of the third capacitor;
the cathode of the first diode is electrically connected with the anode of the second diode, and the cathode of the second diode is electrically connected with the anode of the first electrolytic capacitor and the first end of the second inductor;
the second end of the first inductor is electrically connected with the negative electrode of the second electrolytic capacitor, the first end of the common mode inductor, the positive electrode of the fourth electrolytic capacitor, the positive electrode of the third diode, the output end of the 12V direct current, the first end of the eleventh resistor, the first end of the seventh capacitor, the first end of the eighth capacitor and the VIN pin of the buck chip;
the second end of the second inductor is electrically connected with the positive electrode of the second electrolytic capacitor, the switch power supply chip and the first end of the fifth capacitor, the first end of the ninth resistor is electrically connected with the second end of the fifth capacitor, the second end of the ninth resistor is electrically connected with two GND pins of the switch power supply chip, the negative electrode of the third electrolytic capacitor, the second end of the common mode inductor, the first end of the sixth capacitor and the negative electrode of the fourth diode, the VCC pin of the switch power supply chip is electrically connected with the positive electrode of the third electrolytic capacitor and the negative electrode of the third diode, and the second end of the sixth capacitor is electrically connected with the first end of the tenth resistor;
the VOUT pin of the buck chip is electrically connected with the first end of the ninth capacitor, the positive electrode of the fifth electrolytic capacitor, the first end of the twelfth resistor, the first end of the tenth capacitor and the output end of the 5V direct current;
the second end of the tenth resistor, the anode of the fourth diode, the cathode of the fourth electrolytic capacitor, the second end of the eleventh resistor, the second end of the seventh capacitor, the second end of the eighth capacitor, the GND pin of the buck chip, the second end of the ninth capacitor, the cathode of the fifth electrolytic capacitor, the second end of the twelfth resistor and the second end of the tenth capacitor are all grounded.
4. The thyristor control system of claim 3, further comprising: the middle heating wire and the side heating wire are connected in series with the silicon controlled rectifier control circuit and then connected in parallel with the side heating wire, and the side heating wire is connected between the zero line and the live line;
the thyristor control circuit includes: thirteenth resistor, fourteenth resistor, fifteenth resistor, sixteenth resistor, seventeenth resistor, eleventh capacitor, twelfth capacitor, optocoupler and silicon controlled rectifier;
the first end of the intermediate heating wire is electrically connected with the live wire, the second end of the intermediate heating wire is electrically connected with the first end of the eleventh capacitor, the first end of the silicon controlled rectifier and the fourth pin of the optocoupler, and the second end of the eleventh capacitor is electrically connected with the first end of the thirteenth resistor;
the second end of the silicon controlled rectifier is electrically connected with the first end of the fourteenth resistor and the first end of the sixteenth resistor, the second end of the fourteenth resistor is electrically connected with the first end of the twelfth capacitor and the first end of the fifteenth resistor, and the second end of the sixteenth resistor is electrically connected with the 6 th pin of the optocoupler;
the 2 nd pin of the optical coupler is grounded, the 1 st pin of the optical coupler is electrically connected with the first end of the seventeenth resistor, and the second end of the seventeenth resistor is electrically connected with the MCU control circuit;
the second end of the thirteenth resistor, the third end of the controllable silicon, the second end of the twelfth capacitor and the second end of the fifteenth resistor are all electrically connected with the zero line.
5. The thyristor control system of claim 4, further comprising a connector having a first end electrically connected to the first end of the eleventh capacitor, the first end of the thyristor, and the fourth leg of the optocoupler, and a second end electrically connected to the second end of the intermediate heater, wherein the connector is a copper tab.
6. The thyristor control system of claim 4, wherein the thyristor control circuit further comprises: and the test end is electrically connected with the third end of the controllable silicon.
7. The thyristor control system of claim 4, further comprising: and the double-pole switch is connected between the power supply circuit and the silicon controlled rectifier control circuit.
8. The thyristor control system of claim 7, further comprising: the zero line relay is arranged between the zero line output end of the double-pole switch and the silicon controlled rectifier control circuit, and the zero line relay is electrically connected with the 12V direct current output end and the MCU control circuit.
9. The thyristor control system of claim 7, further comprising: the first end of the live wire relay is electrically connected with the live wire output end of the double-pole switch, and the second end of the live wire relay is electrically connected with the middle heating wire and the side heating wire.
10. A switching power supply, the switching power supply comprising: a thyristor control system according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223128312.XU CN218997925U (en) | 2022-11-24 | 2022-11-24 | Silicon controlled rectifier control system and switching power supply |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202223128312.XU CN218997925U (en) | 2022-11-24 | 2022-11-24 | Silicon controlled rectifier control system and switching power supply |
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| CN218997925U true CN218997925U (en) | 2023-05-09 |
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| CN202223128312.XU Active CN218997925U (en) | 2022-11-24 | 2022-11-24 | Silicon controlled rectifier control system and switching power supply |
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| CN (1) | CN218997925U (en) |
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