Contactor power-saving intelligent control circuit
By adjusting the switching frequency and duty cycle through the contactor's energy-saving intelligent control circuit, the problem of low power consumption of the contactor over a wide voltage range is solved, achieving contactor control with low delay, small size, and high reliability. It is suitable for energy-saving retrofits of various contactor models and new generation wide-voltage input contactors.
Patent Information
- Application Number
- CN202422577284.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-24
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-10-24
AI Technical Summary
Existing contactor control circuits struggle to maintain low power consumption across a wide range of input voltages, while traditional PWM control methods suffer increased losses at high voltages, failing to meet low power consumption requirements.
The contactor adopts an energy-saving intelligent control circuit, which reduces the operating frequency of the switch and adjusts the current to maintain a low power consumption state. Combined with the real-time acquisition of voltage and current by the microcontroller, the duty cycle of the PWM signal is intelligently adjusted to achieve low power consumption operation of the contactor within a wide voltage range.
When the input voltage rises, the current does not increase accordingly, the contactor maintains a low power consumption state, operates stably, has strong resistance to power grid fluctuations, adapts to a wide voltage range, is compatible with multiple contactor models, and features low delay, small size, low cost, high reliability, and anti-tripping capability.
Smart Images
Figure CN223501764U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of contactor technology, specifically relating to a contactor energy-saving intelligent control circuit. Background Technology
[0002] A typical contactor consists of a coil, iron core, armature, spring, contacts, and control circuitry. Its operation is divided into three stages: the pull-in stage, the holding stage, and the turn-off stage. The working process of these three stages is as follows: In the pull-in stage, a large current is generated in the coil, the iron core becomes magnetic, attracting the armature and causing the contactor to change from an open state to a closed state. In the holding stage, the contactor remains in a conducting state. The holding current in this stage is approximately one-tenth of the pull-in current; excessive holding current increases coil losses and wastes energy. In the turn-off stage, the current in the coil becomes zero, the magnetism of the iron core disappears, and the armature returns to its original position under the action of the spring, changing the contactor from a conducting state to a turn-off state. The contactor's control circuit contains a power electronic switch. By controlling the on / off state of the power electronic switch, the current in the coil is controlled, allowing the contactor to switch between the three stages of pull-in, holding, and turn-off.
[0003] To reduce energy consumption, in addition to improving the contactor circuit hardware, the control method during the holding phase also needs improvement. Traditionally, the contactor control circuit keeps the switch constantly on or off, resulting in a large current in the coil and high losses. In contactor energy-saving control circuits, the holding phase typically uses traditional PWM control to control the on / off state of the power electronic switch. This control method works well when the input voltage range is relatively narrow, but as the input voltage range expands and increases, the duty cycle required to maintain the current becomes very small, and the switch conduction time is short. When the switch conduction time reaches its minimum, if the input voltage continues to rise, the coil current will increase further, increasing losses and failing to meet the low-power requirements of the contactor. Therefore, a contactor energy-saving intelligent control circuit is needed to solve these problems. Utility Model Content
[0004] The purpose of this invention is to provide a contactor energy-saving intelligent control circuit to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a contactor power-saving intelligent control circuit, comprising a power input terminal, a power input terminal, a power circuit, an output coil terminal, an output coil terminal, a microcontroller circuit, a +3.3V power supply circuit, a +12V power supply circuit, a voltage acquisition circuit, a current acquisition circuit, a power switch circuit, a PWM drive circuit, a contactor coil, a 24th resistor, a first rectifier bridge D3, a third transistor Q3, a seventh resistor R7, a first capacitor C1, a gate driver IC U1, a high-efficiency diode D4, a fifth resistor R5, a 33rd resistor R33, a linear regulator U3, and a 12th capacitor C16. The power circuit is formed by the power input terminal, the power circuit, the output coil terminal, the contactor coil, the output coil terminal, the power switch circuit, the current acquisition circuit, and the power input terminal 2.
[0006] One and two power input terminals are connected to the power circuit. The power circuit is connected to one end of the output coil. One end of the output coil is connected to the two ends of the output coil via a contactor coil. The two ends of the output coil are connected to the power switch circuit. The voltage acquisition circuit is connected to the current acquisition circuit and the PWM drive circuit. The current acquisition circuit is connected to the power circuit and the microcontroller. The power circuit is connected to the voltage acquisition circuit and the microcontroller. The power circuit is connected to the +3.3V power supply circuit and the +12V power supply circuit. The +3.3V power supply circuit and the +12V power supply circuit are connected to the PWM drive circuit.
[0007] This control circuit reduces the switching frequency when the input voltage rises, preventing the current from increasing with the voltage and maintaining the contactor's low-power operation. This control circuit is widely used in various contactor energy-saving retrofits and new-generation wide-voltage input contactors. It is compatible with most 115A frame upgrades and optimizations on the market. This contactor energy-saving intelligent control circuit requires only one coil, is compatible with multiple contactor models, and features low power consumption, low delay, small size, low cost, high reliability, and strong anti-tripping capability.
[0008] As a preferred embodiment, pin 1 of the power input AC(L), pin 1 of the varistor RV1, pin 1 of the seventeenth capacitor CX1, pin 2 of the first rectifier bridge D3, and pins 2 of the second rectifier bridge D5 are interconnected. Pin 1 of the power input AC(N), pin 2 of the varistor RV1, pin 2 of the seventeenth capacitor CX1, pin 1 of the first rectifier bridge D3, and pin 2 of the second rectifier bridge D5 are interconnected. Pin 4 of the second rectifier bridge D5 is grounded. Pin 3 of the second rectifier bridge D5 is connected to pin 1 of the seventeenth resistor R17. Pin 2 of the seventeenth resistor R17 is connected to pin 1 of the twenty-second resistor R22. Pin 1 of the twenty-second resistor R22, pin 1 of the twenty-fourth resistor R24, pin 1 of the seventh capacitor C9, and pin 10 of the microcontroller U2 are interconnected.
[0009] As a preferred embodiment, pin 2 of the twenty-fourth resistor R24 is connected to pin 1 of the twenty-seventh resistor R27. Pin 2 of the twenty-seventh resistor R27, pin 2 of the seventh capacitor C9, and ground GND are interconnected. Pin 3 of the first rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 1 of the thirteenth resistor R13, pin 1 of the power inductor L1, and pin 1 of the fourth capacitor C4 are interconnected. Pin 4 of the first rectifier bridge D3 and pin 1 of the fourth capacitor C4 are interconnected to ground GND. Pin 2 of the first fast recovery diode D1, pin 3 of the first rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 2 of the second rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 2 of the second rectifier bridge D3, pin 2 of the second rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 2 of the second rectifier bridge D3, pin 2 of the second rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 2 of the second rectifier bridge D3, pin 2 of the second rectifier bridge D3, pin 2 of the second fast recovery diode D1, pin 2 of the second rectifier bridge D3, pin 2 of the second fast recovery diode D1, pin 2 of the second fast recovery diode D27 ... Pin 2 of resistor R13, pin 2 of power inductor L1, pin 1 of first resistor R1, pin 1 of seventh resistor R7, pin 1 of high-efficiency diode D4, pin 1 of eleventh resistor R11, pin 1 of thirty-third resistor R33, and pin 1 of output coil OUT1 are connected to each other. Pin 2 of first resistor R1 is connected to pins 2 and 4 of second transistor Q2. Pin 3 of second transistor Q2 is connected to pin 1 of second resistor R2. Pin 2 of second resistor R2 is connected to pins 2 and 4 of third transistor Q3.
[0010] As a preferred embodiment, pin 3 of the third transistor Q3 is connected to pin 1 of the third resistor R3; pin 2 of the third resistor R3 is connected to pins 2 and 4 of the fourth transistor Q4; pin 3 of the fourth transistor Q4 is connected to pin 1 of the fourth resistor R4; pin 2 of the fourth resistor R4 is connected to pins 2 and 4 of the first transistor Q1; pin 3 of the first transistor Q1, pin 1 of the first capacitor C1, pin 1 of the second capacitor C2, and pin 8 of the linear regulator U3 are interconnected; the seventh... Pin 2 of resistor R7 is connected to pin 1 of the second transistor Q2 and pin 1 of the eighth resistor R8. Pin 2 of the eighth resistor R8, pin 1 of the third transistor Q3, and pin 1 of the ninth resistor R9 are connected to each other. Pin 2 of the ninth resistor R9 is connected to pin 1 of the fourth transistor Q4 and pin 1 of the tenth resistor R10. Pin 2 of the tenth resistor R10 is connected to pin 1 of the first transistor Q1 and pin 1 of the +60V Zener diode D2. Pin 2 of the +60V Zener diode D2 is connected to ground GND.
[0011] As a preferred embodiment, pin 2 of the first capacitor C1 and pin 2 of the second capacitor C2 are connected to ground (GND). Pin 2 of the high-efficiency diode D4 is connected to pin 2 of the power switch TR1, pin 2 of the transient suppression diode D7, and pin 1 of the output coil terminal OUT2. Pin 2 of the transient suppression diode D7 is connected to ground (GND). Pin 2 of the power switch TR1 is connected to pin 2 of the twenty-first resistors R21 and R22, pin 2 of the twenty-third resistor R23, pin 1 of the twenty-fifth resistor R25, and pin 1 of the twenty-sixth resistor R26. Pin 2 of resistor R25 and pin 2 of the 26th resistor R26 are connected to ground (GND). Pin 1 of the 23rd resistor R23 is connected to pin 1 of the 6th capacitor C7 and pin 1 of the microcontroller U2. Pin 2 of the 6th capacitor C7 is connected to ground (GND). Pin 1 of the power switch TR1 is connected to pin 2 of the 20th resistor R20, pin 1 of the 21st resistor R21, and pin 1 of the switching diode D6. Pin 3 of the switching diode D6 is connected to pin 1 of the 18th resistor R18. Pin 2 of the 18th resistor R18 is connected to pin 1 of the 20th resistor R20 and pins 3 and 4 of the gate driver IC U1. Pin 5 of the gate driver IC U1 is connected to pin 1 of the 5th capacitor C6, pin 1 of the 5th resistor R5, pin 2 of the 16th resistor R16, pin 3 of the +12V Zener diode D8, pin 1 of the 13th capacitor C17, and pin 1 of the 16th capacitor C20.
[0012] As a preferred embodiment, pin 2 of the gate driver IC U1 is connected to ground (GND), pin 1 of the gate driver IC U1 is connected to pin 2 of the fifteenth resistor R15, pin 1 of the fifteenth resistor R15 is interconnected with pin 1 of the nineteenth resistor R19 and pin 2 of the microcontroller U2, pin 1 of the nineteenth resistor R19 is connected to ground (GND), pin 2 of the fifth resistor R5 is connected to pin 1 of the first light-emitting diode LED1, pin 1 of the +12V Zener diode D8, pin 2 of the thirteenth capacitor C17, pin 2 of the sixteenth capacitor C20, and pin 2 of the first light-emitting diode LED1 are interconnected with ground (GND), and pin 1 of the sixteenth resistor R16 is connected to the... Pin 2 of the fourteenth resistor R14 is connected. Pin 1 of the fourteenth resistor R14 is connected to pin 2 of the eleventh resistor R11. Pin 2 of the thirty-third resistor R33 is connected to pin 1 of the sixth resistor R6. Pin 2 of the sixth resistor R6, pin 1 of the third capacitor C3, pin 1 of the twelfth resistor R12, pin 1 of the thirtieth resistor R30, and pin 3 of the +4.7V Zener diode D9 are interconnected. Pin 2 of the third capacitor C3, pin 2 of the twelfth resistor R12, and pin 1 of the +4.7V Zener diode D9 are interconnected with ground GND. Pin 2 of the thirtieth resistor R30 is connected to pin 1 of the linear regulator U3.
[0013] As a preferred embodiment, pins 4 and 9 of the linear regulator U3 are connected to ground (GND). Pins 1 and 2 of the linear regulator U3, pin 1 of the ninth capacitor C13, pin 1 of the tenth capacitor C14, and pin 1 of the ferrite bead L2 are interconnected. Pins 2 of the ninth capacitor C13 and pin 2 of the tenth capacitor C14 are interconnected to ground (GND). Pin 2 of the ferrite bead L2, pin 1 of the twenty-eighth resistor R28, pin 8 of the microcontroller U2, pin 1 of the microcontroller program download interface H1, and pin 1 of the fourteenth capacitor C... Pin 1 of capacitor C18 and pin 1 of capacitor C19 are connected to each other. Pin 2 of capacitor C19 is connected to ground (GND). Pin 2 of capacitor C18 is connected to ground (GND). Pin 3 of microcontroller program download interface H1 is connected to ground (GND). Pin 2 of microcontroller program download interface H1 is connected to pin 3 of microcontroller U2. Pin 2 of resistor R28, pin 1 of capacitor C16, pin 4 of microcontroller program download interface H1, and pin 4 of microcontroller U2 are connected to each other.
[0014] As a preferred embodiment, pin 2 of the twelfth capacitor C16 is connected to ground (GND), pin 20 of the microcontroller U2 is connected to pin 1 of the twenty-ninth resistor R29, pin 2 of the twenty-ninth resistor R29 is connected to pin 1 of the second light-emitting diode LED2, pin 2 of the second light-emitting diode LED2 is connected to ground (GND), pin 7 of the microcontroller U2 is connected to ground (GND), pin 5 of the microcontroller U2, pin 1 of the thirty-first resistor R31, pin 1 of the eighth capacitor C10, and pin 3 of the passive crystal oscillator X1 are interconnected, pin 4 of the microcontroller U2 is connected to pin 1 of the thirty-second resistor R32, pin 2 of the thirty-second resistor R32, pin 2 of the thirty-first resistor R31, pin 1 of the eleventh capacitor C15, and pin 1 of the passive crystal oscillator X1 are interconnected, pins 2 and 4 of the passive crystal oscillator X1 are connected to ground (GND), and pins 2 of the eighth capacitor C10 and pin 2 of the eleventh capacitor C15 are interconnected to ground (GND).
[0015] Compared with the prior art, the beneficial effects of this utility model are:
[0016] This invention relates to a control circuit that, when the input voltage rises, reduces the operating frequency of the switch to prevent the current from increasing with the voltage, thus maintaining the contactor's low-power operation. This control circuit is safe and reliable, with stable engagement, fast response, a wide input voltage range, strong resistance to grid fluctuations, and is compatible with both AC and DC power. It requires no short-circuit loop design and can be widely applied in contactor control circuits across various applications. Attached Figure Description
[0017] Figure 1 This is a system block diagram of the present invention;
[0018] Figure 2 This is the circuit diagram of this utility model.
[0019] In the diagram: 1. Power supply input terminal 1; 2. Power supply input terminals 2; 3. Power circuit; 4. Output coil terminal 1; 5. Output coil terminals 2; 6. Microcontroller circuit; 7. +3.3V power supply circuit; 8. +12V power supply circuit; 9. Voltage acquisition circuit; 10. Current acquisition circuit; 11. Power switch circuit; 12. PWM drive circuit; 13. Contactor coil. Detailed Implementation
[0020] The present invention will be further described below with reference to the embodiments.
[0021] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the concept of the present invention are all within the scope of protection claimed by the present invention.
[0022] Please see Figure 1-2 This utility model provides a contactor power-saving intelligent control circuit, including a power input terminal 1, a power input terminal 2, a power circuit 3, an output coil terminal 4, an output coil terminal 5, a microcontroller circuit 6, a +3.3V power supply circuit 7, a +12V power supply circuit 8, a voltage acquisition circuit 9, a current acquisition circuit 10, a power switch circuit 11, a PWM drive circuit 12, a contactor coil 13, a 24th resistor, a first rectifier bridge D3, a third transistor Q3, a 7th resistor R7, a first capacitor C1, and a gate driver IC. The circuit consists of U1, high-efficiency diode D4, fifth resistor R5, thirty-three resistor R33, linear regulator U3, and twelfth capacitor C16. The power circuit is formed by power input terminal 1, power circuit 3, output coil terminal 4, contactor coil 13, output coil terminals 5, power switch circuit 11, current acquisition circuit 10, and power input terminal 22. A microcontroller circuit 6 is set up, and the microcontroller model is STM8L051F3P6.
[0023] Power input terminal 1 and power input terminal 2 are connected to power circuit 3. Power circuit 3 is connected to output coil terminal 4. Output coil terminal 4 is connected to output coil terminal 5 through contactor coil 13. Output coil terminal 5 is connected to power switch circuit 11. Voltage acquisition circuit 9 is connected to current acquisition circuit 10 and PWM drive circuit 12. Current acquisition circuit 10 is connected to power circuit 3 and microcontroller. Power circuit 3 is connected to voltage acquisition circuit 9. Voltage acquisition circuit 9 is connected to microcontroller. Power circuit 3 is connected to +3.3V power supply circuit 7 and +12V power supply circuit 8. +3.3V power supply circuit 7 and +12V power supply circuit 8 are connected to PWM drive circuit 12.
[0024] Pin 1 of the power input AC(L), pin 1 of the varistor RV1, pin 1 of the seventeenth capacitor CX1, pin 2 of the first rectifier bridge D3, and pins 2 of the second rectifier bridge D5 are connected to each other. Pin 1 of the power input AC(N), pin 2 of the varistor RV1, pin 2 of the seventeenth capacitor CX1, pin 1 of the first rectifier bridge D3, and pin 2 of the second rectifier bridge D5 are connected to each other. Pin 4 of the second rectifier bridge D5 is grounded. Pin 3 of the second rectifier bridge D5 is connected to pin 1 of the seventeenth resistor R17. Pin 2 of the seventeenth resistor R17 is connected to pin 1 of the twenty-second resistor R22. Pin 1 of the twenty-second resistor R22, pin 1 of the twenty-fourth resistor R24, pin 1 of the seventh capacitor C9, and pin 10 of the microcontroller U2 are connected to each other.
[0025] Pin 2 of the 24th resistor R24 is connected to pin 1 of the 27th resistor R27. Pin 2 of the 27th resistor R27, pin 2 of the 7th capacitor C9, and ground GND are interconnected. Pin 3 of the first rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 1 of the 13th resistor R13, pin 1 of the power inductor L1, and pin 1 of the fourth capacitor C4 are interconnected. Pin 4 of the first rectifier bridge D3 and pin 1 of the fourth capacitor C4 are interconnected to ground GND. Pin 2 of the first fast recovery diode D1 and pin 2 of the 13th resistor R13... Pin 2, pin 2 of power inductor L1, pin 1 of first resistor R1, pin 1 of seventh resistor R7, pin 1 of high-efficiency diode D4, pin 1 of eleventh resistor R11, pin 1 of thirty-third resistor R33, and pin 1 of output coil 4OUT1 are connected to each other. Pin 2 of first resistor R1 is connected to pin 2 and pin 4 of second transistor Q2. Pin 3 of second transistor Q2 is connected to pin 1 of second resistor R2. Pin 2 of second resistor R2 is connected to pin 2 and pin 4 of third transistor Q3.
[0026] Pin 3 of the third transistor Q3 is connected to pin 1 of the third resistor R3. Pin 2 of the third resistor R3 is connected to pins 2 and 4 of the fourth transistor Q4. Pin 3 of the fourth transistor Q4 is connected to pin 1 of the fourth resistor R4. Pin 2 of the fourth resistor R4 is connected to pins 2 and 4 of the first transistor Q1. Pin 3 of the first transistor Q1, pin 1 of the first capacitor C1, pin 1 of the second capacitor C2, and pin 8 of the linear regulator U3 are connected to each other. Pin 2 of the seventh resistor R7 is connected to pin 3. It is connected to pin 1 of the second transistor Q2 and pin 1 of the eighth resistor R8. Pin 2 of the eighth resistor R8, pin 1 of the third transistor Q3 and pin 1 of the ninth resistor R9 are connected to each other. Pin 2 of the ninth resistor R9 is connected to pin 1 of the fourth transistor Q4 and pin 1 of the tenth resistor R10. Pin 2 of the tenth resistor R10 is connected to pin 1 of the first transistor Q1 and pin 1 of the +60V Zener diode D2. Pin 2 of the +60V Zener diode D2 is connected to ground GND.
[0027] Pin 2 of the first capacitor C1 and pin 2 of the second capacitor C2 are connected to ground (GND). Pin 2 of the high-efficiency diode D4 is connected to pin 2 of the power switch TR1, pin 2 of the transient suppression diode D7, and pin 1 of the output coil terminal 5OUT2. Pin 2 of the transient suppression diode D7 is connected to ground (GND). Pin 2 of the power switch TR1 is connected to pin 2 of the twenty-first resistor R21 and R22, pin 2 of the twenty-third resistor R23, pin 1 of the twenty-fifth resistor R25, and pin 1 of the twenty-sixth resistor R26. The twenty-fifth resistor R25... Pin 2 of the 26th resistor R26 is connected to ground GND. Pin 1 of the 23rd resistor R23 is connected to pin 1 of the 6th capacitor C7 and pin 1 of the microcontroller U2. Pin 2 of the 6th capacitor C7 is connected to ground GND. Pin 1 of the power switch TR1 is connected to pin 2 of the 20th resistor R20, pin 1 of the 21st resistor R21 and pin 1 of the switching diode D6. Pin 3 of the switching diode D6 is connected to pin 1 of the 18th resistor R18. Pin 2 of the 18th resistor R18 is connected to pin 1 of the 20th resistor R20 and pins 3 and 4 of the gate driver IC U1. Pin 5 of the gate driver IC U1 is connected to pin 1 of the 5th capacitor C6, pin 1 of the 5th resistor R5, pin 2 of the 16th resistor R16, pin 3 of the +12V Zener diode D8, pin 1 of the 13th capacitor C17 and pin 1 of the 16th capacitor C20.
[0028] Pin 2 of gate driver IC U1 is connected to ground (GND). Pin 1 of gate driver IC U1 is connected to pin 2 of the fifteenth resistor R15. Pin 1 of the fifteenth resistor R15, pin 1 of the nineteenth resistor R19, and pin 2 of microcontroller U2 are interconnected. Pin 1 of the nineteenth resistor R19 is connected to ground (GND). Pin 2 of the fifth resistor R5 is connected to pin 1 of the first LED (LED1). Pin 1 of the +12V Zener diode D8, pin 2 of the thirteenth capacitor C17, pin 2 of the sixteenth capacitor C20, and pin 2 of the first LED (LED1) are interconnected to ground (GND). Pin 1 of the sixteenth resistor R16 and pin 2 of the fourteenth resistor R14 are interconnected. Connect the fourteenth resistor R14, pin 1 to the eleventh resistor R11, pin 2 to the thirty-third resistor R33, pin 2 to the sixth resistor R6, pin 2 to the sixth resistor R6, pin 2 to the sixth resistor R6, pin 1 to the third capacitor C3, pin 1 to the twelfth resistor R12, pin 1 to the thirtieth resistor R30, and pin 3 to the +4.7V Zener diode D9, pin 2 to the third capacitor C3, pin 2 to the twelfth resistor R12, and pin 1 to the +4.7V Zener diode D9 to ground GND, and pin 2 to the thirtieth resistor R30 to the linear regulator U3.
[0029] Pins 4 and 9 of the linear regulator U3 are connected to ground (GND). Pins 1 and 2 of the linear regulator U3, pin 1 of the ninth capacitor C13, pin 1 of the tenth capacitor C14, and pin 1 of the ferrite bead L2 are interconnected. Pins 2 of the ninth capacitor C13 and pin 2 of the tenth capacitor C14 are interconnected to ground (GND). Pin 2 of the ferrite bead L2, pin 1 of the twenty-eighth resistor R28, pin 8 of the microcontroller U2, pin 1 of the microcontroller program download interface H1, and pin 1 of the fourteenth capacitor C18 are also interconnected. Pin 1 of capacitor C19 and capacitor C18 are connected to each other. Pin 2 of capacitor C19 is connected to ground (GND). Pin 2 of capacitor C18 is connected to ground (GND). Pin 3 of microcontroller program download interface H1 is connected to ground (GND). Pin 2 of microcontroller program download interface H1 is connected to pin 3 of microcontroller U2. Pin 2 of resistor R28, pin 1 of capacitor C16, pin 4 of microcontroller program download interface H1, and pin 4 of microcontroller U2 are connected to each other.
[0030] Pin 2 of the 12th capacitor C16 is connected to ground (GND). Pin 20 of the microcontroller U2 is connected to pin 1 of the 29th resistor R29. Pin 2 of the 29th resistor R29 is connected to pin 1 of the second LED (LED2). Pin 2 of the second LED (LED2) is connected to ground (GND). Pin 7 of the microcontroller U2 is connected to ground (GND). Pin 5 of the microcontroller U2, pin 1 of the 31st resistor R31, pin 1 of the 8th capacitor C10, and pin 3 of the passive crystal oscillator X1 are interconnected. Pin 4 of the microcontroller U2 is connected to pin 1 of the 32nd resistor R32. Pin 2 of the 32nd resistor R32, pin 2 of the 31st resistor R31, pin 1 of the 11th capacitor C15, and pin 1 of the passive crystal oscillator X1 are interconnected. Pins 2 and 4 of the passive crystal oscillator X1 are connected to ground (GND). Pin 2 of the 8th capacitor C10 and pin 2 of the 11th capacitor C15 are interconnected to ground (GND).
[0031] This control circuit reduces the operating frequency of the switch when the input voltage rises, so that the current does not rise with the voltage, and the contactor still maintains a low-power operation. This control circuit is widely used in various contactor energy-saving retrofits and new generation wide-voltage input contactors. It is also used for the upgrade and optimization of most 115A frame types on the market. This control circuit can be widely used in contactor control circuits in various applications.
[0032] The working principle and usage process of this utility model: The power circuit consists of a power input terminal AC(L), a power input terminal AC(N), a varistor RV1, a seventeenth capacitor CX1, a first rectifier bridge D3, a fourth capacitor C4, a power inductor L1, a thirteenth resistor R13, a first fast recovery diode D1, an output coil terminal 4OUT1, a high-efficiency diode D4, an output coil terminal 5OUT2, and a power switch TR1.
[0033] The voltage acquisition circuit 9 consists of the second rectifier bridge D5, the seventeenth resistor R17, the twenty-second resistor R22, the twenty-fourth resistor R24, the twenty-seventh resistor R27, and the seventh capacitor C9;
[0034] The current acquisition circuit 10 consists of the twenty-fifth resistor R25, the twenty-sixth resistor R26, the twenty-third resistor R23, and the sixth capacitor C7;
[0035] The PWM drive circuit 12 includes a +12V drive power supply composed of a nineteenth resistor R19, a fifteenth resistor R15, a gate driver IC U1, a fifth capacitor C6, an eighteenth resistor R18, a twentieth resistor R20, a switching diode D6, a twenty-first resistor R21, an eleventh resistor R11, a fourteenth resistor R14, a sixteenth resistor R16, a +12V Zener diode D8, a thirteenth capacitor C17, a sixteenth capacitor C20, a fifth resistor R5, and a first light-emitting diode LED1.
[0036] The intelligent control microcontroller circuit 6 includes a +3.3V drive power supply consisting of resistors R1, R2, R3, R4, R6, R7, R8, R9, R10; transistors Q1, Q2, Q3, Q4; a +60V Zener diode D2; capacitors C1, C2, C3; and resistors R12, R6, R7, R8, R9, R10. Resistor R33 (33rd resistor), Resistor R30 (30th resistor), Capacitor C13 (9th capacitor), Capacitor C14 (10th capacitor), Linear regulator U3, Ferrite bead L2, Microcontroller U2, Resistor R29 (29th resistor), LED2 (2nd LED), Resistor R28 (28th resistor), Capacitor C16 (12th capacitor), Capacitor C18 (14th capacitor), Resistor R31 (31st resistor), Resistor R32 (32nd resistor), Passive crystal oscillator X1, Capacitor C10 (8th capacitor), Capacitor C15 (11th capacitor), Capacitor C19 (15th capacitor), Microcontroller program download interface H1;
[0037] The contactor energy-saving intelligent control circuit controls the contactor coil 13 to achieve two stages of operation: high current engagement and low current holding.
[0038] The PWM switching frequency is an average square wave signal of 20kHz. During the pull-in phase, the intelligent control microcontroller circuit 6 collects the input power supply voltage in real time through the voltage acquisition circuit 9. When the power supply voltage is greater than 75V, the contactor pulls in. During this phase, the contactor inductance is small, so the duty cycle can be as long as 100%. The microcontroller circuit 6 collects the power circuit current in real time through the current acquisition circuit 0. When the pull-in current is greater than 2A, the PWM square wave signal outputs a low level; when the pull-in current is less than 2A, the PWM square wave signal outputs a high level. The duty cycle of the PWM square wave signal is irregular. The peak current during the pull-in phase is intelligently adjusted by the microcontroller and can be programmably set. The pull-in phase is completed within 86ms from the start of reaching the set pull-in voltage (if the input undervoltage protection is entered during this period, the timer is reset to zero), realizing the transition from the pull-in phase to the holding phase.
[0039] After entering the holding stage, the inductance of the contactor increases, the duty cycle becomes more regular, and the square wave frequency shows periodic jitter, that is, the frequency jitters within the range of ±6.5%.
[0040] The pull-in voltage and turn-off (release) voltage can be programmably set.
[0041] The release voltage (undervoltage protection value) is 54V, which can be programmed. The contactor will disconnect if an input undervoltage occurs or if the user does not enable the protection.
[0042] During the pull-in phase, the duty cycle of the square wave signal output by the microcontroller is controlled by the PWM drive circuit 12 to drive the power switch TR1 to switch on and off. This causes the current in the contactor coil 13 to alternate between rising and falling phases, which keeps the coil current at a relatively small value and the contactor in a low-power state. This keeps the pull-in current at the set value, thereby reducing the power consumption of the contactor during pull-in and holding. This achieves beneficial effects such as energy saving, wide voltage input, and remote control in the contactor control circuit.
[0043] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A contactor energy-saving intelligent control circuit, comprising a power input terminal (1), a power input terminal (2), a power circuit (3), an output coil terminal (4), an output coil terminal (5), a microcontroller circuit (6), a +3.3V power supply circuit (7), a +12V power supply circuit (8), a voltage acquisition circuit (9), a current acquisition circuit (10), a power switch circuit (11), a PWM drive circuit (12), a contactor coil (13), a 24th resistor, a first rectifier bridge D3, a third transistor Q3, a 7th resistor R7, a first capacitor C1, a gate driver IC U1, a high-efficiency diode D4, a fifth resistor R5, a 33rd resistor R33, a linear regulator U3, and a 12th capacitor C16, characterized in that: The power circuit is formed by the power input end (1), power circuit (3), output coil end (4), contactor coil (13), output coil end (5), power switch circuit (11), current acquisition circuit (10), and power input end (2). The power input terminal (1) and the power input terminal (2) are connected to the power circuit (3). The power circuit (3) is connected to the output coil terminal (4). The output coil terminal (4) is connected to the output coil terminal (5) through the contactor coil (13). The output coil terminal (5) is connected to the power switch circuit (11). The voltage acquisition circuit (9) is connected to the current acquisition circuit (10) and the PWM drive circuit (12). The current acquisition circuit (10) is connected to the power circuit (3) and the microcontroller. The power circuit (3) is connected to the voltage acquisition circuit (9). The voltage acquisition circuit (9) is connected to the microcontroller. The power circuit (3) is connected to the +3.3V power supply circuit (7) and the +12V power supply circuit (8). The +3.3V power supply circuit (7) and the +12V power supply circuit (8) are connected to the PWM drive circuit (12).
2. The contactor energy-saving intelligent control circuit according to claim 1, characterized in that: Pin 1 of the power input AC(L), pin 1 of the varistor RV1, pin 1 of the seventeenth capacitor CX1, pin 2 of the first rectifier bridge D3, and pins 2 of the second rectifier bridge D5 are interconnected. Pin 1 of the power input AC(N), pin 2 of the varistor RV1, pin 2 of the seventeenth capacitor CX1, pin 1 of the first rectifier bridge D3, and pin 2 of the second rectifier bridge D5 are interconnected. Pin 4 of the second rectifier bridge D5 is grounded. Pin 3 of the second rectifier bridge D5 is connected to pin 1 of the seventeenth resistor R17. Pin 2 of the seventeenth resistor R17 is connected to pin 1 of the twenty-second resistor R22. Pin 1 of the twenty-second resistor R22, pin 1 of the twenty-fourth resistor R24, pin 1 of the seventh capacitor C9, and pin 10 of the microcontroller U2 are interconnected.
3. The contactor energy-saving intelligent control circuit according to claim 1, characterized in that: Pin 2 of the 24th resistor R24 is connected to pin 1 of the 27th resistor R27. Pin 2 of the 27th resistor R27, pin 2 of the 7th capacitor C9, and ground GND are interconnected. Pin 3 of the first rectifier bridge D3, pin 1 of the first fast recovery diode D1, pin 1 of the 13th resistor R13, pin 1 of the power inductor L1, and pin 1 of the fourth capacitor C4 are interconnected. Pin 4 of the first rectifier bridge D3 and pin 1 of the fourth capacitor C4 are interconnected to ground GND. Pin 2 of the first fast recovery diode D1 and pin 1 of the 13th resistor R13 are interconnected. Pin 2 of the power inductor L1, pin 1 of the first resistor R1, pin 1 of the seventh resistor R7, pin 1 of the high-efficiency diode D4, pin 1 of the eleventh resistor R11, pin 1 of the thirty-third resistor R33 and pin 1 of the output coil (4) OUT1 are connected to each other. Pin 2 of the first resistor R1 is connected to pin 2 and pin 4 of the second transistor Q2. Pin 3 of the second transistor Q2 is connected to pin 1 of the second resistor R2. Pin 2 of the second resistor R2 is connected to pin 2 and pin 4 of the third transistor Q3.
4. The contactor energy-saving intelligent control circuit according to claim 1, characterized in that: Pin 3 of the third transistor Q3 is connected to pin 1 of the third resistor R3. Pin 2 of the third resistor R3 is connected to pins 2 and 4 of the fourth transistor Q4. Pin 3 of the fourth transistor Q4 is connected to pin 1 of the fourth resistor R4. Pin 2 of the fourth resistor R4 is connected to pins 2 and 4 of the first transistor Q1. Pin 3 of the first transistor Q1, pin 1 of the first capacitor C1, pin 1 of the second capacitor C2, and pin 8 of the linear regulator U3 are interconnected. The pin of the seventh resistor R7... Pin 2 is connected to pin 1 of the second transistor Q2 and pin 1 of the eighth resistor R8. Pin 2 of the eighth resistor R8, pin 1 of the third transistor Q3, and pin 1 of the ninth resistor R9 are connected to each other. Pin 2 of the ninth resistor R9 is connected to pin 1 of the fourth transistor Q4 and pin 1 of the tenth resistor R10. Pin 2 of the tenth resistor R10 is connected to pin 1 of the first transistor Q1 and pin 1 of the +60V Zener diode D2. Pin 2 of the +60V Zener diode D2 is connected to ground GND.
5. The contactor energy-saving intelligent control circuit according to claim 3, characterized in that: Pin 2 of the first capacitor C1 and pin 2 of the second capacitor C2 are connected to ground GND. Pin 2 of the high-efficiency diode D4 is connected to pin 2 of the power switch TR1, pin 2 of the transient suppression diode D7, and pin 1 of the output coil (5) OUT2. Pin 2 of the transient suppression diode D7 is connected to ground GND. Pin 2 of the power switch TR1 is connected to pin 2 of the twenty-first resistor R21, R22, pin 2 of the twenty-third resistor R23, pin 1 of the twenty-fifth resistor R25, and pin 1 of the twenty-sixth resistor R26. Pin 2 of the twenty-fifth resistor R25 and pin 2 of the twenty-sixth resistor R26 are connected to each other. Pin 2 of resistor R26 is connected to ground (GND). Pin 1 of the 23rd resistor R23 is connected to pin 1 of the 6th capacitor C7 and pin 1 of the microcontroller U2. Pin 2 of the 6th capacitor C7 is connected to ground (GND). Pin 1 of the power switch TR1 is connected to pin 2 of the 20th resistor R20, pin 1 of the 21st resistor R21, and pin 1 of the switching diode D6. Pin 3 of the switching diode D6 is connected to pin 1 of the 18th resistor R18. Pin 2 of the 18th resistor R18 is connected to pin 1 of the 20th resistor R20 and pins 3 and 4 of the gate driver IC U1. Pin 5 of the gate driver IC U1 is connected to pin 1 of the 5th capacitor C6, pin 1 of the 5th resistor R5, pin 2 of the 16th resistor R16, pin 3 of the +12V Zener diode D8, pin 1 of the 13th capacitor C17, and pin 1 of the 16th capacitor C20.
6. The contactor energy-saving intelligent control circuit according to claim 5, characterized in that: Pin 2 of the gate driver IC ICU1 is connected to ground (GND). Pin 1 of the gate driver IC U1 is connected to pin 2 of the fifteenth resistor R15. Pin 1 of the fifteenth resistor R15, pin 1 of the nineteenth resistor R19, and pin 2 of the microcontroller U2 are interconnected. Pin 1 of the nineteenth resistor R19 is connected to ground (GND). Pin 2 of the fifth resistor R5 is connected to pin 1 of the first light-emitting diode (LED1). Pin 1 of the +12V Zener diode D8, pin 2 of the thirteenth capacitor C17, pin 2 of the sixteenth capacitor C20, and pin 2 of the first light-emitting diode (LED1) are interconnected to ground (GND). Pin 1 of the sixteenth resistor R16 and pin 2 of the fourteenth resistor R14 are interconnected. The fourteenth resistor R14 is connected to pin 1 of the eleventh resistor R11, the thirty-third resistor R33 is connected to pin 1 of the sixth resistor R6, the sixth resistor R6, the third capacitor C3, the twelfth resistor R12, the thirtieth resistor R30, and the +4.7V Zener diode D9 are interconnected, the third capacitor C3, the twelfth resistor R12, and the +4.7V Zener diode D9 are interconnected to ground GND, and the thirtieth resistor R30 is connected to pin 1 of the linear regulator U3.
7. The contactor energy-saving intelligent control circuit according to claim 1, characterized in that: Pins 4 and 9 of the linear regulator U3 are connected to ground (GND). Pins 1 and 2 of the linear regulator U3, pin 1 of the ninth capacitor C13, pin 1 of the tenth capacitor C14, and pin 1 of the ferrite bead L2 are interconnected. Pins 2 of the ninth capacitor C13 and pin 2 of the tenth capacitor C14 are interconnected to ground (GND). Pin 2 of the ferrite bead L2, pin 1 of the twenty-eighth resistor R28, pin 8 of the microcontroller U2, pin 1 of the microcontroller program download interface H1, and pin 1 of the fourteenth capacitor C18 are also interconnected. Pin 1 of capacitor C19 and capacitor C18 are connected to each other. Pin 2 of capacitor C19 is connected to ground (GND). Pin 2 of capacitor C18 is connected to ground (GND). Pin 3 of microcontroller program download interface H1 is connected to ground (GND). Pin 2 of microcontroller program download interface H1 is connected to pin 3 of microcontroller U2. Pin 2 of resistor R28, pin 1 of capacitor C16, pin 4 of microcontroller program download interface H1, and pin 4 of microcontroller U2 are connected to each other.
8. The contactor energy-saving intelligent control circuit according to claim 1, characterized in that: Pin 2 of the twelfth capacitor C16 is connected to ground (GND). Pin 20 of the microcontroller U2 is connected to pin 1 of the twenty-ninth resistor R29. Pin 2 of the twenty-ninth resistor R29 is connected to pin 1 of the second light-emitting diode (LED2). Pin 2 of the second light-emitting diode (LED2) is connected to ground (GND). Pin 7 of the microcontroller U2 is connected to ground (GND). Pin 5 of the microcontroller U2, pin 1 of the thirty-first resistor R31, pin 1 of the eighth capacitor C10, and pin 3 of the passive crystal oscillator X1 are interconnected. Pin 4 of the microcontroller U2 is connected to pin 1 of the thirty-second resistor R32. Pin 2 of the thirty-second resistor R32, pin 2 of the thirty-first resistor R31, pin 1 of the eleventh capacitor C15, and pin 1 of the passive crystal oscillator X1 are interconnected. Pins 2 and 4 of the passive crystal oscillator X1 are connected to ground (GND). Pin 2 of the eighth capacitor C10 and pin 2 of the eleventh capacitor C15 are interconnected to ground (GND).