Contactor activation circuit and contactor control system
The contactor starting circuit with a boost and sampling system, controlled by a microcontroller, addresses the high starting current issue of high-voltage contacts, enabling reliable operation with limited power supplies by ensuring a stable 3A current for 60 milliseconds.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- TYCO ELECTRONICS (SHANGHAI) CO LTD
- Filing Date
- 2025-10-07
- Publication Date
- 2026-04-22
AI Technical Summary
Existing high-voltage contacts require a starting current of more than 3A, which exceeds the power supply capacity of many customers who have limited supplies of 1.5A or less, preventing their application in miniaturized products.
A contactor starting circuit with a boost circuit to increase power supply voltage, a sampling circuit to monitor output voltage, and a microcontroller to control the drive circuit, ensuring a stable starting current of 3A or more for 60 milliseconds, using components like inductors, MOS transistors, and capacitors to manage voltage and current.
The solution ensures that the contactor coil receives a stable starting current of 3A for at least 60 milliseconds, expanding the applicability of high-voltage contacts to customers with limited power supplies.
Smart Images
Figure 2026068712000001_ABST
Abstract
Description
Technical Field
[0001] Cross - reference to Related Applications This application claims the benefit of Chinese Patent Application No. CN202411413642.4, filed with the China National Intellectual Property Administration on October 10, 2024, the entire disclosure of which is incorporated herein by reference.
[0002] The present invention relates to a contact activation circuit and a contact control system including the contact activation circuit.
Background Art
[0003] In the prior art, the main competitive advantage of high - voltage contacts is their small size, which meets the customer's demand for miniaturization applications. However, the starting current of the coil of a miniaturized high - voltage contact is relatively high, usually requiring more than 3A. However, many customers have limited power supply, and the supply current is generally 1.5A or less, and they cannot meet the current requirements for coil startup. As a result, existing high - voltage contacts cannot be applied to many customers' products.
Summary of the Invention
Problems to be Solved by the Invention
[0004] The present invention has been made to overcome or mitigate at least one aspect of the above - mentioned drawbacks.
Means for Solving the Problems
[0005] According to an aspect of the present invention, a contactor starting circuit is provided. The contactor starting circuit comprises: a boost circuit used to increase a power supply voltage Vin such that the output voltage Vout of the boost circuit is higher than the input power supply voltage Vin; a sampling circuit connected to the output terminal of the boost circuit to collect the output voltage Vout of the boost circuit; a drive circuit connected to the output terminal of the boost circuit to supply a stable starting voltage to a contactor coil; and a microcontroller configured to control the drive circuit based on the output voltage Vout of the boost circuit collected by the sampling circuit. When the output voltage Vout of the boost circuit reaches a predetermined voltage, the microcontroller controls the drive circuit to supply a stable starting voltage to the contactor coil so that the contactor coil has a constant starting current during the startup phase and that the duration of this constant starting current is longer than a predetermined time.
[0006] According to another exemplary embodiment of the present invention, when the output voltage Vout of the boost circuit has not reached a predetermined voltage, the microcontroller controls the drive circuit to disconnect the electrical connection between the output terminal of the boost circuit and the contactor coil, and when the output voltage Vout of the boost circuit has reached a predetermined voltage, the microcontroller controls the drive circuit to reconnect the electrical connection between the output terminal of the boost circuit and the contactor coil.
[0007] According to another exemplary embodiment of the present invention, the microcontroller is also configured to control the boost circuit based on the output voltage Vout of the boost circuit collected by the sampling circuit, and when the output voltage Vout of the boost circuit has not reached a predetermined voltage, the microcontroller controls the boost circuit to continue increasing the output voltage Vout, and when the output voltage Vout of the boost circuit has reached the predetermined voltage, the microcontroller controls the boost circuit to stop increasing the output voltage Vout.
[0008] According to another exemplary embodiment of the present invention, the contactor starting circuit can ensure that the starting current of the contactor coil is 3 amperes or more and that the duration of the starting current is 60 milliseconds or more.
[0009] According to another exemplary embodiment of the present invention, the boost circuit includes an inductor L1, one end of which is used to connect to a power supply; an N-type MOS transistor Q2, the drain of which is connected to the other end of the inductor L1, the source of which is grounded, and the gate of which is connected to one output port of a microcontroller; a diode D1, the positive terminal of which is connected to the other end of the inductor L1 and the drain of which is connected to the drain of which is connected to the drain of the N-type MOS transistor Q2; and a capacitor C1, one end of which is connected to the negative terminal of which is connected to the diode D1 and the other end is grounded. One end of inductor L1 functions as the input terminal of the boost circuit, and the other end of capacitor C1 functions as the output terminal of the boost circuit.
[0010] According to another exemplary embodiment of the present invention, the capacitance value of capacitor C1 can be calculated according to the following formula: C1 = I * T / (Vout - Vin) Here, C1 is the capacitance value of capacitor C1, I is the starting current of the contactor coil, T is the duration of the starting current of the contactor coil, Vout is the output voltage of the boost circuit, and Vin is the input power supply voltage.
[0011] According to another exemplary embodiment of the present invention, one output port of the microcontroller is used to output a PWM wave to the gate of an N-type MOS transistor Q2 in order to control the maximum output voltage Vmax of a boost circuit by adjusting the duty cycle D of the PWM wave. The maximum output voltage Vmax of a boost circuit can be calculated according to the following formula: Vmax = Vin / (1 - D) Of these, Vmax is the maximum output voltage of the boost circuit, Vin is the input power supply voltage, and D is the duty cycle of the PWM wave.
[0012] According to another exemplary embodiment of the present invention, the boost circuit further includes a resistor R4, one end of which is connected to one output port of a microcontroller and the other end of which is connected to the gate of an N-type MOS transistor Q2, and a resistor R5, one end of which is connected to one end of resistor R4 and one output port of a microcontroller and the other end is grounded.
[0013] According to another exemplary embodiment of the present invention, the sampling circuit includes a resistor R1, one end of which is connected to the output terminal of a boost circuit, and a resistor R6, one end of which is connected to the other end of resistor R1 and the other end is grounded. The analog-to-digital converter of the microcontroller is connected to the other end of resistor R1 and one end of resistor R6 to acquire a sampling voltage V1. The output voltage Vout of a boost circuit can be calculated according to the following formula: Vout = V1 * (R1 + R6) / R6 Of these, Vout is the output voltage of the boost circuit, and V1 is the sampling voltage acquired by the microcontroller.
[0014] According to another exemplary embodiment of the present invention, the drive circuit includes a P-type MOS transistor Q1, the source of which is connected to the output terminal of the boost circuit; a resistor R3, one end of which is connected to the output terminal of the boost circuit and the other end of which is connected to the gate of the P-type MOS transistor Q1; an N-type MOS transistor Q4, the drain of which is connected to the other end The microcontroller's general-purpose input / output port GPIO1 is connected to the gate of the N-type MOS transistor Q4, and the constant voltage diode D2 is used to supply a stable drive voltage.
[0015] According to another exemplary embodiment of the present invention, when the output voltage Vout of the boost circuit has not reached a predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller outputs a low level to the gate of the N-type MOS transistor Q4, disconnecting both the N-type MOS transistor Q4 and the P-type MOS transistor Q1, thereby disconnecting the electrical connection between the drive circuit and the boost circuit. When the output voltage Vout of the boost circuit reaches a predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller outputs a high level to the gate of the N-type MOS transistor Q4, conducting both the N-type MOS transistor Q4 and the P-type MOS transistor Q1, thereby reconnecting the electrical connection between the drive circuit and the boost circuit.
[0016] According to another exemplary embodiment of the present invention, the drive circuit further includes an N-type MOS transistor Q3, the gate of which is connected to the negative terminal of a constant voltage diode D2 and the other end of a resistor R2, and the drain of which is connected to the drain of a P-type MOS transistor Q1 and one end of a resistor R2; and a freewheeling diode D3, the negative terminal of which is connected to the source of the N-type MOS transistor Q3 and the positive terminal of which is grounded. The positive and negative terminals of the freewheeling diode D3 are connected to the two ends of a contactor coil, respectively.
[0017] According to another exemplary embodiment of the present invention, the starting voltage supplied to the contactor coil by the drive circuit and the starting current of the contactor coil during the starting phase can be calculated according to the following formula: V = VD2 - VQ3 I=V / R V is the starting voltage supplied to the contactor coil by the drive circuit, VD2 is the voltage across the constant voltage diode D2, VQ3 is the threshold voltage of the N-type MOS transistor Q3, I is the starting current of the contactor coil during the startup phase, and R is the resistance of the contactor coil.
[0018] According to another exemplary embodiment of the present invention, the drive circuit further includes a first connection terminal connected to the negative terminal of the freewheel diode D3 and the source of the N-type MOS transistor Q3, and a second connection terminal connected to the positive terminal of the freewheel diode D3 and grounded. The first and second connection terminals are used to connect the two ends of the contactor coil, respectively.
[0019] According to another exemplary embodiment of the present invention, the drive circuit includes a resistor R7, one end of the resistor R7 is connected to the general-purpose input / output port GPIO1 of the microcontroller, and a resistor R8, one end of the resistor R8 is connected to the other end of the resistor R7, and the other end is grounded. The gate of the N-type MOS transistor Q4 is connected to the other end of the resistor R7 and one end of the resistor R8.
[0020] According to another exemplary embodiment of the present invention, the contact activation circuit further includes an LDO circuit. To supply power to the microcontroller, the input end of the LDO circuit is connected to the power supply, and the output end of the LDO circuit is connected to the positive power supply terminal VDD of the microcontroller.
[0021] According to another exemplary embodiment of the present invention, the LDO circuit includes a low dropout linear regulator U1. The input end of the low dropout linear regulator U1 is connected to the positive electrode of the power supply, and the output end of the low dropout linear regulator U1 is connected to the positive power supply terminal VDD of the microcontroller. The LDO circuit further includes capacitors C5 and C3, one end of capacitors C5 and C3 is connected to the input end of the low dropout linear regulator U1, and the other end is grounded, and capacitors C4 and C6, one end of capacitors C4 and C6 is connected to the output end of the low dropout linear regulator U1, and the other end is grounded. The input end of the boost circuit is connected to the input end of the low dropout linear regulator U1.
[0022] According to another exemplary embodiment of the present invention, the LDO circuit further includes a power supply positive connection terminal connected to the input end of the low dropout linear regulator U1, the input end of the boost circuit, and one end of capacitors C5 and C3, and a power supply negative connection terminal connected to the other end of capacitors C5 and C3. The power supply positive connection terminal and the power supply negative connection terminal are used to be connected to the positive and negative electrodes of the power supply respectively.
[0023] According to another aspect of the present invention, a contactor control system is provided. The contactor control system includes the contactor startup circuit for supplying a stable startup voltage to the contactor coil so that the contactor coil has a constant startup current during the startup phase and the duration of the constant startup current is longer than a predetermined time, and a contactor holding circuit used for supplying a stable holding voltage to the contactor coil after the contactor startup circuit completes the startup of the contactor coil so that the contactor coil has a constant holding current during the holding phase. The holding voltage of the contactor coil during the holding phase is lower than the startup voltage of the contactor coil during the startup phase, and the holding current of the contactor coil during the holding phase is lower than the startup current of the contactor coil during the startup phase.
[0024] According to an exemplary embodiment of the present invention, the contactor holding circuit can ensure that the holding current of the contactor coil during the holding phase is 0.65 amperes or less, and the contactor startup circuit can ensure that the startup current of the contactor coil during the startup phase is 3 amperes or more.
[0025] According to another exemplary embodiment of the present invention, in order to control the contactor holding circuit to supply a stable holding voltage to the contactor coil, the other general-purpose input / output port GPO2 of the microcontroller is connected to the contactor holding circuit. After the contactor startup circuit completes the startup of the contactor coil, the microcontroller controls the boost circuit to stop the increase in the output voltage Vout and controls the drive circuit to disconnect the electrical connection between the drive circuit and the boost circuit.
[0026] In the above exemplary embodiment according to the present invention, the contactor startup circuit increases the startup current of the contactor coil by increasing the power supply voltage. Therefore, the startup current of the contactor coil can reach 3 A or more, and the application range of the contactor product is expanded.
[0027] The above-mentioned and other features of the present invention will become more apparent by describing exemplary embodiments of the present invention in detail with reference to the attached drawings. [Brief explanation of the drawing]
[0028] [Figure 1] This is a functional block diagram of a contactor activation circuit according to an exemplary embodiment of the present invention. [Figure 2] This is a circuit diagram of a contactor activation circuit according to an exemplary embodiment of the present invention. [Figure 3] This is a functional block diagram of a contactor control system according to an exemplary embodiment of the present invention. [Modes for carrying out the invention]
[0029] Illustrative embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals refer to the same elements. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so as to make the present disclosure thorough and complete and so as to fully convey the concepts of the present disclosure to those skilled in the art.
[0030] The following detailed description includes numerous specific details for illustrative purposes to provide a thorough understanding of the disclosed embodiments. However, it will be apparent that one or more embodiments can be carried out without these specific details. In other examples, well-known structures and apparatus are shown schematically for the sake of simplifying the drawings.
[0031] According to the general concept of the present invention, a contactor activation circuit is provided. The contactor startup circuit comprises a boost circuit, which is a boost circuit used to increase the power supply voltage Vin so that the output voltage Vout of the boost circuit is higher than the input power supply voltage Vin; a sampling circuit connected to the output terminal of the boost circuit to collect the output voltage Vout of the boost circuit; a drive circuit connected to the output terminal of the boost circuit to supply a stable startup voltage to the contactor coil; and a microcontroller configured to control the drive circuit based on the output voltage Vout of the boost circuit collected by the sampling circuit. When the output voltage Vout of the boost circuit reaches a predetermined voltage, the microcontroller controls the drive circuit to supply a stable startup voltage to the contactor coil so that the contactor coil has a constant startup current during the startup phase and the duration of this constant startup current is greater than or equal to a predetermined time.
[0032] According to another general concept of the present invention, a contactor control system is provided. The contactor control system comprises a contactor starting circuit for supplying a stable starting voltage to a contactor coil such that the contactor coil has a constant starting current during the starting phase and the duration of the constant starting current is for a predetermined time or longer, and a contactor holding circuit used to supply a stable holding voltage to the contactor coil after the contactor starting circuit has completed starting the contactor coil such that the contactor coil has a constant holding current during the holding phase. The holding voltage of the contactor coil during the holding phase is lower than the starting voltage of the contactor coil during the starting phase, and the holding current of the contactor coil during the holding phase is lower than the starting current of the contactor coil during the starting phase.
[0033] Figure 1 shows a functional block diagram of a contactor activation circuit according to an exemplary embodiment of the present invention. Figure 2 shows a circuit diagram of a contactor activation circuit according to an exemplary embodiment of the present invention.
[0034] As shown in Figures 1 and 2, an exemplary embodiment of the present invention discloses a contactor starting circuit. The contactor starting circuit comprises a boost circuit 1, a sampling circuit 2, a drive circuit 3, and a microcontroller 5. The boost circuit 1 is used to increase the power supply voltage Vin so that the output voltage Vout of the boost circuit 1 is higher than the input power supply voltage Vin. The sampling circuit 2 is connected to the output terminal of the boost circuit 1 and is used to collect the output voltage Vout of the boost circuit 1. The drive circuit 3 is connected to the output terminal of the boost circuit 1 and is used to supply a stable starting voltage to the contactor coil. The microcontroller 5 is suitable for controlling the drive circuit 3 based on the output voltage Vout of the boost circuit 1 collected by the sampling circuit 2. When the output voltage Vout of the boost circuit 1 reaches a predetermined voltage, the microcontroller 5 controls the drive circuit 3 to supply a stable starting voltage to the contactor coil so that the contactor coil has a constant starting current during the startup phase and that the duration of this constant starting current is longer than a predetermined time.
[0035] As shown in Figures 1 and 2, in the illustrated embodiment, when the output voltage Vout of the boost circuit 1 has not reached a predetermined voltage, the microcontroller 5 controls the drive circuit 3 to disconnect the electrical connection between the output terminal of the boost circuit 1 and the contactor coil, and when the output voltage Vout of the boost circuit 1 has reached a predetermined voltage, the microcontroller 5 controls the drive circuit 3 to reconnect the electrical connection between the output terminal of the boost circuit 1 and the contactor coil.
[0036] As shown in Figures 1 and 2, in the illustrated embodiment, the microcontroller 5 is also configured to control the boost circuit 1 based on the output voltage Vout collected by the sampling circuit 2. When the output voltage Vout of the boost circuit 1 has not reached a predetermined voltage, the microcontroller 5 controls the boost circuit 1 to continue increasing the output voltage Vout. When the output voltage Vout of the boost circuit 1 reaches a predetermined voltage, the microcontroller 5 controls the boost circuit 1 to stop increasing the output voltage Vout.
[0037] As shown in Figures 1 and 2, in the illustrated embodiment, the contactor starting circuit can ensure that the starting current of the contactor coil is 3 amperes or more and that the duration of the starting current is 60 milliseconds or more.
[0038] As shown in Figures 1 and 2, in the illustrated embodiment, the boost circuit 1 includes an inductor L1, an N-type MOS transistor Q2, a diode D1, and a capacitor C1. One end of the inductor L1 is used to connect to a power supply. The drain of the N-type MOS transistor Q2 is connected to the other end of the inductor L1, its source is grounded, and its gate is connected to one output port of the microcontroller 5. The positive terminal of the diode D1 is connected to the other end of the inductor L1 and the drain of the N-type MOS transistor Q2. One end of the capacitor C1 is connected to the negative terminal of the diode D1, and its other end is grounded. One end of the inductor L1 functions as the input terminal of the boost circuit 1, and one end of the capacitor C1 functions as the output terminal of the boost circuit 1.
[0039] As shown in Figures 1 and 2, in the illustrated embodiment, the capacitance value of capacitor C1 can be calculated according to the following formula. C1 = I * T / (Vout - Vin) Here, C1 is the capacitance value of capacitor C1, I is the starting current of the contactor coil, T is the duration of the starting current of the contactor coil, Vout is the output voltage of boost circuit 1, and Vin is the input power supply voltage.
[0040] As shown in Figures 1 and 2, in the illustrated embodiment, one output port of the microcontroller 5 is used to output a PWM wave to the gate of an N-type MOS transistor Q2, and thus the maximum output voltage Vmax of the boost circuit 1 can be controlled by adjusting the duty cycle D of the PWM wave. The maximum output voltage Vmax of the boost circuit 1 can be calculated according to the following formula: Vmax = Vin / (1 - D) Of these, Vmax is the maximum output voltage of the boost circuit 1, Vin is the input power supply voltage, and D is the duty cycle of the PWM wave.
[0041] As shown in Figures 1 and 2, in the illustrated embodiment, the boost circuit 1 further includes resistors R4 and R5. One end of resistor R4 is connected to one output port of the microcontroller 5, and the other end is connected to the gate of the N-type MOS transistor Q2. One end of resistor R5 is connected to the other end of resistor R4 and one output port of the microcontroller 5, and the other end is grounded.
[0042] As shown in Figures 1 and 2, in the illustrated embodiment, the sampling circuit 2 includes resistors R1 and R6. One end of resistor R1 is connected to the output terminal of the boost circuit 1. One end of resistor R6 is connected to the other end of resistor R1, and the other end is grounded. The analog-to-digital converter (ADC) of the microcontroller 5 is connected to the other end of resistor R1 and one end of resistor R6 to acquire the sampling voltage V1. The output voltage Vout of the boost circuit 1 can be calculated according to the following formula: Vout = V1 * (R1 + R6) / R6 Of these, Vout is the output voltage of the boost circuit 1, and V1 is the sampling voltage acquired by the microcontroller 5.
[0043] As shown in Figures 1 and 2, in the illustrated embodiment, the drive circuit 3 includes a P-type MOS transistor Q1, a resistor R3, an N-type MOS transistor Q4, a resistor R2, and a constant voltage diode D2. The source of the P-type MOS transistor Q1 is connected to the output terminal of the boost circuit 1. One end of the resistor R3 is connected to the output terminal of the boost circuit 1, and the other end is connected to the gate of the P-type MOS transistor Q1. The drain of the N-type MOS transistor Q4 is connected to the other end of the resistor R3 and the gate of the P-type MOS transistor Q1, and its source is grounded. One end of the resistor R2 is connected to the drain of the P-type MOS transistor Q1. The negative terminal of the constant voltage diode D2 is connected to the other end of the resistor R2, and its positive terminal is grounded. The general-purpose input / output port GPIO1 of the microcontroller 5 is connected to the gate of the N-type MOS transistor Q4. The constant voltage diode D2 supplies a stable drive voltage.
[0044] As shown in Figures 1 and 2, in the illustrated embodiment, when the output voltage Vout of the boost circuit 1 has not reached a predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller 5 outputs a low level to the gate of the N-type MOS transistor Q4, disconnecting both the N-type MOS transistor Q4 and the P-type MOS transistor Q1, thereby disconnecting the electrical connection between the drive circuit 3 and the boost circuit 1. When the output voltage Vout of the boost circuit 1 reaches a predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller 5 outputs a high level to the gate of the N-type MOS transistor Q4, conducting both the N-type MOS transistor Q4 and the P-type MOS transistor Q1, thereby reconnecting the electrical connection between the drive circuit 3 and the boost circuit 1.
[0045] As shown in Figures 1 and 2, in the illustrated embodiment, the drive circuit 3 further includes an N-type MOS transistor Q3 and a freewheeling diode D3. The gate of the N-type MOS transistor Q3 is connected to the negative terminal of the constant voltage diode D2 and the other end of the resistor R2, and its drain is connected to the drain of the P-type MOS transistor Q1 and one end of the resistor R2. The negative terminal of the freewheeling diode D3 is connected to the source of the N-type MOS transistor Q3, and its positive terminal is grounded. The positive and negative terminals of the freewheeling diode D3 are used to connect to the two ends of a contactor coil, respectively. In the illustrated embodiment, the constant voltage diode D2 is used to drive the N-type MOS transistor Q3, so that the source voltage of the N-type MOS transistor Q3 is stabilized, thereby achieving the objective of constant current.
[0046] As shown in Figures 1 and 2, in the illustrated embodiment, the starting voltage supplied to the contactor coil by the drive circuit 3 and the starting current of the contactor coil during the starting phase can be calculated according to the following formula: V = VD2 - VQ3 I=V / R V is the starting voltage supplied to the contactor coil by the drive circuit 3, VD2 is the voltage across the constant voltage diode D2, VQ3 is the threshold voltage of the N-type MOS transistor Q3, I is the starting current of the contactor coil during the startup phase, and R is the resistance of the contactor coil.
[0047] As shown in Figures 1 and 2, in the illustrated embodiment, the drive circuit 3 further includes a first connection terminal P1 and a second connection terminal P2. The first connection terminal P1 is connected to the negative terminal of the freewheeling diode D3 and the source of the N-type MOS transistor Q3. The second connection terminal P2 is connected to the positive terminal of the freewheeling diode D3 and is grounded. The first connection terminal P1 and the second connection terminal P2 are used to connect the two ends of the contactor coil, respectively.
[0048] As shown in Figures 1 and 2, in the illustrated embodiment, the drive circuit 3 further includes resistors R7 and R8. One end of resistor R7 is connected to the general-purpose input / output port GPIO1 of the microcontroller 5. One end of resistor R8 is connected to the other end of resistor R7, and the other end is grounded. The gate of the N-type MOS transistor Q4 is connected to the other end of resistor R7 and one end of resistor R8.
[0049] As shown in Figures 1 and 2, in the illustrated embodiment, the contactor activation circuit further comprises an LDO circuit 4. The input terminal of the LDO circuit 4 is connected to a power supply, and its output terminal is connected to the positive power supply terminal VDD of the microcontroller 5, supplying power to the microcontroller 5 with a supply voltage of +5V.
[0050] As shown in Figures 1 and 2, in the illustrated embodiment, the LDO circuit 4 includes a low-dropout linear regulator U1 and capacitors C5, C3, C4, and C6. The input terminal of the low-dropout linear regulator U1 is connected to the positive terminal of the power supply, and its output terminal is connected to the positive power supply terminal VDD of the microcontroller 5. One end of capacitors C5 and C3 is connected to the input terminal of the low-dropout linear regulator U1, and the other end is grounded. One end of capacitors C4 and C6 is connected to the output terminal of the low-dropout linear regulator U1, and the other end is grounded. The input terminal of the boost circuit 1 is connected to the input terminal of the low-dropout linear regulator U1.
[0051] As shown in Figures 1 and 2, in the illustrated embodiment, the LDO circuit 4 further includes a power supply positive terminal P3 and a power supply negative terminal P4. The power supply positive terminal P3 is connected to the input terminal of the low voltage difference linear regulator U1, the input terminal of the boost circuit 1, and one end of capacitors C5 and C3. The power supply negative terminal P4 is connected to the other end of capacitors C5 and C3. The power supply positive terminal P3 and power supply negative terminal P4 are used to connect to the positive and negative terminals of the power supply, respectively.
[0052] Figure 2 is merely an illustrative circuit diagram of the present invention, and the numerical values of each electronic component are illustrative only and can be adjusted according to the actual situation. Furthermore, the circuit diagram for implementing the functional block diagram shown in Figure 1 is not limited to the circuit diagram shown in Figure 2. In the circuit diagram shown in Figure 2, unless otherwise specified, grounding usually refers to connecting the negative terminal of the power supply.
[0053] Figure 3 shows a functional block diagram of a contactor control system according to an exemplary embodiment of the present invention.
[0054] As shown in Figures 1 to 3, a contactor control system is also disclosed in another exemplary embodiment of the present invention. The contactor control system comprises the above-described contactor starting circuit and a contactor holding circuit 6. The contactor starting circuit is used to supply a stable starting voltage to the contactor coil so that the contactor coil has a constant starting current during the starting phase and that the duration of this constant starting current is for a predetermined time or longer. The contactor holding circuit 6 is used to supply a stable holding voltage to the contactor coil after the contactor starting circuit has completed starting the contactor coil so that the contactor coil has a constant holding current during the holding phase. The holding voltage of the contactor coil during the holding phase is lower than the starting voltage of the contactor coil during the starting phase, and the holding current of the contactor coil during the holding phase is lower than the starting current of the contactor coil during the starting phase.
[0055] As shown in Figures 1 to 3, in the illustrated embodiment, the contactor holding circuit 6 can ensure that the holding current of the contactor coil during the holding phase is 0.65 amperes or less, thereby reducing energy consumption. The contactor starting circuit can ensure that the starting current of the contactor coil during the starting phase is 3 amperes or more, thereby ensuring that the contactor coil can be reliably started.
[0056] As shown in Figures 1 to 3, in the illustrated embodiment, the other general-purpose input / output port GPO2 of the microcontroller 5 is connected to the contactor holding circuit 6 and used to control the contactor holding circuit 6 and provide a stable holding voltage to the contactor coil. After the contactor activation circuit has finished activating the contactor coil, the microcontroller 5 controls the boost circuit 1 to stop the rise of the output voltage Vout and controls the drive circuit 3 to disconnect the electrical connection between the drive circuit 3 and the boost circuit 1.
[0057] Those skilled in the art should understand that the embodiments described above are illustrative and not limiting. For example, those skilled in the art can make many modifications to the embodiments described above without structural or principle contradictions, and can freely combine the various features described in different embodiments.
[0058] While several exemplary embodiments have been illustrated and described, it will be understood by those skilled in the art that various modifications or changes can be made to these embodiments without departing from the principles and spirit of this disclosure. The scope of this disclosure is defined in the claims and its equivalents.
[0059] When used herein, elements described in the singular form and preceded by the words "a" or "an" should be understood not to exclude the plural forms of such elements or steps unless it is explicitly stated that such exclusion is excluded. Furthermore, references to "one embodiment" of the present invention are not intended to be construed as excluding the existence of additional embodiments that likewise incorporate the described features. Moreover, unless it is expressly stated otherwise, embodiments that "compile" or "have" one or more elements having a particular characteristic may include additional such elements that do not possess that characteristic.
Claims
1. A contactor activation circuit, A boost circuit (1) is used to increase the input power supply voltage Vin such that the output voltage Vout of the boost circuit (1) is higher than the input power supply voltage Vin. A sampling circuit (2) connected to the output terminal of the boost circuit (1) is used to collect the output voltage Vout of the boost circuit (1), A drive circuit (3) is connected to the output terminal of the boost circuit (1) in order to supply a stable starting voltage to the contactor coil, A microcontroller (5) is configured to control the drive circuit (3) based on the output voltage Vout of the boost circuit (1) collected by the sampling circuit (2), and Equipped with, When the output voltage Vout of the boost circuit (1) reaches a predetermined voltage, the microcontroller (5) controls the drive circuit (3) to supply a stable starting voltage to the contactor coil such that the contactor coil has a constant starting current during the starting phase and the duration of the constant starting current is for a predetermined time or longer, in a contactor starting circuit.
2. When the output voltage Vout of the boost circuit (1) has not reached the predetermined voltage, the microcontroller (5) controls the drive circuit (3) to disconnect the electrical connection between the output terminal of the boost circuit (1) and the contactor coil. The contactor activation circuit according to claim 1, wherein when the output voltage Vout of the boost circuit (1) reaches the predetermined voltage, the microcontroller (5) controls the drive circuit (3) to make an electrical connection between the output terminal of the boost circuit (1) and the contactor coil.
3. The microcontroller (5) is also configured to control the boost circuit (1) based on the output voltage Vout of the boost circuit (1) collected by the sampling circuit (2), When the output voltage Vout of the boost circuit (1) has not reached the predetermined voltage, the microcontroller (5) controls the boost circuit (1) to continue increasing the output voltage Vout. The contactor activation circuit according to claim 1, wherein when the output voltage Vout of the boost circuit (1) reaches the predetermined voltage, the microcontroller (5) controls the boost circuit (1) to stop the increase in the output voltage Vout.
4. The contactor starting circuit according to claim 1, wherein the contactor starting circuit can guarantee that the starting current of the contactor coil is 3 amperes or more and that the duration of the starting current is 60 milliseconds or more.
5. The aforementioned boost circuit (1) is An inductance L1, one end of which is used to connect to a power supply, An N-type MOS transistor Q2, wherein the drain of the N-type MOS transistor Q2 is connected to the other end of the inductor L1, the source of the N-type MOS transistor Q2 is grounded, and the gate of the N-type MOS transistor Q2 is connected to one output port of the microcontroller (5), Diode D1, wherein the positive terminal of diode D1 is connected to the other terminal of inductor L1 and the drain of N-type MOS transistor Q2, A capacitor C1 has one end connected to the negative terminal of diode D1 and the other end to ground. Includes, The contactor activation circuit according to claim 1, wherein one end of the inductor L1 functions as the input terminal of the boost circuit (1), and one end of the capacitor C1 functions as the output terminal of the boost circuit (1).
6. The capacitance value of capacitor C1 can be calculated according to the following formula: C1=I*T / (Vout-Vin) The contactor starting circuit according to claim 5, wherein C1 is the capacitance value of the capacitor C1, I is the starting current of the contactor coil, T is the duration of the starting current of the contactor coil, Vout is the output voltage of the boost circuit (1), and Vin is the input power supply voltage.
7. The one output port of the microcontroller (5) is used to output the PWM wave to the gate of the N-type MOS transistor Q2 in order to control the maximum output voltage Vmax of the boost circuit (1) by adjusting the duty cycle D of the PWM wave. The maximum output voltage Vmax of the boost circuit (1) can be calculated according to the following formula: Vmax=Vin / (1-D) The contactor activation circuit according to claim 5, wherein Vmax is the maximum output voltage of the boost circuit (1), Vin is the input power supply voltage, and D is the duty cycle of the PWM wave.
8. The aforementioned boost circuit (1) is A resistor R4, wherein one end of the resistor R4 is connected to the one output port of the microcontroller (5), and the other end of the resistor R4 is connected to the gate of the N-type MOS transistor Q2, A resistor R5, one end of which is connected to the one end of resistor R4 and the one output port of the microcontroller (5), and the other end of which is grounded. The contactor activation circuit according to claim 7, further comprising:
9. The sampling circuit (2) is A resistor R1, one end of which is connected to the output terminal of the boost circuit (1), A resistor R6, one end of which is connected to the other end of the resistor R1, and the other end of which is grounded, and Includes, The analog-to-digital converter (ADC) of the microcontroller (5) is connected to the other end of the resistor R1 and the one end of the resistor R6 to acquire the sampling voltage V1. The output voltage Vout of the boost circuit (1) can be calculated according to the following formula: Vout=V1*(R1+R6) / R6 The contactor activation circuit according to claim 1, wherein Vout is the output voltage of the boost circuit (1), and V1 is the sampling voltage acquired by the microcontroller (5).
10. The aforementioned drive circuit (3) is A P-type MOS transistor Q1, wherein the source of the P-type MOS transistor Q1 is connected to the output terminal of the boost circuit (1), A resistor R3, wherein one end of the resistor R3 is connected to the output terminal of the boost circuit (1), and the other end of the resistor R3 is connected to the gate of the P-type MOS transistor Q1, An N-type MOS transistor Q4, wherein the drain of the N-type MOS transistor Q4 is connected to the other end of resistor R3 and the gate of P-type MOS transistor Q1, and the source of the N-type MOS transistor Q4 is grounded, Resistor R2, one end of which is connected to the drain of the P-type MOS transistor Q1, A constant voltage diode D2, wherein the negative terminal of the constant voltage diode D2 is connected to the other end of the resistor R2, and the positive terminal of the constant voltage diode D2 is grounded. Includes, The general-purpose input / output port GPIO1 of the microcontroller (5) is connected to the gate of the N-type MOS transistor Q4. The contactor starting circuit according to claim 1, wherein the constant voltage diode D2 is used to supply a stable drive voltage.
11. When the output voltage Vout of the boost circuit (1) has not reached the predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller (5) outputs a low level to the gate of the N-type MOS transistor Q4, disconnecting both the N-type MOS transistor Q4 and the P-type MOS transistor Q1, thereby disconnecting the electrical connection between the drive circuit (3) and the boost circuit (1). The contactor activation circuit according to claim 10, wherein when the output voltage Vout of the boost circuit (1) reaches the predetermined voltage, the general-purpose input / output port GPIO1 of the microcontroller (5) outputs a high level to the gate of the N-type MOS transistor Q4, causing both the N-type MOS transistor Q4 and the P-type MOS transistor Q1 to conduct, thereby establishing an electrical connection between the drive circuit (3) and the boost circuit (1).
12. The aforementioned drive circuit (3) is An N-type MOS transistor Q3, wherein the gate of the N-type MOS transistor Q3 is connected to the negative terminal of a constant voltage diode D2 and the other end of a resistor R2, and the drain of the N-type MOS transistor Q3 is connected to the drain of a P-type MOS transistor Q1 and one end of a resistor R2, A freewheel diode D3, wherein the negative terminal of the freewheel diode D3 is connected to the source of the N-type MOS transistor Q3, and the positive terminal of the freewheel diode D3 is grounded. It further includes, The contactor activation circuit according to claim 11, wherein the positive and negative electrodes of the freewheel diode D3 are connected to the two ends of the contactor coil, respectively.
13. The starting voltage supplied to the contactor coil by the drive circuit (3) and the starting current of the contactor coil during the starting phase can be calculated according to the following formula: V = VD² - VQ³ I = V / R The contactor starting circuit according to claim 12, wherein V is the starting voltage supplied to the contactor coil by the drive circuit (3), VD2 is the voltage of the constant voltage diode D2, VQ3 is the threshold voltage of the N-type MOS transistor Q3, I is the starting current of the contactor coil during the starting stage, and R is the resistance of the contactor coil.
14. The aforementioned drive circuit (3) is The first connection terminal (P1) is connected to the negative electrode of the freewheel diode D3 and the source of the N-type MOS transistor Q3, A second connection terminal (P2) is connected to the positive terminal of the freewheel diode D3 and is grounded. It further includes, The contactor activation circuit according to claim 12, wherein the first connection terminal (P1) and the second connection terminal (P2) are used to connect the two ends of the contactor coil, respectively.
15. The aforementioned drive circuit (3) is Resistor R7, one end of which is connected to the general-purpose input / output port GPIO1 of the microcontroller (5), A resistor R8, one end of which is connected to the other end of resistor R7, and the other end of which is grounded. It further includes, The contactor activation circuit according to claim 11, wherein the gate of the N-type MOS transistor Q4 is connected to the other end of resistor R7 and one end of resistor R8.
16. A contactor activation circuit according to any one of claims 1 to 15, further comprising an LDO circuit (4), the input terminal of which is connected to a power supply and the output terminal of which is connected to the positive power supply terminal VDD of the microcontroller (5) in order to supply power to the microcontroller (5).
17. The LDO circuit (4) is A low voltage drop linear regulator U1, wherein the input terminal of the low voltage drop linear regulator U1 is connected to the positive terminal of the power supply, and the output terminal of the low voltage drop linear regulator U1 is connected to the positive power supply terminal VDD of the microcontroller (5), Capacitors C5 and C3, wherein one end of capacitors C5 and C3 is connected to the input terminal of the low voltage difference linear regulator U1, and the other end is grounded. Capacitors C4 and C6, where one end of capacitors C4 and C6 is connected to the output terminal of the low voltage difference linear regulator U1 and the other end is grounded. Includes, The contactor activation circuit according to claim 16, wherein the input terminal of the boost circuit (1) is connected to the input terminal of the low-dropout linear regulator U1.
18. The LDO circuit (4) is The input terminal of the low-voltage difference linear regulator U1, the input terminal of the boost circuit (1), and the power supply positive terminal (P3) connected to one end of the capacitor C5 and the capacitor C3, The power supply negative terminal (P4) is connected to the other ends of the capacitors C5 and C3. It further includes, The contactor activation circuit according to claim 17, wherein the power supply positive terminal (P3) and the power supply negative terminal (P4) are used to connect to the positive and negative terminals of the power supply, respectively.
19. A contactor control system, A contactor starting circuit according to any one of claims 1 to 18, for supplying a stable starting voltage to a contactor coil such that the contactor coil has a constant starting current during the starting phase and the duration of the constant starting current is for a predetermined time or longer, A contactor holding circuit (6) is used to supply a stable holding voltage to the contactor coil after the contactor activation circuit has finished activating the contactor coil, so that the contactor coil has a constant holding current during the holding phase. Equipped with, A contactor control system wherein the holding voltage of the contactor coil during the holding stage is lower than the starting voltage of the contactor coil during the starting stage, and the holding current of the contactor coil during the holding stage is lower than the starting current of the contactor coil during the starting stage.
20. The contactor control system according to claim 19, wherein the contactor holding circuit (6) can ensure that the holding current of the contactor coil during the holding stage is 0.65 amperes or less, and the contactor starting circuit can ensure that the starting current of the contactor coil during the starting stage is 3 amperes or more.
21. In order to control the contactor holding circuit (6) and supply a stable holding voltage to the contactor coil, the other general-purpose input / output port GPO2 of the microcontroller (5) is connected to the contactor holding circuit (6). The contactor control system according to claim 19, wherein after the contactor activation circuit has completed activating the contactor coil, the microcontroller (5) controls the boost circuit (1) to stop the increase in the output voltage Vout, and controls the drive circuit (3) to disconnect the electrical connection between the drive circuit (3) and the boost circuit (1).