Step-down circuit compatible with high voltage and low voltage and controller

Abstract

The utility model relates to the technical field of step-down circuits, and provides a step-down circuit compatible with high voltage and low voltage and a controller. The control module is connected with the power supply module, provides an input voltage or a preset first voltage, and comprises a divider resistor, a voltage comparator, a first triode and an MOS tube; the chip module is connected with the control module, comprises a voltage stabilizing chip, and is used for stabilizing the input voltage or the first voltage to be a fixed value and then supplying power to the MCU; the divider resistor divides the input voltage to obtain a second voltage, and when the second voltage is smaller than the reference voltage of the voltage comparator, the voltage comparator outputs a high level, the first triode and the MOS tube are conducted, and the control module provides the input voltage; when the second voltage is greater than the reference voltage, the control module provides the first voltage. According to the utility model, the voltage provided for the voltage stabilizing chip is not too high, and a wider working voltage range can be adapted by adjusting the divider resistor and the reference voltage.

Description

Technical Field

[0001] The utility model relates to the technical field of step-down circuits, in particular to a step-down circuit and a controller compatible with high and low voltages. Background Art

[0002] When a motor controller with a speed of 6S or above is running, if the input voltage is too high, the voltage difference between it and the voltage of the voltage regulator chip will be relatively large, and the heat power generated on the voltage regulator chip will be relatively high. Over time, the service life of the voltage regulator chip will be shortened. Therefore, the input voltage should be stepped down before reaching the voltage regulator chip.

[0003] In actual application scenarios, such as controlling a vacuum cleaner through a brushless motor controller, the voltage range adapted by the general hardware step-down circuit is either lower (such as 16-25V) or higher (such as 25-36V), and it can only adapt to one situation. When the user proposes that the working voltage range needs to be compatible with high and low voltages, for example, the working voltage range is 16-36V, although it can be fine-tuned through software, it can only operate at the critical value of the upper and lower limits of the voltage. On this basis, if you want to apply a wider working voltage range, further adjustment of the software cannot be achieved. Utility Model Content

[0004] The main purpose of the utility model is to provide a step-down circuit and a controller that are compatible with high and low voltages, aiming to solve the technical problem that the existing step-down circuit cannot effectively step down the voltage within a relatively wide voltage range.

[0005] In the first aspect, in order to solve the above technical problems, the utility model provides a step-down circuit compatible with high and low voltages, comprising:

[0006] A power module, which is used to provide input voltage;

[0007] A control module connected to the power module; the control module is used to output the input voltage or a preset first voltage;

[0008] A chip module connected to the control module; the chip module includes a voltage stabilizing chip; the voltage stabilizing chip stabilizes the input voltage or the first voltage to a fixed value before supplying power to the MCU;

[0009] In which, the control module includes a voltage-dividing resistor, a voltage comparator, a first transistor and a MOS tube connected in sequence; the voltage-dividing resistor is connected to the power supply module, and is used to divide the input voltage to obtain a second voltage; when the second voltage is less than the reference voltage of the voltage comparator, the voltage comparator outputs a high level, the first transistor is turned on, the MOS tube is turned on, and the control module outputs the input voltage; when the second voltage is greater than the reference voltage of the voltage comparator, the voltage comparator outputs a low level, the first transistor is turned off, the MOS tube is turned off, and the control module outputs the first voltage; when the second voltage is equal to the reference voltage of the voltage comparator, the control module outputs the input voltage or the first voltage.

[0010] In one embodiment of the utility model, the control module also includes a first voltage regulator diode and a first resistor; the positive phase input end of the voltage comparator is respectively connected to the cathode of the first voltage regulator diode and the first end of the first resistor, the negative phase input end of the voltage comparator is connected to the voltage dividing resistor, and the output end of the voltage comparator is connected to the base of the first transistor; the positive pole of the first voltage regulator diode is grounded; the second end of the first resistor is connected to the power supply module; the Zener voltage of the first voltage regulator diode is the reference voltage of the voltage comparator.

[0011] In one embodiment of the utility model, the voltage-dividing resistor includes a second resistor and a third resistor; wherein the first end of the second resistor is connected to the power supply module, and the second end of the second resistor is respectively connected to the first end of the third resistor and the negative phase input end of the voltage comparator; the second end of the third resistor is grounded.

[0012] In an embodiment of the present invention, the Zener voltage of the first voltage regulator diode is 5V.

[0013] In one embodiment of the utility model, the first transistor is an NPN transistor; the MOS transistor is a PMOS transistor; wherein a fourth resistor is connected in series between the gate of the MOS transistor and the collector of the first transistor, and a fifth resistor is connected in series between the gate of the MOS transistor and the power module; the emitter of the first transistor is grounded.

[0014] In one embodiment of the utility model, the control module also includes a sixth resistor, a second transistor and a second zener diode; wherein the second transistor is an NPN transistor; the first end of the sixth resistor is respectively connected to the power supply module and the collector of the second transistor, and the second end of the sixth resistor is respectively connected to the base of the second transistor and the cathode of the second zener diode; the emitter of the second transistor is connected to the chip module; the positive electrode of the second zener diode is grounded; the Zener voltage of the second zener diode is the first voltage.

[0015] In one embodiment of the present invention, the control module further includes a first capacitor; the first capacitor is connected between the second end of the sixth resistor and the anode of the second voltage stabilizing diode.

[0016] In one embodiment of the utility model, the chip module also includes a seventh resistor, a second capacitor and a third capacitor; the first end of the seventh resistor is connected to the control module, and the second end of the seventh resistor is connected to the input end of the voltage stabilizing chip; the first end of the second capacitor is connected to the input end of the voltage stabilizing chip, and the second end of the second capacitor is grounded; the first end of the third capacitor is connected to the output end of the voltage stabilizing chip, and the second end of the third capacitor is grounded.

[0017] In one embodiment of the present invention, the voltage stabilizing chip stabilizes the input voltage or the first voltage to 15V before supplying power to the MCU.

[0018] In a second aspect, in order to solve the above-mentioned technical problem, the utility model also provides a controller, including the above-mentioned step-down circuit that is compatible with high and low voltages.

[0019] The above technical solution of the utility model has at least the following advantages compared with the prior art:

[0020] The utility model discloses a high-low voltage compatible step-down circuit and controller, which (1) divides the input voltage and compares it with the reference voltage of the voltage comparator. When the input voltage is less than the reference voltage, the input voltage is provided to the voltage stabilizing chip; when the input voltage is greater than the reference voltage, a preset first voltage is provided to the voltage stabilizing chip; when the input voltage is equal to the reference voltage, the input voltage or the preset first voltage is provided to the voltage stabilizing chip, so that the voltage at the voltage stabilizing chip will not be too high, and will not cause high heat and power consumption due to the large voltage difference; (2) the resistance value of the voltage divider resistor and the voltage value of the reference voltage can be adjusted to adapt to a wider working voltage range; (3) there is no need to use software to achieve step-down, the structure is simple, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the content of the utility model more clearly understood, the utility model is further described in detail below based on specific embodiments of the utility model in combination with the accompanying drawings.

[0022] Figure 1 It is a structural diagram of a high- and low-voltage compatible step-down circuit in a preferred embodiment of the utility model.

[0023] Description of the Figures in the Specification:

[0024] S1 power module; S2 control module; S3 chip module;

[0025] Vin input voltage; VC voltage comparator; GND ground;

[0026] U1 voltage regulator chip; IN voltage regulator chip input terminal; OUT voltage regulator chip output terminal;

[0027] R1 is the first resistor; R2 is the second resistor; R3 is the third resistor; R4 is the fourth resistor; R5 is the fifth resistor; R6 is the sixth resistor; R7 is the seventh resistor;

[0028] D1 is the first voltage zener diode; D2 is the second voltage zener diode;

[0029] Q1 is the first transistor; Q2 is the second transistor;

[0030] Q3: MOS tube; G gate; D drain; S source;

[0031] C1 is the first capacitor; C2 is the second capacitor; C3 is the third capacitor. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0033] In this application, unless otherwise clearly specified and limited, the terms "first", "second", etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance, and do not represent a sequential relationship. The term "connection" should be understood in a broad sense, and can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. In short, for ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0034] In actual application scenarios, such as controlling a vacuum cleaner through a brushless motor controller, the voltage range adapted by the general hardware step-down circuit is either lower (such as 16-25V) or higher (such as 25-36V), and it can only adapt to one situation. When the user proposes that the working voltage range needs to be compatible with high and low voltages, for example, the working voltage range is 16-36V, although it can be fine-tuned through software, it can only operate at the critical value of the upper and lower limits of the voltage. On this basis, if you want to apply a wider working voltage range, further adjustment of the software cannot be achieved.

[0035] In order to solve the above problems, this embodiment provides a step-down circuit and a controller that are compatible with high and low voltages.

[0036] Embodiment 1

[0037] This embodiment provides a step-down circuit compatible with high and low voltages. Figure 1 As shown, including:

[0038] A power module S1, which is used to provide an input voltage Vin;

[0039] A control module S2 connected to the power module S1; the control module S2 is used to output the input voltage Vin or a preset first voltage;

[0040] A chip module S3 connected to the control module S2; the chip module S3 includes a voltage stabilizing chip U1; the voltage stabilizing chip U1 stabilizes the input voltage Vin or the first voltage to a fixed value and then supplies power to a microcontroller unit (MCU);

[0041] Among them, the control module S2 includes a voltage-dividing resistor, a voltage comparator VC, a first transistor Q1 and a MOS transistor Q3 connected in sequence; the voltage-dividing resistor is connected to the power module S1, and is used to divide the input voltage Vin to obtain a second voltage; when the second voltage is less than the reference voltage of the voltage comparator VC, the voltage comparator VC outputs a high level, the first transistor Q1 is turned on, the MOS transistor Q3 is turned on, and the control module S2 outputs the input voltage Vin; when the second voltage is greater than the reference voltage of the voltage comparator VC, the voltage comparator VC outputs a low level, the first transistor Q1 is turned off, the MOS transistor Q3 is turned off, and the control module S2 outputs the first voltage; when the second voltage is equal to the reference voltage of the voltage comparator VC, the control module S2 outputs the input voltage Vin or the first voltage.

[0042] Next, a high-voltage and low-voltage compatible step-down circuit described in this embodiment is introduced in detail:

[0043] 1. Circuit structure

[0044] Optionally, the control module S2 also includes a first voltage stabilizing diode D1 and a first resistor R1; the positive phase input end of the voltage comparator VC is respectively connected to the cathode of the first voltage stabilizing diode D1 and the first end of the first resistor R1, the negative phase input end of the voltage comparator VC is connected to the voltage dividing resistor, and the output end of the voltage comparator VC is connected to the base of the first transistor Q1; the anode of the first voltage stabilizing diode D1 is grounded GND; the second end of the first resistor R1 is connected to the power module S1; the Zener voltage of the first voltage stabilizing diode D1 is the reference voltage of the voltage comparator VC;

[0045] Specifically, the reference voltage required by the voltage comparator VC is obtained by selecting the first voltage stabilizing diode D1 of corresponding model and specification.

[0046] Optionally, the voltage-dividing resistor includes a second resistor R2 and a third resistor R3;

[0047] Specifically, the first end of the second resistor R2 is connected to the power module S1, and the second end of the second resistor R2 is respectively connected to the first end of the third resistor R3 and the negative input end of the voltage comparator VC; the second end of the third resistor R3 is grounded GND;

[0048] Specifically, the second resistor R2 and the third resistor R3 divide the input voltage Vin to obtain the second voltage;

[0049] Furthermore, by adjusting the resistance ratio of the second resistor R2 and the third resistor R3 so that the voltage at the negative input terminal of the voltage comparator VC is not too large, it is convenient for subsequent voltage comparison and has the function of protecting the circuit and reducing power consumption.

[0050] Optionally, the first transistor Q1 is an NPN transistor, and the MOS transistor Q3 is a PMOS transistor;

[0051] Specifically, a fourth resistor R4 is connected in series between the gate G of the MOS transistor Q3 and the collector of the first transistor Q1, and a fifth resistor R5 is connected in series between the gate G of the MOS transistor Q3 and the power module S1; the emitter of the first transistor Q1 is grounded;

[0052] Specifically, when the voltage comparator VC outputs a high level, the first transistor Q1 is turned on, the branch where the fifth resistor R5 and the fourth resistor R4 are located is turned on and grounded, and the MOS transistor Q3 is turned on.

[0053] Optionally, the control module S2 further includes a sixth resistor R6, a second transistor Q2 and a second voltage stabilizing diode D2;

[0054] Optionally, the second transistor Q2 is an NPN transistor;

[0055] Specifically, the first end of the sixth resistor R6 is respectively connected to the power module S1 and the collector of the second transistor Q2, and the second end of the sixth resistor R6 is respectively connected to the base of the second transistor Q2 and the cathode of the second voltage stabilizing diode D2; the emitter of the second transistor Q2 is connected to the chip module S3; the anode of the second voltage stabilizing diode D2 is grounded GND;

[0056] Specifically, the stable voltage of the second voltage stabilizing diode D2 is the first voltage.

[0057] Optionally, the control module S2 further includes a first capacitor C1; the first capacitor C1 is connected between the second end of the sixth resistor R6 and the positive electrode of the second voltage stabilizing diode D2;

[0058] Specifically, the first capacitor C1 is used for filtering.

[0059] Optionally, the chip module S3 further includes a seventh resistor R7; a first end of the seventh resistor R7 is connected to the control module S2, and a second end of the seventh resistor R7 is connected to an input end IN of the voltage stabilizing chip U1.

[0060] Optionally, the chip module S3 further includes a second capacitor C2 and a third capacitor C3; a first end of the second capacitor C2 is connected to an input end IN of the voltage stabilizing chip U1, and a second end of the second capacitor C2 is grounded GND; a first end of the third capacitor C3 is connected to an output end OUT of the voltage stabilizing chip U1, and a second end of the third capacitor C3 is grounded GND;

[0061] Specifically, the second capacitor C2 and the third capacitor C3 are used for filtering.

[0062] Optionally, the voltage stabilizing chip U1 stabilizes the input voltage Vin or the first voltage to 15V before supplying power to the MCU.

[0063] 2. Working Process

[0064] The following is a specific description taking whether the input voltage Vin is greater than 25V as an example.

[0065] Exemplarily, the Zener voltage of the first voltage stabilizing diode D1 is 5V, the Zener voltage of the second voltage stabilizing diode is 20V, the first resistor R1 is 25K, the second resistor R2 is 25K, and the third resistor R3 is 5K;

[0066] It can be seen that the reference voltage of the voltage comparator VC is 5V, and the first voltage is 20V.

[0067] Specifically, when the input voltage Vin is greater than 25V, the second voltage is greater than 5V, the voltage at the negative input terminal of the voltage comparator VC is greater than the voltage at the positive input terminal, the voltage comparator VC outputs a low level, the first transistor Q1 is turned off, the MOS transistor Q3 is turned off, the second transistor Q2 is turned on, and the second voltage stabilizing diode D2 stabilizes the first voltage at 20V (actually below 20V);

[0068] Specifically, when the input voltage Vin is less than 25V, the second voltage is less than 5V, the voltage at the negative input terminal of the voltage comparator VC is less than the voltage at the positive input terminal, the voltage comparator VC outputs a high level, the first transistor Q1 is turned on, the MOS transistor Q3 is turned on, because the internal resistance of the MOS transistor Q3 is only tens of milliohms after it is turned on, and the current does not flow through the second transistor Q2 at this time, the second transistor Q2 is turned off, and the voltage output by the control module S2 is the input voltage Vin less than 25V;

[0069] Specifically, when the input voltage Vin is equal to 25V, the second voltage is equal to 5V, the negative phase input terminal voltage of the voltage comparator VC is equal to the positive phase input terminal voltage, and the voltage comparator VC will maintain the previous output state;

[0070] It can be seen that no matter whether the input voltage Vin is greater than 25V, the voltage output by the control module S2 is less than 25V; for the voltage stabilizing chip U1, a voltage less than 25V is not too high, and the voltage difference between the two is small. The voltage stabilizing chip U1 generates lower heat power while providing a stable voltage of 15V to the MCU, achieving the desired effect of a high- and low-voltage compatible step-down circuit as described in this embodiment.

[0071] In summary, the present embodiment provides a high- and low-voltage compatible buck circuit, which (1) divides the input voltage and compares it with the reference voltage of the voltage comparator. When the input voltage is less than the reference voltage, the input voltage is provided to the voltage stabilizing chip; when the input voltage is greater than the reference voltage, the preset first voltage is provided to the voltage stabilizing chip; when the input voltage is equal to the reference voltage, the input voltage or the preset first voltage is provided to the voltage stabilizing chip, so that the voltage at the voltage stabilizing chip is not too high, and the heat generation and power consumption are not high due to the large voltage difference; (2) the resistance value of the voltage divider resistor and the voltage value of the reference voltage can be adjusted to adapt to a wider operating voltage range; (3) there is no need to use software to achieve voltage reduction, the structure is simple, and the cost is low.

[0072] Embodiment 2

[0073] This embodiment provides a controller, including a high-voltage and low-voltage compatible buck circuit as described in the first embodiment.

[0074] For an introduction to a controller provided in this embodiment, please refer to Embodiment 1, and this embodiment will not be described in detail here.

[0075] The controller provided in this embodiment has the same beneficial effects as the above-mentioned high-voltage and low-voltage compatible step-down circuit.

[0076] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention of the utility model.

Claims

1. A step-down circuit compatible with high and low voltages, characterized in that: include: A power module, which is used to provide input voltage; A control module connected to the power module; The control module is used to output the input voltage or a preset first voltage; A chip module connected to the control module; the chip module includes a voltage stabilizing chip; the voltage stabilizing chip stabilizes the input voltage or the first voltage to a fixed value before supplying power to the MCU; In which, the control module includes a voltage-dividing resistor, a voltage comparator, a first transistor and a MOS tube connected in sequence; the voltage-dividing resistor is connected to the power supply module, and is used to divide the input voltage to obtain a second voltage; when the second voltage is less than the reference voltage of the voltage comparator, the voltage comparator outputs a high level, the first transistor is turned on, the MOS tube is turned on, and the control module outputs the input voltage; when the second voltage is greater than the reference voltage of the voltage comparator, the voltage comparator outputs a low level, the first transistor is turned off, the MOS tube is turned off, and the control module outputs the first voltage; when the second voltage is equal to the reference voltage of the voltage comparator, the control module outputs the input voltage or the first voltage.

2. A high-voltage and low-voltage compatible step-down circuit according to claim 1, characterized in that: The control module also includes a first voltage regulator diode and a first resistor; the positive phase input end of the voltage comparator is respectively connected to the cathode of the first voltage regulator diode and the first end of the first resistor, the negative phase input end of the voltage comparator is connected to the voltage dividing resistor, and the output end of the voltage comparator is connected to the base of the first transistor; the anode of the first voltage regulator diode is grounded; the second end of the first resistor is connected to the power supply module; the Zener voltage of the first voltage regulator diode is the reference voltage of the voltage comparator.

3. The high-voltage and low-voltage compatible step-down circuit according to claim 2, characterized in that: The voltage-dividing resistor includes a second resistor and a third resistor; Among them, the first end of the second resistor is connected to the power supply module, the second end of the second resistor is respectively connected to the first end of the third resistor and the negative phase input end of the voltage comparator; the second end of the third resistor is grounded.

4. The high-voltage and low-voltage compatible step-down circuit according to claim 2, characterized in that: The Zener voltage of the first voltage regulator diode is 5V.

5. The high-voltage and low-voltage compatible step-down circuit according to claim 1, characterized in that: The first transistor is an NPN transistor; the MOS transistor is a PMOS transistor; A fourth resistor is connected in series between the gate of the MOS tube and the collector of the first transistor, and a fifth resistor is connected in series between the gate of the MOS tube and the power module; the emitter of the first transistor is grounded.

6. The high-voltage and low-voltage compatible step-down circuit according to claim 1, characterized in that: The control module also includes a sixth resistor, a second triode and a second voltage stabilizing diode; Among them, the second transistor is an NPN transistor; the first end of the sixth resistor is respectively connected to the power supply module and the collector of the second transistor, and the second end of the sixth resistor is respectively connected to the base of the second transistor and the cathode of the second Zener diode; the emitter of the second transistor is connected to the chip module; the anode of the second Zener diode is grounded; and the Zener voltage of the second Zener diode is the first voltage.

7. The high-voltage and low-voltage compatible step-down circuit according to claim 6, characterized in that: The control module further includes a first capacitor; the first capacitor is connected between the second end of the sixth resistor and the anode of the second voltage stabilizing diode.

8. The high-voltage and low-voltage compatible step-down circuit according to claim 1, characterized in that: The chip module also includes a seventh resistor, a second capacitor and a third capacitor; the first end of the seventh resistor is connected to the control module, and the second end of the seventh resistor is connected to the input end of the voltage stabilizing chip; the first end of the second capacitor is connected to the input end of the voltage stabilizing chip, and the second end of the second capacitor is grounded; the first end of the third capacitor is connected to the output end of the voltage stabilizing chip, and the second end of the third capacitor is grounded.

9. The high-voltage and low-voltage compatible step-down circuit according to claim 1, characterized in that: The voltage stabilizing chip stabilizes the input voltage or the first voltage to 15V before supplying power to the MCU.

10. A controller, characterized in that: It comprises a high- and low-voltage compatible step-down circuit as described in any one of claims 1-9.

Images