PWM (Pulse Width Modulation) direct-current circuit and electric equipment

Abstract

The utility model provides a PWM direct-current circuit and electric equipment, and the circuit comprises a first transistor which is connected with a divider resistor in parallel; the second transistor and the first transistor are arranged in parallel, and the collector electrode and the base electrode of the second transistor are connected with the source electrode and the drain electrode of the first transistor respectively; the third transistor and the second transistor are arranged in parallel, the third transistor is arranged at the circuit output end, and the base electrode and the emitting electrode of the third transistor are connected with the emitting collector and the base electrode of the second transistor respectively. Through coordination and cooperation among the three transistors, continuous and stable constant current output can be performed, the number and complexity of components are reduced, the whole system is easier to understand and maintain, and compared with a conventional output coordination circuit at the present stage, the output coordination circuit has the advantages that the cost is reduced. The system has the remarkable advantages of simple loop design, high controllability, flexibility in use, convenience in adjustment, stability in operation, wide application range and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of regulating circuits, and particularly refers to a PWM DC circuit and an electrical device. Background Art

[0002] In the field of electronic engineering, constant-current input circuits are key components to ensure the stable operation of electronic devices, and they are responsible for providing precise current to various loads. However, despite their increasing importance, the current design of constant-current input circuits generally faces challenges in terms of structural complexity.

[0003] Existing constant-current input circuits often consist of a series of precise discrete components, including error amplifiers, regulators, feedback networks, and numerous passive components. This complex circuit design not only increases the manufacturing cost but also brings considerable difficulties in circuit design, debugging, and maintenance. More importantly, this complexity may also introduce additional instability factors, affecting the reliability and lifespan of the entire system.

[0004] Therefore, it is particularly urgent to develop a constant-current input circuit with a simplified structure, high cost-effectiveness, and stable performance. Summary of the Invention

[0005] For this reason, the technical problem to be solved by the utility model is to overcome the problem of the complex structural design of the constant-current output circuit in the prior art, and provide a PWM DC circuit and an electrical device.

[0006] To solve the above technical problem, the utility model provides a PWM DC circuit, which includes: a first transistor, the first transistor is arranged in parallel with a voltage-dividing resistor and is arranged at the circuit input end; a second transistor, the second transistor is arranged in parallel with the first transistor, wherein the collector and the base of the second transistor are respectively connected to the source and the drain of the first transistor; a third transistor, the third transistor is arranged in parallel with the second transistor and is arranged at the circuit output end, wherein the base and the emitter of the third transistor are respectively connected to the emitter-collector and the base of the second transistor.

[0007] In an embodiment of the utility model, it further includes a main switch, and the main switch is connected between the circuit input end and the ground end.

[0008] In an embodiment of the utility model, the main switch is an N-type metal-oxide-semiconductor field-effect transistor, its drain is grounded, and its source is connected to the voltage-dividing resistor.

[0009] In an embodiment of the utility model, it further includes a first current-limiting resistor, the first current-limiting resistor is connected between the circuit input end and the ground end and is arranged in series with the voltage-dividing resistor.

[0010] In an embodiment of the present utility model, it further includes a voltage stabilizing diode, and the voltage stabilizing diode is connected in parallel between the voltage dividing resistor and the first transistor, wherein two ends of the voltage stabilizing diode are respectively connected to the source electrode and the gate electrode of the first transistor.

[0011] In an embodiment of the present utility model, it further includes a second current limiting resistor, and the second current limiting resistor is connected between the drain electrode of the first transistor and the base electrode of the second transistor.

[0012] In an embodiment of the present utility model, it further includes an adjusting resistor, and the adjusting resistor is connected in parallel with the third transistor, and two ends of it are respectively connected to the base electrode and the collector of the third transistor.

[0013] In an embodiment of the present utility model, the first transistor is a P-type metal-oxide-semiconductor field effect transistor.

[0014] In an embodiment of the present utility model, both the second transistor and the third transistor are NPN-type triodes.

[0015] The present utility model further provides an electrical equipment, which includes the above-mentioned PWM DC circuit.

[0016] The above technical solution of the present utility model has the following advantages compared with the prior art:

[0017] The PWM DC circuit and the electrical equipment of the present utility model can perform continuous and stable constant current output through the coordinated cooperation among three transistors, which not only ensures the efficient operation of the circuit, but also greatly enhances its applicability, enabling it to be widely applied to the power supply requirements of various motors. The circuit design of this application is simple and intuitive, reducing the number of components and complexity, making the whole system easier to understand and maintain. Compared with the conventional output coordination circuit at the present stage, this application has significant advantages such as simple circuit design, high controllability, flexible use, easy adjustment, stable operation and wide application range, providing a highly efficient, stable, flexible and widely applicable solution for users, and is expected to play an important role in modern electronic circuit design. Description of the Drawings

[0018] In order to make the content of the present utility model easier to be clearly understood, the following further details the present utility model according to the specific embodiments of the present utility model and in conjunction with the attached drawings.

[0019] Figure 1 It is the PWM DC circuit diagram in the preferred embodiment of the present utility model.

[0020] Description of the reference numerals in the drawings of the specification: Q1, main switch; Q2, first transistor; Q3, second transistor; Q4, third transistor; R1, voltage-dividing resistor; R2, first current-limiting resistor; R3, second current-limiting resistor; R4, adjusting resistor; D1, voltage-regulating diode. Detailed implementation manners

[0021] The present utility model will be further described below in conjunction with the drawings and specific embodiments, so that those skilled in the art can better understand the present utility model and be able to implement it, but the embodiments cited do not limit the present utility model.

[0022] Embodiment 1

[0023] Refer to Figure 1 As shown, this embodiment provides a PWM DC circuit, which includes: a first transistor Q2, the first transistor Q2 is arranged in parallel with the voltage-dividing resistor R1 and is arranged at the input end of the circuit; a second transistor Q3, the second transistor Q3 is arranged in parallel with the first transistor Q2, wherein, the collector and the base of the second transistor Q3 are respectively connected to the source and the drain of the first transistor Q2; a third transistor Q4, the third transistor Q4 is arranged in parallel with the second transistor Q3 and is arranged at the output end of the circuit, wherein, the base and the emitter of the third transistor Q4 are respectively connected to the emitter-collector and the base of the second transistor Q3.

[0024] The PWM DC circuit of the present utility model can perform continuous and stable constant current output through the coordinated cooperation among the three transistors, which not only ensures the efficient operation of the circuit, but also greatly enhances its applicability, enabling it to be widely applied to the power supply requirements of various motors. The circuit design of this application is simple and intuitive, reducing the number of components and complexity, making the entire system easier to understand and maintain. Compared with the conventional output coordination circuits at the present stage, this application has significant advantages such as simple circuit design, high controllability, flexible use, easy adjustment, stable operation and wide application range, providing a user with an efficient, stable, flexible and widely applicable solution, and is expected to play an important role in modern electronic circuit design.

[0025] Refer to Figure 1 As shown, in this embodiment, it includes a main switch Q1, the main switch Q1 is connected between the input end of the circuit and the ground end, and it is used to control the turn-off of the overall circuit. Specifically, the main switch Q1 in this embodiment is an N-type metal-oxide-semiconductor field effect transistor (N-type MOS-FET), its drain is grounded, and its source is connected to the voltage-dividing resistor R1. In this embodiment, the main switch Q1 is controlled by an external input voltage: when the external input is high voltage, the main switch Q1 is turned on, and at this time the overall circuit starts to work; when the external input is low voltage, the main switch Q1 is turned off, and at this time the overall circuit stops working.

[0026] See Figure 1 As shown, a first current-limiting resistor R2 is provided at the output end of the switch. The first current-limiting resistor R2 is connected between the input end of the circuit and the ground end and is serially arranged with the voltage-dividing resistor R1. Further, the first current-limiting resistor R2 is used to limit the current flowing through the main switch Q1 to prevent the main switch Q1 from being burned out due to excessive current. In this embodiment, the voltage-dividing resistor R1 and the first current-limiting resistor R2 are serially arranged, which is used to divide the voltage between the gate and the source of the first transistor Q2, thereby realizing the control of the turn-off of the first transistor Q2.

[0027] Further, a zener diode D1 is further included in this embodiment. The zener diode D1 is arranged in parallel between the voltage-dividing resistor R1 and the first transistor Q2. Wherein, both ends of the zener diode are respectively connected to the source and the gate of the first transistor Q2. In this embodiment, the zener diode D1 is specifically used to stabilize the voltage between the gate and the source of Q2.

[0028] See Figure 1 As shown, the first transistor Q2 in this embodiment is preferably a P-type metal-oxide-semiconductor field effect transistor (P-type MOS-FET), and the second transistor Q3 is preferably an NPN-type triode. A second current-limiting resistor R3 is connected between the drain of the first transistor Q2 and the base of the second transistor Q3. Specifically, the second current-limiting resistor R3 is used to stabilize the current flowing into the second transistor Q3, thereby providing protection for the second transistor Q3.

[0029] Correspondingly, the third transistor Q4 in this embodiment is preferably an NPN bipolar junction transistor. When the circuit is in a normal operating state, the first transistor Q2 is turned on. At this time, current flows into the source electrode of the first transistor Q2, flows out of the drain electrode, and passes through the second current-limiting resistor R3 to enter the base electrode of the second transistor Q3. Since there is no current passing through the base electrode of the third transistor Q4 at this time, there is no current between the collector and the emitter of the third transistor Q4. When the collector and the emitter of the second transistor Q3 are connected, current flows into the collector of the second transistor Q3 and out of the emitter, and enters the base electrode of the third transistor Q4. At this time, the voltage difference between the base and the collector of the third transistor Q4 rises. In this embodiment, the voltage difference between the base and the collector of the third transistor Q4 rises from 0V to the saturation voltage of 0.7V. At this time, the output current is I = 0.7V / R4. At this time, the collector and the emitter of the third transistor Q4 are fully conducting, and there is almost no voltage between them. At this time, the emitter voltage of the second transistor Q3 is higher than the base voltage of the second transistor Q3, which causes the second transistor Q3 to turn off. During the output of the current, the above process is continuously cycled, thereby achieving the purpose of stably outputting a PWM waveform direct current at the output end of the circuit. Further, this embodiment also includes an adjusting resistor R4. The adjusting resistor R4 is connected in parallel with the third transistor Q4, and its two ends are respectively connected to the base electrode and the collector of the third transistor Q4, and it is used to adjust the current value flowing through the resistor R4. Specifically, the current I = 0.7V / R4 stably output after being adjusted by the voltage loop in this embodiment.

[0030] Embodiment 2

[0031] This embodiment provides an electrical device, which includes the above-mentioned PWM DC circuit. The electrical device in this embodiment can be an automobile, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc. The automobile can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle, a spaceship, etc.; the electric toy includes a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, a hammer drill, an impact drill, a concrete vibrator, a planer, etc. The embodiments of the present invention do not impose special restrictions on the above-mentioned electrical devices.

[0032] In summary, for the PWM DC circuit and the electrical equipment of the present utility model, through the coordinated cooperation among three transistors, continuous and stable constant current output can be achieved, which not only ensures the efficient operation of the circuit, but also greatly enhances its applicability, enabling it to be widely applied to the power supply requirements of various motors. The circuit design of this application is simple and intuitive, reducing the number of components and complexity, making the entire system easier to understand and maintain. Compared with the conventional output coordination circuit at the present stage, this application has significant advantages such as simple circuit design, high controllability, flexible use, easy adjustment, stable operation, and wide application range, providing users with an efficient, stable, flexible and widely applicable solution, and is expected to play an important role in modern electronic circuit design.

[0033] Obviously, the above embodiments are merely examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill 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 manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the creation of the present utility model.

Claims

1. A PWM DC circuit, characterized in that: include: A first transistor, which is connected in parallel with the voltage-dividing resistor and is arranged at the input end of the circuit; a second transistor, the second transistor being arranged in parallel with the first transistor, wherein a collector and a base of the second transistor are connected to a source and a drain of the first transistor respectively; A third transistor is arranged in parallel with the second transistor and is arranged at the output end of the circuit, wherein the base and the emitter of the third transistor are connected to the emitter and the base of the second transistor respectively.

2. The PWM DC circuit according to claim 1, characterized in that: It also includes a main switch, which is connected between the circuit input terminal and the ground terminal.

3. The PWM DC circuit according to claim 2, characterized in that: The main switch is an N-type metal-oxide-semiconductor field effect transistor, a drain of which is grounded, and a source of which is connected to the voltage-dividing resistor.

4. The PWM DC circuit according to claim 1, characterized in that: It also includes a first current limiting resistor, which is connected between the circuit input terminal and the ground terminal and is arranged in series with the voltage dividing resistor.

5. The PWM DC circuit according to claim 1, characterized in that: It also includes a voltage regulator tube, which is arranged in parallel between the voltage-dividing resistor and the first transistor, wherein two ends of the voltage regulator tube are respectively connected to the source and the gate of the first transistor.

6. The PWM DC circuit according to claim 1, characterized in that: It also includes a second current limiting resistor, which is connected between the drain of the first transistor and the base of the second transistor.

7. The PWM DC circuit according to claim 1, characterized in that: It also includes an adjusting resistor, which is arranged in parallel with the third transistor, and whose two ends are respectively connected to the base and the collector of the third transistor.

8. The PWM DC circuit according to claim 1, characterized in that: The first transistor is a P-type metal-oxide-semiconductor field effect transistor.

9. The PWM DC circuit according to claim 1, characterized in that: The second transistor and the third transistor are both NPN transistors.

10. An electrical equipment, characterized in that: A PWM direct current circuit comprising any one of claims 1 to 9.

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