Switching circuit, controller and electric equipment

Abstract

The utility model relates to the technical field of switching circuits, in particular to a switching circuit, a controller and electric equipment, and the circuit comprises a power supply module which provides an input voltage and a power supply voltage; the signal module provides an input signal; the control module comprises a first triode, a second triode, a diode and a first resistor; the first triode and the second triode are NPN triodes with the same parameters; the base of the first triode is connected with an input signal, the emitter is grounded, and the collector is connected with the base of the second triode; the base electrode of the second triode is connected with the input voltage through the first resistor, the collector electrode is connected with the input voltage, and the emitter electrode is connected with the anode of the diode; the diode cathode is connected with the first triode collector; the switch module comprises an NMOS tube, the grid electrode of the NMOS tube is connected with the emitter electrode of the second triode, the source electrode is grounded, and the drain electrode is connected with power supply voltage. According to the utility model, the conduction loss is low, the bearing capacity of each triode is improved, the structure is simple, and the stability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of switching circuits, in particular to a switching circuit, a controller and an electrical equipment. Background Art

[0002] In the DC power supply of small electrical equipment, it is often necessary to construct a switching circuit between the DC power supply and the electrical equipment to control the on-off of the power supply.

[0003] When only one switching element is used in the switching circuit, it is required that the bearing capacity reflected by the performance indexes such as the maximum working voltage and the maximum working current of the switching element is relatively high; when multiple switching elements are used in the switching circuit, although switching elements with general bearing capacity and low cost can be selected, since the switching element will generate power loss due to the sudden increase of current when switching from the off state to the on state, the more switching elements are used, the greater the power loss will be.

[0004] In addition, the existing switching circuit constructed around the switching element also has the problems of insufficiently simple structure and low stability. Summary of the Utility Model

[0005] Therefore, the technical problem to be solved by the utility model is to overcome the problem that the switching circuit in the prior art is difficult to balance low power consumption, high stability and simple structure while the switching element has sufficient bearing capacity, and provides a switching circuit, a controller and an electrical equipment, which has a simple structure, improves the bearing capacity of the switching element, reduces the conduction loss and has high stability.

[0006] In the first aspect, to solve the above technical problem, the utility model provides a switching circuit, including:

[0007] A power supply module, which provides an input voltage and a supply voltage;

[0008] A signal module, which provides an input signal;

[0009] A control module, including a first triode, a second triode, a diode and a first resistor; the first triode and the second triode are both NPN triodes with the same parameters; the base of the first triode is connected to the input signal, the emitter of the first triode is grounded, and the collector of the first triode is connected to the base of the second triode; the base of the second triode is connected to the input voltage through the first resistor, the collector of the second triode is connected to the input voltage, the emitter of the second triode is connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the collector of the first triode;

[0010] The switch module includes an NMOS transistor; the gate of the NMOS transistor is connected to the emitter of the second triode, the source of the NMOS transistor is grounded, and the drain of the NMOS transistor is connected to the power supply voltage.

[0011] In an embodiment of the present invention, the control module further includes a second resistor, and the second resistor is connected between the emitter of the second triode and the gate of the NMOS transistor.

[0012] In an embodiment of the present invention, the switch module further includes a capacitor, and the capacitor is connected between the gate and the source of the NMOS transistor.

[0013] In an embodiment of the present invention, the control module further includes a third resistor, the first end of the third resistor is connected to the gate of the NMOS transistor, and the second end of the third resistor is grounded.

[0014] In an embodiment of the present invention, the signal module includes a fourth resistor, and the input signal is connected to the base of the first triode through the fourth resistor.

[0015] In an embodiment of the present invention, the switch module further includes a fifth resistor, and the power supply voltage is connected to the drain of the NMOS transistor through the fifth resistor.

[0016] In an embodiment of the present invention, the signal module includes a PWM circuit, and the PWM circuit outputs the input signal to the base of the first triode.

[0017] In a second aspect, to solve the above technical problem, the present invention further provides a controller, including the above-mentioned switch circuit.

[0018] In a third aspect, to solve the above technical problem, the present invention further provides an electrical device, including the above-mentioned controller.

[0019] In an embodiment of the present invention, the electrical device includes a single-chip microcomputer and a sensor.

[0020] The above technical solution of the present invention has at least the following advantages compared with the prior art:

[0021] The switch circuit, controller and electrical device of the present invention adopt two NPN triodes with the same parameters, and only one NPN triode is in the conducting state during operation, with lower conduction loss, improving the bearing capacity of each triode, simple structure and high stability. Description of the Drawings

[0022] In order to make the content of the present utility model easier to be clearly understood, the following further detailed description of the present utility model is provided according to the specific embodiments of the present utility model and in conjunction with the accompanying drawings.

[0023] Figure 1 It is the schematic diagram of a switching circuit in a preferred embodiment of the present utility model.

[0024] Explanation of the reference numerals in the drawings of the specification:

[0025] Q1 is the first triode; Q2 is the second triode; Q3: NMOS transistor;

[0026] D1 is a diode; C1 is a capacitor; 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;

[0027] VCC is the supply voltage; Vout is the output voltage of the control module; PWM is the pulse width modulation signal. Specific embodiments

[0028] The following further description of the present utility model is provided in conjunction with the accompanying 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 given are not intended to limit the present utility model.

[0029] In this application, unless otherwise clearly specified and limited, the term "connection" shall be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0030] In addition, in this application, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0031] In the DC power supply of small electrical devices, it is often necessary to construct a switching circuit between the DC power supply and the electrical device to control the on-off of the power supply. The existing switching circuits have problems in that it is difficult to achieve both sufficient withstand capacity of the switching elements and low power consumption, simple structure and high stability.

[0032] For this reason, the embodiments of this application provide a switching circuit, a controller and an electrical device.

[0033] Embodiment 1

[0034] This embodiment provides a switching circuit, including:

[0035] A power supply module that provides an input voltage and a supply voltage;

[0036] A signal module that provides an input signal;

[0037] A control module, including a first triode, a second triode, a diode, and a first resistor; the first triode and the second triode are both NPN triodes with the same parameters; the base of the first triode is connected to the input signal, the emitter of the first triode is grounded, and the collector of the first triode is connected to the base of the second triode; the base of the second triode is connected to the input voltage through the first resistor, the collector of the second triode is connected to the input voltage, the emitter of the second triode is connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the collector of the first triode;

[0038] A switching module, including an NMOS transistor; the gate of the NMOS transistor is connected to the emitter of the second triode, the source of the NMOS transistor is grounded, and the drain of the NMOS transistor is connected to the supply voltage.

[0039] For the switching circuit provided by this embodiment, (1) two NPN triodes with the same parameters are used, and only one NPN triode is in the conducting state during operation, with lower conduction loss and improved withstand capacity of each triode; (2) the structure is simple and the stability is relatively high; (3) when the input signal is at a high level, the control module outputs a high-level voltage and the NMOS transistor conducts; when the input signal is at a low level, the control module outputs a low-level voltage and the NMOS transistor cuts off, having a unidirectional effect.

[0040] Next, a detailed introduction to the switching circuit provided by this embodiment will be given:

[0041] I. Power supply module

[0042] Specifically, the power supply module provides an input voltage and a supply voltage.

[0043] II. Signal module

[0044] Specifically, the signal module provides an input signal.

[0045] Optionally, as shown in Figure 1 , the signal module includes a fourth resistor R4, and the input signal is connected to the base of the first triode Q1 through the fourth resistor R4.

[0046] Specifically, the fourth resistor R4 plays a role in current limiting and protecting the first triode Q1.

[0047] Optionally, the signal module includes a PWM circuit, and the PWM circuit outputs the input signal to the base of the first triode Q1.

[0048] III. Control Module

[0049] Specifically, the control module includes the first triode Q1, the second triode Q2, the diode D1, and the first resistor R1.

[0050] Specifically, both the first triode Q1 and the second triode Q2 are NPN triodes with the same parameters.

[0051] Specifically, the base of the first triode Q1 receives the input signal, the emitter of the first triode Q1 is grounded, and the collector of the first triode Q1 is connected to the base of the second triode Q2; the base of the second triode Q2 is connected to the input voltage through the first resistor R1, the collector of the second triode Q2 is connected to the input voltage, the emitter of the second triode Q2 is connected to the positive electrode of the diode D1, and the negative electrode of the diode D1 is connected to the collector of the first triode Q1;

[0052] Optionally, the control module further includes a second resistor R2, and the second resistor R2 is connected between the emitter of the second triode Q2 and the gate of the NMOS transistor Q3.

[0053] Specifically, the second resistor R2 is a current-limiting resistor, which can reduce the peak charging current of the gate of the NMOS transistor Q3 and protect the gate and source of the NMOS transistor Q3 from being broken down.

[0054] Optionally, the control module further includes a third resistor R3, the first end of the third resistor R3 is connected to the gate of the NMOS transistor Q3, and the second end of the third resistor R3 is grounded.

[0055] Specifically, when the NMOS transistor Q3 is turned off, the voltage difference between its source and gate is relatively large. Adding the third resistor R3 can help quickly release the charge, so that the NMOS transistor Q3 is quickly turned off, improving the response speed of the switching circuit described in this embodiment.

[0056] IV. Switching Module

[0057] Specifically, the switching module includes the NMOS transistor Q3; the gate of the NMOS transistor Q3 is connected to the emitter of the second triode Q2, the source of the NMOS transistor Q3 is grounded, and the drain of the NMOS transistor Q3 is connected to the supply voltage VCC.

[0058] Optionally, the switch module further includes a capacitor C1, and the capacitor C1 is connected between the gate and the source of the NMOS transistor Q3.

[0059] Specifically, during the operation of the NMOS transistor Q3, when the voltage between its gate and source changes, adding the capacitor C1 can buffer the voltage change to make the operation of the NMOS transistor Q3 more stable.

[0060] Optionally, the switch module further includes a fifth resistor R5, and the supply voltage VCC is connected to the drain of the NMOS transistor Q3 through the fifth resistor R5.

[0061] V. Working Process

[0062] Specifically, when the PWM circuit outputs a high-level signal, that is, the input signal is high level, the first triode Q1 conducts to ground, the base of the second triode Q2 receives a low-level signal, the second triode Q2 cuts off, and the gate-source capacitor Cgs inside the NMOS transistor Q3 quickly discharges through the diode D1 and the first triode Q1. The output voltage Vout of the control module quickly drops to the sum of the saturation voltage drop Vce of the first triode Q1 and the forward conduction voltage drop Vd of the diode D1, that is, Vout = Vce + Vd; the NMOS transistor Q3 cuts off, and a switch circuit described in this embodiment is in the off state.

[0063] Specifically, when the PWM circuit outputs a low-level signal, that is, the input signal is low level, the first triode Q1 cuts off, the base of the second triode Q2 receives a high-level signal from the input voltage through the first resistor R1, the second triode Q2 conducts. At this time, the second triode Q2 is equivalent to an emitter follower to charge the gate-source capacitor Cgs inside the NMOS transistor Q3; after the charging of the gate-source capacitor Cgs is completed, the NMOS transistor Q3 conducts, and a switch circuit described in this embodiment is in the on state.

[0064] Specifically, the input voltage needs to be greater than the sum of the charging voltage of the gate-source capacitor Cgs and the conduction voltage drop of the second triode Q2.

[0065] Exemplarily, if an NMOS transistor with a gate-source capacitor Cgs charging voltage of 11.3V is selected as Q3, then the input voltage needs to be greater than or equal to 12V.

[0066] Embodiment 2

[0067] This embodiment provides a controller, including a switch circuit as described in Embodiment 1.

[0068] For the introduction of a controller provided in this embodiment, please refer to Embodiment 1, which will not be elaborated here.

[0069] A controller provided in this embodiment has the same beneficial effects as the above-mentioned switching circuit.

[0070] Embodiment 3

[0071] This embodiment provides an electrical device, including a controller as described in Embodiment 2.

[0072] Specifically, the electrical device may be, but is not limited to, a single-chip microcomputer and a sensor.

[0073] For the further introduction of an electrical device provided in this embodiment, please refer to Embodiment 1, which will not be elaborated here.

[0074] An electrical device provided in this embodiment has the same beneficial effects as the above-mentioned switching circuit.

[0075] 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 enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A switching circuit, characterized in that, Comprising: A power supply module that provides an input voltage and a supply voltage; A signal module that provides an input signal; A control module, including a first triode, a second triode, a diode, and a first resistor; Both the first triode and the second triode are NPN triodes with the same parameters; the base of the first triode is connected to the input signal, the emitter of the first triode is grounded, and the collector of the first triode is connected to the base of the second triode; the base of the second triode is connected to the input voltage through the first resistor, the collector of the second triode is connected to the input voltage, the emitter of the second triode is connected to the positive electrode of the diode, and the negative electrode of the diode is connected to the collector of the first triode; A switch module, including an NMOS transistor; the gate of the NMOS transistor is connected to the emitter of the second triode, the source of the NMOS transistor is grounded, and the drain of the NMOS transistor is connected to the supply voltage.

2. The switching circuit according to claim 1, wherein, The control module further includes a second resistor, which is connected between the emitter of the second triode and the gate of the NMOS transistor.

3. The switching circuit according to claim 1, characterized in that, The switch module further includes a capacitor, which is connected between the gate and the source of the NMOS transistor.

4. A switching circuit according to claim 1, characterized in that, The control module further includes a third resistor, the first end of which is connected to the gate of the NMOS transistor, and the second end of which is grounded.

5. A switching circuit according to claim 1, wherein The signal module includes a fourth resistor, and the input signal is connected to the base of the first triode through the fourth resistor.

6. The switching circuit according to claim 1, wherein The switch module further includes a fifth resistor, and the supply voltage is connected to the drain of the NMOS transistor through the fifth resistor.

7. A switching circuit according to claim 1, characterized in that, The signal module includes a PWM circuit, and the PWM circuit outputs the input signal to the base of the first triode.

8. A controller, characterized in that, Comprising a switching circuit according to any one of claims 1-7.

9. An electrical device, characterized in that, Comprising a controller according to claim 8.

10. An electrical device according to claim 9, characterized in that, The electrical device includes a single-chip microcomputer and a sensor.

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