A resistive load detection circuit

Abstract

The utility model relates to load detection technical field, especially a kind of resistive load detection circuit, including load switch SR1, drive module and detection module;The input end of drive module and the first data port of controller are electrically connected, the output end of drive module and the control end of load switch SR1 are electrically connected, the first end of load switch SR1 is connected to fire line, the second end of load switch SR1, the input end of detection module are electrically connected with the one end of resistive load, the other end of resistive load is connected to zero line, the output end of detection module and the second data port of controller are electrically connected;Solve the problem that current electronic product cannot detect resistive load in circuit and its load switch operating condition.

Description

Technical Field

[0001] This utility model relates to the field of load detection technology, and in particular to a resistive load detection circuit. Background Technology

[0002] Currently, small household appliances such as health pots, mini hot pots, and tea makers adopt a split structure with a base that has a built-in power supply circuit and a detachable main body. The main body has a resistive load (used for heating). When the main body is placed on the base, the resistive load is powered to work.

[0003] Therefore, the resistive load is electrically connected in series with the power supply circuit through a thyristor to form a power supply loop. The control electrode of the thyristor is electrically connected to a control port of the controller. The detection input terminal of the zero-crossing detection circuit is electrically connected to the power supply loop, and the detection output terminal of the zero-crossing detection circuit is electrically connected to a data port of the controller. The controller detects whether a state signal switch occurs within one voltage cycle at the detection output terminal of the zero-crossing detection circuit to determine whether there is a resistive load in the power supply loop, thereby ensuring that the small household appliances can work normally.

[0004] However, due to the frequent switching on and off of the power supply circuit, the losses of the thyristor and resistive load are severe, which may lead to damage to the thyristor or the resistive load; however, there is currently no detection circuit that can reflect the status of the thyristor and resistive load in real time. Utility Model Content

[0005] To address the aforementioned shortcomings, the purpose of this invention is to propose a resistive load detection circuit that solves the problem that current electronic products cannot detect the resistive load and its load switch operation in the circuit.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] A resistive load detection circuit includes a load switch SR1, a drive module, and a detection module. The input terminal of the drive module is electrically connected to a first data port of a controller, and the output terminal of the drive module is electrically connected to a control terminal of the load switch SR1. The first terminal of the load switch SR1 is connected to a live wire, and the second terminal of the load switch SR1 and the input terminal of the detection module are both electrically connected to one end of a resistive load. The other end of the resistive load is connected to a neutral wire, and the output terminal of the detection module is electrically connected to a second data port of the controller.

[0008] Furthermore, it also includes a conduction buffer module; the first end of the conduction buffer module is electrically connected to the first end of the load switch SR1, and the second end of the conduction buffer module is electrically connected to the second end of the load switch SR1. The conduction buffer module is used to absorb the current surge generated when the load switch SR1 is turned on.

[0009] Furthermore, the detection module includes a capacitor C3, resistors R7, R8, R9, R10, R11, a transistor Q2, and a diode D1. One end of resistor R10 serves as the input terminal of the detection module. The other end of resistor R10 is electrically connected to one end of resistor R9. The other end of resistor R9, one end of resistor R11, and the cathode of diode D1 are all electrically connected to the base of transistor Q2. The collector of transistor Q2 and one end of resistor R8 are all electrically connected to one end of resistor R7. The other end of resistor R7 is connected to the power supply voltage. One end of capacitor C3, the emitter of transistor Q2, the anode of diode D1, and the other end of resistor R11 are all grounded. The other end of capacitor C3 is electrically connected to the other end of resistor R8. The other end of resistor R8 serves as the output terminal of the detection module.

[0010] Furthermore, the conduction buffer module includes resistor R5, resistor R6, and capacitor C2; one end of resistor R5 serves as the first end of the conduction buffer module, the other end of resistor R5 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of capacitor C2, and the other end of capacitor C2 serves as the second end of the conduction buffer module.

[0011] Furthermore, the load switch SR1 is a bidirectional thyristor, the first anode of the bidirectional thyristor is used as the first terminal of the load switch SR1, the second anode of the bidirectional thyristor is used as the second terminal of the load switch SR1, and the gate of the bidirectional thyristor is used as the control terminal of the load switch SR1.

[0012] Furthermore, the driving module includes resistors R1, R2, R3, and R4, capacitor C1, and transistor Q1. One end of resistor R3 serves as the input terminal of the driving module. The other end of resistor R3, one end of resistor R1, and one end of capacitor C1 are all electrically connected to the base of transistor Q1. The other end of resistor R1 and the emitter of transistor Q1 are both connected to the power supply voltage. The other end of capacitor C1 is grounded. One end of resistor R2 and one end of resistor R4 are both electrically connected to the collector of transistor Q1. The other end of resistor R2 and the other end of resistor R4 are electrically connected. The other end of resistor R2 serves as the output terminal of the driving module.

[0013] The technical solution provided by this utility model can include the following beneficial effects: Based on the circuit connection relationship between the load switch SR1, the detection module, and the resistive load, the controller (such as an MCU) can determine whether the load switch SR1 (such as a thyristor, MOSFET, or other switch) or the resistive load is damaged by sending a drive signal to the drive module and receiving a feedback signal from the detection module; specifically, for example:

[0014] When the drive module turns on the load switch SR1 (i.e., the resistive load is working), the detection module and the resistive load will be connected in parallel, causing the detection module to always generate a high level (the signal is not limited, this is just an example). If the load switch SR1 is damaged, it can only be turned off, and the detection module and the resistive load will be forced into series connection, causing the signal generated by the detection module to change, such as generating a pulse signal. Thus, the controller can determine whether the load switch SR1 is damaged when driving the resistive load.

[0015] Similarly, when the drive module drives the load switch SR1 to open (i.e. the resistive load is not working), the detection module and the resistive load will be connected in series, causing the detection module to always generate a pulse signal; if the resistive load is damaged, the pulse signal cannot be generated, for example, it will be changed to continuously generate a high-level signal, so that the controller can determine whether the resistive load is damaged when the drive resistive load is not working. Attached Figure Description

[0016] Figure 1 This is a circuit diagram of a resistive load detection circuit according to one embodiment of the present invention.

[0017] The components include: load switch SR1, drive module 1, detection module 2, resistive load 3, conduction buffer module 4, capacitor C3, resistor R7, resistor R8, resistor R9, resistor R10, resistor R11, transistor Q2, diode D1, resistor R5, resistor R6, capacitor C2, resistor R1, resistor R2, resistor R3, resistor R4, capacitor C1, and transistor Q1. Detailed Implementation

[0018] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0019] In the description of embodiments of this utility model, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of embodiments of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0020] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0021] The following is combined Figure 1 This describes a resistive load detection circuit according to an embodiment of the present invention.

[0022] A resistive load detection circuit includes a load switch SR1, a drive module 1, and a detection module 2. The input terminal of the drive module 1 is electrically connected to the first data port of the controller, the output terminal of the drive module 2 is electrically connected to the control terminal of the load switch SR1, the first terminal of the load switch SR1 is connected to the live wire, the second terminal of the load switch SR1 and the input terminal of the detection module 2 are both electrically connected to one end of the resistive load 3, the other end of the resistive load 3 is connected to the neutral wire, and the output terminal of the detection module 2 is electrically connected to the second data port of the controller.

[0023] This utility model proposes a preferred embodiment of a resistive load detection circuit, such as... Figure 1 As shown, based on the circuit connection relationship between the load switch SR1, the detection module 2, and the resistive load 3, the controller (such as an MCU) can determine whether the load switch SR1 (such as a thyristor, MOSFET, or other switch) or the resistive load 3 is damaged by sending a drive signal to the drive module 1 and receiving a feedback signal from the detection module 2; specifically:

[0024] When the drive module 1 drives the load switch SR1 to conduct (i.e., the resistive load 3 is working), the detection module 2 and the resistive load 3 will be connected in parallel, causing the detection module 2 to always generate a high level (the signal is not limited, this is just an example); if the load switch SR1 is damaged, the load switch SR1 can only be disconnected, and the detection module 2 and the resistive load 3 will be forced in series, causing the signal generated by the detection module 2 to change, such as changing to generate a pulse signal; thus, the controller can determine whether the load switch SR1 is damaged when driving the resistive load 3 to work.

[0025] Similarly, when the drive module 1 drives the load switch SR1 to disconnect (i.e., the resistive load 3 does not work), the detection module 2 and the resistive load 3 will be connected in series, causing the detection module 2 to always generate a pulse signal; if the resistive load 3 is damaged, the pulse signal cannot be generated, for example, it will be changed to continuously generate a high-level signal, so that the controller can determine whether the resistive load 3 is damaged when the drive resistive load 3 is not working.

[0026] Furthermore, it also includes a conduction buffer module 4; the first end of the conduction buffer module 4 is electrically connected to the first end of the load switch SR1, and the second end of the conduction buffer module 4 is electrically connected to the second end of the load switch SR1. The conduction buffer module 4 is used to absorb the current surge generated when the load switch SR1 is turned on.

[0027] In this embodiment, a conduction buffer module 4 is added to the load switch SR1. This can extend the service life of the load switch SR1 and the resistive load 3, and also prevent current surges from disturbing the detection module 2, ensuring the stability of the feedback signal and improving the detection accuracy.

[0028] Furthermore, the detection module 2 includes a capacitor C3, resistors R7, R8, R9, R10, R11, a transistor Q2, and a diode D1. One end of resistor R10 is used as the input terminal of the detection module 2. The other end of resistor R10 is electrically connected to one end of resistor R9. The other end of resistor R9, one end of resistor R11, and the cathode of diode D1 are all electrically connected to the base of transistor Q2. The collector of transistor Q2 and one end of resistor R8 are all electrically connected to one end of resistor R7. The other end of resistor R7 is connected to the power supply voltage. One end of capacitor C3, the emitter of transistor Q2, the anode of diode D1, and the other end of resistor R11 are all grounded. The other end of capacitor C3 is electrically connected to the other end of resistor R8. The other end of resistor R8 is used as the output terminal of the detection module 2.

[0029] In this embodiment, the detection module 2 is preferably composed of capacitor C3, resistors R7, R8, R9, R10, R11, transistor Q2, and diode D1. It can generate high-level signals and pulse signals according to the connection relationship between the detection module 2 and the resistive load 3, and feed them back to the controller. The controller can determine whether the load switch SR1 and the resistive load 3 are damaged by combining the drive signals.

[0030] Specifically, when the drive module 1 drives the load switch SR1 to conduct, if the load switch SR1 is normal, the detection module 2 and the resistive load 3 are connected in parallel, and the current shunting is insufficient to drive the transistor Q2 to conduct. The controller receives the power supply voltage (i.e., VCC, high-level signal). If the load switch SR1 is damaged, the detection module 2 and the resistive load 3 are forced to be connected in series. The resistive load 3 is equivalent to a resistor, which, together with resistors R9, R10, and R11, forms a voltage divider circuit. After voltage division, the voltage and current of resistor R11 cause the transistor Q2 to conduct, and it conducts or cuts off according to the positive and negative half-wave cycle of the mains power, generating a pulse signal.

[0031] Similarly, when the drive module 1 drives the load switch SR1 to disconnect, if the resistive load 3 is normal, the detection module 2 and the resistive load 3 are connected in series to form a voltage divider circuit and generate a pulse signal; if the resistive load 3 is damaged, the equivalent resistance of the resistive load 3 is lost, and a voltage divider circuit cannot be formed, which is insufficient to turn on the transistor Q2, and the controller receives the power supply voltage (i.e., VCC, high level signal) at a constant level.

[0032] Furthermore, the conduction buffer module 4 includes resistors R5 and R6 and capacitor C2; one end of resistor R5 serves as the first end of the conduction buffer module 4, the other end of resistor R5 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of capacitor C2, and the other end of capacitor C2 serves as the second end of the conduction buffer module 4.

[0033] In this embodiment, the RC buffer network serves as the conduction buffer module 4. It has a simple structure and effectively absorbs the conduction current surge through the charging of capacitor C2.

[0034] Furthermore, the load switch SR1 is a bidirectional thyristor. The first anode of the bidirectional thyristor is used as the first terminal of the load switch SR1, the second anode of the bidirectional thyristor is used as the second terminal of the load switch SR1, and the gate of the bidirectional thyristor is used as the control terminal of the load switch SR1.

[0035] In this embodiment, the load switch SR1 is preferably a bidirectional thyristor, which has a gate control terminal and a bidirectional channel composed of two diodes, which can provide a stable power supply channel from the live wire (AC-Lin) to the resistive load 3 (AC-Lout).

[0036] Furthermore, the drive module 1 includes resistors R1, R2, R3, and R4, capacitor C1, and transistor Q1. One end of resistor R3 is used as the input terminal of drive module 1. The other end of resistor R3, one end of resistor R1, and one end of capacitor C1 are all electrically connected to the base of transistor Q1. The other end of resistor R1 and the emitter of transistor Q1 are both connected to the power supply voltage. The other end of capacitor C1 is grounded. One end of resistor R2 and one end of resistor R4 are both electrically connected to the collector of transistor Q1. The other end of resistor R2 and the other end of resistor R4 are electrically connected. The other end of resistor R2 is used as the output terminal of drive module 1.

[0037] In this embodiment, the drive module 1 drives the load switch SR1 through the transistor Q1, and combines low-pass filtering (R3 / C1) to eliminate drive signal noise from the controller and improve anti-interference capability; then, the drive reliability is enhanced by parallel current limiting resistors (R2 / R4), while ensuring that the impact on the controller is reduced when the load switch SR1 or resistive load is damaged.

[0038] Other configurations and operations of the resistive load detection circuit according to the embodiments of this utility model are known to those skilled in the art and will not be described in detail here.

[0039] In this specification, the terms "embodiment," "example," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A resistive load detection circuit, characterized in that: It includes a load switch SR1, a drive module, and a detection module; the input terminal of the drive module is electrically connected to the first data port of the controller, the output terminal of the drive module is electrically connected to the control terminal of the load switch SR1, the first terminal of the load switch SR1 is connected to the live wire, the second terminal of the load switch SR1 and the input terminal of the detection module are both electrically connected to one end of a resistive load, the other end of the resistive load is connected to the neutral wire, and the output terminal of the detection module is electrically connected to the second data port of the controller.

2. The resistive load detection circuit according to claim 1, characterized in that: It also includes a conduction buffer module; the first end of the conduction buffer module is electrically connected to the first end of the load switch SR1, and the second end of the conduction buffer module is electrically connected to the second end of the load switch SR1. The conduction buffer module is used to absorb the current surge generated when the load switch SR1 is turned on.

3. The resistive load detection circuit according to claim 1, characterized in that: The detection module includes a capacitor C3, resistors R7, R8, R9, R10, R11, a transistor Q2, and a diode D1. One end of resistor R10 serves as the input terminal of the detection module. The other end of resistor R10 is electrically connected to one end of resistor R9. The other end of resistor R9, one end of resistor R11, and the cathode of diode D1 are all electrically connected to the base of transistor Q2. The collector of transistor Q2 and one end of resistor R8 are all electrically connected to one end of resistor R7. The other end of resistor R7 is connected to the power supply voltage. One end of capacitor C3, the emitter of transistor Q2, the anode of diode D1, and the other end of resistor R11 are all grounded. The other end of capacitor C3 is electrically connected to the other end of resistor R8. The other end of resistor R8 serves as the output terminal of the detection module.

4. The resistive load detection circuit according to claim 2, characterized in that: The conduction buffer module includes resistor R5, resistor R6, and capacitor C2; one end of resistor R5 serves as the first end of the conduction buffer module, the other end of resistor R5 is electrically connected to one end of resistor R6, the other end of resistor R6 is electrically connected to one end of capacitor C2, and the other end of capacitor C2 serves as the second end of the conduction buffer module.

5. The resistive load detection circuit according to claim 1, characterized in that: The load switch SR1 is a bidirectional thyristor. The first anode of the bidirectional thyristor is used as the first terminal of the load switch SR1, the second anode of the bidirectional thyristor is used as the second terminal of the load switch SR1, and the gate of the bidirectional thyristor is used as the control terminal of the load switch SR1.

6. The resistive load detection circuit according to claim 1, characterized in that: The driving module includes resistors R1, R2, R3, and R4, capacitor C1, and transistor Q1. One end of resistor R3 serves as the input terminal of the driving module. The other end of resistor R3, one end of resistor R1, and one end of capacitor C1 are all electrically connected to the base of transistor Q1. The other end of resistor R1 and the emitter of transistor Q1 are both connected to the power supply voltage. The other end of capacitor C1 is grounded. One end of resistor R2 and one end of resistor R4 are both electrically connected to the collector of transistor Q1. The other end of resistor R2 and the other end of resistor R4 are electrically connected. The other end of resistor R2 serves as the output terminal of the driving module.

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