Motor protection control circuit and electronic lock

Abstract

This invention provides a motor protection control circuit and an electronic lock, including a protection circuit, a power control circuit, and a motor drive circuit. The input terminal of the protection circuit is connected to the motor drive voltage, and the output terminal of the protection circuit is connected to the power supply terminal of the motor drive circuit through the power control circuit. The two enable terminals of the power control circuit are connected one-to-one with the two control ports of the motor drive circuit. Therefore, by adding the protection circuit and the power control circuit, the entire circuit is protected, ensuring that the entire circuit remains unaffected when the motor drive circuit malfunctions.

Description

Technical Field

[0001] This utility model relates to the field of motor drive technology, specifically to a motor protection control circuit and an electronic lock. Background Technology

[0002] Modern electronic locks rely on motors to open and close. These internal motors are controlled by motor driver chips that regulate their forward and reverse rotation. Motor driver chips typically integrate short-circuit and overcurrent protection. However, this protection only applies when the motor driver chip is operating normally. When the chip fails, it often causes the entire circuit to malfunction, thus requiring a dedicated circuit to protect the entire system. Utility Model Content

[0003] To solve one of the aforementioned technical problems, this utility model proposes the following technical solution.

[0004] The first aspect of this utility model provides a motor protection control circuit, including a protection circuit, a power control circuit, and a motor drive circuit. The input terminal of the protection circuit is connected to the motor drive voltage, and the output terminal of the protection circuit is connected to the power supply terminal of the motor drive circuit through the power control circuit. The two enable terminals of the power control circuit are connected one-to-one with the two control ports of the motor drive circuit.

[0005] In addition, the motor protection control circuit according to the above embodiments of the present invention may also have the following additional technical features.

[0006] In some examples, the protection circuit includes a first resistor, a first transistor, a second resistor, and a third resistor. One end of the first resistor is connected to the first terminal of the first transistor and serves as the input terminal of the protection circuit. The other end of the first resistor is connected to the second terminal of the first transistor and serves as the output terminal of the protection circuit. The third terminal of the first transistor is connected to one end of the second resistor. The other end of the second resistor is connected to one end of the third resistor and then connected to a detection port. The other end of the third resistor is grounded.

[0007] In some examples, the power control circuit includes a fourth resistor, a transistor, a fifth resistor, a second transistor, a sixth resistor, a seventh resistor, a first diode, and a second diode.

[0008] One end of the fourth resistor is connected to the first terminal of the transistor and then to the output terminal of the protection circuit. The other end of the fourth resistor, the second terminal of the transistor, and one end of the fifth resistor are connected. The third terminal of the transistor is connected to the power supply terminal of the motor drive circuit. The other end of the fifth resistor is connected to the first terminal of the second transistor. The second terminal of the second transistor is grounded. The third terminal of the second transistor is connected to one end of the sixth resistor and one end of the seventh resistor. The other end of the sixth resistor is connected to the negative terminals of the first diode and the second diode. The other end of the seventh resistor is grounded. The positive terminal of the first diode serves as the first enable terminal of the power control circuit and is connected to the first control port of the motor drive circuit. The positive terminal of the second diode serves as the second enable terminal of the power control circuit and is connected to the second control port of the motor drive circuit.

[0009] In some examples, the motor drive circuit includes a motor drive chip, the power supply pin of the motor drive chip serves as the power supply terminal of the motor drive circuit, the first control pin of the motor drive chip is connected to the first control port through an eighth resistor, and the second control pin of the motor drive chip is connected to the second control port through a ninth resistor.

[0010] In some examples, the first transistor is a PNP transistor.

[0011] In some examples, the transistor is a MOS transistor, and the second transistor is an NPN transistor.

[0012] The second aspect of this utility model provides an electronic lock, which includes the motor protection control circuit proposed in the first aspect of this utility model.

[0013] The technical solution of this utility model embodiment protects the entire circuit by adding a protection circuit and a power control circuit. When the motor drive circuit is abnormal, the entire circuit can be protected from being affected. Attached Figure Description

[0014] Figure 1 This is a structural block diagram of a motor protection control circuit according to an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of the structure of a motor protection control circuit according to an embodiment of the present invention.

[0016] Reference numerals: 1. Protection circuit; 2. Power control circuit; 3. Motor drive circuit. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Figure 1 This is a structural block diagram of a motor protection control circuit according to an embodiment of the present invention.

[0019] like Figure 1 As shown, the motor protection control circuit includes a protection circuit 1, a power control circuit 2, and a motor drive circuit 3. The input terminal of the protection circuit 1 is connected to the motor drive voltage VDD (5V / 12V), and the output terminal of the protection circuit 1 is connected to the power supply terminal of the motor drive circuit 3 through the power control circuit 2. The two enable terminals of the power control circuit 2 are connected one-to-one with the two control ports of the motor drive circuit 3.

[0020] Specifically, the two control ports are the control ports of the motor drive circuit 3 and also the control ports of the power control circuit 2. Through the two control ports of the motor drive circuit 3, the power control circuit 2 can be turned on (conducted), so that the motor drive voltage VDD supplies power to the motor drive circuit 3 through the power control circuit 2. At the same time, the forward and reverse rotation of the motor can be controlled through these control ports.

[0021] The motor drive circuit 3 includes a motor drive chip. When the motor drive circuit malfunctions, such as when the motor drive chip is damaged, the protection circuit 1 activates and disconnects the power supply to the motor drive circuit 3, thereby achieving the purpose of protecting the circuit.

[0022] Therefore, the motor protection control circuit of this utility model embodiment, by adding a protection circuit and a power control circuit, achieves protection for the entire circuit. When the motor drive circuit is abnormal, it can protect the entire circuit from being affected.

[0023] In one example, refer to Figure 2 The protection circuit 1 includes a first resistor R1, a first transistor Q2, a second resistor R5, and a third resistor R8. One end of the first resistor R1 is connected to the first terminal of the first transistor Q2 and serves as the input terminal of the protection circuit 1. The other end of the first resistor R1 is connected to the second terminal of the first transistor Q2 and serves as the output terminal of the protection circuit 1. The third terminal of the first transistor Q2 is connected to one end of the second resistor R5. The other end of the second resistor R5 is connected to one end of the third resistor R8 and then connected to the detection port IN-ZDSBH. The other end of the third resistor R8 is grounded to GND.

[0024] Among them, the first transistor Q2 is a PNP type transistor, with its first electrode being the emitter, the second electrode being the base, and the third electrode being the collector.

[0025] In one example, refer to Figure 2 The power control circuit 2 includes a fourth resistor R3, a transistor Q1, a fifth resistor R4, a second transistor Q3, a sixth resistor R9, a seventh resistor R10, a first diode D1, and a second diode D2.

[0026] One end of the fourth resistor R3 is connected to the first terminal of transistor Q1 and then to the output terminal of protection circuit 1. The other end of the fourth resistor R3, the second terminal of transistor Q1, and one end of the fifth resistor R4 are connected. The third terminal of transistor Q1 is connected to the power supply terminal of motor drive circuit 3. The other end of the fifth resistor R4 is connected to the first terminal of the second transistor Q3. The second terminal of the second transistor Q3 is grounded to GND. The third terminal of the second transistor Q3 is connected to one end of the sixth resistor R9 and one end of the seventh resistor R10. The other end of the sixth resistor R9 is connected to the negative terminal of the first diode D1 and the negative terminal of the second diode D2. The other end of the seventh resistor R10 is grounded to GND. The positive terminal of the first diode D1 is connected to the first control port OUT-MD- of motor drive circuit 3 as the first enable terminal of power control circuit 2. The positive terminal of the second diode D2 is connected to the second control port OUT-MD+ of motor drive circuit 3 as the second enable terminal of power control circuit 2.

[0027] In this transistor, Q2 is a MOSFET, with its first terminal being the source (S), its second terminal being the gate (G), and its third terminal being the drain (D). The second transistor is an NPN transistor, with its first terminal being the collector, its second terminal being the emitter, and its third terminal being the base.

[0028] Furthermore, referring to Figure 2 The motor drive circuit 3 includes a motor drive chip U1. The power supply pin VCC of the motor drive chip U1 serves as the power supply terminal of the motor drive circuit 3. The first control pin IN2 of the motor drive chip U1 is connected to the first control port OUT-MD- through the eighth resistor R6. The second control pin IN1 of the motor drive chip U1 is connected to the second control port OUT-MD+ through the ninth resistor R7.

[0029] Figure 2 The model of the motor driver chip U1 is SS8837T, which is a common driver chip in this industry.

[0030] Specifically, the working principle is as follows: when Q3 is turned on, the gate and source voltage of Q1 is Vgs, Vgs=(R3 / (R4+R4))*(VDD-Vnpn), where Vnpn is the voltage drop after Q3 is turned on.

[0031] When the second control port OUT-MD+ outputs a high level, the voltage will be split into two paths:

[0032] The first path goes through diode D2 to resistor R9. R9 and R10 divide the voltage, and the voltage across R10 is greater than the turn-on voltage Vbe of transistor Q3, thus turning on Q3. After Q3 turns on, R3 and R4 divide the voltage, and the voltage across R3 is greater than the turn-on voltage Vgs of MOSFET Q1, turning on Q1. The voltage VDD then powers the motor driver chip through Q1.

[0033] The second path goes through resistor R7 to pin 6 of the motor driver chip, controlling pin 2 of the motor driver chip to output VDD voltage, driving the motor to rotate forward.

[0034] When the first control port OUT-MD- outputs a high level, the voltage splits into two paths: the first path goes through the first diode D1 to resistor R9. R9 and R10 divide the voltage, and the voltage across R10 is greater than the turn-on voltage Vbe of transistor Q3, thus turning on Q3. After Q3 turns on, R3 and R4 divide the voltage, and the voltage across R3 is greater than the turn-on voltage Vgs of MOSFET Q1, turning on Q1. The voltage VDD then supplies power to the motor driver chip through transistor Q1.

[0035] The second path goes through resistor R6 to pin 5 of the motor driver chip, controlling pin 3 of the motor driver chip to output VDD voltage, driving the motor to reverse.

[0036] Working principle of power control circuit 2:

[0037] The power control circuit 2 and the motor drive chip U1 are controlled by two control ports, OUT-MD+ and OUT-MD-, thus saving one control port. OUT-MD+ powers on the power control circuit 2 via diode D2. OUT-MD- powers on the power control circuit 2 via diode D1. Diodes have unidirectional conductivity; therefore, diodes D1 and D2 prevent OUT-MD+ and OUT-MD- from being energized simultaneously. When control ports OUT-MD+ and OUT-MD- do not output voltage, the power control circuit 2 is disconnected, and the motor drive chip U1 is de-energized.

[0038] The principle of protection circuit 1:

[0039] When the motor driver chip U1 is short-circuited, the short-circuit current Is causes a voltage drop Vr1 across R1. Since Vr1 exceeds the Veb turn-on voltage of transistor Q2, Q2 conducts. At this time, protection circuit 1 activates. IN-ZDSBH detects the abnormal operation and disconnects the output of control port OUT-MD+ or OUT-MD-, thereby disconnecting power control circuit 2 and de-energizing the motor driver chip U1. This achieves overcurrent and short-circuit protection.

[0040] In summary, the motor protection control circuit of this utility model embodiment adds a protection circuit and a power control circuit. The added circuit can disconnect the power to the motor drive circuit when it malfunctions, preventing the motor drive circuit from being in an abnormal state for an extended period and thus damaging it. Simultaneously, when the motor drive chip is damaged, this circuit can isolate the motor drive chip from the entire circuit system, thus preventing impact on other circuits. It reliably protects the circuit from damage during external short circuits, is low in cost, and has good performance.

[0041] This utility model also proposes an electronic lock, including the above-mentioned motor protection control circuit.

[0042] The electronic lock of this utility model embodiment protects the entire circuit by adding a protection circuit and a power control circuit. When the motor drive circuit is abnormal, the entire circuit can be protected from being affected.

[0043] In the description 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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. "A plurality of" means two or more, unless otherwise explicitly specified.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," 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. Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor protection control circuit, characterized by, It includes a protection circuit, a power control circuit, and a motor drive circuit. The input terminal of the protection circuit is connected to the motor drive voltage, and the output terminal of the protection circuit is connected to the power supply terminal of the motor drive circuit through the power control circuit. The two enable terminals of the power control circuit are connected one-to-one with the two control ports of the motor drive circuit. The protection circuit includes a first resistor, a first transistor, a second resistor, and a third resistor. One end of the first resistor is connected to the first terminal of the first transistor, serving as the input terminal of the protection circuit. The other end of the first resistor is connected to the second terminal of the first transistor, serving as the output terminal of the protection circuit. The third terminal of the first transistor is connected to one end of the second resistor. The other end of the second resistor is connected to one end of the third resistor, which is then connected to a detection port. The other end of the third resistor is grounded. The power control circuit includes a fourth resistor, a transistor, a fifth resistor, a second transistor, a sixth resistor, a seventh resistor, a first diode, and a second diode. One end of the fourth resistor is connected to the first terminal of the transistor and then to the output terminal of the protection circuit. The other end of the fourth resistor, the second terminal of the transistor, and one end of the fifth resistor are connected. The third terminal of the transistor is connected to the power supply terminal of the motor drive circuit. The other end of the fifth resistor is connected to the first terminal of the second transistor. The second terminal of the second transistor is grounded. The third terminal of the second transistor is connected to one end of the sixth resistor and one end of the seventh resistor. The other end of the sixth resistor is connected to the cathode of the first diode and the cathode of the second diode. The other end of the seventh resistor is grounded. The anode of the first diode serves as the first enable terminal of the power control circuit and is connected to the first control port of the motor drive circuit. The anode of the second diode serves as the second enable terminal of the power control circuit and is connected to the second control port of the motor drive circuit. The motor drive circuit includes a motor drive chip. The power supply pin of the motor drive chip serves as the power supply terminal of the motor drive circuit. The first control pin of the motor drive chip is connected to the first control port through an eighth resistor, and the second control pin of the motor drive chip is connected to the second control port through a ninth resistor. The first transistor is a PNP type transistor. The transistor is a MOS transistor, and the second transistor is an NPN transistor.

2. An electronic lock characterized by Includes the motor protection control circuit as described in claim 1.

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