Motor overcurrent protection circuit

Abstract

A motor overcurrent protection circuit relates to the field of pan-tilt control, and when a pan-tilt motor is overloaded or stalled, the current flowing through a resistor I in the circuit is increased, the voltage drop on the resistor I is increased accordingly, the voltage at the positive input end of a voltage comparator is greater than the voltage at the negative input end of the voltage comparator, the voltage comparator outputs a high level, and a triode is conducted to conduct a PMOS tube. The alarm unit sends out alarm information to remind workers of timely processing. And if the field staff does not arrive, the voltage output by the output end of the voltage comparator triggers the control electrode of the thyristor, the thyristor is conducted, the power supply circuit of the pan-tilt motor is cut off, and the pan-tilt motor stops rotating. The internal circuit of the pan-tilt motor is effectively prevented from being burnt, and the service life of the pan-tilt is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of gimbal control, specifically to a motor overcurrent protection circuit. Background Technology

[0002] Every motor has a fixed operating power, called its rated power, and the motors used in gimbals are no exception. If the motor inside the gimbal operates for an extended period with actual power exceeding its rated power, the motor will require a higher current than it would normally operate. Prolonged operation under high current will cause the motor temperature to rise, potentially burning out the internal circuitry and even causing a fire, resulting in economic losses. If the motor stalls, the current will also increase, and if it operates in this stalled state for an extended period, the temperature will rise. These temperature increases may not be immediately noticeable, and the abnormal motor operation may not be apparent until some time has passed, especially when the gimbal is operating at night. Therefore, a circuit device for detecting motor current is needed. Summary of the Invention

[0003] In order to overcome the shortcomings of the above-mentioned technologies, this utility model provides a circuit that stops the motor from rotating when the motor is stalled or the load is too large.

[0004] The technical solution adopted by this utility model to overcome its technical problem is:

[0005] A motor overcurrent protection circuit includes:

[0006] The thyristor's anode is connected to one end of the gimbal motor and then connected to the power supply VCC via a switch, while its cathode is grounded.

[0007] The voltage comparator has its negative input terminal connected to the power supply VCC via resistor III and grounded via resistor IV. Its VCC terminal is connected to the power supply VCC, and its ground terminal is grounded. Its positive input terminal is connected to the other end of the gimbal motor and grounded via resistor I.

[0008] The base of the transistor is connected to the output of the voltage comparator and the control terminal of the thyristor, and its emitter is grounded.

[0009] The gate of the PMOS transistor is connected to the collector of the transistor and the power supply VCC, and its source is connected to the power supply VCC.

[0010] The alarm unit is connected to the drain of the PMOS transistor.

[0011] Furthermore, it also includes a fuse. The anode of the thyristor is connected to one end of the gimbal motor, and then connected in sequence to the fuse, switch, and power supply VCC.

[0012] Furthermore, it also includes resistor II and capacitor. The positive input terminal of the voltage comparator is connected to one end of resistor II and one end of capacitor, respectively. The other end of capacitor is grounded, and the other end of resistor II is connected to the other end of gimbal motor and grounded through resistor I.

[0013] Preferably, the transistor is an NPN transistor.

[0014] Furthermore, the base of the transistor is connected to the output of the voltage comparator via resistor VI.

[0015] Furthermore, it also includes resistor V, one end of which is connected to the power supply VCC, and the other end of which is connected to the output of the voltage comparator.

[0016] Furthermore, it also includes resistor VII, one end of which is connected to the gate of the PMOS transistor, and the other end of which is connected to the source of the PMOS transistor.

[0017] Furthermore, the alarm unit includes an LED light and a buzzer. The positive terminal of the LED light is connected to the drain of the PMOS transistor, and its negative terminal is connected to one end of the buzzer. The other end of the buzzer is grounded.

[0018] Furthermore, it also includes diodes, with the negative terminals of the diodes connected to one end of the buzzer and the negative terminal of the LED, and the positive terminals connected to the other end of the buzzer.

[0019] The beneficial effects of this invention are as follows: When the gimbal motor experiences overload or stall, the current flowing through resistor I in the circuit increases, and the voltage drop across resistor I increases accordingly. The voltage at the positive input terminal of the voltage comparator is greater than the voltage at its negative input terminal, causing the voltage comparator to output a high level. This turns on the transistor, which in turn turns on the PMOS transistor, triggering an alarm to alert personnel to handle the situation promptly. If on-site personnel do not arrive, the voltage output from the voltage comparator triggers the control electrode of the thyristor, turning it on and cutting off the power supply to the gimbal motor, thus stopping the motor's rotation. This effectively prevents the internal circuitry of the gimbal motor from burning out, extending the gimbal's lifespan. Attached Figure Description

[0020] Figure 1 This is the circuit diagram of this utility model;

[0021] In the diagram, 1. Gimbal motor 2. Fuse 3. Switch 4. Thyristor 5. Resistor I 6. Resistor II 7. Capacitor 8. Voltage comparator 9. Resistor III 10. Resistor IV 11. Resistor V 12. Resistor VI 13. Transistor 14. Resistor VII 15. PMOS transistor 16. LED light 17. Diode 18. Buzzer. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1The present invention will be further described below.

[0023] A motor overcurrent protection circuit includes: a thyristor 4, whose anode is connected to one end of a gimbal motor 1 and then connected to power supply VCC via switch 3, and whose cathode is grounded; a voltage comparator 8, whose negative input terminal is connected to power supply VCC via resistor III 9 and grounded via resistor IV 10, whose VCC terminal is connected to power supply VCC, whose ground terminal is grounded, and whose positive input terminal is connected to the other end of the gimbal motor 1 and grounded via resistor I 5; a transistor 13, whose base is connected to the output terminal of voltage comparator 8 and the control terminal of thyristor 4, and whose emitter is grounded; and a PMOS transistor 15, whose gate is connected to the collector of transistor 13 and power supply VCC, and whose source is connected to power supply VCC;

[0024] The alarm unit is connected to the drain of PMOS transistor 15. Switch 3 is the master switch. Although the circuit can automatically stop the gimbal motor 1 when it is overloaded or stalled, for personal safety reasons and to prevent other accidents, switch 3 must be manually turned off. After the fault is cleared, switch 3 can be manually turned back on to allow the gimbal motor 1 to operate normally, further improving reliability. When the gimbal motor 1 is operating normally, the voltage at the positive input terminal of voltage comparator 8 is less than its negative input terminal voltage, so voltage comparator 8 outputs a low level, and both transistor 13 and PMOS transistor 15 are cut off. When the gimbal motor 1 is overloaded or stalled, the current flowing through resistor I 5 increases, and the voltage drop across resistor I 5 increases accordingly. The voltage at the positive input terminal of voltage comparator 8 is greater than its negative input terminal voltage, so voltage comparator 8 outputs a high level, transistor 13 conducts, causing PMOS transistor 15 to conduct, and the alarm unit issues an alarm message to remind personnel to handle the situation promptly. If on-site personnel do not arrive in time, the load on gimbal motor 1 will increase, or the stalled filling head will become more severe. The current flowing through resistor I5 in the circuit will surge, causing a corresponding surge in the voltage at the positive input terminal of voltage comparator 8. The voltage output from voltage comparator 8 will trigger the control electrode of thyristor 4, turning it on and cutting off the power supply to gimbal motor 1, thus stopping its rotation. This effectively prevents the internal circuitry of the gimbal motor from burning out, extending the lifespan of the gimbal.

[0025] In one embodiment of this utility model, a fuse 2 is also included. The anode of the thyristor 4 is connected to one end of the gimbal motor 1, and then connected in sequence to the fuse 2, the switch 3, and the power supply VCC. The fuse 2 serves a protective function. When the switch 3 is closed, if the current in the circuit is unstable or a short circuit occurs, the fuse 2 will open, protecting the subsequent circuit.

[0026] In one embodiment of this utility model, a resistor II 6 and a capacitor 7 are also included. The positive input terminal of the voltage comparator 8 is connected to one end of the resistor II 6 and one end of the capacitor 7, respectively. The other end of the capacitor 7 is grounded, and the other end of the resistor II 6 is connected to the other end of the gimbal motor 1 and grounded through a resistor I 5. The resistor II 6 and the capacitor 7 form an RC filter circuit to prevent interference signals from entering the voltage comparator 8 and causing subsequent circuit malfunctions.

[0027] In one embodiment of this utility model, the transistor 13 is an NPN transistor.

[0028] In one embodiment of this invention, the base of transistor 13 is connected to the output of voltage comparator 8 via resistor VI 12. Resistor VI 12 provides a suitable current to the base of transistor 13, enabling transistor 13 to conduct and turn off normally, thereby reducing the power consumption of transistor 13.

[0029] In one embodiment of this invention, a resistor V 11 is further included, one end of which is connected to the power supply VCC, and the other end is connected to the output terminal of the voltage comparator 8. Resistor V 11 is a pull-up resistor, its main function being to ensure that the voltage comparator 8 outputs a high level, improving its driving capability, enhancing anti-interference capability, and reducing chattering. Furthermore, a resistor VII 14 is also included, one end of which is connected to the gate of the PMOS transistor 15, and the other end is connected to the source of the PMOS transistor 15. Resistor VII 14 and resistor V 11 form a voltage divider circuit to adjust the gate voltage of the PMOS transistor 15, controlling its on or off state.

[0030] In one embodiment of this utility model, the alarm unit includes an LED light 16 and a buzzer 18. The positive terminal of the LED light 16 is connected to the drain of the PMOS transistor 15, and its negative terminal is connected to one end of the buzzer 18. The other end of the buzzer 18 is grounded. When the PMOS transistor 15 is turned on, the LED light 16 lights up and the buzzer 18 sounds an alarm, promptly reminding staff to troubleshoot the fault.

[0031] In one embodiment of this utility model, a diode 17 is further included. The negative terminal of the diode 17 is connected to one end of the buzzer 18 and the negative terminal of the LED 16, respectively, and its positive terminal is connected to the other end of the buzzer 18. The diode 17 provides a discharge path for the current of the buzzer 18 when the PMOS transistor 15 switches from on to off, and clamps its voltage at a stable voltage.

[0032] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A motor overcurrent protection circuit, characterized in that, include: The thyristor (4) has its anode connected to one end of the gimbal motor (1) and then connected to the power supply VCC via the switch (3), and its cathode is grounded. The voltage comparator (8) has its negative input terminal connected to the power supply VCC via resistor III (9) and grounded via resistor IV (10). Its VCC terminal is connected to the power supply VCC, and its ground terminal is grounded. Its positive input terminal is connected to the other end of the gimbal motor (1) and grounded via resistor I (5). The base of the transistor (13) is connected to the output of the voltage comparator (8) and the control terminal of the thyristor (4), and its emitter is grounded. The gate of the PMOS transistor (15) is connected to the collector of the transistor (13) and the power supply VCC, respectively, and its source is connected to the power supply VCC. An alarm unit is connected to the drain of a PMOS transistor (15).

2. The motor overcurrent protection circuit according to claim 1, characterized in that: It also includes a fuse (2), and the anode of the thyristor (4) is connected to one end of the gimbal motor (1) and then connected to the fuse (2), switch (3) and power supply VCC in sequence.

3. The motor overcurrent protection circuit according to claim 1, characterized in that: It also includes resistor II (6) and capacitor (7). The positive input terminal of voltage comparator (8) is connected to one end of resistor II (6) and one end of capacitor (7), respectively. The other end of capacitor (7) is grounded, and the other end of resistor II (6) is connected to the other end of gimbal motor (1) and grounded through resistor I (5).

4. The motor overcurrent protection circuit according to claim 1, characterized in that: The transistor (13) is an NPN transistor.

5. The motor overcurrent protection circuit according to claim 1, characterized in that: The base of transistor (13) is connected to the output of voltage comparator (8) via resistor VI (12).

6. The motor overcurrent protection circuit according to claim 1, characterized in that: It also includes resistor V (11), one end of which is connected to power supply VCC and the other end of which is connected to the output of voltage comparator (8).

7. The motor overcurrent protection circuit according to claim 6, characterized in that: It also includes resistor VII (14), one end of which is connected to the gate of PMOS transistor (15), and the other end of which is connected to the source of PMOS transistor (15).

8. The motor overcurrent protection circuit according to claim 1, characterized in that: The alarm unit includes an LED light (16) and a buzzer (18). The positive terminal of the LED light (16) is connected to the drain of the PMOS transistor (15), and its negative terminal is connected to one end of the buzzer (18). The other end of the buzzer (18) is grounded.

9. The motor overcurrent protection circuit according to claim 8, characterized in that: It also includes a diode (17), the negative terminal of which is connected to one end of the buzzer (18) and the negative terminal of the LED (16), and its positive terminal is connected to the other end of the buzzer (18).

Images