Motor braking circuit

Abstract

The utility model discloses a motor braking circuit which comprises a motor, the motor is driven to work by mains supply through a driving power supply, and a capacitor is arranged in the driving power supply. The driving power supply is connected with a mains supply outage detection circuit, the mains supply outage detection circuit sends a mains supply outage signal to the driving power supply when the mains supply is in outage, and the driving power supply drives the motor to rotate reversely after receiving the mains supply outage signal. The utility model has the advantages of simple structure, low cost and timely braking during power failure.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor control field especially relates to a simple structure, low in cost motor brake circuit that can brake in time when power failure. BACKGROUND

[0002] Now life and production cannot leave power motor, power motor generally by driving power supply, the switch power supply in driving power supply by the power input electricity, the switch power supply will control the output direct current, the motor in the controller can control the motor positive rotation and reverse, when the motor load is big, inertia is also big, if the motor rotates in the process of power failure, because the electric quantity of switch power supply internal capacitor storage is not finished, the controller still has power supply, the motor can continue to rotate, until the switch power supply internal capacitor storage electricity is finished, the controller can have power failure, the motor will stop rotating. SUMMARY

[0003] The utility model provides a simple structure, low in cost motor brake circuit that can brake in time when power failure.

[0004] The utility model discloses a motor brake circuit, including motor, the motor is driven by driving power supply by the power and drives motor work, be provided with the capacitor in the driving power supply, be connected with the power failure detection circuit in the driving power supply, and the power failure detection circuit sends the power failure signal to the driving power supply when the power failure, and the driving power supply receives the power failure signal and drives motor reverse.

[0005] As a preferred mode, the driving power supply includes the switch power supply and controller connected with the power, and the power failure detection circuit is connected on the power and sends the detection signal to the controller.

[0006] As a preferred mode, the power failure detection circuit includes the rectifier circuit connected on the power, and the output end of the rectifier circuit is connected with a signal output module, and the signal output module sends the detection signal to the controller.

[0007] As a preferred mode, the input end of the motor is connected with two groups of lines in parallel, wherein the first group of lines is powered by the motor drive circuit in the controller, and the second group of lines of the motor is short-circuited through a normally closed switch, and the normally closed switch is connected with the power line.

[0008] As a preferred mode, the motor is a common permanent magnet motor or a three-phase permanent magnet synchronous motor.

[0009] As a preferred mode, the normally closed switch is a normally closed electromagnetic switch.

[0010] The utility model discloses a power-off detection circuit is added in the drive power supply, when the commercial power is powered off, the electric quantity that utilizes the drive power supply inside capacitor stores is exported power-off signal through the commercial power-off detection circuit, when the drive power supply receives the power-off signal, the drive power supply drive motor reverses, and the motor reverse will consume the electric quantity of big, and the electric quantity of drive power supply inside capacitor is discharged in very short time, and the motor stops rotating. The utility model discloses can make the motor stop rotating in time after the commercial power is powered off in the motor rotating process, and can effectively prevent the accident caused by the continuous rotation of motor. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is structure principle diagram for the utility model embodiment;

[0012] Figure 2 It is circuit principle diagram for the utility model embodiment commercial power-off detection circuit. DETAILED DESCRIPTION

[0013] Reference Figures 1 to 2 As shown in FIG. 1, a motor braking circuit is shown, which comprises a motor 100, the motor 100 is driven by the commercial power through the drive power supply to work, and a capacitor is arranged in the drive power supply. The drive power supply comprises a switching power supply 400 connected to the commercial power and a controller 300 for controlling the operation of the motor 100. In this embodiment, a commercial power-off detection circuit 401 is arranged in the switching power supply 400. When the commercial power is powered off, the commercial power-off detection circuit 401 sends a commercial power-off signal to the MCU in the controller 300 of the drive power supply. After the controller 300 receives the commercial power-off signal, the motor driving circuit 301 in the controller 300 drives the motor 100 to reverse.

[0014] Reference Figure 1 In order to prevent the motor 100 from continuously rotating and causing accidents after the commercial power is powered off during the rotation of the motor 100, the circuit of this embodiment provides a low-cost solution: a commercial power-off detection circuit 401 is added in the switching power supply 400 of the drive power supply. When the commercial power is powered off, the electric quantity stored in the capacitor inside the switching power supply 401 is used to output a power-off signal. The cost of this circuit is less than 2 yuan. The commercial power-off detection circuit 401 in this embodiment is shown in FIG. 2. Figure 2 Reference Figure 1During the rotation of the motor 100, the power supply is cut off, and the switch power supply disconnects the signal output circuit 401 to output a signal to the right controller 300 within 0.5 seconds, and the motor drive circuit 301 in the controller 300 drives the motor 100 to reverse after receiving the power-off signal, and the motor 100 consumes a large amount of power during the reverse rotation, and the power in the internal capacitor of the switch power supply 400 is discharged within a very short time, the controller 300 is powered off, and the motor 100 is stopped. After the power supply is suddenly cut off during the rotation of the motor, the motor 100 can be stopped within 1 second, which can effectively prevent accidents caused by the continuous rotation of the motor 100.

[0015] The circuit of the utility model, refer to Figure 2 On the basis of the foregoing technical solutions, specifically, the power-off detection circuit 401 comprises a rectifier circuit connected to the power supply, and the output end of the rectifier circuit is connected with a signal output module, and the signal output module sends a detection signal to the MCU in the controller 300.

[0016] The circuit of the utility model, refer to Figure 1 On the basis of the foregoing technical solutions, specifically, the input end of the motor 100 is connected with two groups of lines, wherein the first group of lines is powered by the motor drive circuit 301 in the controller 300, and the second group of lines of the motor 100 is short-circuited through normally closed switches K1 and K2, and the normally closed switches are connected with power supply lines; when the power supply stops supplying power, the normally closed switches make the second group of lines short-circuited, and when the power supply supplies power, the normally closed switches make the second group of lines open-circuited. When the elevator, crane, electric door and the like driven by the motor fall or are manually pushed after the normally closed switches K1 and K2 are energized, the normally closed switches are opened, the permanent magnet motor M is reversely driven at high speed through the speed reduction mechanism (the magnetic field and the coil cut the magnetic force lines to move to generate an induced electromotive force), that is, the permanent magnet motor M is converted into a generator, at this time, the motor is not easy to rotate due to the impedance force generated in the motor caused by the short-circuit of the motor, and the damping effect is generated to avoid the harm caused by the falling or inertial motion of the elevator, crane and electric door, and the permanent magnet motor M can be a single-phase ordinary permanent magnet motor or a three-phase permanent magnet synchronous motor (in the embodiment, the permanent magnet motor M is a three-phase permanent magnet synchronous motor). Figure 1

[0017] The circuit of the utility model, refer to Figure 1 And Figure 2 On the basis of the foregoing technical solutions, specifically, the motor 100 is an ordinary permanent magnet motor or a three-phase permanent magnet synchronous motor.

[0018] The circuit of the utility model, refer to Figure 1 And Figure 2 On the basis of the foregoing technical solutions, specifically, the normally closed switches K1 and K2 are normally closed electromagnetic switches.

[0019] ​The above disclosed is only the preferred embodiment of the present application, of course, cannot be limited by this to limit the scope of the present application, therefore, the equivalent changes made according to the present application claims, still belong to the scope covered by the present application.

Claims

1. An electric machine braking circuit, characterized by, The motor is driven by a driving power source, and the driving power source is provided with a capacitor; the driving power source is connected with a power-off detection circuit, and the power-off detection circuit sends a power-off signal to the driving power source when the power supply is powered off; and the driving power source reversely drives the motor after receiving the power-off signal.

2. The motor braking circuit of claim 1, wherein, The driving power source comprises a switching power supply connected with the power supply and a controller, and the power-off detection circuit is connected with the power supply and sends a detection signal to the controller.

3. The motor braking circuit of claim 1, wherein, The power-off detection circuit comprises a rectifier circuit connected with the power supply, and the rectifier circuit is connected with a signal output module at an output end, and the signal output module sends a detection signal to the controller.

4. The motor braking circuit of claim 1, wherein, The input end of the motor is connected with two groups of lines in parallel, wherein the first group of lines is powered by a motor driving circuit in the controller, and the second group of lines of the motor is short-circuited through a normally closed switch connected with a power line. When the power supply stops supplying power, the normally closed switch short-circuits the second group of lines, and when the power supply supplies power, the normally closed switch breaks the circuit of the second group of lines.

5. The motor braking circuit of claim 4, wherein, The motor is a common permanent magnet motor or a three-phase permanent magnet synchronous motor.

6. The motor braking circuit of claim 4, wherein, The normally closed switch is a normally closed electromagnetic switch.

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