TWM444082U - Control circuit of DC brushless motor hair dryer - Google Patents

Description

DC brushless motor blower control circuit

This creation is a hair dryer, especially a hair dryer that uses a one-step or multi-stage speed controller to control the speed of a DC brushless motor.

The existing hair dryer has a selection switch on the body thereof, and a half-wave rectifier and a full-wave rectifier are respectively connected to the selection switch, and the output ends of the rectifiers are connected to a motor in the body, and are switched. Select the position of the switch to output a half-wave or full-wave DC power supply, so that the motor can reach half speed or full speed, so as to change the air volume of the hair dryer; while the motor of the known hair dryer uses a built-in DC brush motor, except for the fan drum. The sound generated by the wind, as well as the noise caused by the friction of the carbon brush and the commutator, has the disadvantages of wear and poor contact due to the continuous friction of the carbon brush and the commutator, so the use of the DC brush motor has friction noise and life. Shortening or poor reliability.

The existing hair dryer, such as China's new patent No. M341435 "DC brushless motor blower", uses a DC brushless motor to replace the DC brush motor, which can reduce the friction noise of the DC brush motor and the poor reliability caused by poor contact. The problem, coupled with a filter capacitor connected to the power supply end of the brushless DC motor, can reduce the chopping in the half-wave or full-wave rectified DC power supply, but it still uses a three-stage selector switch to switch the power supply. The disadvantage of having a limited number of airflow segments is limited, and the DC power supply is not a continuously fixed DC voltage, so that the DC brushless motor is in an inefficient operation. Working under voltage, resulting in poor work efficiency.

As mentioned above, the existing DC brushless motor still uses the selection switch to switch the power supply, so that the number of selectable air flow segments is limited, and the DC power supply is not a continuous and fixed DC voltage, so that the DC brushless motor is often inefficient. Working under working voltage, and having poor working efficiency, the main purpose of this creation is to provide a brushless motor blower control circuit, connect the speed controller to the power supply end of the DC brushless motor, and perform the speed without segment or multi-stage. Adjustment, to solve the problem of limited airflow section of the existing hair dryer and poor working efficiency of the motor.

The main technical means for achieving the foregoing purpose is that the DC brushless motor blower control circuit comprises: a power module comprising a power switch, a rectifier and a step-down coil, the two input ends of the rectifier being connected To an AC power source, the power switch is serially connected between one of the input terminals of the rectifier and the AC power source, the buck coil is connected in series between the other input end of the rectifier and the AC power source; Connected to the output of the rectifier to obtain a DC voltage, and send a speed control signal without a segment or multiple segments; a brushless motor that is connected to the output of the speed controller and driven by the speed control signal of the speed controller to Generate corresponding speeds without segments or segments.

The DC brushless motor blower control circuit composed of the foregoing components, when the power switch is turned on, the AC power source is formed by the rectifier and the step-down coil The power circuit, the output of the rectifier provides the DC voltage required by the speed controller, and the speed controller outputs the speed control signal according to the input signal to drive the DC brushless motor to perform linear or multi-segment linear speed control, thereby improving and maintaining the DC current. The working efficiency of the brush motor solves the problem that the number of air blowers of the existing hair dryer is limited and the working efficiency of the motor is not good.

A first preferred embodiment of the present invention, as shown in FIG. 1 , includes a power module 10 , a speed controller 20 and a brushless motor 30 . The input end of the power module 10 is connected to the outside. An AC power source 40, the output end of the power module 10 is connected to the speed controller 20, and the speed controller 20 is electrically connected to the DC brushless motor 30 to control the rotation speed thereof, wherein the power module 10 includes There is a power switch 11, a rectifier 12 and a step-down coil 13, the rectifier 12 has two input terminals and two output terminals, the input terminals are respectively connected to the aforementioned AC power source 40, the power switch 11 is connected in series to the rectifier Between one of the input terminals 12 and the AC power source 40, the buck coil 13 is connected in series between the other input terminal of the rectifier 12 and the AC power source 40. The output terminals (+, -) of the rectifier 12 are outputs. A rectified DC voltage; in this embodiment, the rectifier 12 is a full wave rectifier.

The speed controller 20 has two input terminals and three output terminals. The input terminals are connected to the output end of the rectifier 12 to obtain the DC voltage, and the output terminals are controlled by the speed of the DC brushless motor 30. For the signal, as shown in FIG. 2, when the speed controller 20 wants to output the stepless speed control signal, the speed controller 20 is configured to include a voltage stabilizing unit 21, a control unit 22 and three sets of switch units 23, the control The unit 22 is electrically connected to the voltage stabilizing unit 21 and each group of switching units 23 respectively. The voltage stabilizing unit 21 obtains a DC voltage V _CC from the input end of the speed controller 20, and provides one of the control unit 22 after being stepped down and stabilized. Low-voltage DC voltage V _DD and a ground terminal (GND); each group of switching units 23 includes electronic switches (MOSQ3, MOSQ4 MOSQ2, MOSQ5 MOSQ1, MOSQ6) connected in series, and these pairs of electronic switches are connected in series ( MOSQ3, MOSQ4 MOSQ2, MOSQ5 MOSQ1, MOSQ6) respectively form two nodes (V _CC and GND) and a series of nodes (MA, MB, MC), and two nodes (V _CC and GND) are respectively connected to the input of the speed controller 20 End to obtain DC voltage, each serial node (MA MB, MC) are respectively connected to the output end (J2) of the speed controller 20 to provide the speed control signal required by the DC brushless motor 30; the control unit 22 includes a plurality of pins, each pin (AT, BT, CT, AB, BB, CB) are electrically connected to each of the electronic switches MOSQ3, MOSQ4, MOSQ2, MOSQ5, MOSQ1, MOSQ6 to control their turn-on or turn-off, and one of the pins (P12) of the control unit 22 is connected to A variable resistor (R18), the characteristic of the linear voltage input by the variable resistor (R18), enables the control unit 22 to output a stepless speed control signal; see also FIG. 3, which is another control unit 22. A wiring method, one of the pins (P12) of the control unit 22 is connected to three switchers (J13, J133, J134), each of which is connected in parallel with one end and one end of which is respectively transmitted through a resistor (R31, R32, R35) Connected to the low-voltage DC voltage V _DD , the other end is grounded through another resistor (R36). By switching the switches, different input voltages are provided, so that the control unit 22 can output the segmentless speed control signal.

Referring to FIG. 4, when the speed controller 20 wants to output a plurality of speed control signals, the three pins (P14, P13, and P12) of the control unit 22 in the speed controller 20 are respectively connected to a switch. The switch (J13, J133, J134), the other end of each switch is connected to the ground, and by switching each switch (J13, J133, J134), the control unit 22 outputs at least three speed control signals (SPEED1) , SPEED2, SPEED3), so that the control unit 22 can output a plurality of speed control signals.

The DC brushless motor 30 is connected to each output end of the rotational speed controller 20, and is driven by the non-segment or multi-segment rotational speed control signal outputted by the rotational speed controller 20 to generate a corresponding rotational speed.

When the power switch 11 is turned on, after the AC power source 40 forms a power supply loop through the rectifier 12 and the step-down coil 13, the output of the rectifier 12 outputs a rectified DC voltage to provide a DC voltage required by the speed controller 20 (V). _CC ), the speed controller 20 can perform stepless linear or multi-stage speed control on the brushless DC motor 30 to improve and maintain the efficiency of the DC brushless motor 30, solve the limited number of air blowers of the existing blower, and the motor work efficiency is not good. The problem.

A second preferred embodiment of the present invention is shown in FIG. 5 , which is substantially the same as the first preferred embodiment. The difference is that the power module 10 is provided with a heating switch 14 and a heating coil 15 . The brushless motor 30 drives a fan (not shown), and the generated air volume is blown through the heating coil 15 to provide a hot air output. As shown, one end of the heating switch 14 is shown. Is connected to the power switch 11, the other end of the heating switch 14 is connected to the heating coil 15, and the other end of the heating coil 15 is connected to the AC power source 40; when the power switch 11 is turned on, the DC brushless motor 30 The wind blown by the fan is a cool air that is not heated by the heating coil 15. When the power switch 11 and the heating switch 14 are simultaneously turned on, the wind blown by the brushless motor 30 by the DC brushless motor 30 is heated by the heating coil 15 to form a hot air. The DC brushless motor 30 performs stepless linear or multi-stage rotational speed control to control the air volume thereof. The hot air volume of the blown hot air is reduced when the air volume is reduced, and the heat of the blown hot air is increased, thereby improving the convenience of the user. Sex.

10‧‧‧Power Module

11‧‧‧Power switch

12‧‧‧Rectifier

13‧‧‧Buck coil

14‧‧‧heating switch

15‧‧‧heating coil

20‧‧‧Speed Controller

21‧‧‧Stabilizer

22‧‧‧Control unit

23‧‧‧Switch unit

30‧‧‧DC brushless motor

40‧‧‧AC power supply

Figure 1 is a block diagram of a circuit of a first preferred embodiment of the present invention.

Fig. 2 is a circuit diagram (1) of the stepless speed controller of the first preferred embodiment of the present invention.

Figure 3 is a circuit diagram (2) of the stepless speed controller of the first preferred embodiment of the present invention.

Figure 4 is a circuit diagram of a multi-segment speed controller of the first preferred embodiment of the present invention.

Figure 5 is a block diagram of a second preferred embodiment of the present invention.

10‧‧‧Power Module

11‧‧‧Power switch

12‧‧‧Rectifier

13‧‧‧Buck coil

20‧‧‧Speed Controller

30‧‧‧DC brushless motor

40‧‧‧AC power supply

Claims (7)

A DC brushless motor blower control circuit comprises: a power module comprising a power switch, a rectifier and a step-down coil, the two input ends of the rectifier being connected to an AC power source, the power switch being serially connected Between one of the input terminals of the rectifier and the AC power source, the buck coil is connected in series between the other input of the rectifier and the AC power source; a speed controller is connected to the output of the rectifier to obtain a DC voltage, And send a speed control signal without a segment or a plurality of segments; a brushless motor is connected, which is connected to the output end of the speed controller, and is driven by the speed control signal of the speed controller to generate a corresponding speed of no segment or segments. The DC brushless motor blower control circuit according to claim 1, wherein the power module is further provided with a heating switch and a heating coil, one end of the heating switch is connected to the power switch, and the other end of the heating switch is a heating coil One end is connected, and the other end of the heating coil is connected to an AC power source. The DC brushless motor blower control circuit of claim 2, the rectifier being a full wave rectifier. The DC brushless motor blower control circuit according to any one of claims 1 to 3, wherein the speed controller comprises a voltage stabilizing unit, a control unit and three sets of switch units, the control unit and the voltage stabilizing unit and each The group switch unit is electrically connected, and each group of switch units comprises an electronic switch connected in series, and the electronic switch is a speed control signal of the output speed controller. A DC brushless motor blower control circuit as claimed in claim 4, The control unit is electrically connected to a variable resistor, so that the control unit outputs a stepless speed control signal. The DC brushless motor blower control circuit according to claim 4, wherein the control unit is electrically connected to the three switch switches respectively, so that the control unit outputs the plurality of speed control signals. The DC brushless motor blower control circuit according to claim 4, wherein the control unit is electrically connected to the three switch switches, wherein the connection switches are connected in parallel with one end and one end is respectively connected to the DC voltage through a resistor, and the other end is Grounding through another resistor allows the control unit to output a segmentless speed control signal.