Claims:We claim:
1. A universal fan with brushless direct current (DC) motor, the fan comprising:
a) plurality of poles in a rotor (103) and plurality of slots in a stator (102), wherein the stator (102) and the rotor (103) are enclosed in a drive end bracket (101);
b) a non-drive end bracket (105) fixed on the surface of the drive end bracket (101) to close the one end of the drive bracket;
c) a controller assembly fixed onto the non-drive end bracket (105) of the motor using plurality of screws (203a, 203b, 203c), wherein the controller assembly provides the commutation of the brushless direct current (BLDC) motor;
d) the stator (102) which is a three phase star connected stator winding fixed into the drive end bracket (101) of the motor; and
e) the rotor (103) supported between two brackets which are housing the stator.
2. The fan as claimed in claim 1, wherein the controller assembly is an integrated circuit for the commutation of the motor.
3. The fan as claimed in claim 1, wherein the controller assembly comprises:
i. a voltage detector;
ii. a voltage rectifier;
iii. a position detector without sensor;
iv. a field controller for controlling the field winding; and
v. a power factor corrector.
4. A method for operating the universal fan with brushless direct current (DC) motor, the method comprising the steps of:
i. switching on the power button;
ii. identifying the type of voltage through the voltage detector;
iii. checking the value of the voltage for predefined value;
iv. switching off the motor using a microcontroller if the voltage value exceeds the predefined value;
v. maintaining the current and the voltage in-line for power factor control; and
vi. allowing the motor to run on any type of voltage (Alternating current or direct current).
, Description:[001] PREAMBLE TO THE DESCRIPTION:
[002] The following specification particularly describes the invention and the manner in which it is to be performed:
[003] DESCRIPTION OF THE INVENTION:
[004] Technical field of the invention
[005] The present invention relates to brushless direct current (DC) motor. More particularly, the invention relates to a fan having a universal motor which works with different voltage type (AC/DC) and levels of voltages.
[006] Background of the invention
[007] The direct current (DC) ceiling fans use brushless DC motors and electrically commuted motors (ECM) to operate. Such fans are usually quieter as they run on direct current and usually have different speeds. However, as these types of fans have many electronic components, there may be a possibility in the failure of operation of these fans. These fans are costlier than AC ceiling fans as they use more complex circuitry than DC motor fans. Currently, DC technology has become more advanced to the extent. It can be applicable in both residential and industrial ceiling fans.
[008] The United States patent number 5200661, discloses about slotless, brushless, large air gap electric motor. This patent discloses about a commutation scheme and a versatile electronic control package that can be used to control several (preferably any) motors designed, regardless of torque and horsepower characteristics. This type of motor is applicable only for low voltage DC and high voltage AC application.
[009] The United States patent number 7196485, discloses about a universal low-power ceiling fan controller that uses a microcontroller to control and drive a brushless motor. It is operated with a feedback device to continuously and automatically determine a position feedback for an automatic compensation of the microcontroller, so as to achieve a constant rotary speed and a remote-control linear stepless speed adjustment of the ceiling fan. This motor is applicable only for AC input (variable) not for the DC input.
[0010] Currently brushed direct current (DC) motors and brushless direct current (DC) motors are used for DC application, and the induction motors are used for alternating current (AC) application. Therefore, separate motors are required for each voltage type (AC/DC) and the voltage level (110V AC / 140V AC / 110V DC). This leads to maintain different records by the user with respect to the working of the motor. Also, the induction motors are bulk in size and the power consumption of such motors is very high due to lower efficiency. The speed is also not constant over the working voltage range.
[0011] Hence, looking at the problems in the prior art, there is a need for a motor which works with different voltage type and levels of voltages. The device must maintain constant speed over the working voltage range and eliminate the user (s) need to maintain the separate records for different voltages/levels. Also, the system must be simple and consume less power.
[0012] Summary of the invention:
[0013] The present invention overcomes the drawbacks in the prior art and provides a universal fan with brushless direct current (DC) motor. The present invention comprises plurality of poles in a rotor and plurality of slots in a stator, wherein the stator and the rotor are enclosed in a drive end bracket. A non-drive end bracket is fixed on the surface of the drive end bracket to close the one end of the drive bracket. A controller assembly is fixed onto the non-drive end bracket of the motor using plurality of screws, wherein the controller assembly provides the commutation of the brushless direct current (BLDC) motor. The stator is a three phase star connected stator winding which is fixed into the drive end bracket of the motor. The rotor is supported between two brackets which are housing the stator.
[0014] In the preferred embodiment of the present invention, the controller assembly is an integrated circuit for the commutation of the motor.
[0015] In the preferred embodiment of the present invention, the controller assembly further comprises a voltage detector, a voltage rectifier, a position detector without sensor, a field controller for controlling the field winding and a power factor corrector.
[0016] In the preferred embodiment of the present invention, the method includes the step for operating the fan. Firstly, the power button is switched ON. The type of voltage is identified through the voltage detector and the value of the voltage for predefined value is checked. Further, the motor is switched OFF using a microcontroller, if the voltage value exceeds the predefined value. The current and the voltage in-line for power factor control are maintained and the motor is allowed to run on any type of voltage (alternating current or direct current).
[0017] Brief description of the drawings:
[0018] The foregoing and other features of embodiments will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
[0019] Figure 1 illustrates an exploded view of the universal motor, in accordance with an embodiment of the invention.
[0020] Figure 2 illustrates an exploded view of the universal motor and control assembly, in accordance with an embodiment of the invention.
[0021] Figure 3 illustrates the process flow for the working of universal motor, in accordance with an embodiment of the invention.
[0022] Detailed description of the invention:
[0023] Reference will now be made in detail to the description of the present subject matter, one or more examples of which are shown in figures. Each embodiment is provided to explain the subject matter and not a limitation. These embodiments are described in sufficient detail to enable a person skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, physical, and other changes may be made within the scope of the embodiments. The following detailed description is, therefore, not be taken as limiting the scope of the invention, but instead the invention is to be defined by the appended claims.
[0024] The present invention provides a common motor for different type of voltages and levels of voltages along with a control assembly which detects the input voltage type and voltage level to run as per the specification.
[0025] The present invention provides a universal fan with brushless direct current (DC) motor. The present invention comprises plurality of poles in a rotor and plurality of slots in a stator, wherein the stator and the rotor are enclosed in a drive end bracket. A non-drive end bracket is fixed on the surface of the drive end bracket to close the one end of the drive bracket. A controller assembly is fixed onto the non-drive end bracket of the motor using plurality of screws, wherein the controller assembly provides the commutation of the brushless direct current (BLDC) motor. The stator is a three phase star connected stator winding which is fixed into the drive end bracket of the motor. The rotor is supported between two brackets which are housing the stator.
[0026] Figure 1 illustrates an exploded view of the universal motor, in accordance with an embodiment of the invention. The universal motor comprises plurality of poles in a rotor (103) and plurality of slots in a stator (102), wherein the stator (102) and the rotor (103) are enclosed in a drive end bracket (101). A non-drive end bracket (105) is fixed on the surface of the drive end bracket (101) to close the one end of the drive bracket. The stator is a three phase star connected stator winding which is fixed into the drive end bracket (101) of the motor. The rotor is supported between two brackets which are housing the stator.
[0027] Figure 2 illustrates an exploded view of the universal motor and control assembly, in accordance with an embodiment of the invention. A controller assembly is fixed onto the non-drive end bracket (105) of the motor assembly (100) using plurality of screws (203a, 203b, 203c) as shown in Figure 2. The controller assembly provides the commutation of the brushless direct current (BLDC) motor.
[0028] The controller assembly comprises a voltage detector to detect the type of input voltage. A voltage rectifier to convert AC to DC as well as for reverse protection in the case of DC supply. A position detector is used without the sensor to detect the position of the motor. A field controller is used for controlling the field winding and a power factor corrector is used to maintain current and voltage in-line.
[0029] In the preferred embodiment of the present invention, a microcontroller unit is used in the control assembly. A microcontroller is a single integrated circuit (printed circuit board (PCB)) containing a processor core (s), memory, programmable input/output peripherals. Microcontrollers are used to identify the type of the voltage automatically. The printed circuit board (202) is shown in figure 2.
[0030] Figure 3 illustrates the process flow for the working of universal motor, in accordance with an embodiment of the invention. The first step is to switch ON the power button. Then, the type of voltage is identified through the voltage detector and the value of the voltage for predefined value is checked. Further, the motor is switched OFF using a microcontroller based on the condition i.e., if the voltage value exceeds the predefined value. The current and the voltage are maintained in-line to control the power factor and the motor is allowed to run on any type of voltage (AC or DC).
[0031] In the preferred embodiment of the present invention, a transient voltage suppressor is used to protect the electronic component from surge voltage. A bridge rectifier is used to convert AC to DC as well as for reverse protection in the case of DC supply. The power factor controller (PFC) is used to maintain the current and voltage in-line. A low dropout regulator is used to step down the voltage (high voltage to low voltage) for drive the controller assembly.
[0032] Hence, the present invention provides a universal motor, which works with both AC/DC voltages and with different voltage levels such as (110V AC / 140V AC / 110V DC). The present invention eliminates the need of maintaining different records, since the single motor is used to work with different voltages. The power consumption of motor is very low due to high efficiency. The speed of the motor is constant over the working voltage range.
[0033] In the preferred embodiment of the present invention, the size of the universal motor is compact and the efficiency of the motor is high.
[0034] It is to be understood, however, that even though several characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.