FIELD OF INVENTION:
[001] The present subject matter described herein, relates to Brush Less Direct Current (BLDC) motor ceiling fan, and, in particular, to wall mount regulator for with shorting type switch to control speed of BLDC motor ceiling fan.
BACKGROUND AND PRIOR ART:
[002] Generally, wall mount regulators were used to control speed of single phase AC Induction motors. These wall mount regulators comprise series of resistors and capacitors for regulating the speed of the fan. These regulators are not efficient and consume more power and have high power losses. Further, these regulators provide AC supply to the motor.
[003] BLDC motors have gain popularity because BLDC are more efficient and consume less energy as compared to traditional known single phase AC induction motors. BLDC motors run on the DC power where DC power is converted from the AC power source by AC-DC and DC-AC converters. Further, BLDC motors are more efficient at converting electricity into mechanical power than brushed DC motors. This improvement is largely due to the absence of electrical and friction losses due to brushes. Therefore, BLDC motor based ceiling fans have gained huge popularity over brushes DC motor.
[004] Generally, speed of the BLDC motor based ceiling fans is controlled by remote control unit having wireless transmitter and digital speed controller. The remote control of the BLDC motor runs on the Pulse Width Modulation concept. BLDC Motor has a controller to receive the signals from the remote transmitter for controlling the speed of the fan. Further, the controller is also connected with the AC-DC converter to receive the DC power. Based on the signal of remote transmitter and DC power, the controller manages the speed of the motor. Where the controller and remote signal receiver is mounted on the BLDC motor. Major disadvantage with this mechanism for controlling the speed of the BLDC motor is that remote control and electronic circuit is costly. Usually user forgets where he put the remote control last time. Further, frequent use of remote control is not required in the fan as compared to TV. Further, remote control requires battery for operation.
[005] Accordingly, it is desirable to provide a regulator for a brushless DC motor which is reliable, simple and relatively inexpensive to control speed of the fan.
OBJECTS OF THE INVENTION:
[006] The principal objective of the present invention is to provide a Wall Mount Regulator which is compatible with the BLDC Motor.
[007] Another object of the present subject matter is to use shorting type switch which has feature of making another contact before breaking the previous contact.
[008] Yet another object of present invention is to provide triac based wall mount regulator for BLDC motor which change the firing angle of the AC supply which is being given to the ceiling fan.
[009] Yet another object of present subject matter is to develop a Wall mount regulator which does not change the DC voltage which is being directly supplied to the BLDC motor.
[0010] Yet another object of the present subject matter is to develop a wall mount regulator which gives set Revolutions per minute (RPM) at particular speed from 90 Volts to 260Volts.
[0011] Yet another object of the present subject matter is to develop a regulator which does not change the duty cycle of the PWM which is used for BLDC speed control.
[0012] Yet another object of the present subject matter is to manage the speed control signal through wall mount regulator having Microcontroller and Triac.

SUMMARY OF THE INVENTION:
[0013] The subject matter present disclosed herein relates to a wall mount regulator for controlling speed of BLDC motor based ceiling fan. More particularly, the present subject matter relates to a triac based wall mount regulator for controlling speed of BLDC motor based ceiling fan. The wall mount regulator has start up section, switch section, microcontroller section, and triac section. In the startup section, zero cross detection of current in the circuit of wall mount regulator is detected. The start phase of the startup section must have zero crossing point and end must be at the negative cycle. The switch section is used to select the speed, i.e., at first level, second level, third level, fourth level. The switch section has shorting type switch which can be rotated by the user to select the desired speed of the fan. The shorting type switch generates a signal based on the selection of the user. The microcontroller section receives two signals one from the startup section having zero detected signal and other a signal generated by the shorting type switch. Upon receiving of both the signals, the microcontroller section analyzes both the signals and generates a modulated signal. The generated modulated signal has information about the firing angle at which the input AC signal is to be cut by the triac section. The triac section receives the main AC signal from the main power source and modulated signal from the microcontroller section. The triac section has triac with gate and anodes terminals. The generated modulated signal is feed to the gate terminal of the TRIAC for firing the gate to make TRIAC in ON state and cut the main input AC signal according to the firing angle. Further, the predefined rules are set in the microcontroller section for generating a firing angle signal based on the selection of the shorting type switch. Firing angle is basically the angle at which the TRIAC conducts. For example, if firing angle is 45o in the modulated signal, till 45o of sine wave of the AC signal TRIAC does not conduct, after 45o of the sine wave of the AC signal TRIAC conducts the sine wave till the cycle completes. The input from the TRIAC is feed to the BLDC motor. When the modulated signal has wide pulse then fan runs at low speed and when narrow signal pulse is given for modulated signal then fan runs at high speed.
[0014] In another embodiment of the present subject matter, the BLDC motor receives the AC input from the TRIAC. The BLDC motor has an AC-DC converter which converts the AC into DC. Further, BLDC motor has a Boost section which boosts the input AC signal if voltage is above 60-70Volts AC and gives constant voltage 400V DC signal. The input DC is given to the microcontroller of the BLDC motor which allows the rotation of the fan motor accordingly. Therefore, the BLDC motor runs at different speed based on the input AC from the TRIAC based wall mount regulator. When narrow pulse is given more input AC signal comes for longer duration which runs the BLDC motor at high speed because BLDC motor gets the continues DC current from the motor controller for longer time.
[0015] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0017] Fig. 1 illustrates Symbol of Triac, in accordance with an embodiment of the present subject matter;
[0018] Fig. 2 illustrates the circuit diagram of the TRIAC, in accordance with the present subject matter;
[0019] Fig. 3 illustrates Circuit Diagram of Triac based Wall Mount regulator, in accordance with an embodiment of the present subject matter;
[0020] Fig. 4 illustrates Zero Crossing Detection Circuit for wall mount regulator, in accordance with an embodiment of the present subject matter;
[0021] Fig. 5 illustrates AC sine waveform and AC signal waveform generated by the TRIAC, in accordance with an embodiment of the present subject matter;
[0022] Fig. 6 illustrates wave forms of wall mount control from Micro Controller, in accordance with an embodiment of the present subject matter;
[0023] Fig. 7 illustrates Narrow and Wide Signal Pulses of the modulated signal and input AC signal based on the narrow and wide signal pulses, in accordance with an embodiment of the present subject matter;
[0024] Fig. 8 illustrates block diagram of the BLDC motor based ceiling fan, in accordance with an embodiment of the present subject matter; and
[0025] Fig. 9 illustrates Circuit Diagram of Shorting Type Switch of the wall mount regulator, in accordance with an embodiment of the present subject matter.
[0026] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0027] The present subject matter relates to wall mount regulator for controlling speed of BLDC motor ceiling fan. More particularly, the present subject matter relates to a triac based wall mount regulator for controlling speed of BLDC motor ceiling fan. In the induction motor it is simple to control the speed of fan by reducing the Alternating Current (AC) supply by the regulator, whereas the Brush Less Direct Current (BLDC) motor works on the Direct current and it is difficult to control the DC from the regulator, because wall mount regulator can reduce AC only. The wall mount regulator has start up section, switch section, microcontroller section, and triac section. In the startup section, zero cross detection of current in the circuit of wall mount regulator is detected. The start phase of the startup section must has zero crossing point and end must be at the negative cycle. The switch section is used to select the speed, i.e., at first level, second level, third level, fourth level. The switch section has shorting type switch which can be rotated by the user to select the desired speed of the fan. The shorting type switch generates a signal based on the selection of the user. The microcontroller section has a microcontroller. The microcontroller section receives two signals one from the startup section having zero detected signal and other a signal generated by the shorting type switch. Upon receiving of both the signals, the microcontroller section analyzes both the signals and generates a modulated signal. The generated modulated signal has information about the firing angle at which the input AC signal is to be cut by the triac section. The triac section receives the main AC signal from the main power source and modulated signal from the microcontroller section. The triac section has triac with gate and anodes terminals. The generated modulated signal is feed to the gate terminal of the TRIAC for firing the gate to make TRIAC in ON state and cut the main input AC signal according to the firing angle. Further, the predefined rules are set in the microcontroller section for generating a firing angle signal based on the selection of the shorting type switch. Firing angle is basically the angle at which the TRIAC conducts. For example, if firing angle is 45o in the modulated signal, till 45o of sine wave of the AC signal TRIAC does not conduct, after 45o of the sine wave of the AC signal TRIAC conducts the sine wave till the cycle completes. The input from the TRIAC is feed to the BLDC motor. When the modulated signal has wide pulse then fan will run at low speed and when narrow signal pulse is given for modulated signal then fan runs at high speed.
[0028] In another embodiment of the present subject matter, the BLDC motor receives the AC input from the TRIAC. The BLDC motor has an AC-DC converter which converts the AC into DC. Further, BLDC motor has a Boost section which boosts the input AC signal which is below 85 volts to constant 400 volts DC signal. The DC signal is given to the microcontroller of the BLDC motor which allows the rotation of the fan motor accordingly. The BLDC motor runs at different speed based on the input AC signal from the TRIAC based wall mount regulator. When narrow pulse is given more input AC signal comes for longer duration which runs the BLDC motor at high speed because BLDC motor gets the continues DC current from the motor controller for longer time period.
[0029] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be constructed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0030] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0031] Fig. 1 illustrates structure of TRIAC, in accordance with the present subject matter. The TRIAC is used in the present wall mount regulator for controlling the speed of the BLDC motor based ceiling fan. Further, the TRAIC is equivalent to two thyristors connected back to back and its bi-directional switching device. So, when it's in conduction mode, current flows in both the directions. This switching is called as TRIAC. As shown in Fig 1, Terminal T1 is taken as reference point for the measurement of the voltages, where currents at other two terminals G and T2. The thyristors conducts with the current direction from Anode to Cathode, when a positive pulse is fed at the Gate terminal with respect to Cathode, and at that time, with positive voltage applied between Anode and Cathode terminals, being connected in series with the load.
[0032] Fig. 2 illustrates circuit diagram of TRIAC, in accordance with the present subject matter. In the present circuit diagram, the TRIAC receives modulated signal from Microcontroller section at terminal Gate and receives the main input AC signal at terminal T2. The TRIAC conducts based on the received modulated signal and gives the output AC signal based on the modulated signal.
[0033] Fig. 3 illustrates Circuit Diagram of Wall Mount regulator with TRIAC, in accordance with an embodiment of the present subject matter. The wall mount regulator 300 has start up section 302, switch section 304, microcontroller section 306, and triac section 308. The startup section 302 receives main input AC signal from the main power source 302a and generates a waveform with zero cross detection. The zero cross detection waveform confirms the smooth input of AC signal from the main power source. The switch section 304 has shorting type switch which is rotated to select desired speed, i.e., at first level, second level, third level, fourth level of the fan. The shorting type switch generates a switch signal based on the selection of the user. The microcontroller section 306 has a microcontroller which is embedded with a predefined program to calculate a modulated signal based on the input signal from the startup section 302 and the switching section 304. The microcontroller section 306 receives two signals one from the startup section 302 having zero cross detection waveform and other switch signal generated by the switch section 304. Upon receiving of both the signals, the microcontroller section 306 analyzes both the signals and generates a modulated signal 306a. The generated modulated signal 306a has information about the firing angle at which the input AC signal 310 is to be cut by the triac section 308.
[0034] The triac section 308 receives the input AC signal 310 from the main power source and the generated modulated signal 306a from the microcontroller section 306. The triac section 308 has TRIAC with Gate and two other anode terminals. The generated modulated signal 306a is feed to the gate terminal of the TRIAC for firing the gate to make TRIAC in ON state and cut the main input AC signal according to the firing angle. Based on the firing angle, such as 45o, 90o, 135o, the main input AC signal is cut for particular time duration. Further, the predefined rules are set in the microcontroller section for generating a firing angle signal based on the selection of the shorting type switch. The TRIAC generates the input AC signal based on the modulated signal 306a, detailed explanation is provided in the figure 5 and 7.
[0035] Fig. 4 illustrates Zero Crossing Detection waveform for wall mount regulator, in accordance with an embodiment of the present subject matter. When the main power source is ON and the startup section 302 receives the main input signal. The startup section 302 detects Zero Crossing Detection in the input AC signal for proper functioning of the wall mount regulator. The waveform of the wall mount regulator is shown in figure 3. Now turn the VR to the 1st position and see the waveform for positive and negative edge. Both the pulses are of different duration. The start of the cutting phase must be at the zero crossing point and the end must be in the negative cycle.
[0036] Fig. 5 illustrates the sine wave forms of input AC signal at different firing angle by the TRIAC based on the modulated signal, in accordance with the present subject matter. The TRAIC conducts in positive direction from MT2 to MT1, when a positive pulse is applied to the Gate terminal with respect to MT1. Similarly, the Triac conducts in negative direction. Firing angle is basically the angle at which the TRIAC conducts. For example, if firing angle is 45o in the modulated signal, till 45o of sine wave of the AC signal TRIAC does not conduct, after 45o of the sine wave of the AC signal TRIAC conducts the sine wave till the cycle completes. When the modulated signal has wide pulse then fan will run at low speed and when narrow signal pulse is given for modulated signal then fan runs at high speed. Fig. 5(a) illustrates the input AC signal supply sine waveform. Fig 5(b) illustrates AC input signal after Firing the TRIAC at 45o angle. Fig 5(c), illustrates AC input signal after Firing the TRIAC at 90° Angle. Fig 5(d) illustrates AC input signal after Firing the TRIAC at 135° Angle. For example if firing angle is 90°, then it means till 90° of the input sine wave TRIAC not conducts, after that TRIAC will conduct till the cycle completes. For firing angle at 45o, the TRIAC conduct only after 45o of input AC sine wave passes. The firing angle 45o generates a narrow pulse wave for the modulated signal which cuts the sine wave of the input AC signal for short time period and gives the wide sine wave of the input AC signal to the BLDC motor. Similarly, the firing angle 135o generates a wide pulse wave for the modulated signal which cuts the sine wave of the input period for long time period and gives the shortest or narrow sine wave of input AC signal to the BLDC motor. Accordingly, when pulse wave of the modulated signal is wide, BLDC motor fan runs at slow speed. When pulse wave of the modulated signal is narrow, BLDC motor fan runs at fast speed.
[0037] By the firing angles, TRIAC conducts for predefined time periods based on the width of the modulated signal from the microcontroller. When firing angle is low, the modulated signal has narrow wide and less time period for conducting the TRIAC. When firing angle is high, the modulated signal has wide and more time period for conducting the TRIAC. When pulse width and time period of the modulated signal is high, the TRIAC allows passage of small AC input to the BLDC motor.
[0038] For example, the AC signal which is of frequency 50 Hertz and has 20 msec time period, 20 msec time period means firing angle is low and at the low firing angle fan is running at high speed. Assume the signal pulse of the modulated signal which is coming from microcontroller has time period of 10 msec, when it fires the TRIAC it generates the AC signal of 10 msec period it means fan is running at medium speed, here TRIAC firing angle is 90 degree. When the signal pulse is the modulation signal is of duration 15msec (firing angle 135o) and at the time of firing, the AC signal has time period of 5msec, then the fan will run at lowest speed having a firing angle of 135 degree.

[0039] Fig 6 shows the Wall Mount Control, in the positive half cycle, live point (L) is positive w.r.t. the neutral point(N) and in the negative half cycle, the live point(L) is negative w.r.t. the neutral (N). Based on the microcontroller section 306, the modulated signal 604 cuts the sine wave 602 of the input AC signal and gives the cut input AC signal to the BLDC motor for operations.
[0040] Fig 7 (a) and (b) illustrate the Wide and Narrow signal Pulses of the modulated signal, in accordance with an embodiment of the present subject matter. Fig. 7(a) illustrates wide signal pulse 704a of the modulated signal which cuts the input AC signal sine wave 702 for long time period 702a. Resultantly, TRIAC conducts the input AC signal for short time period and small input AC signal goes to BLDC motor. Fig. 7(b) illustrates narrow signal pulse 704b of the modulated signal 704 which cuts the input AC signal sine wave 702 for short time period 702b. Resultantly, TRIAC conducts the input AC signal for long time period and high input AC signal goes to BLDC motor. Accordingly, when Wide Signal Pulse 704a of the modulated signal 704 comes to the TRIAC, the BLDC motor Fan runs at low speed and when Narrow Signal Pulse 704b of the modulated signal 704 comes to the TRIAC, the BLDC motor fan the fan runs at high speed.
[0041] Fig. 8 illustrates the block diagram of the BLDC motor, in accordance with the present subject matter. The input AC signal 312 from the wall mount regulator feed into the BLDC motor ceiling fan. The BLDC motor ceiling fan has an AC-DC converter 802, boost section 804, motor controller 806, and BLDC motor fan 808. The input AC signal 312 is feed into the AC-DC converter 802 for the selected time period based on the wall mount regulator mechanism. The AC-DC converter 802 converts the input AC signal 312 into the DC signal. Further, the boost section 804 has power factor circuit which boost the weak signal of 85 volts upto constant 400 volts. The fan controller 806 receives the input DC signal for selected time period. Further, the fan controller 806 has predefined rules for generating revolution per minute based on the time period of the input DC signal. For example, if input AC signal 312 is feed for 10 ms, the fan runs at low speed. Similarly, if input AC signal 312 is feed for 20 ms, the fan runs at high speed.
[0042] Fig. 9 illustrates Circuit Diagram of Shorting Type Switch of the wall mount regulator, in accordance with an embodiment of the present subject matter. The TRIAC based wall mount regulator has shorting type switch in the switch section 302 (as illustrated in the figure 3). The shorting type switch is a rotary switch which is operated by allowing the rotation to control different circuit functions. The rotary switch has layered structure to allow use of multiple poles, where each layer is equivalent to one pole. In the present wall mount regulator, 2 pole 6 way shorting switch is used. In the center 2 pins denotes the poles A, B and the outer pins are the ways. Based on the rotation of the switch, speed of the BLDC motor fan is selected. In the present structure, the speed of the BLDC fan can be selected upto six (6) levels. Turning the spindle connects each pole to its way to turn the switching. The shorting type switch has feature of making contact before breaking the previous contact, the shorting type switch provides the signal to the microcontroller with loosing contact with the switch pin, due to this there is no delay in signal to microcontroller of the wall mount regulator. Upon receiving the continued signal from the switch signal, the microcontroller generates the modulated signal without delay. Accordingly, input AC signal is feed to the BLDC motor without any delay and BLDC motor fan run smoothly without any jerk and delay.
[0043] The present wall mount regulator is based on the TRIAC to generate input AC signal for BLDC motor. The present wall mount regulator feed the input AC signal into BLDC motor in different time fractions based on the selection of switch. Through the present subject matter, it is possible to control the BLDC motor based ceiling fan through wall mount regulator in a robust way.
[0044] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

Claims:
1. A wall mount regulator (300) for controlling speed of Brush Less Direct Current (BLDC) motor based ceiling fan, the wall mount regulator (300) comprising:
a switch section (304) to select speed level of the BLDC motor based ceiling fan, wherein the switch section (304) generates a switching signal;
a microcontroller section (306) receives input AC signal (310, 302a) and generated switching signal from the switch section (304), the microcontroller section (306) generates a modulated signal (306a) based on the switching signal; and
a TRIAC section (308) receives the modulated signal (306a) and input AC signal (310), the TRIAC section (308) allow passage of input AC signal (312) based on the modulated signal (306a).
2. The wall mount regulator (300) as claimed in claim 1, wherein the wall mount regulator (300) further comprises a startup section (302) which receives input AC signal (302a) and generates a zero cross detection wave form for smooth functioning of the wall mount regulator (300).
3. The wall mount regulator (300) as claimed in claim 1, wherein the modulated signal (306a) has information about firing angles for the TRIAC section (308) for conducting input AC signal (310).
4. The wall mount regulator (300) as claimed in claim 1, wherein the TRIAC section (308) cut the input AC signal (310) into predefined time frames based on the firing angles of the modulated signal (306a).
5. The wall mount regulator (300) as claimed in claim 1, wherein the TRIAC section (308) cuts the input AC signal (310) at various angles
if wide signal pulse (704a) of the modulated signal (306a) comes, the BLDC motor based ceiling fan run at low speed; and
if narrow signal pulse (704b) of the modulated signal (306a) comes, the BLDC motor based ceiling fan runs at high speed.
6. The wall mount regulator (300) as claimed in claim 1, wherein the TRIAC section (308) allows passage of the input AC signal (310) for longer time period when firing angle is minimum and for shortest time period when firing angle is maximum.
7. The wall mount regulator (300) as claimed in claim 1, wherein the switching section (304) has shorting type switch which provides signal to the microcontroller section (306) without any delay.
8. The wall mount regulator (300) as claimed in claim 1, wherein the wall mount regulator (300) gives the input AC signal (310) for different time frames based on the selection for controlling the speed of the BLDC motor based ceiling fan.
9. The wall mount regulator (300) as claimed in claim 1, wherein the wall mount regulator (300) gives set number of revolutions per minute (RPM) based on the selection of the switch.
10. The wall mount regulator (300) as claimed in claim 1, wherein the microcontroller section (306) has predefined rules for generating the modulated signal (306a) based on the switching signal and the zero detection wave form.