DESC:

FIELD OF INVENTION

The present invention relates to an efficient ceiling fan. More particularly, the present invention relates to a ceiling fan motor with a switching mechanism for controlling rotation speed of the ceiling fan motor at low voltages.

BACKGROUND ART

Basically, ceiling fan is an AC induction motor which works on AC supply. When supply voltage goes down by any means, it has tendency to drop its performances also. In ruler areas mostly, power cut-off take place by electricity board they either cut off power or making single phasing of supply, at that time voltage goes below 150 V, at same voltage fan will work but not at its desired output. Fan will rotate at relative low speed and ultimate output of fan is air delivery that is also drastically reduced. So main problem is at lower voltages fan speed does not gives relative air volume to that room for which it is to be designed.

The Induction motor is different form normal Induction motors as under:-
1. Rating: -
That internal rotor construction is required due to high output rating ie. Above 2200 watts and load on motor is very high External rotor motor used where output of motor very very less i.e. 70-80 watts and load on motor is also very low.
2. Costing: -
In external rotor motors, rotor is kept outside of stator so that stamping diameter of the stator is very low and it gives less copper consumption. So less copper and low stamping OD will give over all low cost. The cost saving up to 30-40 %.
3. Torque: -
As load on motor is high for internal motor it required high torque to rotate the rotor. Whereas in external rotor motor load on motor is very less so that torque requirements are very less.

V I W N
100 0.159 16.2 129
110 0.176 19.6 148
120 0.195 23.7 165
130 0.213 28.0 191
140 0.233 32.9 215
150 0.252 38.2 238
160 0.27 43.5 266
170 0.285 48.9 291
180 0.296 53.8 315
190 0.304 58.3 333
200 0.312 63.0 348
210 0.316 66.9 358
220 0.322 72.1 366
230 0.328 76.2 375
245 0.342 85.2 385

Above table shows the how ceiling fan is works at different voltages. How its performance is deteriorated with respect to voltages variation.

Normally fan has its speed around 370 rpm @230V, when power cut off happens or single phasing done at the same time voltage drops and fan will rotate relatively lower rpm as describe in image it is around 230 rpm @150V. So air volume at the same room will be low so fan will be ineffective.

Further, the applicant has done a consumer survey that gives us regions where the voltage fluctuations were very high and very relatively happens. The voltage band in India is shown in below figure 2. There are regions where the voltage fluctuation will take place relatively high. People were facing the problem with same low voltages with low output performances.

As there is problem for low voltages for ceiling fan, we have an solution with take care of the low voltages also. In order to solve the problem discussed above the applicant herein are making the motor winding in split type so that two windings are available in main windings. When supply is in normal mode i.e 230V then these two windings were connect as in series connection. And when supply voltage drops below 140-150 volts same winding get connected as they were in parallel connection, so at lower voltages also fan works like a normal fan ie it work at desired output performances.

SUMMARY OF INVENTION

The primary objective of the present invention is to provide a ceiling fan motor with a switching mechanism device for controlling rotation speed of the ceiling fan motor, which is capable of controlling rotation speed of the ceiling fan automatically. The efficient ceiling fan will work at low voltages as well as normal voltages.

It is another object of the present invention is to provide a ceiling fan motor configuration which is configured to work at low voltages at around 130V (i.e. Below 150V) by maintaining high speeds as compared with other fans of prior art.

It is another object of the present invention is to provide an external regulator circuit, wherein the ceiling fan is also configured to work with regulator also ie. Even at low speed due to regulation this will work with the help of PCB programming.

It is another object of the present invention is to provide a ceiling fan motor with a switching mechanism device configured to prevent any damage at lower voltages.

To achieve the above objectives, a ceiling fan motor with a switch device for controlling rotation speed and direction of the ceiling fan motor, comprises: a motor with a main coil and an auxiliary coil, wherein the main coil is centrally tapped; a motor starting capacitor electrically connected between the main coil and the secondary coil; a plurality of multi-stage relay switch including a common contact, configured to switching the tapped main coil in series and parallel at least one rotation speed contact electrically connected to the second main contact. The motor starting capacitor cooperates with the multi-stage relay switches in order to control the rotation speed and direction of the ceiling fan.

Preferably, the multi-stage relay switch configured to switch between series and parallel connection in the main coil. The mail coil of the motor winding is split type so that two windings are available in main windings. When supply is in normal mode i.e 230V then these two windings were connect as in series connection. And when supply voltage drops below 130-150 volts same winding get connected as they were in parallel connection, so at lower voltages also fan works like a normal fan ie it work at desired output.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 illustrates a graph for Voltage (V) –Vs- speed (RPM) for a ceiling fan;
Figure 2 illustrates a survey result for the voltage fluctuation in India;
Figure 3 illustrates the proposed block diagram for efficient ceiling fan in accordance with the present invention;
Figure 4 illustrates the proposed circuitry (coil tap diagram) for efficient ceiling fan in accordance with the present invention;
Figure 5 illustrates the flowchart (working) for efficient ceiling fan in accordance with the present invention.

DETAILED DESCRIPTION

Normal Ceiling fans were generally use on 230V ac supply. The motor used in ceiling fan is mostly induction motor. Induction motor has natural tendency to fluctuate with respect to voltage variation. In India voltage fluctuation are very frequent most in north east regions. Some time it drops below 150V for 4-5 Hours also. So, at that condition all apparatus were used at lower voltages, some may get damage but ceiling fan was operating at lower Revolution per minutes. So, the disclosed solution takes care of such kind of faults where voltage fluctuations are more.

Generally, in fan industry, motor were designed @230V ac supply that is standard set by Gov of India. Due to some electricity Board problem or any other instable voltage concurrences voltage supply to the fans will be reduced up-to 150V and below. Basically, working of ac induction motor fan is based on voltages. As RPM (Revolution Per Minutes) and AD (Air delivery) is function of Voltage, it is directly proportional to the voltage. Whenever the supply voltage drops fan will work at lower voltages that means fan will work on lower output performance (lower RPM and Lower AD).

Fig : 1 illustrates a voltage (V) Vs speed (RPM) ceiling fan showing the actual working of the ceiling fan. In figure at almost 50% less voltages fan performance will also de-graded by 50%. Therefore, the present invention is configured to take care of the aforesaid discussed problem. Whenever the voltages drops below certain voltage level fan performance also drops to that proportional voltage drop. With voltage drop in power supply, this invention changes its winding to respective connection (series or parallel) and will give performance as per requirements. At lower voltages it will work on parallel windings and at normal voltages it will work on series windings.

In Ceiling fan motor used is single phase ac induction motor. It has a winding (wound stator). Motor is designed for a voltage and its tolerance. Windings contains no of turns of copper wire. These turns are directly proportional to the voltages. i.e if voltage drop by 50% then turns also drops by 50%.

In an example an experiment wass carried out with low voltage and simultaneously increasing the same upto 245V and following results were obtained.:-

Normal With innovation
V N N
100 129 267
110 148 350
120 165 363
130 191 378
140 215 385
150 238 388
160 266 266
170 291 291
180 315 315
190 333 333
200 348 348
210 358 358
220 366 366
230 375 375
245 385 385

In an exemplary example, and as shown in Fig 4, the main winding has some turns 200 for 230V design, so for 115V the turns for the winding were 100. By splitting the main winding in 50% (ie 100 turns per side) now there are two winding in a single stator for main windings. So whenever power supply is normal these two windings were connected as in series so at 230V the motor turns were 200 that’s for what it is designed. And for 115V these two windings were connected in parallel so effective turns were 100 for 115V. So at lower voltages also the motor delivers an optimum output performance in terms of speed and air delivery.

Since single phase motor has its own wide range of application uses. So traditional single-phase motors are modified as per the need discussed in the prior art. The ceiling fan has its own construction and working:

Difference @low voltages:-

Sr.no Specification Normal fan Invented fan
1 Speed Rotation of fan blade are very low ie around 160 RPM Rotation of fan blade are very High ie around 380 RPM
2 Air delivery air delivery is around 100 CMM air delivery is around 200 CMM ie almost equal to normal fan at 230V
3 Regulator At low voltage, at lower speed regulation ie 1/2 fan will not work At low voltage, at lower speed regulation ie ½ fan will normally work

The ceiling fan motor is provided with a with a programmable switch device / circuit for controlling rotation speed and direction of the ceiling fan motor as shown in Fig 3. The motor is provided with a main coil and an auxiliary coil, wherein the main coil is centrally tapped as shown in Fig 4. In an embodiment, there is provided a plurality of sensors, configured for recordal and providing feedback signals for initiating switching at low voltages and / or low fan speed from the set threshold level of input voltage and / or the optimum fan speed. The motor starting capacitor is electrically connected between the main coil and the secondary coil. The circuit includes a plurality of multi-stage relay switch including a common contact, configured to switching the tapped main coil in series and parallel at least one rotation speed contact electrically connected to the second main contact. The motor starting capacitor cooperates with the multi-stage relay switches in order to control the rotation speed and direction of the ceiling fan.

While working, the multi-stage relay switch configured to switch between series and parallel connection in the main coil. The mail coil of the motor winding is split type so that two windings are available in main windings. When supply is in normal mode i.e 230V then these two windings were connect as in series connection. And when supply voltage drops below 130-150 volts same winding get connected as they were in parallel connection, so at lower voltages also fan works like a normal fan ie it work at desired output.

Control PCB (controller) working as shown in Fig 5:-
when fan is ON ,
-PCB check the input voltage By using relay 1,

If voltage is Above 140V – relay 1 gives indication to relay 2 that is basically make coils as per for series connection.

If voltage is below 140V - relay 1 gives indication to relay 3 that is basically make coils as per for parallel connection.

This checking of voltage by control PCB (controller) is done with continuous interval of time, In an example, for checking it will required 2 sec in that period of 2 sec supply to the fan is totally off and the regulator will be completely out of circuit. It basically checks the voltage change is made by regulator or by line supply.

The PCB circuit is connected in series with the fan, supply and regulator. So from flow chart supply is on the it goes to regulator then it forward to PVB and finally goes to fan..
- Stage 3 –In this invention supply goes to PCB where 3 relays are connected in such way that relay no1 sense the voltages.
- Stage 4 – At this stage PCB relay senses the voltage across the fan and check the condition whether it is voltage drop of 140V or not.
- Stage 5-
IF yes
If PCB relay No1 sense the voltage drop of 140 volts then again condition occurs that checks the that voltage drop is done by regulator or power supply.
• If voltages drop by regulator, then PCB relay no 01 gives information to relay no 02 to keep the winding in series i.e. in normal condition.
• If voltages drop by power supply, then PCB relay no 01 gives information to relay no 03 to keep the winding in parallel i.e. in speed boost condition.
IF NO,
If PCB relay No1 sense the NO voltage drop of 140 volts then again condition occurs that checks the that No voltage drop is done by regulator or power supply.
• If No voltages drop by regulator, then PCB relay no 01 gives information to relay no 02 to keep the winding in series i.e. in normal condition.
• If No voltages drop by power supply, then PCB relay no 01 gives information to relay no 02 to keep the winding in series i.e. in normal condition.

- Stage 6 - again at this stage condition occurs which is comes under equal interval of time i.e. PCB sense the voltages drop after equal interval of time for 2 sec when the fan is out of power source.

Although the foregoing description of the present invention has been shown and described with reference to particular embodiments and applications thereof, it has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the particular embodiments and applications disclosed. It will be apparent to those having ordinary skill in the art that a number of changes, modifications, variations, or alterations to the invention as described herein may be made in complete specification, none of which depart from the spirit or scope of the present when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.

,CLAIMS:
1. A ceiling fan motor with a switching circuitry for controlling rotation speed of the ceiling fan motor at low voltages comprising of :
a motor with a main coil and an auxiliary coil, wherein the main coil is centrally tapped dividing the same into first main coil and second main coil;
a motor starting capacitor electrically connected between the main coil and the auxiliary coil;
a plurality of multi-stage relay switch including a common contact, configured the switching the tapped main coil in series and parallel for at least one rotation speed contact electrically connected to the second main coil contact; wherein
the motor starting capacitor cooperates with the multi-stage relay switches in order to control the rotation speed and direction of the ceiling fan.

2. The ceiling fan motor as claimed in claim 1, wherein the said the multi-stage relay switch is configured to switch between series and parallel connection in the main coil.
3. The ceiling fan motor as claimed in claim 1, wherein the said mail coil of the motor winding is split type so that two windings (first and second) are available in main windings.
4. The ceiling fan motor as claimed in claim 1, wherein under condition that the supply is in normal mode i.e 230V then the said two windings were connect as in series connection.
5. The ceiling fan motor as claimed in claim 1, wherein under condition that the supply voltage drops below 140-150 volts same winding get connected as they were in parallel connection.
6. The ceiling fan motor as claimed in claim 1, further includes external regulator circuit, wherein the ceiling fan is configured to work with said regulator.
7. The ceiling fan motor as claimed in claim 1, wherein the said switching circuitry / device is configured to prevent any damage at lower voltages.
8. The ceiling fan motor as claimed in claim 1, wherein the said switching circuitry / device is configured the checking of voltage, for a regular period.
9. The ceiling fan motor as claimed in claim 1, wherein the said motor is single phase ac induction motor and has a winding (wound stator) configured for a voltage and tolerance.
10. The ceiling fan motor as claimed in claim 1, wherein the said windings changes makes fan to rotate at highest speed even if supply voltage is very low almost about 130V with air delivery as compared with to normal rating voltage of fan.