Title of Invention

REMOTE OPERATED ELECTRIC FAN AND LAMP CONTROLLER

Abstract

Remote operated electric fan and lamp controller located in a housing and comprising a plurality of first triacs corresponding to the different speed setting of the fan, the first main terminals of the first triacs being connected to an AC power supply, the second main terminal of one of the first triacs corresponding to the full speed setting of the fan being connected to one end of first resettable fuse through a surge resistor, the second main terminals of the remaining first triacs corresponding to the remaining speed setting of the fan each being connected to the said one end of the first resettable fuse through a capacitor and surge resistor combination in series, the capacitance and resistance values of the capacitor and surge resistors differing corresponding to the remaining speed setting of the fan, the other end of the first resettable fuse being connected to the fan, a second triacs whose first main terminals is connected to the AC power supply and second main terminal is connected to the lamp through a second resettable fuse, the gate terminals of the first and second triacs being connected to the outputs of a microcontroller, an infra red sensor unit connected to an input of the microcontroller, a losseless capacitor dropper DC supply connected to the AC power supply and to the microcontroller, a non-volatile memoryconnected to the microconyroller, a operational status indicating display mounted on the housing and connected to yhe microcontroller and a manually operable swiching unit connected to another input of the microcontroller.

Full Text

FORM 2 THE PATENTS ACT, 1970 (39 of 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006 COMPLETE SPECIFICATION (See section 10 and rule 13) TITLE OF INVENTION Remote operated electric fan and lamp controller APPLICANTS Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli Mumbai 400025, Maharashtra, India an Indian Company The following specification particularly describes the nature of this invention and the manner in which it is to be performed FIELD OF INVENTION This invention relates to a remote operated electric fan and lamp controller. PRIOR ART Manually operated fan speed controllers may comprise a plurality of power resistors or inductors or capacitors connected in series with an AC power supply and switched in series with the fan by a rotary switch. The resistor based controllers suffer from high power losses due to excess heat generation in the resistors. Due to excess heating, the resistors tend to burn out thereby reducing the life of the controllers. Besides during speed changing high currents appear across the contacts resulting in sparking and wear and tear to the switching contacts. This also reduces the life of the controllers. Also transients of high amplitude are created in the AC power supply when the resistors are switched in series with the fan. In the case of inductor based fan speed controllers, power losses are reduced but they also suffer from the other problems discussed earlier. Power losses are eliminated in the capacitor based fan speed controllers. But disadvantages of wear and tear to contacts due to high currents appearing across the 2 contacts during switching and generation of transients of high amplitude in the AC power supply persist in such fan speed controllers. Besides the capacitors are switched in series with the fan at random because of which there are chances of the capacitors being charged at the instance when the sinewave of the power supply is passing through its peak. This will introduce excessive stresses in the capacitors thereby reducing their life and the life of the controllers. Another manually operated fan speed controller comprises a triac whose first main terminal is connected to an AC power supply and second main terminal is connected to the fan. A diac is connected to the gate terminal of the triac and the junction of a variable resistor and capacitor combination in series which in turn is connected across the AC power supply and fan. During operation of the controller the capacitor starts charging after every zero crossing of a half cycle of a sinewave of the power supply through the variable resistor. When the voltage across the capacitor reaches the breakdown voltage of the diac, the diac triggers the triac and applies a current to the fan causing the fan to rotate. The resistor and capacitor combination creates a delay for triggering the triac ie switching the triac on at various points of the half cycle of the 3 sinewave of the AC power supply. Thus it allows controlled currents to flow to the fan corresponding to the various speed settings thereof. In such a fan speed controller, surge currents are generated during switching on and off of the triac. The surge currents flow into the fan causing a humming or buzzing noise during its operation. Since each half cycle of a sinewave of the power supply is chopped a large number of harmonics are also generated in the controller which result in conducted and radiated interferences in the surroundings. A remote operated fan and lamp controller comprises two triacs whose gate terminals are connected to two outputs of a microcontroller. The first main terminals of the two triacs are connected to an AC power supply and second main terminals are connected to the fan and lamp, respectively. A DC supply derived from the AC power supply is connected to the micro controller. An infra red sensor unit is connected to an input of the microcontroller. The fan and lamp controller is remote operated by an IR hand set. On pressing a key corresponding to a fan speed setting or lamp brightness setting on the handset, a unique code is transmitted by the handset as a stream of infra red light pulses which are picked-up by the IR sensor unit. The IR sensor unit outputs a corresponding 4 digital signal to the microcontroller which decodes the signal and outputs a pulse to trigger the respective triac and apply a current to the fan or the lamp causing the fan to rotate at that particular speed or the lamp to glow at that particular intensity of brightness as the case may be. The pulse generated by the microcontroller at specific time delays from the zero crossing point of the half cycle of a sinewave of the AC power supply corresponds to the different speed settings of the fan or different brightness settings of the lamp, as the case may be. In the case of such a controller the fan gives a humming sound during its operation as surge currents generated in the controller during switching of the respective triac flow into the fan. Due to the wave form being chopped, conducted and radiated interferences are also generated in the surroundings. When the fan and lamp are switched on after they were switched off at a particular speed and brightness setting or after a power failure, the last selected speed and brightness setting of the fan and lamp are not revived and retained ie the fan and lamp do not rotate and glow at the last selected speed and brightness setting, respectively. Instead the fan and lamp rotate and glow at some random or default speed setting and brightness, respectively as the controller is without any memory. In another version of such a controller it may be without the lamp and corresponding triac. 5 OBJECTS OF INVENTION An object of the invention is to provide a remote operated electric fan and lamp controller which controls the operations of both a fan and a lamp and is user friendly. Another object of the invention is to provide a remote operated electric fan and lamp controller which ensures noise free operation of the fan at different speed settings ie without humming or buzzing sound . Another object of the invention is to provide a remote operated electric fan and lamp controller which retains the speed setting of the fan at which it operated immediately before power to the controller was switched off or power failure occurred. Another object of the invention is to provide a remote operated electric fan and lamp controller which visually continuously indicates the fan and light operational status. Another object of the invention is to provide a remote operated electric fan and lamp controller which prevents damage to the fan and 6 light under overload condition and resumes normal operation of the controller when the overload condition is rectified. Another object of the invention relates is to provide a remote operated electric fan and lamp controller which reduces conducted and radiated interferences in the surroundings. Another object of the invention relates is to provide a remote operated electric fan and lamp controller which does not introduce excessive stresses in the capacitors thereby improving the life of the capacitors and that of the controller. Another object of the invention is to provide a remote operated electric fan and lamp controller which eliminates drawbacks associated with conventional fan and lamp controllers. DETAILED DESCRIPTION OF INVENTION According to the invention there is provided a remote operated electric fan and lamp controller located in a housing and 7 comprising a plurality of first triacs corresponding to the different speed settings of the fan, the first main terminals of the first triacs being connected to an AC power supply, the second main terminal of one of the first triacs corresponding to the full speed setting of the fan being connected to one end of a first resettable fuse through a surge resistor, the second main terminals of the remaining first triacs corresponding to the remaining speed settings of the fan each being connected to the said one end of the first resettable fuse through a capacitor and surge resistor combination in series, the capacitance and resistance values of the capacitors and surge resistors differing corresponding to the remaining speed settings of the fan, the other end of the first resettable fuse being connected to the fan, a second triac whose first main terminal is connected to the AC power supply and second main terminal is connected to the lamp through a second resettable fuse, the gate terminals of the first and second triacs being connected to the outputs of a microcontroller, an infra red sensor unit connected to an input of the microcontroller, a lossless capacitor dropper DC supply connected to the AC power supply and to the microcontroller, a non-volatile memory connected to the microcontroller, a operational status indicating display mounted on the housing and connected to the microcontroller and a 8 manually operable switching unit connected to another input of the microcontroller. The following is a detailed description of the invention with reference to the accompanying drawings, in which : Fig 1 is a block and schematic circuit diagram of a remote operated electric fan and lamp controller according to an embodiment of the invention; and Figs 2a, 2b and 2c are schematic views of the operational status indicating display of the controller of Fig 1 according to an embodiment of the invention illustrating the different operational status of the fan and lamp. The remote operated electric fan and light controller 1 as illustrated in Figl of the accompanying drawings is located in a housing 2 and comprises a plurality of first triacs 3, 4, 5 and 6 corresponding to the different speed settings of a fan 7. The first main terminals 8, 9, 10 and 11 of the first triacs are connected to an AC power supply 12. The second main terminal 13 of one of the triacs namely triac 6 corresponding to the 9 full speed setting of the fan is connected to one end of a first resettable fuse 14 through a surge resistor 15. The second main terminals 16, 17 and 18 of the remaining first triacs 3, 4 and 5 corresponding to the remaining speed settings of the fan are connected to the said one end of the first resettable fuse through combinations of capacitor 19 and surge resistor 20, capacitor 21 and surge resistor 22 and capacitor 23 and surge resistor 24 in series, respectively. The values of the above capacitors 19, 21 and 23 and resistors 20, 22 and 24 differ corresponding to the remaining speed settings of the fan. The other end of the first resettable fuse 14 is connected to the fan. 25 is a second triac whose first main terminal 26 is connected to the AC power supply and second main terminal 27 is connected to a lamp 28 through a second resettable fuse 29. The gate terminals 30, 31, 32, 33 and 34 of triacs 3, 4, 5, 6 and 25, respectively are connected to the outputs of a 8 bit microcontroller 35. 36 is an infra red sensor unit connected to an input of the microcontroller. 37 is a lossless capacitor dropper DC supply connected to the AC power supply and the microcontroller. 38 is a non¬volatile memory connected to the microcontroller. 39 is an operational status indicating display which as illustrated in Figs 2a, 2b and 2c of the accompanying drawings comprises a light emitting diode array comprising a plurality of light emitting diodes (LEDS) 40, 41, 42, 43, 44 10 and 45 mounted on the housing and connected to the microcontroller. One of the light emitting diodes namely 40 is located at the centre of a circle 46 defined on the housing. The remaining light emitting diodes 41 - 45 are located at the circumference of the circle and correspond to the various speed settings of the fan. The diode array further comprises a light emitting diode 47 located at the circumference of the circle and connected to the microcontroller. The light emitting diode 47 corresponds to the lamp. 48 is a manually operable switch unit connected to another input of the microcontroller. The manually operable switch unit may comprise on/off switches (not shown) for the fan and lamp and power supply and switches (not shown) corresponding to the various speed settings of the fan. When the power to the controller is turned on and key corresponding to the full speed setting of the fan on the IR remote handset (not shown) is depressed, a stream of corresponding infra red pulses are transmitted by the handset. The pulses are sensed by the infra red sensor unit and converted into a corresponding digital signal. This digital signal is applied to the microcontroller which decodes the signal and switches on triac 6 which allows current to flow into the fan 11 through resistor 15 and resettable fuse 14 and the fan rotates at full speed. In the switched on position of the controller if any other key corresponding to a speed setting of the fan other than the full speed setting thereof is depressed on the IR remote handset, a stream of infra red pulses corresponding to that speed setting are transmitted by the handset. The pulses are sensed by the IR sensor unit and converted into a corresponding digital signal. This digital signal is applied to the microcontroller which decodes the signal and initially momentarily switches on triac 6 and allows the capacitors 19, 2l and 23 to discharge. Due to the inherent nature of triacs, the triac 6 switches off at the zero crossing of the half cycle of the sinewave of the AC power supply. At this instant, the microcontroller switches on one of the triacs 3-5 corresponding to the desired speed setting thereby enabling the respective capacitor to charge from zero crossover of the sinewave of the power supply and provide a controlled current to the fan to enable the fan to rotate at the desired speed. Anyone of the capacitors 19, 21 and 23 in circuit will thus always start charging at the zero crossover of the sinewave of the AC power supply. In the turned on position of the controller, if the key corresponding to the lamp is depressed on the IR remote hand set, a stream of corresponding in frared pulses are 12 transmitted by the hand set. The pulses are sensed by the infra red sensor unit and converted into a corresponding digital signal. This digital signal is applied to the microcrontroller which decodes the signal and switches on triac 25 which allows current to flow into the lamp through resettable fuse 29 and the lamp glows. According to the invention the controller thus controls both the fan and lamp operations and is user friendly. Instead of using the remote operated handset, the fan and lamp also may be operated by the respective switches on the manually operable switch unit at the option of the user. In the turned on position of the AC power supply centre LED 40 will glow. When a particular fan speed setting is selected either by depressing a key on the IR remote handset or by operating the switches on the manually operable switch unit one of the LEDs 41-45 located at the circumference of the circle 46 corresponding to the selected speed setting will glow. As per Gestalt laws of perception, glowing of the centre LED 40 and one of the LEDs 41-45 gets connected in the mind of the observer and creates an illusion of a line between the two LEDs analogous to a pointer of an analog meter indicating speed on the dial thereof (not 13 shown). For instance, in Figs 2b and 2c LEDs 40 and 41 and LEDs 40 and 45 are observed as connected indicating the lowest speed and full speed of the fan, respectively. On selecting the remaining speeds of the fan, the user or observer will perceive the centre LED connected to the corresponding LEDs at the circumference of the circle. When the lamp is switched on/off by the remote handset or manually the corresponding LEDs marked 47 will glow or turn off. The controller thus visually indicates the fan and light operational status. Surge currents generated in the controller during switching of the triacs are reduced by the resistors 15, 20, 22 and 24 connected in series with the respective triacs and are not thus allowed to reach the fan thereby allowing noise free operation of the fan. Therefore humming and buzzing of the fan at its different speed settings is eliminated. The resettable fuses offer high impedance when currents higher than rated currents flow through them and revert to their low impedance state when the fault is rectified thereby ensuring protection to the controller in overload conditions. As triac 6 corresponding to the full speed setting of the fan is always selected first by the controller during fan operation, capacitors 19,21 and 23 are discharged. Triac 6 turns off at the zero crossing of the sinewave 14 of the AC power supply and the controller switches on one of the triacs 3 - 5 corresponding to the desired speed setting thereby enabling the respective capacitor to charge from zero crossing. Therefore the capacitors 19, 21 and 23 are not subjected to high voltage stresses thereby increasing their life span and that of the controller. The non-volatile memory of the controller stores the operational settings of the fan and lamp. If the power supply is switched off or if there is a power failure at a particular speed setting of the fan and the lamp is in the turned on/off position the non¬volatile memory stores the information and feeds it to the microcontroller. On turning on the power supply or restoring the power supply the microcontroller restores the status of the fan and lamp prevailing at the instance of switching off the power supply or power failure. For instance, if the fan was rotating at the lowest speed and the lamp was glowing, that status will be restored and if the fan was rotating at the speed just next to the full speed and the lamp was turned off such status of the fan and lamp will be restored. Since full sine wave of the AC power supply is always applied to the fan, conducted and radiated interferences in the surroundings are reduced. The fan and lamp controller of the invention eliminates the drawbacks associated with the conventional fan and lamp controllers. 15 There may be variations / modifications in the invention without deviating from the scope thereof. For instance the DC power supply may be another DC power supply capable of giving the required voltage for operation of the microcontroller. For instance, it may be switch mode power supply or a linear transformer based power supply. The number of first triacs will vary depending upon the speed settings. Two or more fans and lamps may be operated by the controller by having corresponding numbers of first triacs and second triacs and microcontrollers. A 4 bit or 16 bit microcontroller may also be used in the invention. The LED corresponding to the lamp may be anywhere on the housing and need not necessarily be at the circumference of the circle. The operational status indicating display may be of any other construction or configuration for instance it may be LCD (Liquid Crystal Display) or graphic LCD based. Such variations / modifications of the invention are to be construed and understood to be within the scope of the invention. 16 WE CLAIM 1. Remote operated electric fan and lamp controller located in a housing and comprising a plurality of first triacs corresponding to the different speed settings of the fan, the first main terminals of the first triacs being connected to an AC power supply, the second main terminal of one of the first triacs corresponding to the full speed setting of the fan being connected to one end of a first resettable fuse through a surge resistor, the second main terminals of the remaining first triacs corresponding to the remaining speed settings of the fan each being connected to the said one end of the first resettable fuse through a capacitor and surge resistor combination in series, the capacitance and resistance values of the capacitor and surge resistors differing corresponding to the remaining speed settings of the fan, the other end of the first resettable fuse being connected to the fan, a second triac whose first main terminal is connected to the AC power supply and second main terminal is connected to the lamp through a second resettable fuse, the gate terminals of the first and second triacs being connected to the outputs of a microcontroller, an infra red sensor unit connected to an input of the microcontroller, a lossless capacitor dropper DC supply connected to the AC power supply and to the microcontroller, a non-volatile memory 17 connected to the microcontroller, a operational status indicating display mounted on the housing and connected to the microcontroller and a manually operable switching unit connected to another input of the microcontroller. 2) A remote operated electric fan and lamp controller as claimed in claim 1, wherein the operational status indicating display is a light emitting diode array comprising a plurality of light emitting diodes, one of the light emitting diodes being located at the centre of a circle defined on the housing and the remaining light emitting diodes being located at the circumference of the circle and corresponding to the fan, the diode array further comprising a further light emitting diode corresponding to the lamp and located on the housing. 3) A remote operated electric fan and lamp controller as claimed in claim 2, wherein the further light emitting diode corresponding to the lamp is located at the circumference of the circle. 18 4) A remote operated electric fan and lamp controller as claimed in anyone of claims 1 to 3, wherein the microcontroller is an 8 bit microcontroller. 5) A remote operated electric fan and lamp controller as claimed in any one of claims 1 to 4, wherein the manually operable switching unit comprises on/off switches for the fan and lamp and power supply and switches corresponding to the various speed settings of the fan. 6) A remote operated electric fan and lamp controller substantially as herein described particularly with reference to Figs 1,2a, 2b and 2c of the accompanying drawings. Dated this 15th day of July 2004 (Jose M A) of Khaitan & Co Agent for the Applicants

Documents:

757-mum-2004-cancelled pages(15-07-2004).pdf

757-mum-2004-claims(granted)-(02-01-2007).doc

757-mum-2004-claims(granted)-(02-01-2007).pdf

757-mum-2004-correspondence(14-09-2007).pdf

757-mum-2004-correspondence(ipo)-(11-04-2007).pdf

757-mum-2004-form 1(15-07-2004).pdf

757-mum-2004-form 18(11-02-2005).pdf

757-mum-2004-form 2(granted)-(02-01-2007).doc

757-mum-2004-form 2(granted)-(02-01-2007).pdf

757-mum-2004-form 26(02-01-2007).pdf

757-mum-2004-form 3(15-07-2004).pdf