DESC:FIELD OF THE INVENTION
[001] The present invention relates to a regulator and in particular, a regulator to control voltage across electrical devices such as ceiling fan with specific wattage.

BACKGROUND OF THE INVENTION
[002] Regulators are widely used to control voltage across electrical loads such as electrical appliances. Commonly, regulators are used to control speed of fan, intensity of light sources and other appliances, whereby the regulator is connected between the electrical appliance and a switch. Types of regulators, typically for fans include an electric regulator, a movable-type electronic regulator and a step type regulator. The electric regulator incurs significant heat losses besides being quite bulky in size, whereas the movable-type electronic regulator creates unwanted noise in the fan when fan speed is low. The step type fan regulator on the other hand is widely used owning to energy saving features.
[003] Figure 1 illustrates a regulator 100 for a ceiling fan (not shown) of specified wattage as per prior art. The regulator 100 is a step type regulator. The regulator 100 includes a top housing 110, a bottom housing 120 and a PCB 130. A shaft is rotatably mounted in the top housing 110 and extends from a top end to a bottom end. At the top end, the shaft extends upwards from the top housing and is configured for allowing a knob to be mounted thereon. At the bottom end, a contact plate is provided whereby rotation of the knob causes the shaft and the contact plate to rotate. The bottom housing 120, as shown in the figure, is provided below the top housing 110, and the top housing 110 and the bottom housing 120 are interlocked. The bottom housing 120 comprises of plurality of contact pads provided on its top surface. The top housing 110 and the bottom housing 120 are provided such that the contact plate of the shaft and the plurality of the contact pads are in contact, whereby upon rotation of the shaft, the contact plate rotates, and arms of the contact plate selectively make contact with one of the metal pads present on the top surface of the bottom housing 120 depending upon position of the knob/shaft. Further, the bottom housing 120 has a plurality of terminals on a bottom surface of the bottom housing 120. The plurality of terminals is connected to the plurality of pads on the top surface of the bottom housing 120. The plurality of terminals is in turn, mounted to the PCB 130. The PCB 130 has electrical components such as resistors and plurality of capacitors 140 and a plurality of resistors which are connected with the terminals of the bottom housing 120.
[004] The bottom housing 120 occupies significant space in the regulator 100 just for the limited functionality of housing the plurality of pads and the plurality of terminals. Further, in conjunction with the top housing 110 and the plurality of capacitors 140, the fan regulator 100 becomes bulky in size.
[005] Further, as modern switchboards are quickly adapting sleek designs, the fan regulator struggles to adapt to space and size constraints besides being aesthetically unsightly in contemporary décor. In addition, the bottom housing 120 adds to manufacturing costs.
[006] Thus, there is a need in the art for a regulator which addresses the aforementioned problems.

SUMMARY OF THE INVENTION
[007] In one aspect the present invention provides a regulator, comprising: a housing; a shaft rotatably mounted in the housing, the shaft extending from a top end to a bottom end, at the top end the shaft extends upwards from the housing and is configured for allowing a knob to be mounted thereon, and at the bottom end a contact plate is provided whereby rotation of the knob causes the shaft and the contact plate to rotate; and a printed circuit board (PCB) comprising plurality of pads of conductive material provided on a top surface of the PCB, and plurality of resistors and plurality of capacitors mounted on the top surface and/or bottom surface of the PCB and electrically connected with the plurality of pads, the plurality of pads comprises a pad having a circular profile, and plurality of pads provided adjacent to outer periphery of the pad, the housing mounted on the PCB such that the contact plate of the shaft and the plurality of the conductive pads are in contact, whereby upon rotation of the shaft, the contact plate rotates, and arms of the contact plate selectively make contact with one of the plurality of pads present on the top surface of the PCB depending upon position of the knob /shaft.

BRIEF DESCRIPTION OF THE DRAWINGS
[008] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates an exploded view of a regulator in accordance with a prior art of the invention.
Figure 2 illustrates an exploded view of a regulator in accordance with an embodiment of the invention.
Figure 3 illustrates a printed circuit board (PCB) of the regulator in accordance with an embodiment of the invention.
Figure 4 illustrates a contact plate mounted on a shaft of the regulator in accordance with an embodiment of the invention.
Figure 5 illustrates a schematic diagram of interconnection of components mounted on the PCB in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION
[009] The present invention is directed towards a regulator and in particular, a regulator to control voltage across ceiling fans of specified wattages.
[010] Figure 2 shows an exploded view of a regulator 200 for a ceiling fan (not shown) in accordance with an embodiment of the invention. The regulator 200 is a step-type regulator for regulating speed of the fan by regulating the voltage. However, the regulator 200 may also be for any other kind of electrical appliance such as a filament bulb. Thus, it is to be understood that the illustrated regulator 200 should not be construed to be limiting the scope of the present invention.
[011] The regulator 200 comprises a housing 210, a PCB 260, wherein the housing 210 is mounted on the PCB 260. A shaft 240 is rotatably mounted in the housing 210 and extends from a top end 240a to a bottom end 240b. At the top end 240a, the shaft 240 extends upwards from the housing 210 and is configured for allowing a knob to be mounted thereon. At the bottom end 240b, a contact plate 250 is provided whereby rotation of the knob causes the shaft 240 and the contact plate 250 to rotate. In an embodiment, the regulator 200 is a step type regulator, wherein the shaft 240 is configured to rotate in steps. In this regard, the shaft 240 has plurality of spaced apart protrusions forming a plurality of slots 240c therebetween and a rocker 230 configured to be accommodated in one of the plurality of slots 240c. The rocker 230 is mounted on a spring 220. Upon rotation of the shaft 240, the protrusion pushes the rocker 230 whereby the spring 220 compresses allowing the shaft 240 to rotate. During rotational movement, as the protrusion passes the rocker 230, the spring 220 pushes the rocker 230, and the rocker is accommodated in the slot 240c and remains in position until it is rotated further. This creates a step effect. The number of slots 240c will depend on the type of regulator - 4 step regulator, 5 step regulator, 6 step regulator, etc. The rocker 230 keeps the shaft 240 at the centre of the housing 210. Further, the rocker spring 220 provides suspension to the rocker 230.
[012] Figure 3 illustrates the PCB 260 in accordance with an embodiment of the invention. The PCB 260 comprises plurality of pads Pn provided on a top surface of the PCB 260. The plurality of pads Pn are made of conductive material such as metals etched on the PCB 260. The metals can be PCB grade tinned copper. The plurality of pads Pn comprises a pad PC having a circular profile, and plurality of pads P1 to P6. The pads P1 to P6 are provided adjacent to outer periphery of the circular pad PC and the pads P1 to P6 are spaced apart from each other. As discussed hereinbefore, the housing 210 is mounted on the PCB 260. In this regard, the housing 210 is mounted such that the contact plate 250 of the shaft 240 and the plurality of the conductive pads Pn are in contact, whereby upon rotation of the shaft 240, the contact plate 250 rotates, and arms of the contact plate 250 selectively make contact with one of the plurality of pads Pn present on the top surface of the PCB 260 depending upon position of the knob /shaft 240. The present invention thus obviates the need of a bottom housing 120 required in the prior-art. The regulator 200 of the present invention is thus compact and also reduces manufacturing time and associated costs.
[013] Further, plurality of resistors (not shown) and plurality of capacitors 270C1, 270C2, 270C3 are mounted on the PCB 260, and the resistors and capacitors 270C1, 270C2, 270C3 are electrically connected with the plurality of pads Pn. The plurality of capacitors 270C1, 270C2, 270C3 are disposed on a bottom surface of the PCB 260 and the plurality of resistors are disposed either on the bottom surface or on the top surface of the PCB 260. A schematic diagram of interconnection of components mounted on the PCB 260 is illustrated in Figure 5. As illustrated, the plurality of capacitors 270C1, 270C2, 270C3 are connected individually in parallel with a resistor R1, R2, R3. In an embodiment, the resistor R1, R2, R3 can have a resistance of 220 kilo-ohm. The resistor R1, R2, R3 enables discharging the plurality of capacitors 270C1, 270C2, 270C3 thereby, avoiding sparking during change-over from each step to a next step. Further, the resistors R4, R5 are disposed between the pads and the plurality of capacitors 270C1, 270C2, 270C3. The resistors R4, R5 are configured to operate as a current limiter i.e., to limit the inrush current into the plurality of capacitors 270C1, 270C2, 270C3. When capacitance value increases, voltage across a fan increases and thus, the plurality of capacitors 270C1, 270C2, 270C3 can be selectively incorporated by operating the regulator 200 to manipulate fan speed. Further, the capacitors 270C1, 270C2, 270C3 have different capacitance values and at least capacitor 270C2 has a greater capacitance value than capacitor 270C3. A plurality of connecting wires (not shown) is connected, by means of soldering, onto the PCB 260. The plurality of connecting wires connects the regulator 200 with input voltage i.e., a switch or a source. Further, the plurality of connecting wires connects the regulator 200 with the output i.e., an electrical appliance such as a fan or a light bulb. Further, a plurality of traces (not shown) on the PCB 260 allow flow of current between components of the regulator 200.
[014] Figure 4 illustrates the contact plate 250 mounted on the shaft 240 of the regulator 200 in accordance with an embodiment of the invention. The contact plate 250 is affixed to the bottom end 240b of the shaft 240 at a pair of mounting slots 255 via welding. The contact plate 250 has four arms 250a, 250b, 250c. 250d that upon rotation of the contact plate 250 connect selectively to one of the pads Pn of the PCB 260. The arm 250a of the contact plate 250 is continuously in contact with the main pad PC etched of the PCB 260 throughout the rotation of the contact plate 250.
[015] In an embodiment, the regulator 200 is a step type fan regulator having a total of six steps, whereby the shaft 240 is rotatable 360° in six steps i.e., each rotation of the knob causes the shaft 240 to rotate by 60°. Accordingly, the regulator 200 has six positions: a normal position and five operative positions. In the normal position, the regulator 200 maintains the fan in an OFF condition whereas, in the operative positions, the regulator 200 regulates the voltage across the fan and thereby, the speed of the fan. In this regard, depending upon the position of the shaft 240, the arms of the contact plate 250 selectively makes contact with the conductive pads Pn of the PCB 260 as follows:
[016] When the regulator 200 is in a normal position, only the arm 250a of the contact plate 250 is in contact with the pad PC of the PCB 260. Remainder of the arms 250b, 250c, and 250d are not in contact with any pad of the PCB 260. Therefore, the electrical circuit is incomplete and consequently, no current flows to the fan and 0 V is obtained at the output.
[017] When the regulator 200 is rotated to a first operative position, the contact plate 250 rotates as a consequence. In this position, the arm 250a of the contact plate 250 is in contact with the pad PC and the arm 250C is in contact with the pad P5 of the PCB 260. The pad P5 is connected with the capacitor 270C3 having least capacitance in the plurality of capacitors 270C1, 270C2, 270C3. As capacitance is low, a low voltage of approximately 87 V is generated as an output and thus the fan runs at low speed.
[018] When the regulator 200 is rotated to a second operative position, the contact plate 250 rotates further from the first step as a consequence. In this position, the arm 250a of the contact plate 250 is in contact with the pad PC and the arm 250C in contact with the pad P3 of the PCB 260. The pad P3 is connected with the capacitor 270C2. The capacitor 270C2 has greater capacitance than C3 in the plurality of capacitors 270C1, 270C2, 270C3. As capacitance increases, an increased voltage of approximately 137 V is generated as an output and thus, the fan runs at a greater speed at the second operative position compared to the first operative position of the knob.
[019] When the regulator 200 is rotated to a third operative position, the contact plate 250 rotates further from the second step as a consequence. In this position, the arm 250a of the contact plate 250 is in contact with the pad PC, and contact arms 250D and 250C are in contact with the pad P3 and a pad P4 of the PCB 260. The pads P3 and P4 are connected with the capacitor 270C2 and capacitor 270C1. The capacitors 270C2 and 270C1 have greater capacitance than 270C2 standalone. As capacitance increases, an increased voltage of approximately 176 V is generated as an output and thus, the fan runs at a greater speed at the third step compared to the second step.
[020] When the regulator 200 is rotated to a fourth operative position, the contact arm 250a of the contact plate 250 is in contact with the pad PC, and the contact arms 250C, 250B and 250D are in contact with the pad P4, the pad P1 and the pad P6 respectively of the PCB 260. The pads P4, P1 and P6 are connected with the three capacitors 270C1, 270C2 and 270C3. The three capacitors altogether will have highest capacitance. As capacitance increases, an increased voltage of approximately 205 V is generated as an output and thus, the fan runs at a greater speed at the fourth step compared to the third operative position. In all the preceding operative positions, the resistors R4, R5 operate as a current limiter.
[021] When the regulator 200 is rotated to a fifth operative position, the arm 250a of the contact plate is in contact with the pad PC and the other pads are not in contact with any of the pads, and the contact plate 250 bypasses all the capacitors. In absence of any impedance from the plurality of capacitors 270C1, 270C2, 270C3, voltage will be around 230 V, and thus the fan runs at its highest speed at the fifth operative position.
[022] Advantageously, the present invention provides a regulator that embeds a plurality of conductive pads directly onto a PCB. Resultantly, the regulator is smaller in size and thus, can meet the space constraints of modern switchboard aesthetics. Further, due to absence of a bottom part as present in the prior art, assembly of the components is simpler, time-efficient and cost effective.
[023] The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since the modifications of the disclosed embodiments incorporating the substance of the invention may occur to the person skilled in the art, the invention should be construed to include everything within the scope of the invention.
,CLAIMS:WE CLAIM:
1. A regulator 200, comprising:
a housing 210;
a shaft 240 rotatably mounted in the housing 210, the shaft 240 extending from a top end 240a to a bottom end 240b, at the top end 240a the shaft 240 extends upwards from the housing 210 and is configured for allowing a knob to be mounted thereon, and at the bottom end 240b a contact plate 250 is provided whereby rotation of the knob causes the shaft 240 and the contact plate 250 to rotate; and;
a printed circuit board (PCB) 260 comprising plurality of pads Pn of conductive material provided on a top surface of the PCB 260, and plurality of resistors and plurality of capacitors 270C1, 270C2, 270C3 mounted on the top surface and/or bottom surface of the PCB 260 and electrically connected with the plurality of pads Pn, the plurality of pads Pn comprises a pad PC having a circular profile, and plurality of pads P1 to P6 provided adjacent to outer periphery of the pad PC, the housing 210 mounted on the PCB 260 such that the contact plate 250 of the shaft 240 and the plurality of the conductive pads Pn are in contact, whereby upon rotation of the shaft 240, the contact plate 250 rotates, and arms of the contact plate 250 selectively make contact with one of the plurality of pads Pn present on the top surface of the PCB 260 depending upon position of the knob /shaft 240.
2. The regulator 200 as claimed in claim 1, wherein the shaft 240 is configured to rotate in steps, the shaft 240 having plurality of spaced apart protrusions forming a plurality of slots 240c therebetween and a rocker 230 mounted on a spring 220 configured to be accommodated in one of the plurality of slots 240c whereby upon rotation of the shaft 240, the protrusion pushes the rocker 230 and the spring 220 compresses allowing the shaft 240 to rotate.
3. The regulator 200 as claimed in claim 1, wherein the conductive material is a metal etched on the PCB 260.
4. The regulator 200 as claimed in claim 3, wherein the metal is PCB grade tinned copper.
5. The regulator 200 as claimed in claim 1, wherein the contact plate 250 has four arms 250a, 250b, 250c, 250d that upon rotation of the contact plate 250 connect selectively to one of the pads Pn of the PCB 260.

Dated this 10th day of June 2022.

GM MODULAR PRIVATE LIMITED
By their Agent & Attorney

(Janaksinh Jhala)
of Khaitan & Co
Reg No IN/PA-2193