FIELD OF THE INVENTION
The present invention includes an auxiliary coil for the electric machine capable of being accommodated in a two-wheeler or a three-wheeler.
BACKGROUND
A motor has a fixed Ke and Kt depending on the number of turns in each phase. The range of the motor can be extended by many methods such as the flux weakening, the double stator, reconfiguring the stator coils and even moving the rotor to provide less flux path, thereby operating the motor efficiently in each possible speed band.
A way of reconfiguring the coils is done with the help of switches (or relays) to extend the operating speed band. Usually, the switches are energized with the help of voltage supplied from the controller. If the switches are to be energized by the controller, then it needs additional input or output ports on the controller, additional current from the controller or even sensors to calculate the speed to alter the switching configurations.
DISCUSSION ON PRIOR ART
US2006/0181238 A1 titled “Variable speed motor” describes a variable speed motor that comprises a main winding that includes the first and second main windings, and also an auxiliary winding that includes the first and second auxiliary windings. Both the main winding and the auxiliary winding are wound on the stator to form more than one pole and relay that execute a switching operation between the connections of the first and the second main windings or first and second auxiliary windings that can be parallel or serial. The variable speed motor comprises a stator having wounded a four and a twelve pole winding, there are more than one tap winding that are connected to the four poles main winding in series and form four poles, extends the variable range of motor’s rotation speed during the four pole operation mode, and a phase control circuit that varies the motor’s rotational speed by controlling during a twelve-pole operation mode a phase of an input power-supply signal. The variable speed

motor extends the range of the variable speed of the motor greatly, and an additional drive unit is not required for varying the motor speed, such that there is a great reduction in the production costs and electromagnetic vibration noise generated by the low-speed control mode of the motor. The rotation speed of the motor is controlled by the winding switching operation and the phase control operation so that the power consumption is reduced and the motor speed is controlled by the variable motor.
However, the variable speed motor described above needs additional electronic control system for the switches to be energized by the controller, which in turn needs additional input or output ports on the controller.
US2010/0039060 A1 titled “Two speed induction motor with tapped auxiliary winding” describes a two-speed motor that increases the low-speed efficiency. The invention comprises a six lead, two speed, and single-phase induction motor, consequently wound with a tapped auxiliary winding that has two modes: a two-pole high-speed mode and a four pole low-speed mode. A portion of the auxiliary winding, in series, is connected with the four pole winding. The four pole low-speed mode has an efficiency of over 80%.
Accommodation of such multi-speed configuration complicates the construction of the motor and also requiring additional components especially to accommodate in a compact two-wheeler or a three-wheeler.
US2011/0187307 A1 titled “Multispeed induction motor” describes a multi-speed induction motor that comprises two stator windings, that is, a low pole and a high pole count winding that is wound around a common stator core. The stators teeth radially extend itself inward from a stator yoke and have slots open in the inner diameter. The high poled count winding is wound first on the stator core in a way that the high pole count winding is next to the stator yoke. The low pole count winding is wound later and is interior radially to the high pole count winding.

WO2009154007A1 titled “Permanent magnet type rotating electric machine” describes the deterring of the increased magnetization current during demagnetization and magnetization and achievement of variable-speed high-output operation over a wide range from low speed to high speed. A rotor consists a rotor core, permanent magnets for which the product in the magnetic direction of the magnetic coercive force and the thickness is small and a permanent magnet for which this same product is large. A magnetic field is caused to act in the opposite direction of the direction of the magnetization of the permanent magnets with the help of the armature coil current, to reduce the interlinking of the magnetic fluxes of the permanent magnets. Likewise, to increase the interlinking of the magnetic fluxes of the permanent magnets, the magnetic field is caused to act in the same direction of the direction of the magnetization of the permanent magnets with the help of the armature coil current. An inductive current is induced in the short-circuit coils, which are provided at the flux path portions of the permanent magnets excluding the permanent magnets, by the magnetic fields produced by the magnetization current and by the inductive current magnetic fields are generated around the short-circuit coils. The permanent magnets are magnetized by the latter magnetic fields and by the magnetic fields generated by the magnetization current.
The available electric machines described above require electronic control based switching system that requires the use of the input and output ports of the controllers for detection of speed and for controlling the switches. Thus, the number of components used such as speed sensors, switch controls adds to the cost of the system.
Thus, there is a need for a system that eliminates the requirement of speed sensors and controller based control and yet capable of providing an electrical machine with effective coil reconfiguration.

SUMMARY OF THE INVENTION
The present invention includes an auxiliary coil wound around the stator tooth and the voltage induced in the auxiliary coil is used to control the switches that are used for winding reconfiguration. The voltage induced in the coils depending on the speed of rotation for a given number of turns. To operate the reconfiguration switches, the voltage has to be above a threshold, which is achieved above a rotational speed. The switches for reconfiguration are arranged such that they are normally in one configuration, and when energized, they give rise to another winding configuration, resulting in changed motor characteristics. Since the motor characteristics need to change above a predetermined rotational speed which is served by the auxiliary coils energizing the switches above a predetermined speed. Instead of using the sensors for speed to alter switching configuration, or using additional current from the controller, or additional input or output ports on the controller, this invention uses the voltage induced in the auxiliary coil to operate the switches. This process saves the energy and the controller modifications.
This can be used in any (Integrated starter generator) ISG system to provide high starting torque and to generate less voltage at high rpm. Also, can be used in any traction motor to extend the speed range of the motor.
The voltage from the controller is used to operate the reconfiguration switches, with feedback from a rotational speed sensor.
This invention is the electric machine that saves energy and controller modifications, said electric machine comprising, a rotor and a stator separated by an air-gap, the main coil wound around a plurality of teeth of said stator, and one or more switches connected to said main coil for winding reconfiguration. The electric machine includes an auxiliary coil wound around said teeth of said stator said one or more switches functionally connected to said auxiliary coil and said auxiliary coil depending on the pre-determined parameter of the electric machine enables switching of said one or more switches for winding reconfiguration. The voltage induced in the auxiliary coil is used to control said switches used for

winding reconfiguration. The voltage induced in the coils depended on the speed of rotation for a given number of turns and said speed of rotation is one of said pre-determined parameter. To enable winding reconfiguration through the switches, the voltage is required to be above a threshold voltage, which is achieved above a pre-determined rotational speed of said rotor. The switches for winding reconfiguration are disposed of such that the winding configuration under normal condition is different from the one under an energized form thus results in transformed motor characteristics.
The auxiliary coils are connected in series and all tooth of each phase such as a reconfiguration for a three-phase diode bridge that generates a three-phase voltage is, operates with a three-phase bridge having six diodes, to provide full-wave rectification with two diodes for each line of three phases, output of the auxiliary coil of the electrical machine is connected to a diode rectifier. A coil of three-phase voltage from the auxiliary coil of the electrical machine is connected to a point at which a cathode of diode D2 is connected to an anode of diode D1. Another coil is connected to a point at which the cathode of diode D4 is connected to the anode of diode D3. Another coil is connected to the point at which the cathode of diode D6 is connected to the anode of diode D5. The anodes of diodes D2, D4, D6 are connected together to make a common point for DC negative terminal of output power, and cathodes of diodes D1, D3, D5 are connected together to form a common point for the DC positive terminal of the output power. To meet the back-emf constant Kea of the auxiliary coil turns are calculated for each phase, thereby generating the required voltage at the set rpm.
The auxiliary coils are connected in series and wound on at least one tooth in any one of the phases to produce the necessary voltage to toggle the switches. A reconfiguration of a single-phase diode bridge is the coils are wound only in one phase, rectified and regulated to the voltage required by the switch for toggling its condition. Diodes D7, D8, D9, D10 are arranged in “series pairs” with only two diodes conducting current during each half cycle. During the positive half cycle of supply, the diodes D7 and D10 conduct in series while the diodes D8 and D9 are

reverse biased, and the current flows through the load. During the negative half cycle of the supply, the diodes D8 and D9 conduct in series, but the diodes D10 and D7 switch “OFF” as they are reverse biased with the direction of current flow through the load in the same direction as earlier. The voltage required for closing the switches are supplied by the electric machine and does not require either the controller or battery to provide the voltage. To meet the back-emf constant Kea of the auxiliary coil, the turns are calculated and is wound around the tooth for any one of the phases, thereby generating the required voltage at the set rpm. The voltage induced in the auxiliary coil is used to operate the switches for altering switching configuration. A two-wheeler or a three-wheeler provided with said electric machine as claimed above.
Thus the present subject matter provides an electric machine that saves energy and controller modifications. The electric machine includes a rotor and a stator separated by an air-gap. The main coil wound around a plurality of teeth or tooth of the stator. One or more switches connected together to the main coil for winding reconfiguration. The electric machine includes an auxiliary coil wound around the teeth of said stator. One or more switches functionally connected together to the auxiliary coil. The auxiliary coil depending on the pre-determined parameter of the electric machine enables switching of the one or more switches for winding reconfiguration. The pre-determined parameter may be the speed of the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 illustrates the electronic circuit with an odd number of sections of coils in the stator. When the switches are operated, the motor winding gets reconfigured to have a wider operational speed band.
Figure 2 illustrates the vehicle with an electric machine which has an auxiliary coil, in accordance with one embodiment of the present subject matter.
Figure 3 illustrates the electronic circuit with a three-phase diode bridge
Figure 4 illustrates the electronic circuit with single-phase diode bridge.

DETAILED DESCRIPTION OF THE EMBODIMENTS
An electric machine (16) consists of a rotor (18) and a stator (15) separated by an air-gap. The rotor (18) is rotatable about the rotor axis relative to the fixed stator (15), it has multiple pairs of magnets pasted on the inner surface of the rotor (18). The stator (15) consists of slots through which the wires or main coil(s) (19) are wound according to the winding configuration. The winding configuration depends upon the number of poles and slots in said electric machine (16). The electric machine (16) can be an n-phase machine with a minimum configuration of at least two phases. When current is applied to the coils wound around the stator teeth, the stator teeth become an electromagnet. When the current is applied in an appropriate direction, there exists a force of attraction between the magnet poles and the opposite electromagnetic poles. This results in torque being applied on the rotor (18). In the present invention, the motor’s stator (15) is composed of multiple coils for each phase, while some switches (s101, s102) are connected at the coil ends. The terms ‘motor’ and ‘electric machine’ are interchangeably used. The switches (s101, s102) are useful in changing the motor’s winding pattern, for example, the number of parallel paths. An example of main coil (19) along with the switches (s101, s102) in the motor configuration is shown as in Figure 1. The present invention includes an auxiliary coil (20) in the electric machine (16) for toggling the switches. The auxiliary coil (20) (as shown in Figure 2) does not aid in torque production, and it is wound over or adjacent to the main coil (19) in the stator winding. Figure 2 is an exemplary vehicle (11) having one or more wheels (12, 13), which is colloquially referred to as a two-wheeler or a three-wheeler. The vehicle (11) is provided with an electric machine (16) mounted onto a power unit (14) of said vehicle (11). In the depicted embodiment, (as shown in Figure 2), the stator (15) is having the main coil (19) wound around the stator teeth, and also the auxiliary coil (20) wound around the stator teeth separate from the main coil (19). The purpose of the auxiliary coils is to turn-on the switches (s101, s102) that are used for purposes other than creating a rotating magnetic field, such as reconfiguring the coils in the stator winding.

Embodiment 1: The auxiliary coils are connected in a series configuration and wound on all tooth of each phase. The switches (s101, s102) can be relays which can be operated by the voltage induced by the auxiliary coil (20) of the electric machine (16). The switches (s101, s102) are required to operate only after the set speed. The voltage induced in the auxiliary coil (20) should be able to meet the voltage required by the switch for toggling after the set speed. The turns of the auxiliary coil (20) are chosen such that the required voltage is generated only after the set speed. The set speed is the speed at which the switches are turned on to extend the speed range of the motor to the next possible speed range. The next possible speed range is the minimum change in the value of the Ke that is affected by the winding reconfiguration once the switches (s101, s102) are energized. The reconfiguration is elaborated in the later part of this document. For example, if the voltage required to turn on the switches is 5 volts, the sufficient number of turns on auxiliary winding is wound on each phase, so that it reaches the voltage at the set rpm and the switches (s101, s102) are closed thereby enabling the coils to be reconfigured. This saves energy as the auxiliary coil (20) automatically and effectively controls the switches (s101, s102) without the need for the control unit energy.
The number of turns to be wound in the auxiliary coils also depends on the geometry of the electric machine (16) and the set rpm at which the coils have to be reconfigured. A number of turns will generate the voltage even before the set rpm thereby closing the switches (s101, s102) and extending the speed range before it is required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the electric machine (16) to extend its speed range to its next permissible band. The back-emf of the auxiliary coil (20) of the electric machine (16) depends on many parameters like number of poles, winding factor, rotor’s (18) outer radius, average air-gap flux density, number of slots per pole per phase and the number of turns. Since the switches (s101, s102) that are to be closed needs 5 volts (for example) at the set rpm, the back-emf of the auxiliary coil (20) of the electric machine (16) can be calculated by dividing the voltage to be induced with the motor set speed in radius per second. The back-

emf of the auxiliary coil (20) of the electric machine (16) is fixed for the geometry of the machine, and the only changing part can be the turns in this case. To meet the Kea of the electric machine (16) the turns are calculated for each phase, thereby generating the required voltage at the set rpm. Kea is the back-emf constant for the auxiliary coil.
Consider a case where the no-load rpm of the electric machine (16) is 900 rpm. The switches (s101, s102) are set to close at 850rpm as the set speed. The voltage required to turn on the switches (s101, s102) is 5volts (for example). The back-emf of the auxiliary coil (20) can be calculated by dividing voltage induced by no-load speed in rad/s. Therefore, the back-emf constant of the auxiliary coil (20) of the electric machine (16) would be 5/(2*3.14*850/60)=0.056v/rads-1. To reach this required value of Kea, as the geometry (such as rotor outer radius, average air-gap flux density) and pole slot combinations (number of poles, winding factor, number of slots per pole per phase) are fixed for the electric machine (16), the only change is the number of turns to be wound on the electric machine (16) (auxiliary winding). This will ensure the required voltage being met for the set speed of 850rpm. As the electric machine (16) crosses 850rpm, the switches (s101) and (s102) (as in Figure 1), which can be relays, are energized by closing the switches, thereby increasing the speed range of the motor. The effect of closing the switches (s101) and (s102) are explained later in this document. The switches (s101, s102) can be operated with a single electric pulse or can be operated individually.
An ideal motor needs high starting torque at the starting, with a wide speed band. To produce this starting torque, the electric machine (16) is initially designed with higher Kt. To produce higher Kt, more number of turns is needed. Instead of having all the turns as a coil with the single section, it is possible to have a coil with multiple sections. These coils with multiple sections are wound on the same tooth of the stator (15). The start and end wires of each section of the coils are then taken out and are connected by switches (s101, s102). During starting, each section of coils are connected such a way that the end of the first section of coils

and the start of the next section of coils are connected, the start of the first section of coil is connected together to the phase of the controller and the end wire of the last section of coil is connected to the ground. Then, each phase has more number of turns that are connected in a series configuration with respect to each other. To increase the speed range of the motoring mode to the next lowest possible limit, the switch configurations are energized such that there are some sections of coils which are connected in parallel and some sections of coils are in series, based on the sections and the turns in the entire section of coils. The electric machine (16) is allowed to operate at that operating range so that the resistance is reduced and it can be conveniently operated in the highest efficiency of that band. Further, the speed bands are increased by switching arrangements to reduce the turns and to increase the sections of the coils in parallel, to make sure that the electric machine (16) is always operated near the maximum efficiency range by all possible switch combinations.
In an odd number of section of coils, for example, three as in Figure 1, in normal operation, switches (s101) and (s102) are open, all the coil sections are connected in a series configuration. The higher turns in series configuration give a higher Kt. After the set speed, the switches (s101, s102) are closed by the voltage induced in the machine (16). The coils sections are now connected in parallel, reducing the resistance of the electric machine (16), thereby improving the efficiency of the machine. The three coils sections are now connected in parallel, reducing the turns, thereby increasing the no-load speed and the operating range of the motor. The parallel combination also offers less resistance. The efficiency of the motor is also shifted to the right side of the curve, improving the system efficiency.
Embodiment 2: The auxiliary coils can also be connected in series and wound on at least one tooth in each phase, to produce the necessary voltage to toggle the switches (s101, s102). In this case, all the turns that are required to produce the voltage at the set speed be wound on one single tooth in each phase. This maintains the Kea of the electric machine (16) to the same value as in the previous case. The switches (s101, s102) can be relays which can be operated by the

voltage induced from the auxiliary coil (20) of the electric machine (16). The switches (s101, s102) are required to operate only after the set speed. The voltage induced in the auxiliary coil (20) should be able to meet the voltage required by the switch for toggling after the set speed. The turns in the auxiliary coil (20) are chosen such that the required voltage is generated only after the set speed. The set speed is the speed at which the switches (s101, s102) are turned on to extend the speed range of the motor to the next possible speed range. The next possible speed range is the minimum change in the value of the Ke that is affected by the winding reconfiguration once the switches are energized. The reconfiguration is elaborated in the later part of this document. If the voltage required to turn on the switches (s101, s102) is 5 volts, the sufficient number of turns (auxiliary winding) are wound on the tooth of each phase, so that it reaches the voltage at the set rpm and the switches are closed thereby enabling the coils to be reconfigured.
The number of turns to be wound in the auxiliary coils also depends at least in part on the geometry of the electric machine (16) and the set rpm at which the coils have to be reconfigured. More the number of turns will generate the voltage even before the set rpm thereby closing the switches (s101, s102), and extending the speed range before it is required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the electric machine (16) to extend its speed range to its next permissible band. The back-emf of the electric machine (16) depends on many parameters like number of poles, winding factor, rotor outer radius, average air-gap flux density, number of slots per pole per phase, and the number of turns. Since the switches (s101, s102) that is to be closed needs 5 volts (for example) at the set rpm, the back-emf of the electric machine (16) can be calculated by dividing the voltage to be induced with the motor set speed in rad/s. The back-emf of the electric machine (16) is fixed for the geometry of the machine and the only changing part can be the turns in this case. To meet the Kea of the electric machine (16) the turns are calculated for each phase, thereby generating the required voltage at the set rpm.

Embodiment 3: The auxiliary coils can also be connected in series and wound on at least one tooth in any one of the phases, to produce the necessary voltage to toggle the switches (s101, s102). In this case all the turns that are required to produce the voltage at the set speed be wound on one single tooth in any one of the phases. This maintains the Kea of the electric machine (16) to the same value as in the previous case. The switches (s101, s102) can be relays which can be operated by the voltage induced from the auxiliary coil (20) of the machine. The switches (s101, s102) are required to operate only after the set speed. The voltage induced in the auxiliary coil (20) should be able to meet the voltage required by the switch for toggling after the set speed. The turns in the auxiliary coil (20) are chosen such that the required voltage is generated only after the set speed. The set speed is the speed at which the switches (s101, s102) are turned on to extend the speed range of the motor to the next possible speed range. The next possible speed range is the minimum change in the value of the Ke that is affected by the winding reconfiguration once the switches (s101, s102) are energized. The reconfiguration is elaborated in the later part of this document. If the voltage required to turn on the switches is 5volts, the sufficient number of turns (auxiliary winding) are wound on that one tooth in any one of the phases, so that it reaches the voltage at the set rpm and the switches (s101, s102) are closed thereby enabling the coils to be reconfigured.
The number of turns to be wound in the auxiliary coils also depends on the geometry of the electric machine (16) and the set rpm at which the coils have to be reconfigured. More the number of turns will generate the voltage even before the set rpm thereby closing the switches (s101, s102) and extending the speed range before it is required. Less number of turns will not be able to produce the required voltage at the set rpm thereby not allowing the electric machine (16) to extend its speed range to its next permissible band. The back-emf of the machine (16) depends on many parameters like number of poles, winding factor, rotor outer radius, average air-gap flux density, number of slots per pole per phase and the number of turns. Since the switches (s101, s102) that are to be closed needs 5 volts (for example) at the set rpm, the back-emf of the electric machine (16) can

be calculated by dividing the voltage to be induced with the motor set speed in rad/s. The back-emf of the electric machine (16) is fixed for the geometry of the machine and the only changing part can be the turns in this case. To meet the Kea of the machine (16) the turns are calculated and it is wound around the tooth for any one of the phases, thereby generating the required voltage at the set rpm.
The electronic circuit consisting of three-phase diode bridge, as shown in Figure 3, is connected in case of the first two embodiments as the voltage generated will be a three-phase ac, which has to rectify and regulated to the voltage required by the switch for toggling its condition. The rectifier for these three-phase circuits must use a three-phase bridge, which has six diodes D1, D2, D3, D4, D5, D6 to provide full-wave rectification with two diodes for each line of the three phases, D1 and D2, D3 and D4, D5 and D6. Figure 3 shows the electrical diagram for a three-phase bridge rectifier. From this diagram, it has to be noted that the output of the auxiliary coil (20) of the electrical machine (16) is shown connected to the diode rectifier. Coil A of the three-phase voltage from the auxiliary coil (20) of the electrical machine (16) is connected to the point where the cathode of diode D2 is connected to the anode of diode D1. Coil B is connected to the point where the cathode of diode D4 is connected to the anode of diode D3, and Coil C is connected to the point where the cathode of diode D6 is connected to the anode of diode D5. The anodes of diodes D2, D4 and D6 are connected to provide a common point for the DC negative terminal of the output power. The cathodes of diodes D1, D3 and D5 are connected to provide a common point for the DC positive terminal of the output power.
A circuit consisting of single-phase diode bridge is shown in Figure 4, is used in case of the third embodiment as the coils are wound only on one phase and can be rectified and regulated to the voltage required by the switch for toggling its condition. The four diodes labeled D7, D8, D9, D10 are arranged in “series pairs” such that during each half cycle only two diodes conducting current. During the positive half cycle of the supply, diodes D7 and D10 conduct in series while diodes D8 and D9 are reverse biased and the current flows through the load as

shown below. During the negative half cycle of the supply, diodes D8 and D9 conduct in series, but diodes D10 and D7 switch “OFF” as they are now reverse biased. The current flows through the load in the same direction as before.
The required voltage for closing the switches (s101, s102) is provided by the machine (16) in this case, and it does not require the controller or battery to provide the voltage.

WE CLAIM:
1. An electric machine (16) that saves energy and controller modifications,
said electric machine (16) comprising:
a rotor (18) and a stator (15) separated by an air-gap;
main coil (19) wound around a plurality of teeth of said stator (15); and
one or more switches (s101, s102) connected to said main coil (19) for winding reconfiguration, wherein:
said electric machine (16) includes an auxiliary coil (20) wound around said teeth of said stator (15), said one or more switches (s101, s102) functionally connected to said auxiliary coil (20), and said auxiliary coil (20) depending on pre-determined parameter of the electric machine (16) enables switching of said one or more switches (s101, s102) for winding reconfiguration.
2. The electric machine (16) of Claim 1, wherein voltage induced in the auxiliary coil (20) is used to control said switches (s101, s102) used for winding reconfiguration.
3. The electric machine (16) of Claim 1, wherein the voltage induced in the coils depended on the speed of rotation for a given number of turns and said speed of rotation is one of said pre-determined parameter.
4. The electric machine (16) of Claim 1, wherein to enable winding reconfiguration through the switches (s101, s102) the voltage is required to be above a threshold voltage, which is achieved above a pre-determined rotational speed of said rotor (18).
5. The electric machine (16) of Claim 1, wherein the switches (s101, s102) for winding reconfiguration are disposed of such that the winding configuration under normal condition is different from the one under an energized form thus results in transformed motor characteristics.

6. The electric machine (16) of Claim 1, wherein the auxiliary coils are
connected in series, and all tooth of each phase such as a reconfiguration
for a three-phase diode bridge that generates a three-phase voltage is,
(i) Operates with a three-phase bridge having six diodes, (D1, D2, D3, D4, D5, D6) to provide full-wave rectification with two diodes, (D1) and (D2, D3) and (D4, D5) and (D6), for each line of three phases;
(ii) Output of the auxiliary coil (20) of the electrical machine (16) is connected to a diode rectifier;
(iii) A Coil A of three-phase voltage from the auxiliary coil (20) of the electrical machine (16) is connected to a point at which a cathode of diode D2 is connected to an anode of diode D1;
(iv) A Coil B is connected to a point at which the cathode of diode D4 is connected to the anode of diode D3;
(v) A Coil C is connected to the point at which the cathode of diode D6 is connected to the anode of diode D5;
(vi) The anodes of diodes (D2, D4, D6) are connected together to make a common point for DC negative terminal of output power, and cathodes of diodes (D1, D3, D5) are connected together to form a common point for the DC positive terminal of the output power; and
(vii) To meet the back-emf constant Kea of the auxiliary coil (20) turns are calculated for each phase, thereby generating the required voltage at the set rpm.
7. The electric machine (16) of Claim 1, wherein the auxiliary coils are
connected in series and wound on at least one tooth in any one of the
phase to produce the necessary voltage to toggle the switches (s101, s102),
a reconfiguration for a single-phase diode bridge is,
(i) The coils are wound only on one phase, rectified and regulated to the voltage required by the switch for toggling its condition;

(ii) Diodes (D7, D8, D9, D10) are arranged in “series pairs” with only two diodes conducting current during each half cycle;
(iii) During positive half cycle of supply, the diodes (D7) and (D10) conduct in series while the diodes (D8) and (D9) are reverse biased, and the current flows through the load;
(iv) During negative half cycle of the supply, the diodes (D8) and (D9) conduct in series, but the diodes (D10) and (D7) switch “OFF” as they are reverse biased with the direction of current flow through the load same direction as earlier;
(v) The voltage required for closing the switches (s101, s102) is supplied by the electric machine (16), and does not require either the controller or battery to provide the voltage; and
(vi) To meet the back-emf constant Kea of the auxiliary coil (20), the turns are calculated and is wound around the tooth for any one of the phases, thereby generating the required voltage at the set rpm.
8. The electric machine (16) of Claim 1, wherein the voltage induced in the auxiliary coil (20) is used to operate the switches (s101, s102) for altering switching configuration.
9. A two-wheeler or a three-wheeler (11) provided with said electric machine (16) as claimed in any of the preceding claims.