Abstract: Magnet wires wound in slots in a lamination stack of a dynamoelectric machine are encapsulated, in whole or in part, with plastic. The plastic may be thermally conductive and have features molded therein that enhance heat transfer. The plastic may stiffen the armature and increase its critical speed. Characteristics of the plastic, its geometry and its distribution may be varied to adjust spinning inertia and resonant frequency of the armature. The magnet wires may be compressed into the slots, by application of iso-static pressure or by the pressure of the plastic being molded around them. Larger magnet wire can then be used which increases the power of the electric motor using the armature having the larger magnet wire. A two or three plate mold may be used to mold the plastic around the armature. Balancing features can be molded in place. The plastic can have a base polymer that is a blend of two or more polymers and various thermally conductive fillings.

Abstract: A generator starting system utilizes a portable universal battery pack to start an internal combustion engine of the generator. The system is adapted to utilize any one of a plurality of universal battery packs having outputs of varying voltage. The generator can include a permanent magnet generator having first and second sets of windings. One set of windings generates AC power. The second set of windings is used to drive the PMG as an electric motor using power from the universal battery pack. In an embodiment, the system includes a brushless DC controller that electronically commutates the second set of windings to drive the PMG as a brushless DC motor.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A system and method for reducing the cost of producing a brushless DC motor is presented. The brushless DC motor provides higher power density and efficiency with an increased tool run time. The brushless DC motor includes a rotor assembly that has an unmagnetized permanent magnet affixed to a shaft. The permanent magnet remains unmagnetized until the motor is partially assembled. A plurality of coils for producing a magnetic field are wound about the rotor assembly. The coils include end turns that enclose the rotor assembly such that the rotor assembly is not removable. Since the windings are wound with the rotor assembly already enclosed, the windings do not require large end coils to allow subsequent insertion of the rotor. Minimizing the end coils reduces the length of wire required per turn, thereby reducing the resistance of the winding.

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 541, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A system and method for controlling a brushless DC motor (58) is provided. The motor (58) includes a rotor (72) and a stator (96) having at least three phases. The rotor (72) is magnetically coupled to and moveable by the stator (96) when the coils (94) are appropriately energized. Each of the coils (94) is characterized by a corresponding voltage waveform. No more than two position sensors (122) are provided for sensing the position of the rotor (72) during a start-up mode. Each position sensor (122) has an associated position sensor signal. The position sensors (122) are aligned to sense the rotor position such that each position sensor signal indicates a zero torque point corresponding to a phase voltage waveform. The position of the rotor (72) is sensed such that the position sensor signals indicate the start-up operating state of the motor (58). During a first ambiguous start-up state, two predetermined coils (94) are alternately energized.

Abstract: An excitation circuit for a flux switching motor. The circuit includes a low-value film capacitor across the DC side of a bridge rectifier. A plurality of electronic switches are arranged in an H-bridge configuration for switching current flow through an armature winding of the motor in accordance with a PWM control scheme and single-pulse control scheme controlled by a microcontroller. A start-up diode is placed across the field winding of the motor and is electronically switched out of the circuit after a startup phase of the motor has completed. The circuit implements armature energy recirculation through the field winding during startup to promote more uniform and quicker startup of the motor. The use of a film capacitor improves the power factor of the circuit, helps to eliminate the introduction of harmonics into the AC voltage source, and helps in mitigating EMI. Reverse commutation is used to bring the motor to a quick stop when it is powered off.

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A system and method for controlling a brushless DC motor (58) is provided. The motor (58) includes a rotor (72) and a stator (96) having at least three phases. The rotor (72) is magnetically coupled to and moveable by the stator (96) when the coils (94) are appropriately energized. Each of the coils (94) is characterized by a corresponding voltage waveform. No more than two position sensors (122) are provided for sensing the position of the rotor (72) during a start-up mode. Each position sensor (122) has an associated position sensor signal. The position sensors (122) are aligned to sense the rotor position such that each position sensor signal indicates a zero torque point corresponding to a phase voltage waveform. The position of the rotor (72) is sensed such that the position sensor signals indicate the start-up operating state of the motor (58). During a first ambiguous start-up state, two predetermined coils (94) are alternately energized.

Abstract: A system and method for reducing the cost of producing a brushless DC motor (58) is presented. The brushless DC motor (58) provides higher power density and efficiency with an increased tool run time. The brushless DC motor (58) includes a rotor assembly (72) that has an unmagnetized permanent magnet (74) affixed to a shaft. The permanent magnet (74) remains unmagnetized until the motor is partially assembled. A plurality of coils (94) for producing a magnetic field are wound about the rotor assembly (72). The coils (94) include end turns that enclose the rotor assembly (72) such that the rotor assembly (72) is not removable. Since the windings (94) are wound with the rotor assembly (72) already enclosed, the windings (94) do not require large end coils to allow subsequent insertion of the rotor (72). Minimizing the end coils reduces the length of wire required per turn, thereby reducing the resistance of the winding (94).

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A system of cordless power tools includes a cordless power tool adapted to removably receive a rechargeable battery pack. The system further includes a battery pack charger and a converter for converting AC electricity to DC electricity. A battery pack interface block is captured between clam shell halves of a battery pack housing and includes a plurality of male blade terminals. The male blade terminals are received within recessed female terminals of a tool terminal block and similarly received by recessed female terminals of the charger. The tool terminal block further includes a pair of male terminals which engage recessed female terminals of the converter.

Abstract: A battery pack 13 comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.

Abstract: A battery pack 13 (FIG. 2) comprises an elongated cylindrical, metal casing 35, a plurality of cells 41, 43 in casing 35 and three coaxial pack terminals 46, 54, 61. For enhanced convenience, pack terminals 46, 54, 61 are electrically connectable in a cordless device 11 regardless of the angular orientation of the pack 13 about casing axis 33. To reduce cost and increase durability, pack 13 has no welded connections and will permit high current discharge rates. Cells 41, 43 are electrically connected but are mechanically disconnected. A spring 73 engages cell 41 and biases cells 41, 43 tightly together in compression to form good, low resistance electrical contact between cells 41, 43, casing base cap 45 and top 53. To provide a pack with two output voltages, the third pack terminal 61 has a polarity (relative to first pack terminal 46) the same as second pack terminal 54 and is electrically connected to the cell can terminal 43b of forward cell 43, thereby electrically by-passing cell 43.