Abstract: A method of connecting stranded wire to a lead-frame body 10 includes the provision of a stranded wire 12. It is ensured that insulation is stripped from an end 14 of the stranded wire. An electrically conductive lead-frame connection structure 16 is associated with the lead-frame body. The end 14 of the stranded wire is inserted into the lead-frame connection structure 16 so that the lead-frame connection structure substantially surrounds the wire end. Solder flux is injected so as to be substantially about a portion of the end of the stranded wire. The lead-frame connection structure is placed in contact with a bottom resistance welding electrode 18 or a top resistance welding electrode 20.

Abstract: A closed-loop control system for a DC motor includes a DC motor 12, a current sensor 14 for determining a current of the motor, a voltage sensor 32 for measuring a voltage of the motor 12, and a micro-controller 33. The micro-controller is constructed and arranged to (1) compare the determined current with a set point and output a pulse width modulated (PWM) duty cycle to control the motor, and (2) calculate a PWM duty cycle limit based on the measured voltage and compare the outputted PWM duty cycle to the PWM duty cycle limit such that when the outputted PWM duty cycle greater than the PWM duty cycle limit, the outputted PWM duty cycle is set to the PWM duty cycle limit. A method, in a DC motor, of preventing a current surge during severe voltage changes is also disclosed.

Abstract: A closed-loop control system for a DC motor includes a DC motor 12, a current sensor 14 for determining a current of the motor, a voltage sensor 32 for measuring a voltage of the motor 12, and a micro-controller 33. The micro-controller is constructed and arranged to (1) compare the determined current with a set point and output a pulse width modulated (PWM) duty cycle to control the motor, and (2) calculate a PWM duty cycle limit based on the measured voltage and compare the outputted PWM duty cycle to the PWM duty cycle limit such that when the outputted PWM duty cycle greater than the PWM duty cycle limit, the outputted PWM duty cycle is set to the PWM duty cycle limit. A method, in a DC motor, of preventing a current surge during severe voltage changes is also disclosed.

Abstract: An actively controlled regenerative snubber configuration for use in unipolar brushless direct current motors comprises a first inductor, a first switch and a capacitor, all of which are connected in series to a positive voltage supply and in parallel with a second inductor and a second switch. The regenerative snubber is used to maintain constant voltage across the switches to prevent braking of the motor through conduction of motor back EMF and to return excess energy stored in the motor phase coils to the positive voltage supply. The return of energy to the positive rail is done in a manner so as to minimize conducted electromagnetic interference at the power leads.

Abstract: An apparatus and method for minimizing electromagnetic interference in a unipolar phase motor having a supply current is provided. The motor further has a plurality of motor phases energizable with pulse width modulation (PWM). The method includes calculating the current harmonics on a right edge aligned PWM, calculating the current harmonics on a left edge aligned PWM pulse, determining the supply current by summing the current harmonics for the right edge aligned PWM pulse and the current harmonics for the left edge aligned PWM pulse, energizing a first motor phase with PWM, and staggering the PWM pulses for each successive motor phase by varying the energizing of any two adjacent energized phases based on the amount of supply current in the motor, the staggering of the PWM pulses minimizing electromagnetic interference and current harmonic generation due to an increase in the supply current.

Abstract: An actively controlled regenerative snubber configuration for use in unipolar brushless direct current motors comprises a first inductor, a first switch and a capacitor, all of which are connected in series to a positive voltage supply and in parallel with a second inductor and a second switch. The regenerative snubber is used to maintain constant voltage across the switches to prevent braking of the motor through conduction of motor back EMF and to return excess energy stored in the motor phase coils to the positive voltage supply. The return of energy to the positive rail is done in a manner so as to minimize conducted electromagnetic interference at the power leads.

Abstract: An actively controlled regenerative snubber configuration for use in unipolar brushless direct current motors comprises a first inductor, a first switch and a capacitor, all of which are connected in series to a positive voltage supply and in parallel with a second inductor and a second switch. The regenerative snubber is used to maintain constant voltage across the switches to prevent braking of the motor through conduction of motor back EMF and to return excess energy stored in the motor phase coils to the positive voltage supply. The return of energy to the positive rail is done in a manner so as to minimize conducted electromagnetic interference at the power leads.