Abstract: A turn off circuit for a multiphase motor is provided, comprising a D.C. powered system including a three element choke core having two outer cores with loosely coupled windings and a central core closely coupled to the outer cores to enhance pulse generation.A modified SCR ring counter is provided to supply D.C. power to the load to produce a three phase wave shape with less wave distortion and lower noise.Pulse width modulation is supplied to the negative SCRs of the ring counter through steering SCRs which are turned on by discharge from capacitors in the steering circuit.Pulse width modulation is fed to the ring counter through the outer core elements, while the central core functions to improve pulse width of the discharge capacitors. Free wheeling energy from the motor is fed to the discharge capacitors and increases firing energy.

Abstract: A turn off circuit for a multiphase motor is provided comprising a DC powered system including a three element core having a central core element and an inner and outer core element coupled thereto.A series of capacitors are connected to an outer core element to discharge simultaneously and turn off positively and negatively biased SCRs which sequentially fire and produce a suitable pulse width and frequency to the motor.A control system is provided to produce a variable pulse frequency and pulse width to a power circuit which sequentially fires and admits battery power to the motor.

Abstract: A turn off circuit for a multiphase motor is provided comprising a DC powered system including a three element core having a control core element and an inner and outer core element coupled thereto.A series of capacitors are coupled to the central core winding to produce suitably shaped pulses to turn off positively and negatively biased SCRs which control power switching SCRs.A control system is provided to produce a variable pulse frequency and pulse width to a power circuit which sequentially fires and admits the battery power to the motor.