A pulse controller for controlling the energization and regenerative braking of a DC electric motor. An electronic switch connects the motor to a power source during motor driving and controls motor current during regenerative braking, the switch being rendered alternately conductive and non-conductive during both driving and braking and the ratio of conductive to non-conductive periods being controlled. The conductive and non-conductive periods are interrelated such that, regardless of the ratio between the periods, during regenerative braking the switch alternates between its conductive and non-conductive states at a rate sufficient to automatically maintain the generated motor current within desired maximum and minimum limits.
The present invention provides a system and a method for controlling and detecting faults in a pump system for use in a gas detection device. The system comprises a power source and a switch in operative or electrical connection with the power source. The system further comprises a pump motor in operative connection with the switch such that the pump motor receives energy from the power source when the switch in a first state, and the pump motor does not receive energy from the power source when the switch in a second state. The system preferably also comprises regeneration circuitry in operative connection with the pump motor. The regeneration circuitry operates to redirect energy produced from momentum of the pump motor while the switch is in the second state back to the pump motor. Transmitting circuitry is preferably provided to transmit a motor signal proportional to the speed of the pump motor during the second state of the switch. Preferably, the switch is modulated between the first state and the second state using a processing or control unit such as a microprocessor. The processing unit preferably controls the modulation of switch in response to the motor signal received from the transmitting circuitry.
A deceleration apparatus of an AC servo motor for use in an industrial sewing machine performs a regenerating braking operation during a motor deceleration period. At an early time in the regenerating braking operation of the motor, an intermittent regenerating braking operation is carried out by supplying a current in a control circuit of a motor drive circuit. Subsequently, a continuous regenerating braking operation in the motor is carried out. A drive element comprising a switching element or a transistor in the control circuit is protected in accordance with an intermittent regenerating braking operation or a small regenerating braking current.
Several embodiments of electric vehicle control and control apparatus wherein the amount of regenerative braking of the vehicle and the type of braking is determined by current conditions to provide simpler and more effective control regardless of condition of the power source for the vehicle.
A motor controller comprises a plug detect circuit which detects "continuous" plug diode conduction during plug braking. The plug detect circuit detects "continuous" plug braking by detecting when a plug diode is or is not conducting current throughout substantially the entire time that a power MOSFET controlling the plug braking is conductive in one pulse width modulated MOSFET switching cycle. Continuous plug detection facilitates the motor controller's controlling a vehicle so that the vehicle has a more constant and smooth plug braking deceleration and subsequent powered acceleration in the opposite direction. According to another aspect of the invention, a motor controller comprises a POT HI and a POT LO driver circuit. The POT HI and POT LO driver circuits allow the detection of faults in throttle devices and the connections of the throttle devices to the POT HI and POT LO driver circuits. One of the POT HI and POT LO driver circuits has a greater current limit than does the other driver circuit so that numerous faults including open circuit breaks in the connection of a throttle device as well as shorts across or through the throttle device are detectable by the motor controller.
An electronically commutated motor (4) has a permanent-magnet rotor (28) and has a stator (14) that has two winding phases (25, 26). During one rotor rotation of 360.degree. el., firstly current is delivered to the one winding phase (25) within a first rotation angle range via an associated first semiconductor switch (68); and within a subsequent second rotation angle range, current is delivered to the other winding phase (26) via an associated second semiconductor switch (70). The motor further has a commutation apparatus for alternatingly switching ON the first semiconductor switch (68) and the second semiconductor switch (70). This commutation apparatus comprises a bistable multivibrator (FF90) whose switching state is controlled, via at least one comparator (126, 128), by the voltage that is induced by the permanent-magnet rotor (28) in that winding phase (25 or 26) which is currentless at that instant and which, in the instantaneous rotation angle range of the rotor (28), is not being supplied with current via its associated semiconductor switch (68 or 70).
