Abstract: A multiple phase full wave motor drive transistor bridge inverter control circuit in which the base drive power supply for the transistors is transformer isolated from the on/off logic circuits, and the current control function for all of the inverter transistors is performed by a single current regulation circuit. A separate transformer is provided for each phase of the bridge inverter, and the transformer primaries are connected series to form the load of the current regulation circuit. The transformer secondaries supply base current to the upper and lower transistors of each respective phase, and the logic circuits schedule the conduction of the inverter transistors such that one transistor of each phase is always conductive, neglecting dead time. Each of the secondary circuits includes an impedance matching circuit to maintain balanced loading under conditions wherein the inverter transistors are reverse biased due to lagging power factor motor winding currents.

Abstract: An AC motor control based on an iterative computation of the motor load and method of accurately determining motor load. At the initiation of motor operation, the load term (%LOAD) is initialized to zero, and the motor is energized in accordance with a predetermined voltage and frequency schedule for producing motor rotation. During the starting interval the power loss term LOSSES and the load term (%LOAD) are iteratively computed as a function of the input voltage and current (V.sub.bus, I.sub.bus) and the motor inverter frequency (IF). When a predetermined motor speed has been achieved, the run mode is initiated. At this point, the load is known based on the iterative load calculations performed during starting, and the motor voltage and inverter frequency are scheduled as a function of motor speed and load. The iterative computation of losses and load continue during the run mode so that changes in the motor load are taken into account.

Abstract: An FET bridge protection circuit preventing shoot-through caused from both FETs being biased on at the same time, while also maximizing the frequency at which the bridge output can alternate between high and low is described.

Abstract: The disclosure describes an impedance matching circuit for maintaining the input impedance, of a drive transistor as sensed by a driver circuit, substantially constant. The circuit is connected to the input of the drive transistor such that when the drive transistor is forward biased, the input impedance sensed by the drive circuit is the input impedance of the drive transistor, and when the drive transistor is reverse biased, the input impedance sensed by the driver circuit is the combination of the input impedance of the drive transistor and an impedance of the matching circuit.

Abstract: A power window control circuit for a motor vehicle includes a FET and SCR in series across the power supply with their junction connected to one side of a motor armature, the other side of the motor armature being switchable between power supply terminals. To provide reverse battery protection, no anti-parallel diode is provided around the SCR. The activation circuit for the FET includes a capacitor bootstrap circuit controlled by a switching transistor and a zener diode from the drain to the gate. When conduction from the switch through the motor and SCR is stopped, the inductive energy from the armature windings dissipates through the internal anti-parallel diode of the FET. When opposite conduction from the FET through the motor and switch is stopped, the inductive energy causes the voltage across the FET to rise to the zener voltage and turn on the FET sufficiently to dissipate it.

Abstract: The stator winding of a single-phase brushless DC motor with symmetrical rotor and stator air gap geometry is comprised of two serially connected relatively displaced sections energized with a source of direct current in accordance with the rotary position of the motor rotor. In the run mode, the full winding is energized; in the start mode, one of the sections is momentarily short-circuited if the initial winding energization fails to produce sufficient torque for starting.

Abstract: The speed command for an open-loop brushless motor speed control system is overridden whenever the speed of the motor is less than a relatively low reference speed in order to quickly accelerate the motor to a running speed, despite a relatively low speed command. In the event of a motor overcurrent condition, the override is itself overridden to protect the controller.

Abstract: A control circuit for a one-touch vehicle window control uses a pair of switches, each switch actuating a still window for movement in one of two opposite directions but being effective to stop a window moving in the opposite direction from that which it initiates. The motor is in an H-switch bridge with SCRs and FETs, with each switch providing actuating signals to an SCR and FET for one armature current direction and further providing an actuating signal through an impedance to a discharge transistor connected across a capacitor connected to the gate of the FET for the opposite armature current direction. The base of each discharge transistor is connected to another capacitor and through another impedance to the junction of a FET and a motor armature terminal.

Abstract: A control for a vehicle window driving motor in an H-switch semiconductor bridge with an SCR and a FET in each opposite armature current path includes control logic circuitry enabling one-touch actuation of window movement in either direction with stoppage by actuating either actuation device and with flip-flop control of the bridge elements to prevent shorting out the power supply. A variation provides automatic stoppage in the up direction by stall current sensing with automatic reverse after a time delay to allow the SCR conducting during upward movement to turn off.

Abstract: Power window control apparatus for a motor vehicle window includes a motor actuatable to drive the window toward a predetermined position, an operator controlled actuator effective only during actuation to actuate the motor, a further actuator effective upon actuation of the operator controlled actuator for a time intermediate first and second predetermined time periods to maintain actuation of the motor after deactivation of the operator controlled actuator and an automatic deactivator effective to stop the motor and deactivate the further actuator when the window reaches the predetermined position. The window thus moves under operator control for very short or long movements but can be set to move under automatic control by actuation of the single operator control for a specified intermediate time duration.

Abstract: The electric drive motor of an internal combustion engine radiator cooling fan that is arranged to be energized by the output potential of a dynamoelectric generator driven by the engine is supplied with operating potential in such a manner that the average supplied drive motor power is directly proportional to engine speed while engine temperature is within the range between a predetermined first temperature and a predetermined higher second temperature and the engine is operating within a selected speed range.

Abstract: A direct current ramp potential signal which is produced in synchronism with each half cycle of the alternator output voltage and increases in magnitude within a predetermined range during each half cycle is compared with a direct current reference potential signal inversely proportional to alternator connected load. Circuitry is provided for effecting the electrical energization of the alternator field winding in response to an electrical signal produced when the potential level of the ramp potential signal has reached a value equal to that of the reference potential signal. Provision is also made for effecting the deenergization of the alternator field winding with sustained overvoltage conditions and for ramping the output voltage down linearly with conditions of output potential frequencies less than the desired frequency.

Abstract: The terminal ends of a center tapped primary transformer winding are connected to the positive polarity direct current input terminal through the anode-cathode electrodes of respective power silicone controlled rectifiers which are alternately triggered conductive and the center tap is connected to the negative polarity direct current input terminal. Simultaneously with each power silicon controlled rectifier, a corresponding commutating capacitor charge circuit silicon controlled rectifier is triggered conductive to establish a charge circuit for the corresponding commutating capacitor across the direct current input terminals. Each power silicon controlled rectifier is commutated not conductive by the charge upon the corresponding commutating capacitor applied in an inverse polarity relationship across the anode-cathode electrodes thereof through a commutating silicon controlled rectifier.