Abstract: A motor controller with a reverse-bias preventing mechanism includes a pre-charging unit, a protection unit, a conversion unit and a control unit. The pre-charging unit receives a power signal through a first electric-conduction path, and converts the power signal into a pre-charging signal according to a control signal. The protection unit receives the power signal through a second electric-conduction path, and determines whether to output the power signal, according to the polarity of the power signal. The conversion unit, coupled to the protection unit, receives the power signal outputted by the protection unit, and converts the power signal into a work voltage. The control unit, coupled to the conversion unit and the pre-charging unit, receives the work voltage to generate the control signal. The current of the power signal flowing through second electric-conduction path is smaller than the current flowing through first electric-conduction path.

Abstract: A motor controller with a reverse-bias preventing mechanism includes a pre-charging unit, a protection unit, a conversion unit and a control unit. The pre-charging unit receives a power signal through a first electric-conduction path, and converts the power signal into a pre-charging signal according to a control signal. The protection unit receives the power signal through a second electric-conduction path, and determines whether to output the power signal, according to the polarity of the power signal. The conversion unit, coupled to the protection unit, receives the power signal outputted by the protection unit, and converts the power signal into a work voltage. The control unit, coupled to the conversion unit and the pre-charging unit, receives the work voltage to generate the control signal. The current of the power signal flowing through second electric-conduction path is smaller than the current flowing through first electric-conduction path.

Abstract: A charge-or-start system applied in an electric vehicle is provided. The charge-or-start system includes a charge-or-start device coupled to an external power source, an on-car electric source coupled to the charge-or-start device and a battery unit coupled to the charge-or-start device for storing and providing power. In charge mode, under control of the charge-or-start device, anyone of the external power source and the on-car electric source provides power to the battery unit for charging the battery unit through the charge-or-start device. In starting mode, under control of the charge-or-start device, the battery unit provides power to the on-car electric source for activating the on-car electric source through the charge-or-start device.

Abstract: A charge/start system applied in an electric vehicle is provided. The charge/start system includes a charge/start device coupled to an external power source, an on-car electric source coupled to the charge/start device and a battery unit coupled to the charge/start device for storing and providing power. In charge mode, under control of the charge/start device, anyone of the external power source and the on-car electric source provides power to the battery unit for charging the battery unit through the charge/start device. In starting mode, under control of the charge/start device, the battery unit provides power to the on-car electric source for activating the on-car electric source through the charge/start device.

Abstract: A cross-level digital signal transmission device between two systems for cross-level digital signal transmission. Bi-directional symmetrical transmission is achieved without using additional control signals, and use of the transmission signal itself eliminates the positive feedback loop. Thus, neither additional control signals nor resulting unsymmetrical circuits need be provided.

Abstract: A cross-level digital signal transmission device between two systems for cross-level digital signal transmission. Bi-directional symmetrical transmission is achieved without using additional control signals, and use of the transmission signal itself eliminates the positive feedback loop. Thus, neither additional control signals nor resulting unsymmetrical circuits need be provided.

Abstract: A charge equalizer adapted a battery charger to equally charge series of connected battery strings, comprising battery voltage sensing circuits, a microcontroller, logic and driving circuits, and flyback converters, operates to prevent the batteries of the series of connected battery strings from overcharging by activating the flyback converters to draw out the overcharging currents of the batteries in the series of connected battery strings and charging the whole battery strings by recharging currents which proportion to said drawn out currents as detecting each of the battery voltages in the battery strings being higher than a pre-determined voltage value during charging and digitizing the detected battery voltage signals; so as to achieve the purposes of equal charge in each battery and hence to improve the life of the battery strings as a whole.

Abstract: Provided is a brushless DC motor speed controller in which the speed feedback signal needed for speed control is obtained from the commutation signals generated by the magnetic-pole sensor in the brushless DC motor. The-brushless DC motor speed controller includes an edge detector, which generates a pulse each time a rising or falling edge is detected in the signal from the magnetic-pole sensor of the brushless DC motor. A frequency multiplier is used to multiply the frequency of the pulse train from said edge detector. A frequency-to-voltage converter is used to convert the output pulse train from said frequency multiplier into a positive analog voltage, with the level of the positive analog voltage being in proportion to the speed of the brushless DC motor. A motor rotating direction detecting circuit receives the output signal from said magnetic-pole sensor and thereby detects in which direction the brushless DC motor currently rotates.

Abstract: A method and device for controlling the torque of a brushless DC motor used in an electric motorcycle, in which a single current loop is employed to obtain a feedback current by a current detector from a DC bus which simplifies the construction of the circuit scheme. The device of this invention operates by two input signals; one of them is a torque command signal to generate a positive torque of the motor, and the other is brake command signal to generate a negative torque of the motor so as to operate a control brake command and to store the energy generated during a braking operation into a battery of the motorcycle, as well as to stop the rotation of the brushless DC motor within 120.degree. of its electrical angle of reversed rotation.

Abstract: The speed of a brushless DC motor driving an electric vehicle is controlled with a speed feedback signal proportional to rotation speed of the motor by processing the back electromotive force (EMF) waves of the brushless DC motor. In this method, the back EMF waves of plural phases are taken to pass the differential amplifiers for each phase, and the back EMF signals in the rising and falling regions of the back EMF waves of each phase are obtained to synthesize, by the commutation signals of a magnetic pole sensor passing the phase detecting circuit, after full-wave rectification and low-pass filtering, a [speed feedback signal. This method differs from normal speed control of a motor, in which a speed feed-back element such as a DC tachometer or an encoder is necessary for controlling the speed. This invention permits the brushless DC motor to control the speed without a feedback element such as a DC tachometer or an encoder, thereby decreasing the cost of the brushless DC motor speed control system.

Abstract: A current limiting device to limit the maximum allowable electric current to be supplied to a motor in driving an electric vehicle. The current limiting device includes (a) a first thermal switch to prevent the power switching element of the motor from being abnormally overheated, (b) a second thermal switch to prevent the motor from being abnormally overheated, and (c) a brake switch. The three switches altogether and in association with a certain hysteresis band work to switch the limits of the electric current passing through the motor between two or more predetermined electric current values. Under normal operating conditions, the limit of the current is set at a high level which is associated with a hysteresis action, and when one of the thermal switches or the brake switch is actuated, the limit of the electric current is switched to a lower value which is still associated with a hysteresis action.