Abstract: A controlling/driving apparatus for an electrically-driven compressor of an air conditioner mounted in an automobile. The apparatus comprises a DC-AC converting invertor 4 for converting a DC voltage into a pseudo AC voltage (e.g. a pulse train of positive and negative pulses), a DC voltage detector 7, and a pulse width changing unit 8 for changing the width of each pulse of the pulse train in accordance with the DC voltage detected by the DC voltage detector. Thus, the apparatus enables safe and efficient operation of the compressor with improved electric insulation and durability when large fluctuations in the power source voltage of the compressor occur.

Abstract: An electric car air-conditioning apparatus, which is small in size and capable of preventing abnormal heating upon occurrence of a failure and preventing damage when a capacitor is connected with its polarity reversed, provided with a current-conduction detecting device for detecting the operation of current conduction of a current conducting device for charging the capacitor with a current from a battery, and a power breaking device for breaking a current from the battery, wherein a control section actuates the power breaking device to break the current from the battery in the case where the current-conduction detecting device detects the operation of current conduction for a period longer than a predetermined time when the control section is not outputting a control signal for closing a switching device through which power is supplied from the battery to drive a motor-driven compressor, and in the case where the current-conduction detecting device detects the operation of current conduction when the control

Abstract: An electric-vehicle air-conditioning apparatus small in size, simple in construction and high in reliability, which can be used for many types of vehicles, includes a battery, a conducting device connected in series with the battery, a switching device connected in parallel to the conducting device, a capacitor charged from the battery through the conducting device, a device supplied with power from the battery through the switching device for driving an electrically-operated air-conditioning compressor. The conducting device is adapted to charge the capacitor with a constant current.

Abstract: A rapid voltage drop due to generator output saturation is prevented by providing a generator output saturation detection means that extracts a generator output saturation detection signal from the collector terminal of the field transistor controlling the excitation current of the automotive generator and measures the duty ratio of the field transistor in the control device to detect saturation of the generator output, and a compressor control means for reducing the speed of the electrical compressor when saturation is detected.