摘要:
Disclosed is a washing method in which parts and products are washed free of residual smudges without using fleon-family solvents. The method of washing members such as parts or products comprises a first degreasing step for degreasing in nonaqueous liquid the members to be washed after worked, a second degreasing step for degreasing the members being washed in an aqueous liquid which dissolves the nonaqueous liquid, a finish washing step for washing in the aqueous liquid, a rinsing step, and a drying step, wherein the drying step is performed in a plurality of pure water baths, the temperature of a last pure water bath is established to a range of 70.degree. to 85.degree. C., and the washed members are taken out from the pure water bath for drying the surfaces thereof.Also, the washing method is disclosed in which pure water in a plurality of the pure water baths has temperature gradient in the sequence of washing steps.Furthermore, the washing method is disclosed in which the speed of taking out the washed members from the last pure water bath is established so as to be in inverse proportion to the surface area of the washed member.
摘要:
A controller for electric vehicles comprising a vector control inverter for controlling motors, which drive wheels of the electric vehicles, by dividing the primary current of the motors into an exciting current component and a torque current component, and controlling respective of the current components based on a respectively designated command, characterized in further comprising a dectector for detecting a wheel velocity (including a rotor frequency of the motor proportional to the wheel velocity), a detector for detecting slipping and skidding of the wheel based on a differential value (a changing rate with time) of the detected wheel velocity, a dectector for detecting re-adhesion of the wheel based on the differential value and a twice differential value of the detected wheel velocity, and an adjuster for adjusting the designated command for the torque current component in response to the detectors.
摘要:
An inverter using gate turn-off thyristors (GTOs) is controlled by means of pulse width modulation (PWM) to control the speed of an induction motor. If the current flowing through the induction motor becomes an overcurrent which can still be cut off by the GTOs, a gate off signal is supplied to respective GTOs to interrupt the overcurrent. If any one of arms respectively corresponding to phases is short-circuited, a gate on signal is supplied to all GTOs to distribute the short circuit current among the arms, and the main circuit is interrupted by a high-speed breaker. At this time, a simultaneous gate on signal is given priority. If the simultaneous gate on signal is present, a simultaneous gate off signal is disabled. Owing to this configuration, destruction of the GTOs due to consecutive guard operation can be prevented.
摘要:
In accordance with the present invention, a plurality of strip-shaped emitter layers on the cathode side are radially arranged on one main surface of the semiconductor substrate while forming a plurality of rings. A gate electrode is in ohmic contact with a part of a base layer which surrounds and is adjacent to each of said emitter layers on the cathode side. Between rings formed by said emitter layers on the cathode side, a ring-shaped gate collecting electrode is provided to be connected to said gate electrode. The gate collecting electrode is provided at a position to balance the potential differences produced by gate currents respectively corresponding to inside and outside of said gate collecting electrode.
摘要:
A control apparatus for an electric railcar that provides control so that when rotational speed of a motor decreases below a required value, torque of the motor will decrease at a required rate of change, a current limiter for limiting a torque current command “(A)Iqp” output from a current command arithmetic unit is provided to ensure that when the rotational speed of the motor decreases below the required value, the torque current command will be limited to a command value “(B)Iqp” smaller than that command value, and to ensure that a carrier frequency at which PWM signals are created when switching elements of the electric power converter are controlled by carrier generator is controlled to become lower than a carrier frequency existing when the rotational speed of the motor decreases below the required value.
摘要:
The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.
摘要:
An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise. Each of the semiconductor modules includes a plurality of switching device chips and at least one diode chip formed on a metal substrate. Electrode plates are provided in locations of the module adjacent to the switching device chips and the diode chips to facilitate connection of the electrodes of the respective chips to one another and to the outside of the module.
摘要:
An inverter device includes plural modules, each module being formed by a series circuit having a parallel circuit of a first switching device and a first diode, and a parallel circuit of a second switching device and a second diode, allowing a reduced size, high reliability, high frequency switching and low noise.
摘要:
In order to reduce an induction problem, which might otherwise be caused by a higher-harmonic current leaking to the outside of an inverter device, with a simple construction, an inverter device casing and a heat receiving plate mounted thereon are insulated from each other, and the heat receiving plate and a filter capacitor in the power supply circuit are connected through a predetermined inductance. Since the higher harmonics current is bypassed to the filter capacitor through the resonance filter which is formed by of the electrostatic capacity in a switching element and the inductance, the induction problem can be reduced by simple construction.
摘要:
The invention is directed to a neutral point clamped electric power conversion apparatus having four semiconductor switching elements connected in series. The capacity of outer free wheel diodes connected in reverse parallel with outer semiconductor switching elements are increased compared to that of inner free wheel diodes, thereby minimizing, an imbalance in losses between the inner and the outer free wheel diodes.