摘要:
An ac/dc converting circuit adapted to output a direct voltage that is higher than a full wave rectified voltage of an alternating input voltage is provided which includes an alternating current filter, and a condenser with a positive electrode and a negative electrode coupled to a dc output side of a full wave rectifying circuit. The full wave rectifying circuit includes a switching portion having upper and lower arms each having a semiconductor rectifying element and a self-commutated semiconductor switching element, and a rectifying portion having upper and lower arms each having a semiconductor rectifying element. The semiconductor rectifying elements in the upper arms of the full wave rectifying circuit has a common cathode coupled to the positive electrode, and the semiconductor rectifying elements in the lower arms has a common anode coupled to the negative electrode. The ac/dc converting circuit further includes a resistor provided between a coupling point of the rectifying elements of the upper arms of the fill wave rectifying circuit and the negative electrode. In operation, a signal for controlling an ON/OFF state of the switching element of the lower arm of the switching portion is generated while the switching element of its upper arm is in an OFF state, when the direct output voltage is higher than the input alternating voltage, and a voltage at an ac input terminal between the rectifying elements of the switching portion is lower than a voltage at an ac input terminal between the rectifying elements of the rectifying portion.
摘要:
An ac/dc converting circuit adapted to output a direct voltage that is higher than a full wave rectified voltage of an alternating input voltage is provided which includes an alternating current filter, and a condenser with a positive electrode and a negative electrode coupled to a dc output side of a full wave rectifying circuit. The full wave rectifying circuit includes a switching portion having upper and lower arms each having a semiconductor rectifying element and a self-commutated semiconductor switching element, and a rectifying portion having upper and lower arms each having a semiconductor rectifying element. The semiconductor rectifying elements in the upper arms of the full wave rectifying circuit has a common cathode coupled to the positive electrode, and the semiconductor rectifying elements in the lower arms has a common anode coupled to the negative electrode. The ac/dc converting circuit further includes a resistor provided between a coupling point of the rectifying elements of the upper arms of the full wave rectifying circuit and the negative electrode. In operation, a signal for controlling an ON/OFF state of the switching element of the lower arm of the switching portion is generated while the switching element of its upper arm is in an OFF state, when the direct output voltage is higher than the input alternating voltage, and a voltage at an ac input terminal between the rectifying elements of the switching portion is lower than a voltage at an ac input terminal between the rectifying elements of the rectifying portion.
摘要:
A game machine having a control unit as a first game chance control device generating a game chance achieving at least one winning combination in winning combinations whose achievement probability varies in a game within a predetermined range provided to the player in exchange for medals, a dividend value control device setting a correspondence relationship between the winning combinations and the dividend values for the player, a dividend display control device displaying an odds display section where the winning combinations are related with the dividend values on a monitor according to the correspondence relationship set by the dividend value control device, a dividend creating device generating the dividend for the player corresponding to the achieved winning combination according to the correspondence relationship set by the dividend value control device when any winning combination is achieved, and a condition determining device determining whether a predetermined dividend change condition is established within the predetermined range.
摘要:
A driving circuit for driving an IGBT includes a forward-bias power supply, a reverse-bias power supply, a forward-bias semiconductor switch, a reverse-bias semiconductor switch, a first resistor for limiting forward-bias current, and a second resistor for limiting reverse-bias current. In this driving circuit, one terminal of a capacitor is connected to a common node of the resistor for limiting forward-bias current, the resistor for limiting reverse-bias current, and a gate of the IGBT. A mode switching semiconductor switch is connected at one terminal to the other terminal of the capacitor. The other terminal of the mode switching semiconductor switch is connected to a common node of the forward-bias power supply and the reverse-bias power supply. In operation, the mode switching semiconductor switch is turned on and turned off so as to establish a given rate of change of voltage which is independently selected for turn-on and turn-off of the IGBT.
摘要:
An apparatus for restarting an inverter after momentary interruption by detecting a power restoration after a momentary outage of a power supply that supplies power to the inverter for driving a synchronous motor. The apparatus includes a frequency detecting portion that detects the frequency of a terminal voltage of the synchronous motor, a phase difference detector that detects the phase difference between the terminal voltage of the synchronous motor and the output voltage command value of the inverter, a phase controller that performs synchronous control so that the frequency and phase of the output voltage command value of the inverter and those of the terminal voltage of the synchronous motor agree with each other, and a restarting portion that restarts the inverter under the condition that the synchronization has been completed after the power restoration of the power supply. This makes it possible to reduce the restarting time after a momentary interruption of the power supply, and to reduce the rush current at the restarting, and the capacity of the inverter.
摘要:
An aspect of the invention provides a game machine including: a second game chance control device that generates at least one game chance that is allowed to establish a predetermined winning condition in a game within a predetermined range provided to a player in exchange for a game value; a symbol arrangement control device that determines types of symbols to be arranged on a predetermined area on a game screen with a predetermined positional relationship according to the generation of the game chance; and a first winning determining device that determines whether the winning condition is established based on the types and the arrangement of the symbols arranged on the predetermined area.
摘要:
A forming and processing method for a valve lifter. The forming and processing method includes the steps of: (a) forming a hole in the valve lifter at a site where a cam is slidably contacted with; (b) forming a diameter-increasing section along an edge of the valve lifter, the edge defining a part of the hole and being located on a side with which the cam is slidably contacted; and (c) carrying out a surface treatment to whole of a surface of the valve lifter which surface is on the side with which the cam is slidably contacted.
摘要:
The apparatus calculates a torque that an induction motor generates while considering an iron loss even in a boosting state for exceeding the rated excitation. The calculation is based on a reference voltage value fed to an inverter for driving the induction motor, a q-axis current component and a d-axis current component resolved from a detected current of the induction motor on a rotating coordinate system, a primary resistance of the induction motor and a primary angular frequency. The apparatus includes an iron loss calculator that calculates the iron loss of the induction motor based on hysteresis characteristics of the stator core, a divider that divides the calculated iron loss by the primary angular frequency and an adder that calculates the generated torque by subtracting the result of the division from the torque calculated without considering the iron loss.
摘要:
An output voltage control apparatus for performing feedback control on an output voltage of an inverter which drives an AC machine. The output voltage control apparatus converts a command value for the output voltage of the inverter into a pulse density using a converter (PDM), and converts a detection value of the output voltage of the inverter into a pulse density using a .DELTA.-.SIGMA. modulation converter. The proportional control ability and integral control ability for the output voltage are realized by digital hardware including an up-counter, a down-counter and a shift circuit.
摘要:
This invention provides an aerator comprising a jet stream generator for ejecting a gas and a liquid in a mixed state from a nozzle, and a tubular flow straightener for mixing the bubble-containing stream ejected from the nozzle with ambient water and discharging the resulting mixture from the discharge orifice thereof, characterized in that the flow straightener has a tubular form whose internal diameter is reduced from the inlet toward the discharge orifice through at least a part of its length.This aerator can produce a stream containing minute gas bubbles, even when a gas is supplied thereto in such a large amount as to give a gas-to-liquid volume ratio of 3/1.