Ricoh Company, Ltd.

Tohoku Ricoh Co., Ltd.

Other

Hisahiro Kamata

Yoshiyuki Shishido

Tsuneo Ikenoue

Masahiro Noguchi

Masakazu Fujita

Atsushi Nunokawa

Eiki Hirama

Fumihito Takahashi

An inverter includes transformers having identical characteristics. Exciting windings of the transformers are connected in parallel so that the transformers are excited simultaneously. Output windings of the transformers are connected in series so that waveforms of output voltages of the output windings are time-synchronized. Each transformer includes a core having an identical shape and including an inner leg having an independent closed magnetic circuit. The excitation winding and the output winding are wrapped around the inner leg of the core in layers. The inner leg of the core has a gap whose size is steplessly adjustable in a state where the excitation current is applied to the excitation winding. The size of the gap is adjusted to regulate exciting inductances of the transformers to a same predetermined value.

High-voltage inverter

An inverter device applies an excitation current to an excitation winding of a step-up transformer through a switching element, and outputs an output voltage with an alternating-current half-wave waveform from an output winding of the step-up transformer. The inverter device includes: an input-voltage detecting unit that detects a state of the input voltage, as a voltage; a current detecting unit that converts a current flowing through the switching element into a voltage to detects the current; and a comparing unit that compares a detected current value detected by the current detecting unit with a detected input voltage value detected by the input-voltage detecting unit, and detects a high-current period in which the detected current value exceeds the detected input voltage value. Based on information indicating the high-current period detected by the comparing unit, the control circuit adjusts a period in which the switching element is turned on.

Inverter device

A transformer includes: a first winding; a second winding provided to maintain a first distance to the first winding; and a shell that seals the first winding and the second winding.

Transformer and plasma generator

An inverter device includes: multiple inverters that switch input voltages by turning on and off respective switching elements to thereby apply excitation currents to primary excitation windings of respective boosting transformers and output alternating-current voltages from secondary output windings of the respective boosting transformers, the multiple inverters having the same output characteristics, and a common control circuit, on/off control of the switching elements of the inverters being performed by the same switching signal output from the common control circuit.

Inverter device, plasma generating device, sheet-member reforming device, and alternating-current voltage output method

Excitation current is applied to an excitation winding of a step-up transformer by switching an input voltage with a first switching element. Excitation energy stored causes a voltage resonant state in the secondary side of the step-up transformer during a period when the excitation current is shut off. When the excitation current is shut off, a second resonant circuit provided in the primary side of the step-up transformer enters a resonant state. When a second switching element of the second resonant circuit is turned on, energy returning to an input side in a region where the output voltage is negative is commutated through a second diode to be absorbed in the input voltage. The second switching element is kept off while the second resonant circuit is in the resonant state, turned on when the resonant state ends, and turned off after the first switching element is turned on.

Voltage resonant inverter, control method, and surface treatment device

An inverter switches input voltage Vin to flow an excitation current to excitation winding Np of a transformer and output to a discharger an alternating voltage Vout from the output winding Ns. In an output circuit flowing a current to the discharger, a voltage-responsive connector is connected in series with the winding Ns to interrupt or connect the output circuit according to a voltage applied to between opposed electrodes. The voltage-responsive connector has characteristics of keeping the electrodes in an insulated state until an instantaneous value of the alternating voltage reaches a predetermined value, and holding the electrodes in a conduction state while the instantaneous value of the alternating voltage has reached the predetermined value and continues to exceed the predetermined value, and quickly returning the electrodes to the insulated state when the instantaneous value of the alternating voltage has fallen below the predetermined value.

High-voltage inverter, dielectric-barrier discharge evice and cation apparatus

An inverter device includes a switching device which performs on-off switching of an input voltage, a step-up transformer which applies an excitation current to its winding during a switching-device-on period and outputs an output voltage during a switching-device-off period, an input-voltage detector which detects the input voltage and output an input-voltage detection signal, an output voltage detector which detects the output voltage and output an output-voltage detection signal, an output-produced-period detector which detects a period when the output voltage is produced based on the output-voltage detection signal, a comparator which detects a period when the output-voltage detection signal exceeds the input-voltage detection signal and output information indicating the output-high period, and a shifting unit which shifts the information indicating the output-high period to a next period when absence of the output produced period is detected. The control unit adjusts the switching-device-on period based on information indicating the shifted output-high period.

Inverter device, plasma generator apparatus and control method

A high voltage inverter device uses, as an input voltage (Vin), a DC voltage or a voltage composed of a DC component with a pulsating current superposed thereon, switches the input voltage by a switching element (Qsw) to apply an exciting current to an excitation winding (NP) of a resonant transformer () and output an alternating-current high voltage (Vout) from an output winding (NS) of the resonant transformer. An abnormal voltage detection circuit () including a varistor () detects an abnormal voltage generated in the excitation winding (NP) of the resonant transformer (), and when the abnormal voltage is detected, its signal is transmitted by a photocoupler () to a control circuit (), thereby causing the control circuit () to stop its oscillation operation to stop a switching operation of the switching element (Qsw).

High voltage inverter device

In a high voltage inverter device switching an input voltage to apply an exciting current to an excitation winding of a transformer and output an alternating-current high voltage from an output winding to supply the high voltage to a load from output lines, a point on the output line is connected to a frame ground. Each of a first and a second winding of the electrical leakage detecting transformer is interposed in series with the output line on a side where current flows out of the point and a side where current flows into the point respectively. A detection voltage Vd outputted from an amplifying winding is compared by a comparison voltage Vref, and an electrical leakage detection signal Sd is outputted when Vd&#x3e;Vref. The first and second winding are opposite in winding direction to each other and equal in number of turns.

High voltage inverter device and electrical leakage detector thereof

The high voltage inverter device receives, as an input voltage, a DC voltage or a voltage within Safety Extra Low Voltage composed of a DC component with a pulsating flow superposed thereon. The input voltage is switched by a switching element to pass an exciting current to excitation windings on a primary side of a plurality of separate transformers having same characteristics to simultaneously excite the excitation windings. Output windings of the plurality of transformers are connected in parallel or in series with one another, and time axes of waveforms of output voltages of the output windings are synchronized. Thereby, a high-power high voltage is outputted continuously, stably, and safely from both ends of the output windings connected in parallel or in series.

High voltage inverter device for delivering a high-power AC high voltage

An improved switching power unit is of the type which uses a capacitor C1 of large capacitance value as a primary DC power supply, inputs primary DC power from the capacitor C1 to a series circuit formed of the primary winding N1 of a high-frequency transformer 6 and a switching element Q, induces AC power in the secondary winding N2 of the transformer 6 by switching the switching element Q, and rectifies and smooths the AC power to produce and output DC power. In the improved switching power unit, an inductor L1 and/or inductor L2 of small inductance value are/is connected in series with the capacitor C1 of large capacitance value for smoothing the primary DC power, a bypass capacitor Cp is connected in parallel with a series circuit formed of the primary winding N1 of the high-frequency transformer 6 and the switching element Q, thereby bypassing high-frequency noise caused by switching and preventing it from passing through the capacitor C1, and a series circuit formed of a grounding resistor Rg and a grounding capacitor Cg is connected between frame ground G and a hot line 4p or a common line 4n. As a result, the operation of a switching circuit 11 of the switching power unit is stabilized, while electromagnetic interference noise is markedly suppressed since high-frequency noise leaking to frame ground G is converted to heat by the resistor Rg.

Stabilized high frequency switching power supply with suppressed EMI

Disclosed a high-frequency core bobbin which comprises: a winding bobbin member on which a wingding is to be wound; a first bobbin member for accommodating therein a predetermined portion of the winding bobbin; a second bobbin member coupled with the first bobbin coaxially so as to cover a portion of the winding bobbin member exposed from the first bobbin member, or put on the first bobbin member in the axial direction so as to shut off a space portion of a portion opposite to the winding bobbin member; and a leading-out guide provided on the second bobbin member for insertion and leading-out of lead wires of the winding.

Growing community of inventors

Kanagawa, Japan

Hisahiro Kamata