Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q value determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q value determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q value determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q value determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q valued determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: In a wireless power transfer system, a resonant circuit is formed on the secondary coil side, phase information of a resonant current flowing in the resonant circuit is detected, and, based on this phase information, a driving frequency is determined so that the current phase of a driving current flowing in a primary coil slightly delays from the voltage phase, thereby driving the primary coil. A Q valued determined based on a leakage inductance of the secondary coil, a capacitance of a resonant capacitor, and an equivalent load resistance is set to a value greater than or equal to a value determined by Q=2/k2 (k is a coupling coefficient).

Abstract: An auxiliary power generation circuit adopted for use on a filter power circuit includes a first voltage stabilization capacitor and a second voltage stabilization capacitor connecting to the first voltage stabilization capacitor via a first diode. The first and second voltage stabilization capacitors form a capacitor voltage division circuit. The first voltage stabilization capacitor and first diode are bridged by a first connection point which is connected to a short circuit element and a second diode with a set on current opposite to the short circuit element. The short circuit element has a control end connecting to a first Zener diode which is connected to a first resistor with a desired resistance. The first resistor is connected to a second connection point between the second voltage stabilization capacitor and first diode.

Abstract: Provided is a transformer, comprising a first winding and a second winding that interlink with a main magnetic flux; and a third winding that interlinks with a magnetic flux leakage interlinking with only one of the first winding and the second winding.

Abstract: A small balancer coil for cold-cathode florescent lamps having sufficient shunt/balance effects, comprises a discharge lamp, a conductor located close to the discharge lamp, and two coils whose magnetic fluxes face each other. The magnetic fluxes generated in the coils face and cancel each other. Lamp currents of the discharge lamps are balanced by making the sum of the reactances of the mutual inductance of the balancer coil larger than the negative resistance of the discharge lamp. Section winding is applied to each coil of the balancer coil so as to maintain shunt and balance effects even in a small/flat balancer coil by making self-resonance frequency of each of the coils higher.

Abstract: Disclosed is a low-cost parallel lighting system for discharge lamps for a surface light source, which reduces nonuniform brightness and static noise, and fulfills a requirement that lamp currents of individual cold-cathode fluorescent lamps should be uniform and stabilized.

Abstract: A current balancing circuit for first and second lamp sets includes a step-up transformer and a current balancer. The step-up transformer is adapted to be coupled to a power supply for receiving an alternating-current source power, and for generating a drive signal by varying magnitude of the alternating-current source power. The step-up transformer is further adapted to be coupled to the first and second lamp sets for providing the drive signal thereto. The current balancer includes first and second shunt transformers. Each of the first and second shunt transformers includes primary and secondary windings that correspond to each other in number of turns thereof. The first and second shunt transformers are adapted to be coupled to corresponding discharge lamps of the first lamp set. The current balancer is adapted to mirror current flowing through the first and second shunt transformers to the second lamp set.

Abstract: An inverter circuit for discharge lamps for multi-lamp lighting in which the value of a negative resistance characteristic of a fluorescent lamp is controlled, and an excessively set reactance is eliminated by causing a shunt transformer to have a reactance exceeding the negative resistance characteristic. Two coils connected to a secondary winding of a step-up transformer of the inverter circuit are arranged and magnetically coupled to each other to form a shunt transformer for shunting current such that magnetic fluxes generated thereby cancel each other out. Discharge lamps are connected to the coils, respectively, with currents flowing therethrough being balanced. Each discharge lamp is lighted because a reactance of an inductance related to the balancing operation which is in an operating frequency of the inverter circuit, exceeds a negative resistance of the discharge lamps.

Abstract: Provided is a transformer, comprising a first winding and a second winding that interlink with a main magnetic flux; and a third winding that interlinks with a magnetic flux leakage interlinking with only one of the first winding and the second winding.

Abstract: A small balancer coil for cold-cathode florescent lamps having sufficient shunt/balance effects, comprises a discharge lamp, a conductor located close to the discharge lamp, and two coils whose magnetic fluxes face each other. The magnetic fluxes generated in the coils face and cancel each other. Lamp currents of the discharge lamps are balanced by making the sum of the reactances of the mutual inductance of the balancer coil larger than the negative resistance of the discharge lamp. Section winding is applied to each coil of the balancer coil so as to maintain shunt and balance effects even in a small/flat balancer coil by making self-resonance frequency of each of the coils higher.

Abstract: A high conversion efficiency inverter circuit by providing the current-mode resonant type efficient in using a power source.

Abstract: A highly stable current-mode resonant inverter circuit operates by detecting resonance current in the secondary side circuit. The inverter circuit comprises a step-up transformer with a secondary winding connected to a secondary side circuit with a capacitive component. The leakage inductance and the secondary winding and the capacitive component compose a series resonant circuit. The inverter circuit is configured to detect a current flowing through the secondary winding or capacitive component in the secondary side circuit, and determine a switching timing in response to the detected current. The determined switching timing allows the inverter circuit to oscillate self-excitedly at a resonance frequency of the series resonant circuit.

Abstract: A small balancer coil for cold-cathode florescent lamps having sufficient shunt/balance effects, comprises a discharge lamp, a conductor located close to the discharge lamp, and two coils whose magnetic fluxes face each other. The magnetic fluxes generated in the coils face and cancel each other. Lamp currents of the discharge lamps are balanced by making the sum of the reactances of the mutual inductance of the balancer coil larger than the negative resistance of the discharge lamp. Section winding is applied to each coil of the balancer coil so as to maintain shunt and balance effects even in a small/flat balancer coil by making self-resonance frequency of each of the coils higher.

Abstract: A lamp driving circuit includes a step-up transformer, a detector, and a controller. The step-up transformer includes a primary winding, and a secondary winding configured to cooperate with a discharge lamp to form a tank circuit that generates a tank current. The detector is adapted for detecting current magnitude of current flowing through the discharge lamp, and outputs a detecting signal corresponding to the current magnitude. The controller receives the detecting signal from the detector, and generates a drive signal for driving the step-up transformer. The controller includes a capacitor, and configures a waveform of the drive signal by controlling charging of the capacitor based on a calculation value that corresponds to a frequency of the drive signal, a start-setting value, and a difference between the detecting signal and a current-setting signal.

Abstract: A high efficiency current resonance inverter circuit for a discharge lamp includes: a step-up transformer, a primary winding of the step-up transformer having a center tap being connected to a power source side, two other terminals of the primary winding being connected to collectors of two transistors, respectively, emitters of the two transistors being connected to respective terminals of a primary winding of a current transformer having a center tap, the center tap of the current transformer being connected to a ground side. A secondary winding of the current transformer is connected to bases of the two transistors to detect emitter currents of the two transistors in order to detect a resonance current, thereby performing oscillation. When the current resonance inverter circuit is used for a discharge lamp, the need for a conventional collector resonance inverter circuit is eliminated.

Abstract: Disclosed is a low-cost parallel lighting system for discharge lamps for a surface light source, which reduces nonuniform brightness and static noise, and fulfills a requirement that lamp currents of individual cold-cathode fluorescent lamps should be uniform and stabilized.