Murata Manufacturing Co., Ltd.

Nobuaki Imamura

Hisashi Takiguchi

Haruo Takahashi

Hiroshi Ikeuchi

Masaru Omura

Yasuhiko Toda

Yasunobu Saida

Tadao Nagai

Masahiko Kitamoto

Nobuhiro Oyama

An igniter transformer includes a secondary coil and a primary coil which are closely coupled. A plurality of round single-core wires disposed substantially parallel to one another in a common plane are bonded side by side to form a flat multicore wire that is substantially rectangular in cross-section. The secondary coil includes the flat multicore wire which is edgewise wound such that the larger surfaces of the flat multicore wire face each other in the turns while standing upright. The primary coil includes a wide thin metal sheet wound substantially perpendicularly to an axis of the secondary coil.

Igniter transformer

A resonant power supply circuit includes a flyback transformer. A first FET and a power supply are connected to a primary winding of the flyback transformer. A resonant capacitor and a damper diode are connected between the drain and the source of the first FET. A clamping circuit that includes a diode and a second FET is connected in parallel to the primary winding of the flyback transformer. A control circuit controls the first FET and the second FET. After a flyback pulse is generated, the second FET is turned ON. After the second FET is turned OFF, the first FET is turned ON. When T represents a period of a ringing pulse that is generated after the second FET is turned OFF, the first FET is turned ON after a period of approximately (3T/4) elapses from the time that the second FET is turned OFF.

Resonant power supply circuit

A deflection current/high voltage integration type power supply has a flyback transformer having a primary winding and a secondary winding; a series circuit of a deflection coil and a first capacitor, connected in series to the primary winding of the flyback transformer; a resonance capacitor connected in parallel to the series circuit of the deflection coil and the first capacitor; a first switching element, connected in parallel with the series circuit of the deflection coil and the first capacitor, to be turned on/turned off by a drive signal so that a high voltage is generated at the secondary winding of the flyback transformer and a deflection current flows in the deflection coil; a parallel connection circuit of a second switching element and a second capacitor, connected in series to the primary winding of the flyback transformer; and a switching control means to control the deflection current flowing in the deflection coil and the high voltage generated at the secondary winding of the flyback transformer by controlling the on-timing and the off-timing of the second switching element in approximate synchronism with the drive signal.

Deflection current/high voltage integration type power supply

A high-voltage generating circuit includes a high-voltage production circuit, a high-voltage detecting circuit, and a control circuit. The high-voltage detecting circuit has a high-voltage circuit section to which a voltage of 1 kV to several tens of kilovolts is applied and a low-voltage circuit section to which a voltage of several tens of volts is applied. In the high-voltage circuit section, a parallel circuit formed of a first voltage-dividing resistor and a part of a second voltage-dividing resistor and a speed-up capacitor, and another parallel circuit formed of the remaining part of the second voltage-dividing resistor and a third voltage-dividing resistor and another speed-up capacitor are connected in series to form a two-stage parallel circuit.

High-voltage generating circuit

A high-voltage generating circuit includes a high-voltage production circuit, a high-voltage detecting circuit and a control circuit. The high-voltage production circuit includes clamping diodes to provide a good response for stabilizing a high voltage. The control circuit applies pulse-width control to a power source voltage. The high-voltage detecting circuit has a high-voltage circuit section to which a voltage of 1 kV to several tens of kilovolts is applied and a low-voltage circuit section to which a voltage of several tens of volts is applied. The high-voltage circuit section comprises a parallel circuit including voltage-dividing resistors and a speed-up capacitor. The speed-up capacitor is set to 1000 pF or less.

High voltage generating circuit including high voltage circuit section

A resonance power circuit comprises: a transformer having a primary coil and a secondary coil; a driving power source connected to the primary coil; a single switching device for conducting an ON/OFF control of a current which flows through the primary coil; a resonance capacitor which cooperates with the primary coil for producing a series resonance to generate a voltage pulse when the switching device is in an OFF state; a detector connected to the secondary coil for detecting a high voltage output from the secondary coil; a control circuit for controlling an ON period of the switching device on the basis of the high voltage detected by the detector to control a peak level of the voltage pulse; a damper diode for allowing a reverse current to flow through the primary coil during a damper period; and a clamping circuit for clamping a voltage across both terminals of the resonance capacitor to a voltage of the driving power source during a period from an end of the damper period to a start of the ON period of the switching device.

Resonance power circuit with clamping circuit

The high voltage generating apparatus includes a flyback transformer to be employed in television equipment and has a circuit for stabilizing a high voltage output. This circuit comprises an additive voltage generating coil, a reference voltage generating circuit, a voltage detector, a comparison amplifier, a switching circuit and a voltage multiplying rectifier circuit. The reference voltage generating circuit generates an inclined voltage in the flyback time of the horizontal deflection cycle and the voltage detector detects a mode of the high voltage output. The comparison amplifier compares an inclined voltage and a detection voltage and generates a control signal. The switching circuit operates with the control signal. With this operation, an additive voltage generated by the additive voltage generating coil is supplied to the high voltage coil of the flyback transformer through the voltage multiplying rectifier circuit. The voltage to be supplied compensates the voltage fall if the high voltage output and accordingly the high voltage output is stabilized.

High voltage generating apparatus for television equipment

High voltage generators are generally arranged to step up flyback pulses from a horizontal deflection circuit by means of a flyback transformer consisting of a primary low voltage coil and a secondary high voltage coil, rectifying the high voltage output through a rectification circuit for application to the anode of a cathode-ray tube. However, such a flyback transformer construction has an inherent drawback that the voltage of the high voltage output is varied by variations in the high voltage output current due to leakage inductance, resulting in load fluctuations. To overcome this problem, the high voltage generator is provided with a tertiary coil for generating an output voltage corresponding to 1/n of the maximum variation of the load fluctuations, a summing control circuit for controlling the rate of the high voltage output to be additively supplied to the secondary coil from the tertiary coil on the basis of a variation detection signal from a high voltage, variation detector circuit which serves to detect the load fluctuations, and a multiplying circuit for multiplying the voltage received from the summing control circuit by n-times for supply to the low voltage end of the secondary coil, thereby stabilizing the voltage of the high voltage output substantially at a constant level irrespective of the variations in the high voltage output current.

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Omihachiman, Japan

Nobuaki Imamura