JPH0670190A - Flyback transformer - Google Patents

Abstract

PURPOSE:To simply configure an inexpensive and small sized flyback transformer by eliminating a high voltage capacitor from a 2-fold voltage rectifier circuit. CONSTITUTION:Secondary windings of a flyback transformer are consisted of plural windings 13, 14, 15 wound in alignment in a same direction, stray capacitance 18, 19 between the secondary windings are used for high voltage capacitors of a 2-fold voltage rectifier circuit to form the 2-fold voltage rectifier circuit dispensing with any high voltage capacitor. Thus, the high voltage capacitor is eliminated from a secondary side high voltage 2-fold voltage rectifier circuit and the inexpensive 2-fold voltage rectifier circuit is simply configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flyback transformer used in a television receiver or the like.

[0002]

2. Description of the Related Art The structure of a conventional flyback transformer will be described below with reference to FIG.

FIG. 3 shows the internal structure of a conventional flyback transformer. Here, 1 is a switching transistor, 2 is a damper diode, 3 is a resonance capacitor, 4 is a primary winding, 5 is a ferrite core, 6 is a secondary winding, 7 to 8 are high voltage capacitors, 9 to 10 are high voltage diodes, Reference numeral 11 is a DC power supply.

The DC voltage of the DC power supply 11 is switched by the switching transistor 1, and the positive AC voltage is boosted by the primary winding 4, the ferrite core 5 and the secondary winding 6, and 2
Transmit to the next side. On the secondary side, the high voltage capacitors 7 to 8 and the high voltage diodes 9 to 10 constitute the voltage doubler rectifier circuit 10 to generate a high voltage.

[0005]

In such a conventional flyback transformer, high-voltage components such as a high-voltage capacitor are required to form a voltage doubler rectifier circuit, which complicates the mounting mechanism and increases high voltage. There is a problem that the shape becomes large due to the insulation.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an FBT in which the number of parts, particularly a high voltage capacitor is reduced, and the secondary side of the FBT which generates a high voltage can be made compact and simple. .

[0007]

In order to solve the above problems, the flyback transformer of the present invention has a structure in which the secondary winding is divided into a plurality of layers and wound in layers, and each layer is insulated by an insulating film. The voltage doubler circuit is configured by using the stray capacitance generated between the layers as a high voltage capacitor.

[0008]

According to the present invention, a high-voltage capacitor can be eliminated from the voltage booster circuit on the secondary side by the above configuration, and a compact and simple voltage booster circuit can be constructed at low cost.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, reference numeral 12 is a flyback transformer of this embodiment. Reference numerals 13 and 14 and 15 are all secondary windings of the flyback transformer 12, and thus the secondary windings are separately wound into a plurality of layers and wound in line. An insulating film is interposed between the windings of each layer, and the windings of each layer are insulated by this insulating film. Reference numerals 16 and 17 are rectifying diodes.

The winding start side 13a of the secondary winding 13 is connected to ground, and the winding end side 13b is not connected to anything. The winding start side 14a of the secondary winding 14 is not connected anywhere, the winding end side 14b is connected to the cathode side of the diode 16, and the anode side of the diode 16 is connected to ground.

The anode side of the diode 17 is connected to the winding end side 14b of the secondary winding 14, and the cathode side of the diode 17 is connected to the winding end side 15b of the secondary winding 15. The winding start side 15a of the secondary winding 15 is not connected anywhere. Cathode side of diode 17, ie 2
A high voltage output is taken out from the winding end side 15b of the next winding 15.

The secondary windings 13, 14 and 15 have a laminated winding structure in which an insulating film is interposed between the secondary windings 13 and 14 to insulate them from each other, and float between the secondary winding 13 and the secondary winding 14. Capacity 1
8 exists, and a stray capacitance 19 also exists between the secondary winding 15 and the ground side. The stray capacitances 18 and 19 and the diodes 16 and 17 form a voltage doubler rectifier circuit.

FIG. 2 is a circuit diagram showing in detail the secondary winding and the rectifying circuit of the flyback transformer of this embodiment.

Next, the operation of the flyback transformer configured as described above will be described. The DC voltage of the DC power supply 11 is switched by the switching element 1. The alternating voltage generated by this switching is applied to the primary winding 4. Therefore, an AC voltage having a high peak value is generated in the secondary windings 13, 14, 15.

At this time, on the secondary side, the stray capacitance 18 is charged through the diode 16 in the first half cycle. When the peak value of the AC voltage generated in the secondary windings 13, 14, 15 is V, the voltage of the stray capacitance 18 becomes a voltage V equal to this peak value.

In the next half cycle, the stray capacitance 19 is charged through the stray capacitance 18 and the diode 17. That is, the voltage 2V that is the sum of the voltage V generated in the secondary winding and the voltage V of the floating capacitance 18 is applied to the floating capacitance 19, and the floating capacitance 19 is charged to the voltage 2V. In this way, the double pressure rectification operation is performed. At this time, the stray capacitance 19 is, for example, a CRT.
The secondary winding 15 can be deleted if the capacity of the above can be substituted.

[0018]

As described above, according to the present invention, the secondary winding is divided into a plurality of layers and wound in layers, and each layer is insulated by the insulating film, and the high voltage capacitor is floated between the secondary windings. Since the circuit is configured by using the capacity, the secondary voltage doubler rectifier circuit can be inexpensively and easily configured, and the secondary side voltage doubler rectifier can be realized in a small size and at a low cost.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a flyback transformer according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing in detail a secondary winding and a rectifier circuit of a flyback transformer according to an embodiment of the present invention.

FIG. 3 is a circuit diagram of a conventional flyback transformer.

[Explanation of symbols]

 12 Flyback transformer 13, 14, 15 Secondary winding 16, 17 Diode 18, 19 Stray capacitance

Claims (1)

[Claims] 1. A flyback transformer having a primary winding and a secondary winding, wherein the secondary winding is formed by a plurality of secondary windings aligned and wound in the same direction. The wire has a laminated structure, the first winding start of this secondary winding is connected to the ground, the end of the first winding is not connected to anything, and the second winding is the second layer. Of the first diode is connected to the cathode side of the first diode, the anode side of this diode is connected to the ground, and the anode side of the other second diode is connected to the secondary side. The winding is connected to the connection point on the cathode side of the first diode, the winding end of the third layer secondary winding is connected to the cathode side of the second diode, and where is the winding start side of the third layer. Is not connected, and the output is output from the cathode side of the second diode. Flyback transformer, characterized in that issue.