JPH01148040A - High-voltage power source device - Google Patents

Abstract

PURPOSE:To improve the efficiency of space and reduce the number of parts, by forming a capacitor with a case and electrodes on the inner and outer surfaces of the case. CONSTITUTION:The case 10 of a DC high-voltage power source device 20 is formed of a dielectric material while a capacitor is formed by providing an inside electrode 22 and an outside electrode 24 respectively so as to be opposed to each other while pinching said case 10 between the inner surface of the outside electrode 24 and the outer surface of the inside electrode 22 and the capacitor is used as the smoothing capacitor of a high-voltage rectifying circuit 8 accommodated in the case 10. Pin terminals 26, 28 project inwardly from the case 10 to connect respective electrodes 22, 24 to the high-voltage rectifying circuit 8. A power transistor 41 for constituting an oscillating circuit 4 is attached to the outside electrode 24 of the case 10. According to this method, the capacitor functions as the smoothing capacitor of the high-voltage rectifying circuit 8, therefore, an independent capacitor becomes unnecessary whereby the efficiency of space may be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a high voltage power supply device for, for example, an electrostatic copying machine or other electrical equipment.

[Conventional technology]

This type of high-voltage power supply, for example, a DC high-voltage power supply, as shown in FIG. It is equipped with a high-voltage transformer 6 that boosts the voltage to a high voltage, and a high-voltage rectifier circuit 8 that rectifies the alternating current from the transformer. Contains vessels 83, 84, etc. 61, 62, and 63 are a primary winding, a secondary winding, and a core (for example, a ferrite core) of the high voltage transformer 6, respectively.

As a concrete structure, conventionally, for example, as shown in FIG. 4, a part of the core 63 of the high voltage transformer 6 as described above is exposed, and its winding part is covered with an insulating case 10. The high-voltage rectifier circuit 8 as described above is assembled on a small board and housed in the case IO. 1
Reference numeral 2 denotes an input/output cable, but if the cable is mounted on a wiring board (for example, the wiring board 16 in FIG. 5), a plurality of pin terminals may be used instead.

Further, the power transistor 41 for the oscillation circuit 4 is connected to a wiring board 1 on which the oscillation circuit 4 and the like are assembled, for example, as shown in FIG.
6, and a heat sink 14 made of aluminum or the like was attached thereto.

[Problem that the invention seeks to solve]

However, in the conventional high-voltage power supply device as described above, the capacitor 82 housed in the case 10 is a high-voltage capacitor and is large, so the space inside the case 10 is inefficient, and moreover, the high-voltage transformer 6 Furthermore, since the case 10 and the like, the power transistor 41, and the heat sink 14 are constructed and arranged separately, there are problems in that the space outside the case 10 is not efficiently used and the number of parts is large.

Therefore, an object of the present invention is to provide a high-voltage power supply device that improves on these points.

[Means for Solving the Problems] In the high voltage power supply device of the present invention, the case is formed of a dielectric material, and an inner electrode and an outer electrode are provided on the inner and outer surfaces of the case so as to face each other to form a capacitor. and use this as a capacitor of the high voltage rectifier circuit,
Further, a power transistor for configuring an oscillation circuit connected to the primary side of the high-voltage transformer is attached to an outer electrode portion of the case.

[Effect]

According to the above structure, a capacitor is formed by the case and the electrodes on the inner and outer surfaces of the case, so that an independent capacitor as in the conventional case is not required.

Furthermore, since the outer electrodes, high-voltage transformer, etc. provided in the case act as a heat sink for the power transistor, there is no need for an independent heat sink as in the conventional case.

As a result, the space inside and outside the case becomes more efficient and the number of parts decreases.

〔Example〕

FIG. 1 is a perspective view showing an example of a DC high voltage power supply device according to an embodiment of the present invention mounted on a wiring board;
This figure is a sectional view partially showing an example of the case portion of the DC high voltage power supply device shown in FIG.

The same reference numerals are given to the same or corresponding parts as in the examples shown in FIGS. 3 to 5, and the differences therefrom will be mainly explained below.

Referring to FIG. 2, the DC high voltage power supply device 20 of this embodiment has a case 1O as described above made of a dielectric material, and inner and outer surfaces of the case 10 are arranged so as to face each other with the case 10 sandwiched therebetween. The electrode 22 and the outer electrode 24 are provided to form a capacitor, which is used as the smoothing capacitor 82 of the high voltage rectifier circuit 8 housed in the case 10.

Further, in this example, pin terminals 26 and 28 are provided protruding toward the inside of the case IO for connection with the high voltage rectifier circuit 8, and the former is electrically connected to the inner electrode 22 and the latter is electrically connected to the outer electrode 24. It is connected to the. 221 is the inner electrode 22
This hole is provided to ensure insulation distance.

In this case, in terms of electrical insulation, etc., it is preferable to set the inner electrode 22 on the hot side and the outer electrode 24 on the ground side. Therefore, in this example, a grounding pin terminal 30 (see Fig. 1) is used.
connect the outer electrode 24 to the ground line of the wiring board 16 (
(not shown).

Furthermore, the regions in which the inner electrodes 22 and the outer electrodes 24 are formed do not necessarily have to be the entire inner and outer surfaces of the case 1O, and may be appropriately selected depending on the required capacitance and the like.

Further, referring to FIG. 1, a power transistor 41 for forming the oscillation circuit 4 described above is attached to the outer electrode 24 of the case IO by, for example, adhesive.

This power transistor 41 is connected to the outer electrode 2 of the case lO.
When attaching to the four parts, screws, special metal fittings, etc. may be used.

Note that this DC high voltage power supply device 20 uses a plurality of pin terminals (not shown in the figure) protruding toward the wiring board 16 side for input/output.

In this DC high-voltage power supply 20, the capacitor formed by the case IO made of dielectric material and the electrodes 22, 24 on its inner and outer surfaces functions as the smoothing capacitor 82 of the high-voltage rectifier circuit 8. This eliminates the need for smoothing capacitors (high-voltage capacitors). As a result, the efficiency of the space outside the case 10 is improved.

In addition, since the outer electrode 24, the high voltage transformer 6, etc. provided in the case 10 act to dissipate heat from the power transistor 41,
There is no need for an independent heat sink 14 as in the conventional case. Moreover, since the power transistor 41 is attached to the outer electrode 24 instead of being disposed separately as in the conventional case, the efficiency of the space outside the case 10 is also improved. Therefore, case 1
It is possible to achieve compactness within or outside of 0. Furthermore, the heat dissipation effect of the power transistor 41 is also improved compared to the case where the conventional heat sink 14 is used.

Furthermore, by grounding the outer electrode 24, an electrical shielding effect can be obtained, so other external circuit components (
It is also possible to reduce the distance between the two (not shown).

Furthermore, since there is no need for an independent smoothing capacitor or heat sink as in the prior art, the number of parts is reduced, thereby making it possible to reduce costs.

Incidentally, in the above embodiments, a DC high voltage power supply for DC output was explained, but the high voltage power supply device of the present invention
It may be an AC high voltage power supply for AC output. In this case, in the circuit shown in FIG.
It functions as oscillation stabilization, and the diode 81 and resistor 8
4 is unnecessary.

〔Effect of the invention〕

As described above, according to the present invention, an independent capacitor for the high-voltage rectifier circuit and an independent heat sink for the power transistor are not required. As a result, the space inside and outside the case can be made more efficient (and more compact), and the number of parts can be reduced, so costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a DC high voltage power supply device according to an embodiment of the present invention mounted on a wiring board. FIG. 2 is a sectional view partially showing an example of the case portion of the DC high voltage power supply device shown in FIG. FIG. 3 is a circuit diagram showing an example of a DC high voltage power supply. FIG. 4 is a perspective view showing an example of a conventional DC high voltage power supply device. Figure 5 shows
FIG. 4 is a perspective view showing a conventional example of mounting the power transistor for the oscillation circuit shown in FIG. 3; 4...Oscillation circuit, 41...Power transistor, 6
...High voltage transformer, 8...High voltage rectifier circuit, 82...
- Smoothing capacitor, lO... Case, 20... DC high voltage power supply device according to the example, 22... Inner electrode, 2
4...Outer electrode.

Claims (1)

[Claims] (1) In a high-voltage power supply device in which at least the winding portion of a high-voltage transformer is covered with an insulating case and a high-voltage rectifier circuit is housed within the case, the case is formed of a dielectric material and the inner and outer surfaces thereof are opposed to each other. An inner electrode and an outer electrode are respectively provided to form a capacitor, which is used as a capacitor of the high-voltage rectifier circuit, and a power transistor is connected to the primary side of the high-voltage transformer to constitute an oscillation circuit. A high voltage power supply device characterized by being attached to the outer electrode part of the case.